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Biomedical subjects

A S Avrunin

Publications and source records attributed to A S Avrunin.

At least 19 recordsLinked to original sources
PubMed2006

[Role of biorhythms in scatter of data of serial red blood cell tests in the preoperative period].

Serial preoperative tests carried out in 826 and 382 patients with primary total and revision hip arthroplasty, respectively, revealed a considerable data scatter in red blood cell values that exceeded instrumental errors. Thirty-day examinations of 7 healthy volunteers indicated the similar data scatter and the change fluctuations in the indices under study. The peripheral blood levels of erythrocytes (Er) and hemoglobin (Hb) fluctuated at hemicircaseptanic intervals and the mean content of hemoglobin (MCH) in the red blood cells did at circaseptanic intervals. There were fluctuations around the trend whose value changed with the circadiseptanic (Er and Hb) and circavigintanic (MCH) periods. It is suggested that these biorhythms are a cause in the observed data scatter.

Arthroplasty, Replacement, Hip↗
PubMed2006

[Interconnection of morpho-functional changes at various levels of the cortical bone hierarchic organization in aging].

The authors define two groups of levels of cortical bone hierarchic organization. The first three levels (molecular, supra-molecular and tissue) are characterized by age-dependent changes in connections and geometry of collagen fibers, deviations in orientation and interaction between collagen and minerals, increase in crystallinity and size of the latter, resulting in matrix hypermineralization. It causes water and organic fraction displacement, as well as intermolecular space reduction, which provides for lesser amount of matrix deformations under the influence of mechanical forces. At the next three levels (structural-functional, organ-forming structures, organ) adaptation processes contribute to deformation increase due to a greater volume of cavities (Haversian canals and medullar cavity of the diaphysis of long tubular bones). These are due to the fact that osseous tissue cells possess superior and inferior thresholds of deformation perception, and through modeling/remodeling provide for extracellular matrix migration in the direction limited by these thresholds. Bone geometry changes leading to bone mass loss are also caused by age-dependent rise of the inferior threshold of sensitivity to mechanical impulses and decrease of muscle functional activity. Prevention of the described changes may be possible through elaboration of new, pathogenesis-based ways of drug therapy, including 1) osseous tissue mineralization reduction with the help of osteocyte pump regulators for predominant washing out of Ca2+, 2) lowering the threshold of electric impulses initiation arising in the osteocyte network under mechanical deformations.

Aging↗
PubMed2005

[Levels of bone mineral matrix organization and the mechanisms determining parameters of its formation].

Authors suggest to regard bone mineral matrix as the four-level structure. The first level is represented by an internal structure of a mineral, the second--by mineral morphological structure, the third--by coplanar association of minerals, and the fourth--by macroassociation of minerals in a single complex inside each bone. The most probable mechanisms determining stability of reproduction of mineral matrix parameters on each of these levels are shown. As a result of their functioning, the variants of bone mineral matrix structures are formed that are the programmed reflection of specificity of the given site of organic structures.

Animals↗
PubMed2005

[Aging of the osseous tissue. Theoretical basis for new directions of mechanotransduction optimization].

On the basis on literature studies and the results of personal studies, the authors describe ultra- and micro-structural changes in the osseous tissue associated with the process of aging. Functional disturbances in tissue processes causing osseous tissue loss and osteoporosis development are characterized. It is suggested that the described changes are induced by age-dependent hypermineralization of the osseous tissue with the consequent disturbances of mechano-transduction. A hypothesis is discussed concerning a novel approach to pharmacological treatment of osteoporosis. Development of a new group of drugs controlling the calcium exchange between the osseous compartment and the blood is considered. Presumed pathogenetic and clinical effects of these drugs are described.

Aging↗
PubMed2004

[The limits of fluctuations of the laboratory findings in the preoperative period during uncomplicated revision endoprosthesing of the hip joint].

The revision endoprosthesis of the hip joint for aseptic loose components was performed in 482 patients (297 women and 185 men). Before operation the assessment of 44 laboratory indices was made which included clinical blood tests, investigation of the coagulating system, protein and mineral exchange, enzymatic activity and other biochemical criteria. The postoperative course was even, without variations. The work shows the limits of deviations of the parameters with respect to normal condition and gender. The authors believe that they can be considered as a variant of the clinically adequate reaction rather than as a criterion of the unfavorable prognosis of the postoperative course.

Arthroplasty, Replacement, Hip↗
PubMed2003

[Seasonal fluctuations of intraoperative blood loss in hip joint replacement].

Under analysis was the level of intraoperative blood loss in total endopropsthesis of the hip joint in 513 patients operated upon for degenerative-dystrophic processes of consequences of trauma in the period from 1996 to 1999. The assessment of seasonal variations of its value was made. It was shown that the volume of blood loss is dependent on two groups of factors: medical and associated with the influence of the environment. The least "chronorisk" of excessive blood loss was noted in the period from July to November, the greatest--from January to June (with the maximum in March and reduction in May).

