Size of membrane microparticles (MPs) from blood plasma and MPs produced in vitro by activated endothelial cells (ECs), monocytes, THP-1 monocytic cells, granulocytes, and platelets was evaluated by ...dynamic light scattering. MPs were sedimented from the culture media, cell supernatants, and plasma at 20 000 g for 30 min. Average diameters of all types of MPs ranged from 300 to 600 nm. Plasma MPs had the smallest size. Close sizes were registered for MPs from platelets and THP-1 cells. MPs from monocytes were larger, and MPs from granulocytes and ECs were the largest ones. The data obtained indicate that the size of membrane MPs depends on the type of their cell-producers.
A ptamers are a new class of oligonucleotide compounds capable of specific binding to various molecular targets and inhibiting their activity. Aptamers are selected from a library of randomly ...syn-thesized oligonucleotides (from 20 to 60 nucleotides long) based on their ability to bind to the target molecule. In the future, such primary aptamers can be chemically modified to optimize their structure and increase stability. Aptamers are considered to be chemical (oligonucleotide) analogues of monoclonal antibodies: their specificity is similar to that of antibodies, and they have high affinity to their targets. Aptamers are widely used to create pharmacological medicines. As pharmacological substances, they have a number of benefits over antibodies and other protein molecules. Aptamers are practically non-immunogenic, chemically synthesized without the use of biological producers, and their antidotes can easily be created using complementary sequences. The review highlights reports devoted to the development of new anticoagulant aptamer-based medications. The most detailed studies, both preclinical and clinical (various phases of clinical trials), were performed in relation to the study of aptamers against vWF, factor IX and thrombin.
Disturbances of blood flow upon vascular occlusions and spasms result in hypoxia and acidosis, while its subsequent restoration leads to reoxygenation and pH normalization (re-alkalization) in ...ischemic sites of the vascular bed. The effect of hypoxia/reoxygenation on activation and stimulation of apoptosis in cultured human endothelial cells was studied. The cells were subjected to hypoxia (2% O₂, 5% CO₂, 93% N₂) for 24 h followed by reoxygenation (21% O₂, 5% CO₂, 74% N₂) for 5 h. Reoxygenation was carried out at different pH-6.4 (preservation of acidosis after hypoxia), 7.0, and 7.4 (partial and complete re-alkalization, respectively). Hypoxia only slightly (by ~30%) increased the cell adhesion molecule ICAM-1 content on the cell surface, whereas reoxygenation more than doubled its expression. The reoxygenation effect depended on the medium acidity, and ICAM-1 increase was more pronounced at pH 7.0 compared to that at pH 6.4 and 7.4. Neither hypoxia nor reoxygenation induced expression of two other cell adhesion molecules, VCAM and E-selectin. Incubation of cells under hypoxic conditions but not reoxygenation stimulated secretion of von Willebrand factor and increased its concentration in the culture medium by more than 4 times. The percentage of cells containing apoptosis marker, activated caspase-3, was increased by approximately 1.5 times upon hypoxia as well as hypoxia/reoxygenation. Maximal values were achieved when reoxygenation was performed at pH 7.0. These data show that hypoxia/reoxygenation stimulate pro-inflammatory activation (ICAM-1 expression) and apoptosis (caspase-3 activation) of endothelial cells, and the extracellular pH influences both processes.
The input dose for an ideal digital detector depends quadratically on the threshold contrast detail detectability (TCDD). The TCDD at the level of image quality sufficiency should be minimized for ...diagnosis; initial parts of detector amplitude response, as well as pulse fluoroscopy adapted to organ mobility, should be used.
The results of numerous foreign and russian researches indicate that administration of trimetazidine MB, including its russian generic drug Deprenorm® MV, in the treatment of patients with ischemic ...heart disease, including those with concomitant chronic heart failure, is a real opportunity to improve the effectiveness of treatment of such patients.
Nicotinic acetylcholine receptors (nAChRs) represent a class of therapeutic targets with the potential to impact numerous diseases and disorders where significant unmet medical needs remain. The ...latter include cognitive and neurodegenerative diseases; psychotic disorders, such as schizophrenia; acute nociceptive, neuropathic and inflammatory pain; affective disorders, such as depression and inflammation, where nAChR subtypes modulate key cellular pathways involved in anti-inflammatory processes as well as cell survival. Our increased understanding of the heterogeneity of nAChR targets is defining the relationship of biologic effects to specific receptor subtypes, which in turn, will allow further refinement of desired therapeutic activities. Both preclinical and clinical evidence support the notion that novel compounds targeting specific nAChR subtypes will offer increased potency and efficacy, longer lasting effects, fewer side effects and a more rapid onset of action and less dependence, compared with existing therapies. Clinical proof-of-concept is rapidly emerging and will solidify the position of this new therapeutic approach.
Platelets bearing leukocyte antigen CD45 were identified in the blood of patients with myocardial infarction (MI) and healthy donors by flow cytofluorimetry. Part of these platelets contained tissue ...factor (TF)–primary initiator of blood clotting. The number of CD45
+
and CD45
+
/TF
+
platelets in MI patients at the first day was comparable with their level in healthy donors, but was increased at 8–12 days after MI onset. At that time in some patients the amount of CD45
+
and CD45
+
/TF
+
platelets reached 5–6 and 2–3% of their total number. It is assumed that CD45
+
/TF
+
platelets could be formed as a result of platelet interaction with leukocytes or leukocyte produced membrane microparticles.
This article describes issues relating to monitoring vibrations affecting the processing equipment. Especially, the problem of negative influence from the increased vibration background in well ...drilling, where the issue is the most acute, is being described. The urgency of creating methods to monitor vibration condition, due to which it becomes possible to design reliable and efficient structures with the required characteristics and purpose, is shown. Particular attention is paid to passive methods for monitoring torsional vibrations of pipe columns. In this case, the developed method for monitoring the vibration condition of torsional vibrations is presented, and its effectiveness is shown. In addition, a new device for monitoring torsional vibrations to the developed method, which is distinguished by its simplicity as well as high potential of reliability and efficiency, is shown.
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