Atrial Fibrillation: a Marker or Risk Factor for Stroke

Atrial fibrillation (AF) is strongly associated with stroke risk, but an association by itself does not necessarily imply causation. The question remains whether AF is a risk factor for stroke and whether treatment that reduces the severity of AF will also reduce the burden of stroke. On the other hand, it is possible that AF is a risk marker associated with atrial insufficiency, in which structural and electrical atrial remodeling coexist, leading  to the clinical manifestations of AF and the risk of stroke simultaneously. Atrial fibrillation and stroke are inextricably linked to the classic Virchow pathophysiology, which explains thromboembolism as blood stasis in a fibrillating left atrium. This concept has been reinforced by the proven efficacy of oral anticoagulants for the prevention of stroke in AF. However, a number of observations showing that the presence of AF is neither necessary nor sufficient for stroke cast doubt on the causal role of AF in vascular brain injury. The growing recognition of the role of atrial cardiomyopathy and the atrial substrate in the development of stroke associated with AF, as well as stroke without AF, has led to a rethinking of the pathogenetic model of cardioembolic stroke. A number of recent studies have shown that AF is a direct cause of stroke. Studies in which cardiac implantable devices have been used to collect data on pre-stroke AF do not appear to show a direct time relationship. The presence of AF is neither necessary nor sufficient for stroke, which casts doubt on the causal role of AF in cerebrovascular injury. Known risk factors for stroke in the presence of AF are also recognized risk factors for ischemic stroke, regardless of the presence of AF. The risk of stroke in patients with AF in the absence of risk factors differs little from that in patients without AF. This work is devoted to an attempt to answer the question whether AF is a marker or a risk factor for ischemic stroke

Safety and interaction of direct oral anticoagulants with antiarrhythmic drugs

The use of direct oral anticoagulants minimized the risks associated with vitamin K antagonist (warfarin) therapy. Currently, direct oral anticoagulants have priority over warfarin for the prevention of thromboembolic events in patients with atrial fibrillation and a number of other conditions requiring anticoagulant therapy. Direct oral anticoagulants along with antiarrhythmic therapy are the accepted strategy for atrial fibrillation treatment. At the same time, the effect of drug-drug interactions (DDI) between direct oral anticoagulants and antiarrhythmic drugs, which have common points of metabolic application, has not been fully elucidated. In order to provide effective and safe anticoagulant and antiarrhythmic therapy in patients with AF, it is important to understand the mechanisms and severity of DDI of direct oral anticoagulants and antiarrhythmic agents. This review discusses the issues of DDI of direct oral anticoagulants and antiarrhythmic drugs used to treat atrial fibrillation

ДИАГНОСТИКА, ДИФФЕРЕНЦИАЛЬНАЯ ДИАГНОСТИКА И ЛЕЧЕНИЕ БРОНХООБСТРУКТИВНОГО СИНДРОМА: МЕСТО КОМБИНИРОВАННЫХ ПРЕПАРАТОВ Β2-АГОНИСТОВ И ИНГАЛЯЦИОННЫХ ГЛЮКОКОРТИКОСТЕРОИДОВ

Diagnosis, differentiation and management of bronchial obstructive syndrome: a role of β2-agonists and inhaled steroids combined in a single inhalerДиагностика, дифференциальная диагностика и лечение бронхообструктивного синдрома: место комбинированных препаратов β2-агонистов и ингаляционных глюкокортикостероидо

Thrombocytopenia Induced by Direct Oral Anticoagulants: a Clinical Case and Literature Review

