470 research outputs found

    Pulmonary hypertension, how to diagnose and who to treat?

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    # The Author(s) 2011. This article is published with open access at Springerlink.com Pulmonary arterial hypertension is a fatal disease with an estimated survival rate of only 50 % after 5 years [1]. Over the last years, knowledge in the field of pulmonary hypertension has grown consistently and significantly. New diagnostic tools, as well as the efficacy of new medications and drug combinations, have been described. How to define and diagnose pulmonary arterial hypertension is the first important issue. Should echocardiography be the method of choice? It is easy to access, cheap and noninvasive. However, the cut-off values are debatable. In the ESC guidelines of 2009 [2] an estimated peak pulmonary artery pressure of>50 mmHg is stated as ‘pulmonary hypertension is likely’, while a PAP of 37–50 is defined as ‘possible PH’. However, the gold standard remains heart catheterisation. Now the definition is made using a mean pulmonary artery pressure of 25 mmHg or more. Age and gender seem to have an important impact on the incidence and severity of PH. For instance, female patients with an atrial septal defect do present with pulmonary hypertension, while in male ASD patients pulmonary hypertension is seldom if ever seen. In order to simplify the clinical management of patients, the classification of pulmonary hypertension was changed in 2009 [3]. Pre-capillary PH is defined as a wedge pressure <15 mmHg and can be divided into pulmonary arterial hypertension, PH due to lung disease, chronic thromboembolic PH or PH with unclear and/or multifactorial mechanisms. Post-capillary PH is defined as a wedge pressure above 15 mmHg and is due to left-sided heart disease. Who should be screened for pulmonary hypertension? Should all patients undergoing non-cardiac surgery b

    Free Will in a Quantum World?

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    In this paper, I argue that Conway and Kochen’s Free Will Theorem (1,2) to the conclusion that quantum mechanics and relativity entail freedom for the particles, does not change the situation in favor of a libertarian position as they would like. In fact, the theorem more or less implicitly assumes that people are free, and thus it begs the question. Moreover, it does not prove neither that if people are free, so are particles, nor that the property people possess when they are said to be free is the same as the one particles possess when they are claimed to be free. I then analyze the Free State Theorem (2), which generalizes the Free Will Theorem without the assumption that people are free, and I show that it does not prove anything about free will, since the notion of freedom for particles is either inconsistent, or it does not concern our common understanding of freedom. In both cases, the Free Will Theorem and the Free State Theorem do not provide any enlightenment on the constraints physics can pose on free will

    Observation of Dirac plasmons in a topological insulator

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    Plasmons are the quantized collective oscillations of electrons in metals and doped semiconductors. The plasmons of ordinary, massive electrons are since a long time basic ingredients of research in plasmonics and in optical metamaterials. Plasmons of massless Dirac electrons were instead recently observed in a purely two-dimensional electron system (2DEG)like graphene, and their properties are promising for new tunable plasmonic metamaterials in the terahertz and the mid-infrared frequency range. Dirac quasi-particles are known to exist also in the two-dimensional electron gas which forms at the surface of topological insulators due to a strong spin-orbit interaction. Therefore,one may look for their collective excitations by using infrared spectroscopy. Here we first report evidence of plasmonic excitations in a topological insulator (Bi2Se3), that was engineered in thin micro-ribbon arrays of different width W and period 2W to select suitable values of the plasmon wavevector k. Their lineshape was found to be extremely robust vs. temperature between 6 and 300 K, as one may expect for the excitations of topological carriers. Moreover, by changing W and measuring in the terahertz range the plasmonic frequency vP vs. k we could show, without using any fitting parameter, that the dispersion curve is in quantitative agreement with that predicted for Dirac plasmons.Comment: 11 pages, 3 figures, published in Nature Nanotechnology (2013

    Unusual cause of severe toxic methemoglobinemia in an infant: a case report

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    Toxic methemoglobinemia is an uncommon blood disorder induced by exposure to certain oxidizing agents and drugs. In severe cases, this condition may rapidly lead to major cardiopulmonary compromise and constitutes an emergency requiring prompt recognition and early management. We report an unusual case of severe toxic methemoglobinemia following wide cutaneous application of a pomade containing benzocaine, resorcin, and oxyquinoline (Nestosyl®) in an infant

