Publications by authors named "Oleg V Evgenov"

Introduction: Interventional radiology procedures and endoscopies are performed commonly worldwide, often necessitating pharmacological sedation to optimise patient comfort. It is unclear to what extent non-anaesthetists should provide procedural sedation.

Methods: We studied adult patients who previously lived independently and underwent a non-ambulatory interventional radiology or gastroenterology procedure under anaesthetist-directed or non-anaesthetist-directed sedation at a large healthcare network.

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Soluble guanylate cyclase (sGC) is a key enzyme in the nitric oxide (NO) signalling pathway. On binding of NO to its prosthetic haem group, sGC catalyses the synthesis of the second messenger cyclic guanosine monophosphate (cGMP), which promotes vasodilation and inhibits smooth muscle proliferation, leukocyte recruitment, platelet aggregation and vascular remodelling through a number of downstream mechanisms. The central role of the NO-sGC-cGMP pathway in regulating pulmonary vascular tone is demonstrated by the dysregulation of NO production, sGC activity and cGMP degradation in pulmonary hypertension (PH).

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Pulmonary hypertension is defined as an increase of mean pulmonary arterial pressure ≥25 mmHg at rest as assessed by right heart catheterization. According to different combinations of values of pulmonary wedge pressure, pulmonary vascular resistance and cardiac output, a hemodynamic classification of pulmonary hypertension has been proposed. Of major importance is the pulmonary wedge pressure which allows to distinguish pre-capillary (pulmonary wedge pressure ≤15 mmHg) and post-capillary (pulmonary wedge pressure >15 mmHg) pulmonary hypertension.

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Background: A direct pharmacological stimulation of soluble guanylate cyclase (sGC) is an emerging therapeutic approach to the management of various cardiovascular disorders associated with endothelial dysfunction. Novel sGC stimulators, including riociguat (BAY 63-2521), have a dual mode of action: They sensitize sGC to endogenously produced nitric oxide (NO) and also directly stimulate sGC independently of NO. Little is known about their effects on tissue remodeling and degeneration and survival in experimental malignant hypertension.

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Aims: Here we investigated the mechanisms by which cardiovascular CB1 cannabinoid receptors may modulate the cardiac dysfunction, oxidative stress, and interrelated cell death pathways associated with acute/chronic cardiomyopathy induced by the widely used anti-tumour compound doxorubicin (DOX).

Methods And Results: Both load-dependent and -independent indices of left-ventricular function were measured by the Millar pressure-volume conductance system. Mitogen-activated protein kinase (MAPK) activation, cell-death markers, and oxidative/nitrosative stress were measured by molecular biology/biochemical methods and flow cytometry.

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Objective: Tissue factor (TF), a major initiator of blood coagulation, contributes to inflammation, atherosclerosis, angiogenesis, and vascular remodeling. Pharmacological agonists of soluble guanylate cyclase (sGC) attenuate systemic and pulmonary hypertension, vascular remodeling, and platelet aggregation. However, the influence of these novel pharmacophores on TF is unknown.

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Chronic pseudomonal bronchopulmonary infections in cystic fibrosis patients are frequently controlled with inhaled antibiotics. Dry-powder inhalable antibiotics are an attractive alternative to nebulized medications. We produced and evaluated microparticles composed of dipalmitoylphosphatidylcholine, albumin, and lactose as a model system for intrapulmonary delivery of ceftazidime, ciprofloxacin, and several combinations of the two, none of which is presently available for inhalation.

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Rationale: Nitric oxide-independent agonists of soluble guanylate cyclase (sGC) have been developed.

Objectives: We tested whether inhalation of novel dry-powder microparticle formulations containing sGC stimulators (BAY 41-2272, BAY 41-8543) or an sGC activator (BAY 58-2667) would produce selective pulmonary vasodilation in lambs with acute pulmonary hypertension. We also evaluated the combined administration of BAY 41-8543 microparticles and inhaled nitric oxide (iNO).

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Hypoxic pulmonary vasoconstriction (HPV) preserves systemic arterial oxygenation during lung injury by diverting blood flow away from poorly ventilated lung regions. Ventilator-induced lung injury (VILI) is characterized by pulmonary inflammation, lung edema, and impaired HPV leading to systemic hypoxemia. Studying mice congenitally deficient in inducible nitric oxide synthase (NOS2) and wild-type mice treated with a selective NOS2 inhibitor, L-N(6)-(1-iminoethyl)lysine (L-NIL), we investigated the contribution of NOS2 to the impairment of HPV in anesthetized mice subjected to 6 h of either high tidal volume (HV(T)) or low tidal volume (LV(T)) ventilation.

