145 research outputs found

    The effect of sacubitril/valsartan compared to olmesartan on cardiovascular remodelling in subjects with essential hypertension: the results of a randomized, double-blind, active-controlled study

    Get PDF
    Aims: Progressive aortic stiffening eventually leads to left ventricular (LV) hypertrophy and heart failure if left untreated. Anti-hypertensive agents have been shown to reverse this to some extent. The effects of sacubitril/valsartan (LCZ696), a dual-action angiotensin receptor blocker (ARB), and neprilysin inhibitor, on arterial stiffness and LV remodelling have not been investigated. Methods and results: This was a randomized, multi-centre, double-blind, double-dummy, active-controlled, parallel group, study to compare the effects on cardiovascular remodelling of sacubitril/valsartan with those of olmesartan in patients with hypertension and elevated pulse pressure. Magnetic resonance imaging scans were used to assess LV mass and local aortic distensibility, at baseline and at 12 and 52 weeks after initiation of treatment. Central pulse and systolic pressure were determined using a SphymoCor® XCEL device at each time point. A total of 114 patients were included, with 57 in each treatment group. The mean age was 59.8 years, and 67.5% were male. Demographic characteristics did not vary between the two sets of patients. Left ventricular mass index decreased to a greater extent in the sacubitril/valsartan group compared to the olmesartan group from baseline to 12 weeks (−6.36 vs. −2.32 g/m2; P = 0.039) and from baseline to 52 weeks (−6.83 vs. −3.55 g/m2; P = 0.029). These differences remained significant after adjustment for systolic blood pressure (SBP) at follow-up (P = 0.036 and 0.019 at 12 and 52 weeks, respectively) and similar signals (though formally non-significant) were observed after adjusting for changes in SBP (P = 0.0612 and P = 0.0529, respectively). There were no significant differences in local distensibility changes from baseline to 12 or 52 weeks between the two groups; however, there was a larger reduction in central pulse pressure for the sacubitril/valsartan group compared to the olmesartan group (P = 0.010). Conclusion: Since LV mass change correlates with cardiovascular prognosis, the greater reductions in LV mass indicate valuable advantages of sacubitril/valsartan compared to olmesartan. The finding that LV mass index decrease might be to some extent independent of SBP suggests that the effect of the dual-acting agent may go beyond those due to its BP-lowering ability

    A case of acute myeloid leukemia (AML) with an unreported combination of chromosomal abnormalities: gain of isochromosome 5p, tetrasomy 8 and unbalanced translocation der(19)t(17;19)(q23;p13)

    Get PDF
    BACKGROUND: Acute myeloid leukemia (AML) comprises a spectrum of myeloid malignancies which are often associated with distinct chromosomal abnormalities, and the analysis of such abnormalities provides us with important information for disease classification, treatment selection and prognosis. Some chromosomal abnormalities albeit recurrent are rare such as tetrasomy 8 or isochromosome 5p. In addition, erratic chromosomal rearrangements may occur in AML, sometimes unbalanced and also accompanied by other abnormalities. Knowledge on the contribution of rare abnormalities to AML disease, progression and prognosis is limited. Here we report a unique case of acute monoblastic leukemia with gain of i(5)(p10), tetrasomy 8, an unbalanced translocation der(19)t(17;19)(q23;p13.3) and mutated NPM1. RESULTS: Bone marrow cells were examined by conventional karyotyping, fluorescence in situ hybridization (FISH) and mutation analysis at diagnosis and follow-up. At diagnosis we detected trisomy 8, an unbalanced translocation der(19)t(17;19)(q23;p13.3) and mutated NPM1. During the course of the disease we observed clonal evolution with gain of i(5)(p10), tetrasomy 8 and eventually duplication of der(19)t(17;19)(q23;p13.3). By using the der(19)t(17;19) as clonal marker, we found that i(5)(p10) and tetrasomy 8 were secondary genetic events and that tetrasomy 8 had clonally evolved from trisomy 8. CONCLUSIONS: This case of acute monoblastic leukemia presents a combination of rare chromosomal abnormalities including the unbalanced translocation der(19)t(17;19)(q23;p13.3), hitherto un-reported in AML. In addition, our case supports the hypothesis of a step-wise clonal evolution from trisomy 8 to tetrasomy 8 in AML. Reporting and collecting data of rare chromosomal abnormalities will add information to AML disease, progression and prognosis, and may eventually translate to improved patient management

    RIS-Jamming: Breaking Key Consistency in Channel Reciprocity-based Key Generation

    Full text link
    Channel Reciprocity-based Key Generation (CRKG) exploits reciprocal channel randomness to establish shared secret keys between wireless terminals. This new security technique is expected to complement existing cryptographic techniques for secret key distribution of future wireless networks. In this paper, we present a new attack, reconfigurable intelligent surface (RIS) jamming, and show that an attacker can prevent legitimate users from agreeing on the same key by deploying a malicious RIS to break channel reciprocity. Specifically, we elaborate on three examples to implement the RIS jamming attack: Using active nonreciprocal circuits, performing time-varying controls, and reducing the signal-to-noise ratio. The attack effect is then studied by formulating the secret key rate with a relationship to the deployment of RIS. To resist such RIS jamming attacks, we propose a countermeasure that exploits wideband signals for multipath separation. The malicious RIS path is distinguished from all separated channel paths, and thus the countermeasure is referred to as contaminated path removal-based CRKG(CRP-CRKG). We present simulation results, showing that legitimate users under RIS jamming are still able to generate secret keys from the remaining paths. We also experimentally demonstrate the RIS jamming attack by using commodity Wi-Fi devices in conjunction with a fabricated RIS prototype. In our experiments, we were able to increase the average bit disagreement ratio (BDR) of raw secret keys by 20%. Further, we successfully demonstrate the proposed CRP-CRKG countermeasure to tackle RIS jamming in wideband systems as long as the source of randomness and the RIS propagation paths are separable.Comment: 15 pages, 14 figure
    • …
    corecore