    Mice expressing a human KATP channel mutation have altered channel ATP sensitivity but no cardiac abnormalities

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    AIMS/HYPOTHESIS: Patients with severe gain-of-function mutations in the Kir6.2 subunit of the ATP-sensitive potassium (K(ATP)) channel, have neonatal diabetes, muscle hypotonia and mental and motor developmental delay-a condition known as iDEND syndrome. However, despite the fact that Kir6.2 forms the pore of the cardiac K(ATP) channel, patients show no obvious cardiac symptoms. The aim of this project was to use a mouse model of iDEND syndrome to determine whether iDEND mutations affect cardiac function and cardiac K(ATP) channel ATP sensitivity. METHODS: We performed patch-clamp and in vivo cine-MRI studies on mice in which the most common iDEND mutation (Kir6.2-V59M) was targeted to cardiac muscle using Cre-lox technology (m-V59M mice). RESULTS: Patch-clamp studies of isolated cardiac myocytes revealed a markedly reduced K(ATP) channel sensitivity to MgATP inhibition in m-V59M mice (IC(50) 62 μmol/l compared with 13 μmol/l for littermate controls). In vivo cine-MRI revealed there were no gross morphological differences and no differences in heart rate, end diastolic volume, end systolic volume, stroke volume, ejection fraction, cardiac output or wall thickening between m-V59M and control hearts, either under resting conditions or under dobutamine stress. CONCLUSIONS/INTERPRETATION: The common iDEND mutation Kir6.2-V59M decreases ATP block of cardiac K(ATP) channels but was without obvious effect on heart function, suggesting that metabolic changes fail to open the mutated channel to an extent that affects function (at least in the absence of ischaemia). This may have implications for the choice of sulfonylurea used to treat neonatal diabetes

    Atherosclerotic renal artery stenosis is prevalent in cardiorenal patients but not associated with left ventricular function and myocardial fibrosis as assessed by cardiac magnetic resonance imaging

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    <p>Abstract</p> <p>Background</p> <p>Atherosclerotic renal artery stenosis (ARAS) is common in cardiovascular diseases and associated with hypertension, renal dysfunction and/or heart failure. There is a paucity of data about the prevalence and the role of ARAS in the pathophysiology of combined chronic heart failure (CHF) and chronic kidney disease (CKD). We investigated the prevalence in patients with combined CHF/CKD and its association with renal function, cardiac dysfunction and the presence and extent of myocardial fibrosis.</p> <p>Methods</p> <p>The EPOCARES study (ClinTrialsNCT00356733) investigates the role of erythropoietin in anaemic patients with combined CHF/CKD. Eligible subjects underwent combined cardiac magnetic resonance imaging (cMRI), including late gadolinium enhancement, with magnetic resonance angiography of the renal arteries (MRA).</p> <p>Results</p> <p>MR study was performed in 37 patients (median age 74 years, eGFR 37.4 ± 15.6 ml/min, left ventricular ejection fraction (LVEF) 43.3 ± 11.2%), of which 21 (56.8%) had ARAS (defined as stenosis >50%). Of these 21 subjects, 8 (21.6%) had more severe ARAS >70% and 8 (21.6%) had a bilateral ARAS >50% (or previous bilateral PTA). There were no differences in age, NT-proBNP levels and medication profile between patients with ARAS versus those without. Renal function declined with the severity of ARAS (p = 0.03), although this was not significantly different between patients with ARAS versus those without. Diabetes mellitus was more prevalent in patients without ARAS (56.3%) against those with ARAS (23.8%) (p = 0.04). The presence and extent of late gadolinium enhancement, depicting myocardial fibrosis, did not differ (p = 0.80), nor did end diastolic volume (p = 0.60), left ventricular mass index (p = 0.11) or LVEF (p = 0.15). Neither was there a difference in the presence of an ischemic pattern of late enhancement in patients with ARAS versus those without.</p> <p>Conclusions</p> <p>ARAS is prevalent in combined CHF/CKD and its severity is associated with a decline in renal function. However, its presence does not correlate with a worse LVEF, a higher left ventricular mass or with the presence and extent of myocardial fibrosis. Further research is required for the role of ARAS in the pathophysiology of combined chronic heart and renal failure.</p

