Publications by authors named "Yu Aleksandrov"

11 Publications

  • Page 1 of 1

[NON-SURGICAL ASPECTS OF THYROID SURGERY].

Georgian Med News 2021 Mar(312):14-22

1I.M. Sechenov First Moscow State Medical University (Sechenov University), Department of Faculty Surgery N2, Russian Federation.

The level of calcium in the blood serum, voice function, thyroid status and quality of life of patients up to 1 year after removal of the thyroid gland were studied. Thyroidectomy is an operation associated with a high risk of postoperative hypocalcemia with clinical manifestations (19.6%), which is transient in 15.5%, and permanent in 4.1%. After thyroidectomy transient voice disorders are observed that are not associated with paresis of the laryngeal nerves. These voice disorders spontaneously resolve in the period from 2 to 6 months after the operation. The effectiveness and safety of therapy for postoperative hypothyroidism, the correct selection of the dose of L-thyroxine depends not only on the level of TSH, but also on the genetic characteristics of the patient. Pharmacogenetic testing allows predicting the effectiveness of hypothyroidism correction. The quality of life after thyroidectomy is generally worse than after organ-preserving operations. To a large extent, it is determined by hypothyroidism. In the long term, the quality of life after thyroidectomy approaches the estimates of patients after organ-preserving operations. For an adequate assessment of the results of the operation, it is necessary to analyze the results no earlier than 1 year later.
View Article and Find Full Text PDF

Download full-text PDF

Source
March 2021

[SUBACUTE THYROIDITIS AND COVID-19 (REVIEW)].

Georgian Med News 2021 Feb(311):98-103

2I.M. Sechenov First Moscow State Medical University (Sechenov University), Russian Federation, Department of Faculty Surgery N2, Russian Federation.

The COVID-19 pandemia has shown that there is not enough knowledge today to fully control it. Along with severe respiratory syndrome, attention has recently been paid to extrapulmonary lesions, including endocrinopathies. The aim of the study was to summarize the current literature data about the effects of the SARS-CoV-2 coronavirus on the thyroid gland. One of the most striking manifestations of viral aggression is de Quervain's subacute thyroiditis. The analysis of works from the most authoritative international abstract bibliographic databases was carried out using methods of analysis and processing of scientific resources. Based on the analysis, it was concluded that subacute thyroiditis can be both a clinical manifestation and a complication of COVID-19. The SARS-CoV-2 coronavirus can also trigger other thyroid diseases. The causes of subacute thyroiditis are considered to be the direct effect of the SARS-CoV-2 coronavirus on thyroid cells due to the use of ACE2 receptors, the subsequent inflammatory reaction and apoptosis, as well as central hypothalamus-pituitary mechanisms. The clinical variants of subacute thyroiditis in COVID-19 are diverse and have not been fully evaluated. In this regard, it can be concluded that the true incidence of subacute thyroiditis in COVID-19 is much greater, since it is masked by severe lesions of other organs.
View Article and Find Full Text PDF

Download full-text PDF

Source
February 2021

[PHYSIOLOGICAL TREMOR INSTANTANEOUS FREQUENCY DYNAMICS UNDER VARIOUS EMOTIONALY LOADED STIMULATION].

Ross Fiziol Zh Im I M Sechenova 2016 Oct;102(10):1224-32

Emotionally evoked physiological tremor dynamics was investigated on varying stimulus efficiency. Experimental protocol includes randomized presentation of four variant visual stimuli, one of the followed - subject’s second name, random shuffled letters of second name, graphic representation of simple arithmetic expression with correct or incorrect answer. The physiological tremor acquisition was implemented by 3-axial digital accelerometers, fixed on external side of index fingers. The data analysis explained unconscious psychomotor activity dynamics under emotional status transitions. Evoked reactions specificity gives an opportunity to suppose stimulus-dependent lateralization of unconscious motor responses. Valid differences of the right hand psychomotor reactions were achieved for the most emotionally loaded stimulus - second name.
View Article and Find Full Text PDF

Download full-text PDF

Source
October 2016

Phylogenetic position of the Gansu mole Scapanulus oweni Thomas, 1912 and the relationships between strictly fossorial tribes of the family talpidae.