Arthroplasty, Replacement, Hip↗
PubMed2003

[Biorhythmical characterization of exacerbations of the degenerative-dystrophic process in patients with the impaired hip joint].

The age-dependent structure of the contingents treated conservatively at the local outpatient clinics (197 women aged 17-82 and 59 men aged 25-85) and patients subjected to operations of total endoprosthesis of the hip joint for coxarthrosis (663 women aged 19-89 and 304 men aged 22-82) was investigated. The structure of the indices under study was found to fluctuate with the average period length 10.7 years (sigma = 2.7 years), 8.2 years (sigma = 3.5 years), 7.3 days (sigma = 3.0 years), 9.5 years (sigma = 2.1 years) respectively. A comparison of the fluctuation curves of the age-dependent structure of the women treated conservatively and operated upon showed the coincidence of the maximums in 35, 43, 60, 65, 69, 74-74 years of age, in men--in 34-35, 41, 75-76. It can be supposed that the revealed age-dependent fluctuations of activity of the inflammatory process and the pain syndrome correspondingly might be considered as an element of the periodic disease in pathogenesis of degenerative-dystrophic lesions of the hip joint.

Adolescent↗
PubMed2002

[Emergency endoprosthesis of the hip joint. Risk of hospital mortality].

An analysis of case histories of 854 patients operated upon for fractures of the proximal part of the femoral bone at the R.R. Vreden Research Institute of Traumatology and Orthopedics for the period from September 1997 to December 2000 was made in order to assess the intrahospital lethality. The maximum season fluctuations were found to take place in October and March, minimum in September, December and April. The trend was characterized by a gradual rise from September to June. The authors associate these fluctuations with the action of external rhythmically changing factors, the growing trend--with the role of the factor of tiredness of the medical personnel. It was also shown that duration of the time interval from operation to the moment of death as well as the diversity of the value of this index was maximum in December-January and December correspondingly.

Aged↗
PubMed2002

[Weak stress factors in the prevention of postoperative complications in elective orthopedic surgery].

Based on their personal and literature data the authors propose to use weak stressogenic factors (pyrogenal and interrupting normobaric hypoxia) as an element of preoperative preparation of patients for prevention of postoperative complications. The using of this method made the frequency of postoperative complications in the area of the operation wound twice as rare, outside the wound--three times as rare.

Case-Control Studies↗
PubMed2001

[Reorganization of the mineral matrix of the bone tissue].

Basing on experimental and clinical chronobiological investigations with an application of three different methods of estimation of osseous tissue mineral density: biochemical (phosphates content in bone tissue mineral matrix), roentgenographic densitometry and dual photon X-ray absorption, it has been shown that 4.5% of mineral matrix mass are in constant interchange with body fluids. It corresponds to the degree of fluctuations of osseous tissue mineral density (in the direction of increase or decrease) both locally and in the skeleton on the whole during the period of time amounting to about one week. This fact should be taken into consideration while evaluating the effect of drug therapy in patients with osteoporosis.

Absorptiometry, Photon↗
PubMed2001

[Adaptive mechanisms of bone tissue and regulatory-metabolic profile of the body].

The interrelationship of mechanisms of osseous tissue adaptation to the changes of mechanical loads and regulatory-metabolic influences is discussed on the basis of authors' findings and literature analysis. It is proposed to use the following concepts, which reflect the essence of functioning of different groups of mechanisms at various hierarchical levels of adaptation processes: organic matrix restructuring, osteocytic restructuring of minerals, osteocytic remodelling, osteoclastic-osteoblastic remodelling and reparative osteogenesis. The peculiarities of functioning of these mechanisms depend upon regulatory-metabolic changes which should be defined as organism regulatory-metabolic profile.

Adaptation, Physiological↗
PubMed2000

[Diagnosis of short-term subclinical shifts in the level of humoral parameters].

Algorithm of evaluating the blood humoral parameters has been theoretically and experimentally validated and clinically tried with due consideration for the circaseptan fluctuations in their levels. Probability of deviations from the normal range of values depends on the number of measurements making use of the suggested algorithm.

Adult↗
PubMed1999

[Remodeling of the cortical layer of the tibia after osteotomy of the femur in the same extremity].

Chronobiological characteristics of temporal [correction of temper]-dimensional organization of compact bone remodelling in right tibia after the femoral diaphysis osteotomy on the same side were studied using roentgenometry and roentgenodensitometry. These characteristics were studied in experiments on 179 outbred male albino rats. Circaseptan periodicity of osseous tissue reorganization was established.

Absorptiometry, Photon↗
PubMed1998

[Positional regulators of bone tissue--a basis for the autoregulatory mechanism of the development and reproduction of osteoporosis].

A hypothesis on autoregulatory mechanism of reproduction of bone matrix structural changes was proposed resulting from the theoretical study based on author's own data and data documented in literature. This mechanism seems to underly osteoporosis development. All etiological factors of osteoporosis reported were united into a common pathogenetic mechanism on the basis of this conception.

Aging↗