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Soluble guanylate cyclase (sGC) is a key signal-transduction enzyme activated by nitric oxide (NO). Impaired bioavailability and/or responsiveness to endogenous NO has been implicated in the pathogenesis of cardiovascular and other diseases. Current therapies that involve the use of organic nitrates and other NO donors have limitations, including non-specific interactions of NO with various biomolecules, lack of response and the development of tolerance following prolonged administration.

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Phosphodiesterase 1 (PDE1) modulates vascular tone and the development of tolerance to nitric oxide (NO)-releasing drugs in the systemic circulation. Any role of PDE1 in the pulmonary circulation remains largely uncertain. We measured the expression of genes encoding PDE1 isozymes in the pulmonary vasculature and examined whether or not selective inhibition of PDE1 by vinpocetine attenuates pulmonary hypertension and augments the pulmonary vasodilator response to inhaled NO in lambs.

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Reactive oxygen and nitrogen species, particularly peroxynitrite, are potent inducers of tissue damage during systemic inflammatory response and circulatory shock. Recent evidence indicates that the toxicity of these species largely depends on their ability to trigger activation of the nuclear enzyme poly(adenosine 5'-diphosphate ribose) polymerase-1 (PARP-1). Following excessive activation, PARP-1 depletes the intracellular stores of its substrate, nicotinamide adenine dinucleotide, thus slowing glycolysis, generation of high energy phosphates, and mitochondrial electron transport.

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Background: Inhaled nitric oxide (NO) is a potent and selective pulmonary vasodilator, which induces cGMP synthesis by activating soluble guanylate cyclase (sGC) in ventilated lung regions. Carbon monoxide (CO) has also been proposed to influence smooth muscle tone via activation of sGC. We examined whether direct stimulation of sGC by BAY 41-2272 would produce pulmonary vasodilation and augment the pulmonary responses to inhaled NO or CO.

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Nitric oxide (NO), synthesized by NO synthases (NOS), plays a pivotal role in regulation of pulmonary vascular tone. To examine the role of endothelial NOS (NOS3) in hypoxic pulmonary vasoconstriction (HPV), we measured left lung pulmonary vascular resistance (LPVR), intrapulmonary shunting, and arterial PO2 (PaO2) before and during left mainstem bronchus occlusion (LMBO) in mice with and without a deletion of the gene encoding NOS3. The increase of LPVR induced by LMBO was greater in NOS3-deficient mice than in wild-type mice (151 +/- 39% vs.

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Aging is associated with profound changes in the structure and function of the heart. A fundamental understanding of these processes, using relevant animal models, is required for effective prevention and treatment of cardiovascular disease in the elderly. Here, we studied cardiac performance in 4- to 5-mo-old (young) and 24- to 26-mo-old (old) Fischer 344 male rats using the Millar pressure-volume (P-V) conductance catheter system.

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Objective: To evaluate the cardiopulmonary effects of the novel endothelin receptor antagonist tezosentan in endotoxin-induced lung injury in sheep and to assess the dose response to tezosentan and endothelin-1 in healthy sheep.

Design: Prospective, randomized, controlled experimental study.

Setting: University animal laboratory.

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Objective: Recent experimental evidence suggests that activation of adenosine triphosphate (ATP)-sensitive potassium channels contributes to vascular failure and early mortality after hemorrhagic shock. The present investigation evaluated the effects of the water-soluble sodium salt of glipizide, an inhibitor of ATP-sensitive potassium channels, in anesthetized and awake rats subjected to severe controlled hemorrhage.

Design: Prospective, randomized, controlled study.

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Flagellin is a recently identified bacterial product that elicits immune response via toll-like receptor 5. Here, we demonstrate that flagellin is an extraordinarily potent proinflammatory stimulus in the lung during sepsis. In vitro, flagellin triggers the production of interleukin (IL)-8 by human lung epithelial (A549) cells, with 50% of the maximal response obtained at a concentration of 2 x 10(-14) M.

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Objective: To evaluate the effects of a combination of methylene blue, an inhibitor of the nitric oxide pathway, and inhaled nitric oxide on endotoxin-induced acute lung injury in awake sheep.

Design: Prospective, randomized, controlled experimental study.

Setting: University animal laboratory.

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Pulmonary hypertension and edema are mainstays of acute lung injury (ALI). We synthesized linear polyethylenimine-nitric oxide/nucleophile adduct (DS-1), a water-soluble nitric oxide donor, and demonstrated that it is a potent relaxant of precontracted rat aortic rings without inducing desensitization. Moreover, DS-1 does not suppress the viability of human pulmonary epithelial cells in vitro.

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