Dokl Biol Sci 2015 4;464:230-4. Epub 2015 Nov 4.

Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, 117071, Russia.

The results of the first molecular study focused on the phylogenetic position of the Gansu mole, Scapanulus oweni are presented. The analysis based on sequences of the mitochondrial cytb gene and five nuclear genes supports the monophyly of the Scalopini tribe including S. oweni and shows that two highly fossorial talpid tribes, Talpini and Scalopini, are not immediate sister taxa. These results highlight the role of morphological parallelism as a potential source of conflict between molecular and morphology-based phylogenies in Talpidae.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1134/S0012496615050038DOI Listing
August 2016

Crocidura shantungensis, a new species for Mongolia and Buryatia.

Dokl Biol Sci 2009 Jan-Feb;424:68-71

Moscow State University, Moscow 119991, Russia. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskii pr 33, Moscow, 119071 Russia

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1134/s0012496609010207DOI Listing
May 2009

Learning and memory: traditional and systems approaches.

Authors:
Yu I Aleksandrov

Neurosci Behav Physiol 2006 Nov;36(9):969-85

V. B. Shvyrkov Laboratory for the Neurophysiological Bases of the Mind, Institute of Psychology, Russian Academy of Sciences, Moscow.

The aims of the present work were to consider the characteristics of learning and memory from the point of view of a systems approach and to compare this view with the traditional approach. Neuron activity is regarded not as a response to the synaptic influx resulting in excitation but as a means of altering the cell's relationship with its environment, whose "action" is to eliminate discordance between the cell's "needs" and its microenvironment. The neuronal mechanisms of learning and consolidation of memory are regarded not as formation of a stable increase in the efficiency of synaptic transmission in circuits of connected neurons, but as a system genesis event which confers new system specializations on neurons which do not have to be directly connected synaptically. The roles of the processes of selection, reconsolidatory modification of previously formed memories, gene activation, neurogenesis, and apoptosis in systems genesis occurring both in normal and pathological conditions are discussed. Individual development is regarded as a sequence of system genesis events. The systems approach is applied to the phenomenon of long-term potentiation. In conclusion, a scheme including different types and stages of memory formation is presented.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11055-006-0133-6DOI Listing
November 2006

Neuron activity in the anterolateral motor cortex in operant food-acquiring and alcohol-acquiring behavior.

Neurosci Behav Physiol 2005 Jun;35(5):501-9

V. B. Shvyrkov Laboratory for the Neurophysiological Bases of Mental Activity, Institute of Psychology, Russian Academy of Sciences, Moscow.

The interactions of the neuronal mechanisms of food-acquiring behavior and newly formed operant alcohol-acquiring behavior were studied by recording the activity of individual neurons in the anterolateral area of the motor cortex in chronically alcoholized rabbits. Adult animals learned food-acquiring behavior in a cage with two feeders and two pedals, in the comers (the food in the feeders was presented after pressing the corresponding pedal). After nine months of chronic alcoholization, the same rabbits learned an alcohol-acquiring behavior in the same experimental cage (gelatin capsules filled with 15% ethanol solution were placed in the feeders instead of food). Analysis of neuron activity showed that the set of neurons involved in supporting food-acquiring and alcohol-acquiring behaviors overlapped, though not completely. These experiments not only help us understand the neuronal mechanisms of the newly formed and the previously formed behaviors, but also facilitate the development of concepts of the similarity of the neuronal mechanisms of long-term memory and long-term modifications of the nervous system, occurring in conditions of repeated intake of addictive substances.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11055-005-0085-2DOI Listing
June 2005

pH dependence of the efficiency of binding of iron cations to the donor side of photosystem II.

Biochemistry (Mosc) 2004 Mar;69(3):331-9

Faculty of Biology, Lomonosov Moscow State University, Moscow 119899, Russia.