The last decade has dramatically changed the strategy of anticoagulant therapy in patients with atrial fibrillation. Direct oral anticoagulants have replaced vitamin K antagonists: either direct thrombin blockers (dabigatran) or factor IIa blockers (apixaban, rivaroxaban, edoxaban). According to the regulatory domestic and foreign documents, the use of direct oral anticoagulants in patients with atrial fibrillation has priority in comparison with vitamin K antagonists, since they have a predictable anticoagulant effect, the possibility of taking fixed doses without the need for routine anticoagulant monitoring, rapid onset and termination of action, relatively low potential for food and drug interactions. Direct oral anticoagulants are used for the prevention of thromboembolic complications in patients with atrial fibrillation, for the prevention of deep vein thrombosis in patients who have undergone surgery on the knee or hip joints, for emergency treatment and secondary prevention of deep vein thrombosis and pulmonary embolism. Alertness to side effects tends to focus on the likelihood of bleeding, with the possibility of other side effects of direct oral anticoagulants receiving less attention or going unnoticed. These mainly include liver damage, kidney damage and a number of other rare adverse reactions. The finding of isolated thrombocytopenia in patients taking direct oral anticoagulants may be associated with a high risk of life-threatening bleeding. The article analyzes published data on the occurrence of thrombocytopenia associated with the intake of direct oral anticoagulants, and presents a clinical case of thrombocytopenia while taking apixaban

A semi-field evaluation in Thailand of the use of human landing catches (HLC) versus human-baited double net trap (HDN) for assessing the impact of a volatile pyrethroid spatial repellent and pyrethroid-treated clothing on; Anopheles minimus; landing

BACKGROUND: The mosquito landing rate measured by human landing catches (HLC) is the conventional endpoint used to evaluate the impact of vector control interventions on human-vector exposure. Non-exposure based alternatives to the HLC are desirable to minimize the risk of accidental mosquito bites. One such alternative is the human-baited double net trap (HDN), but the estimated personal protection of interventions using the HDN has not been compared to the efficacy estimated using HLC. This semi-field study in Sai Yok District, Kanchanaburi Province, Thailand, evaluates the performance of the HLC and the HDN for estimating the effect on Anopheles minimus landing rates of two intervention types characterized by contrasting modes of action, a volatile pyrethroid spatial repellent (VSPR) and insecticide-treated clothing (ITC). METHODS: Two experiments to evaluate the protective efficacy of (1) a VPSR and (2) ITC, were performed. A block randomized cross-over design over 32 nights was carried out with both the HLC or HDN. Eight replicates per combination of collection method and intervention or control arm were conducted. For each replicate, 100 An. minimus were released and were collected for 6 h. The odds ratio (OR) of the released An. minimus mosquitoes landing in the intervention compared to the control arm was estimated using logistic regression, including collection method, treatment, and experimental day as fixed effects. RESULTS: For the VPSR, the protective efficacy was similar for the two methods: 99.3%, 95% CI (99.5-99.0) when measured by HLC, and 100% (100, Inf) when measured by HDN where no mosquitoes were caught (interaction test p = 0.99). For the ITC, the protective efficacy was 70% (60-77%) measured by HLC but there was no evidence of protection when measured by HDN [4% increase (15-27%)] (interaction test p < 0.001). CONCLUSIONS: Interactions between mosquitoes, bite prevention tools and the sampling method may impact the estimated intervention protective efficacy. Consequently, the sampling method must be considered when evaluating these interventions. The HDN is a valid alternative trapping method (relative to the HLC) for evaluating the impact of bite prevention methods that affect mosquito behaviour at a distance (e.g. VPSR), but not for interventions that operate through tarsal contact (e.g., ITC)

Шестилетняя выживаемость больных с тяжелой дыхательной недостаточностью, получавших длительную кислородотерапию на дому