    Leadership Competencies for Digital Transformation : Evidence from Multiple Cases

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    Digital transformation (DT) is disrupting industrial organizations, which require significant changes in their properties to remain competitive. This calls for strong leadership to drive this transformation. However, what leadership competencies are required to lead DT impactfully is unclear. Therefore, we seek to identify the key leadership competencies by employing a qualitative, grounded theory approach. By conducting interviews of ten DT experts from two hardcore industrial organizations, we highlight five key leadership competencies that industrial organizations need to develop in their leaders: digital vision, digital knowledge, failing fast, empowerment, and managing diverse teams. The results of this study will help industrial organizations to strategically prepare their leadership for the requirements of DT.©2020 Springer. This is a post-peer-review, pre-copyedit version of an article published in Advances in Human Factors, Business Management and Leadership: Proceedings of the AHFE 2020 Virtual Conferences on Human Factors, Business Management and Society, and Human Factors in Management and Leadership, July 16-20, 2020, USA. The final authenticated version is available online at: http://dx.doi.org/0.1007/978-3-030-50791-6_11.fi=vertaisarvioitu|en=peerReviewed

    Interleukin 10 inhibits pro-inflammatory cytokine responses and killing of Burkholderia pseudomallei.

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    Melioidosis, caused by Burkholderia pseudomallei, is endemic in northeastern Thailand and Northern Australia. Severe septicemic melioidosis is associated with high levels of pro-inflammatory cytokines and is correlated with poor clinical outcomes. IL-10 is an immunoregulatory cytokine, which in other infections can control the expression of pro-inflammatory cytokines, but its role in melioidosis has not been addressed. Here, whole blood of healthy seropositive individuals (n = 75), living in N. E. Thailand was co-cultured with B. pseudomallei and production of IL-10 and IFN-γ detected and the cellular sources identified. CD3- CD14+ monocytes were the main source of IL-10. Neutralization of IL-10 increased IFN-γ, IL-6 and TNF-α production and improved bacteria killing. IFN-γ production and microbicidal activity were impaired in individuals with diabetes mellitus (DM). In contrast, IL-10 production was unimpaired in individuals with DM, resulting in an IL-10 dominant cytokine balance. Neutralization of IL-10 restored the IFN-γ response of individuals with DM to similar levels observed in healthy individuals and improved killing of B. pseudomallei in vitro. These results demonstrate that monocyte derived IL-10 acts to inhibit potentially protective cell mediated immune responses against B. pseudomallei, but may also moderate the pathological effects of excessive cytokine production during sepsis

    Gene expression and matrix turnover in overused and damaged tendons

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    Chronic, painful conditions affecting tendons, frequently known as tendinopathy, are very common types of sporting injury. The tendon extracellular matrix is substantially altered in tendinopathy, and these changes are thought to precede and underlie the clinical condition. The tendon cell response to repeated minor injuries or “overuse” is thought to be a major factor in the development of tendinopathy. Changes in matrix turnover may also be effected by the cellular response to physical load, altering the balance of matrix turnover and changing the structure and composition of the tendon. Matrix turnover is relatively high in tendons exposed to high mechanical demands, such as the supraspinatus and Achilles, and this is thought to represent either a repair or tissue maintenance function. Metalloproteinases are a large family of enzymes capable of degrading all of the tendon matrix components, and these are thought to play a major role in the degradation of matrix during development, adaptation and repair. It is proposed that some metalloproteinase enzymes are required for the health of the tendon, and others may be damaging, leading to degeneration of the tissue. Further research is required to investigate how these enzyme activities are regulated in tendon and altered in tendinopathy. A profile of all the metalloproteinases expressed and active in healthy and degenerate tendon is required and may lead to the development of new drug therapies for these common and debilitating sports injuries
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