Catheter-related thrombosis in hematologic patients

For many years central venous catheters (CVC) have been utilized to monitor hemodynamics and to deliver parenteral nutrition, blood products, pharmacological therapies or infusion fluids. Recently, CVC use has greatly increased with significant impact on the administration of chemotherapy, stem cell transplantation and other treatments to cancer patients. However, CVC use may be accompanied by a variety of side-effects, which increase with the duration of implantation. The most common catheter-related complications are thrombotic events and blood-stream infections. The true incidence of these complications is still uncertain and has changed over time due to CVC device improvement. More data are available in solid tumor than in oncohematologic patients. Recently, much attention has been paid to the issues of prevention and treatment of these complications. Some strategies have been proposed: fixed dose warfarin or low molecular weight heparins have been evaluated in some clinical trials of thromboprophylaxis in this condition. However, more studies are still needed to address this issue. This review will focus on CVC use and complications in oncohematologic patients

Endocrine disorders in childhood and adolescence. Natural history of subclinical hypothyroidism in children and adolescents and potential effects of replacement therapy: a review.

OBJECTIVE: Subclinical hypothyroidism (SH) is quite common in children and adolescents. The natural history of this condition and the potential effects of replacement therapy need to be known to properly manage SH. The aim of this review is to analyse: 1) the spontaneous evolution of SH, in terms of the rate of reversion to euthyroidism the persistence of SH or the progression to over hypothyroidism; 2) the effects of replacement therapy, with respects to auxological data, thyroid volume and neuropsychological functions. Methods: We systematically searched PubMed, Cochrane and EMBASE (1990 to 2012) and identified 39 potentially relevant articles of which only 15 articles were suitable to be included. Results and Conclusions: SH in children is a remitting process with a low risk of evolution toward overt hypothyroidism. Most of the subjects reverted to euthyroidism or remained SH, with a rate of evolution toward overt hypothyroidism ranging between 0% to 28.8%, being 50% in only one study (9 articles). The initial presence of goiter and elevated thyroglobulin-antibodies, the presence of coeliac disease and a progressive increase in thyroperoxidase-antibodies and TSH value predict a progression toward overt hypothyroidism. Replacement therapy is not justified in children with SH but with TSH 5-10 mIU/L, no goiter and negative anti-thyroid antibodies. An increased growth velocity was shown in children treated with levothyroxine (2 articles). Levothyroxine reduced thyroid volume in 25% to 100% of children with SH and autoimmune thyroiditis (2 studies). No effects on neuropsychological functions (one study) and post-treatment evolution of SH (one study) were reported

The effect of lower body negative pressure on phase 1 cardiovascular responses at exercise onset in healthy humans

We tested the hypothesis that vagal withdrawal and increased venous return interact in determining the rapid cardiac output response (Phase I) at exercise onset. We used lower body negative pressure (LBNP) to increase blood dislocation to the heart by muscle pump action and simultaneously reduce resting vagal activity. At exercise start, we expected larger response amplitude for stroke volume and smaller for heart rate at progressively stronger LBNP levels, so that the cardiac output response would remain unchanged. Ten subjects performed 50 W exercise supine in Control condition and during -45 mmHg LBNP exposure. On single beat basis, we measured heart rate (HR), stroke volume (SV), and we calculated cardiac output (CO). We computed Phase I response amplitudes (A1) using an exponential model. SV A1 was higher under LBNP than in Control (p < 0.05). Conversely, the A1 of HR, was 23 ± 56 % lower under LBNP than in Control (although NS). Since these changes tended to compensate each other, the A1 for CO was unaffected by LBNP. The rapid SV kinetics at exercise onset is compatible with an effect of increased venous return, whereas the vagal withdrawal conjecture cannot be dismissed for HR kinetics. The rapid CO response may indeed be the result of two independent yet parallel mechanisms, as hypothesized, one acting on SV, the other on H

Phase III studies on novel oral anticoagulants for stroke prevention in atrial fibrillation -a look beyond the excellent results

In this overview we address the three phase III studies that compared new oral anticoagulants (dabigatran, rivaroxaban and apixaban) with warfarin in the setting of stroke prevention in atrial fibrillation. Strengths and weaknesses of the studies were examined in detail through indirect comparison. We analyze and comment the inclusion and exclusion criteria, the characteristics of randomized patients, the primary efficacy and safety end points and side effects. All new oral anticoagulants resulted in being non-inferior to vitamin K antagonists in reducing stroke or systemic embolism in patients with atrial fibrillation. Dabigatran 150 mg and apixaban were superior to vitamin K antagonists. Importantly, new oral anticoagulants significantly reduced hemorrhagic stroke in all three studies. Major differences among new oral anticoagulants include the way they are eliminated and side effects. Both dabigatran and apixaban were tested in low- to moderate-risk patients (mean CHADS2 [Congestive heart failure, Hypertension, Age, Diabetes, Stroke] score = 2.1-2.2) whereas rivaroxaban was tested in high-risk patients (mean CHADS2 score = 3.48) and at variance with dabigatran and apixaban was administered once daily. Apixaban significantly reduced mortality from any cause. The choice of a new oral anticoagulant should take into account these and other differences between the new drugs

Annihilation of low energy antiprotons in silicon

The goal of the AE$\mathrm{\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\mathrm{\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$$ precision on the measurement of $\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\mathrm{\bar{g}}$IS experiment. We also present a first comparison with Monte Carlo simulations (GEANT4) for antiproton energies below 5 MeVComment: 21 pages in total, 29 figures, 3 table

Hypernuclear spectroscopy with K−^- at rest on 7^7Li, 9^9Be, 13^{13}C and 16^{16}O

The FINUDA experiment collected data to study the production of hypernuclei on different nuclear targets. The hypernucleus formation occurred through the strangeness-exchange reaction K^-_{stop} + \; ^AZ \rightarrow \; ^A_{\Lambda}Z + \pi^-. From the analysis of the momentum of the emerging $\pi^-$, binding energies and formation probabilities of $^7_{\Lambda}$Li, $^9_{\Lambda}$Be, $^{13}_{\Lambda}$C and $^{16}_{\Lambda}$O have been measured and are here presented. The behavior of the formation probability as a function of the atomic mass number A is also discussed.Comment: Accepted for publication in PL