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Biomedical subjects

A A Alekseev

Publications and source records attributed to A A Alekseev.

At least 19 recordsLinked to original sources
PubMed2006

[The mechanism of the effect of apterous56f mutation on the reproductive function of Drosophila melanogaster].

The effects of L-dihydroxyphenylalanine (L-DOPA) and 20-hydroxyecdysone (20E) were studied with respect to the content of dopamine (DA), intensity of the juvenile hormone (JH) degradation, and fecundity of the wildtype flies (Canton S) and JH-deficient apterous56f mutants (in young females, carrying this mutation, the levels of DA and 20E production were strongly increased). Fly feeding with L-DOPA proved to increase the level of DA in a dose-dependent manner and reduce JH degradation in 2-day-old females of both strains. Feeding with 20E produced the same effect. Treating the wild-type flies with 2.5 mg L-DOPA caused a 24-h delay in beginning of oviposition and reduction in fecundity throughout the experiment. An L-DOPA dose of 1 mg caused no such changes. An experimental increase in 20E titer led to reduced fecundity of the wild-type flies, though no delay in oviposition was observed. In mutant flies, an increase in DA and 20E levels accelerated beginning of oviposition and increased fecundity of young females, though the latter parameter was reduced in mature individuals. Thus, an increase in endogenous DA and 20E characteristic of young apterous56f females is assumed to be a compensatory response that leads to a higher JH titer and induction of vitellogenesis.

Animals↗
PubMed2005

Effects of dopamine on juvenile hormone metabolism and fitness in Drosophila virilis.

The effects of dopamine (DA) on juvenile hormone (JH) metabolism and fitness (estimated as fecundity and viability levels under heat stress (38 degrees C)) in Drosophila virilis have been studied. An increase of DA level obtained by feeding with DA reduced fitness of wild-type (wt) flies under stress, and decreased JH degradation in young wt females while increasing it in sexually mature wt females. A decrease in DA levels resulted from 3-iodo-tyrosine treatment and caused a decrease in JH degradation in sexually mature wt and heat sensitive (hs) mutant females (DA level in hs females is twice as high in wt females). A dramatic decrease in viability under stress and fecundity under normal conditions in wt, but not hs, females was observed. 3-iodo-tyrosine treatment also reduced the number of oocytes at stages 8-14, delayed oocyte transition to stage 10 and resulted in the accumulation of mature eggs in wt females. It delayed maturation of wt, but not hs, males as well, but did not affect their fertility. This advances our understanding of the regulation of JH metabolism by DA in Drosophila and suggests a crucial role for the basal DA level in fitness.

Age Factors↗
PubMed2005

Juvenile hormone, 20-hydroxyecdysone and dopamine interaction in Drosophila virilis reproduction under normal and nutritional stress conditions.

To elucidate the role of the juvenile hormone (JH) in the control of Drosophila reproduction under stress, JH degradation, dopamine (DA) content and reproduction were studied upon 20E treatment in Drosophila virilis females of wild type (wt) and a mutant, with increased 20E level and decreased fertility, under normal and nutritional stress conditions. 20E treatment of wt flies for 7 days results in an increase of DA content in young females, but a decrease in mature females, a decrease of JH degradation in both young and mature females, an 1-day delay in onset of oviposition and a decrease of fecundity to the level typical of mutant flies. One day of 20E treatment in 7-day-old fed and starved flies results in a small decrease of JH degradation in the fed females and a great decrease in the starved ones. Fecundity decreases in the fed flies to the levels of the starved untreated flies in both wt and mutant strains. An oviposition arrest is observed in the treated and the untreated starved, but not in the treated fed, females of both strains. The data obtained suggest ecdysone control of JH metabolism mediated via DA.

Animals↗
PubMed2002

[Efficacy of clinical-serologic diagnosis of wound infection in burned patients].

Titer of antibodies to microorganisms obtained from wound and blood of 46 patients with burns of IIIAB--IV degree was studied. The majority of the burned patients have ability to synthesize antibodies. Agglutination of the bacteria by antibodies promoted location of infectious agent in primary focus and impeded bacteria to spread into blood and generalization of process. Not all microorganisms of wound provoke antibodies synthesis, i.e. wound infection. Therefore bacteriologic study must be supplemented by serum diagnosis. Detection of bacteria in the blood without serologic data do not permit to consider these bacteria as etiologic factor of wound infection.

Adolescent↗
PubMed2001

[Prediction and diagnosis of drug intolerance in patients with purulent infection and burn disease].

The immunological study was made in which the drug sensitivity index according to S. M. Demyanenko was estimated in 76 patients (24 women and 52 men aged 17-73 years): in patients with soft tissue purulent infection (group 1, n = 46) and surface thermal burns (degree III-IV) of 40% body surface (group 2, n = 30). Patients with satisfactory drug tolerance served control (16 patients of group 1 and 10 ones of group 2). Correlations between humoral and cellular immunity parameters and drug sensitivity index were studied. The results may serve a basis for development of early and adequate correction of immunological disorders in the above patients, of drug-related complications caused by immunological imbalance.