Long-term oxygen therapy (LTOT) improves survival of patients with chronic obstructive pulmonary disease (COPD) having severe respiratory failure and chronic hypoxemia. In our study 51 patients received LTOT at home via concentrators (34 males, the mean age, 65.5 ± 7.8 yrs; 17 females, the mean age, 62.8 ± 4.1 yrs). Of them, 37 (72.5 %) survived 6-year period and 14 died (13 males and 1 female). Causes of death were acute respiratory viral infection (in 1 patient), insult (in 1 patient), chronic heart and lung failure (in 12 patients). Survival of patients with chronic restrictive pulmonary diseases was not longer than 3 years. A control group included 45 COPD patients with severe respiratory failure not receiving LTOT (30 males, the mean age, 66.3 ± 8.5 yrs; 15 females, the mean age, 69.1 ± 4.6 yrs). Of them, 16 survived 6 years and 29 died (5 females, the mean age, 72.6 ± 3.6 yrs, 24 males, the mean age, 67.8 ± 5.2 yrs). So, LTOT at home improves survival of COPD patients with severe respiratory failure.Длительная кислородотерапия на дому (ДКТ) увеличивает выживаемость больных хронической обструктивной болезнью легких (ХОБЛ) с явлениями тяжелой дыхательной недостаточности и хронической гипоксемии. Курсы ДКТ на дому при помощи концентраторов кислорода получали 51 пациент (34 мужчины, средний возраст — 65,5 ± 7,8 лет; 17 женщин, средний возраст — 62,8 ± 4,1 года). В течение 6 лет выжили 37 (72,5 %) и умерли 14 пациентов (13 мужчин, 1 женщина). Причинами смерти были: острая респираторно вирусная инфекция (1), инсульт (1), нарастающие явления сердечно-легочной недостаточности (12). Выживаемость пациентов с заболеваниями легких, приводящими к реструктивным нарушениям функции внешнего дыхания, не превышала 3 лет. В контрольной группе пациентов наблюдались 45 больных ХОБЛ, не получавших ДКТ на дому (30 мужчин, средний возраст — 66,3 ± 8,5 лет; 15 женщин, средний возраст — 69,1 ± 4,6 года). В течение 6 лет умерли 29 пациентов, выжили 16 (35,5 %). Среди умерших были 5 женщин (средний возраст — 72,6 ± 3,6 года) и 24 мужчины (средний возраст — 67,8 ± 5,2 лет). Причинами смерти в контрольной группе были: инсульт (4), повторный инфаркт миокарда (4), нарастающие явления сердечнолегочной недостаточности (21). Заключение: ДКТ на дому увеличивает выживаемость больных ХОБЛ с явлениями тяжелой дыхательной недостаточности

Simulation of wavepacket tunneling of interacting identical particles

We demonstrate a new method of simulation of nonstationary quantum processes, considering the tunneling of two {\it interacting identical particles}, represented by wave packets. The used method of quantum molecular dynamics (WMD) is based on the Wigner representation of quantum mechanics. In the context of this method ensembles of classical trajectories are used to solve quantum Wigner-Liouville equation. These classical trajectories obey Hamilton-like equations, where the effective potential consists of the usual classical term and the quantum term, which depends on the Wigner function and its derivatives. The quantum term is calculated using local distribution of trajectories in phase space, therefore classical trajectories are not independent, contrary to classical molecular dynamics. The developed WMD method takes into account the influence of exchange and interaction between particles. The role of direct and exchange interactions in tunneling is analyzed. The tunneling times for interacting particles are calculated.Comment: 11 pages, 3 figure

Wigner function quantum molecular dynamics

Classical molecular dynamics (MD) is a well established and powerful tool in various fields of science, e.g. chemistry, plasma physics, cluster physics and condensed matter physics. Objects of investigation are few-body systems and many-body systems as well. The broadness and level of sophistication of this technique is documented in many monographs and reviews, see for example \cite{Allan,Frenkel,mdhere}. Here we discuss the extension of MD to quantum systems (QMD). There have been many attempts in this direction which differ from one another, depending on the type of system under consideration. One direction of QMD has been developed for condensed matter systems and will not discussed here, e.g. \cite{fermid}. In this chapter we are dealing with unbound electrons as they occur in gases, fluids or plasmas. Here, one strategy is to replace classical point particles by wave packets, e.g. \cite{fermid,KTR94,zwicknagel06} which is quite successful. At the same time, this method struggles with problems related to the dispersion of such a packet and difficulties to properly describe strong electron-ion interaction and bound state formation. We, therefore, avoid such restrictions and consider a completely general alternative approach. We start discussion of quantum dynamics from a general consideration of quantum distribution functions.Comment: 18 pages, based on lecture at Hareaus school on computational phyics, Greifswald, September 200