Light-induced interaction of Fe(II) cations with the donor side of Mn-depleted photosystem II (PS II(-Mn)) results in the binding of iron cations and blocking of the high-affinity (HAZ) Mn-binding site. The pH dependence of the blocking was measured using the diphenylcarbazide/2,6-dichlorophenolindophenol test. The curve of the pH dependence is bell-shaped with pK1 = 5.8 and pK2 = 8.0. The pH dependence of the O2-evolution mediated by PS II membranes is also bell-shaped (pK2 = 7.6). The pH dependence of the process of electron donation from exogenous donors in PS II(-Mn) was studied to determine the location of the alkaline pH sensitive site of the electron transport chain. The data of the study showed that the decrease in the iron cation binding efficiency at pH > 7.0 during blocking was determined by the donor side of the PS II(-Mn). Mössbauer spectroscopy revealed that incubation of PS II(-Mn) membranes in a buffer solution containing 57Fe(II) + 57Fe(III) was accompanied by binding only Fe(III) cations. The pH dependence of the nonspecific Fe(III) cation binding is also described by the same bell-shaped curve with pK2 = 8.1. The treatment of the PS II(-Mn) membranes with the histidine modifier diethylpyrocarbonate resulted in an increase in the iron binding strength at alkaline pH. It is suggested that blocking efficiency at alkaline pH is determined by competition between OH- and histidine ligand for Fe(III). Because the high-affinity Mn-binding site contains no histidine residue, this fact can be regarded as evidence that histidine is located at another (other than high-affinity) Fe(III) binding site. In other words, this means that the blockage of the high-affinity Mn-binding site is determined by at least two iron cations. We assume that inactivation of oxygen-evolving complex and inhibition of photoactivation in the alkaline pH region are also determined by competition between OH- and a histidine residue involved in coordination of manganese cation outside the high-affinity site.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1023/b:biry.0000022066.38297.8aDOI Listing
March 2004

Long-term potentiation and evoked spike responses in the cingulate cortex of freely mobile rats.

Neurosci Behav Physiol 2003 Oct;33(8):763-72

Laboratory for the Neurophysiological Basis of the Psyche, Institute of Psychology, Russian Academy of Sciences, Moscow.

Long-term potentiation of synaptic efficiency is regarded as a major candidate for the role of the physiological mechanism of long-term memory. However, the limited development of concepts of the cellular and subcellular characteristics of the induction of long-term potentiation in animals in conditions of free behavior does not correspond to the importance of this question. The present study was undertaken to determine whether the characteristics of potentiation in the cingulate cortex in response to stimulation of fibers of the subiculo-cingulate tract are truly long-term, i.e., develop through all known phases and last at least 24 h, in freely moving animals. In addition, the study aims included identification of the effects of application of blockers of different types of glutamate receptors on the development of long-term potentiation and identification of the characteristics of spike responses of single cingulate cortex neurons to stimulation of the subiculo-cingulate tract. Long-term potentiation, lasting more than 24 h, was obtained in freely moving adult rats not treated with GABA blockers. Injection of glutamate NMDA synapse blockers led to significant decreases in evoked cingulate cortex potentials in response to test stimulation. Activatory short-latency spike responses were characterized by a low probability of spike generation, and this increased with increases in the stimulation current. These data demonstrated that it is methodologically possible to compare, in freely moving rats, the involvement of individual neurons in the mechanisms involved in learning one or another type of adaptive behavior and the dynamics of their evoked spike activity during the formation of long-term potentiation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1023/a:1025189013402DOI Listing
October 2003

Small mammals disperse micromycete spores.

Dokl Biol Sci 2003 May-Jun;390:225-30

Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow State University, Moscow, Russia.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1023/a:1024401432211DOI Listing
November 2003

Distribution of behaviorally specialized neurons and expression of transcription factor c-Fos in the rat cerebral cortex during learning.

Neurosci Behav Physiol 2003 Feb;33(2):139-42

Institute of Psychology, Russian Academy of Sciences.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1023/a:1021765713160DOI Listing
February 2003