Adolescent↗
PubMed2000

[The clinical laboratory assessment of vancomycin (Edicin) efficacy in treating suppurative wounds of the skin and soft tissues, burn wounds and the infectious complications of burns].

Clinical and bacteriological efficacies of vancomycin (Edicin, LEK) in the treatment of 17 patients with wound infection and 13 patients with thermal affections were studied. The clinical efficacy in the group of the patients with purulent wounds of the soft tissues amounted to 94.1 per cent and that in the patients with thermal affections was 92.3 per cent. The bacteriological effect was recorded in 86.6 per cent of the patients with purulent wounds of the soft tissues and in 69.3 per cent of the patients with burn infections. The drug intolerability was observed in two cases.

Adult↗
PubMed2000

[Clinico-diagnostic significance of fibronectin level determination in severely burnt].

Fibronectin content was determined in plasma and granulation tissues of burnt wounds in burnt patients as well as in plasma and wound exudate of patients operated on for large postoperative abdominal hernia and in whom for several days after surgery the continuous discharge of the wound exudate through the drainage tubes was observed. The same data were observed in fibroblast cultures and nutritional medium in which they have been cultured. It was established that dynamic determination of plasma fibronectin in burn disease allows to estimate the adequacy of the treatment to timely predict probability of development of complications and the outcome of the disease, while determination of fibronectin content in the granulation tissues of burn wounds indicates optimal terms for transplantation of fibroblasts and autotransplants as well as a significant increase of the effectiveness of surgical treatment for victims with spacious burns.

Biomarkers↗
PubMed2000

[Morphological examinations of infected burn wounds].

Electron microscopical and electron radioautographic methods have been used for morphological examination. This allowed to raise sensitivity of the tests facilitating detection of living solitary bacterial cells (by intensive mark above them). Radioautography showed functional status of wound bacteria (the intensity of the metabolism and reproduction). It was determined that in living tissues, not damaged by the burn and unchanged morphologically bacteria do not penetrate. Especially massive accumulations of the microorganisms are found in necrotic tissues, under the scab, at the external border of demarcation protuberance, and they represent colonization of the wound. When modern methods of treatment and early necrectomy are used, morphological examination usually does not reveal pathogenic microorganisms. Only inflammatory reaction of the wound tissues could be seen: oedema, hyperemia, hemorrhages, cellular infiltrates. The development of granulation tissue indicated cessation of wound infection. Especially favourable feature, demonstrating healing of the wound, was appearance and reproduction of young cells of fat tissue (indusion of labelled thymidine). The results of the study have confirmed the advantage of new electronic methods for microscopy in infected burn wounds.

Autoradiography↗
PubMed1999

[Neuroprotective effects of glycine in the acute period of ischemic stroke].

Both the efficiency of glycine in the acute period of hemispheric ischemic stroke and mechanisms of its action were studied in a double blind placebo-controlled trial including 200 patients. Orgogozo's and Scandinavian scales for objective assessment of the condition severity and of a degree of neurologic deficiency, and Bartel's scale--for evaluation of functional recovery were used and measurements were made of the levels of autoantibodies to the structural component of glutamate NMDA-receptors in blood serum and concentrations of neurotransmitter amino acids and of the products of lipid peroxidation in cerebrospinal fluid. Sublingual glycine application in daily dose of 1-2 g was found effective beginning with the first 6 hours of the stroke development during 5 days. Multicomponent neuroprotective action of glycine was established directed at correction of the unbalance between stimulating and inhibiting aminoacidergic neurotransmitters, as well as at a decrease of excitotoxicity and oxidant stress.

Acute Disease↗
PubMed1999

[Levels of neurotransmitter amino acids in the cerebrospinal fluid of patients with acute ischemic stroke].

The dynamics of the levels of both excitatory (aspartate, glutamate) and inhibitory (GABA, glycine) neurotransmitter amino acids was estimated in cerebrospinal fluid of 110 patients with hemispheric ischemic stroke. A significant increase of the contents of glutamate and aspartate was found beginning with the first 6 hours of the disease onset. The degree and duration of such elevation correlated with severity of the stroke. Maximal GABA and glycine levels were registered to the end of the 1st day of the stroke, that reflected delayed triggering of the protective inhibitory mechanisms. It was established that insufficiency of GABA-mediation in hemispherical location of the stroke was much responsible for both the severity of its clinical manifestations and potential of the restorative processes. Early significant biochemical criteria for objective assessment of the severity of cerebral ischemia as well as of the stroke course and outcome were defined. The most unfavourable prognostic signs were low GABA concentration (or impossibility of its evaluation) during the first days of the stroke, progredient elevation of the aspartate level until the 3d day of the disease and the severe fall of glutamate concentration (in spite of its initial increase on the 1st day).

Acute Disease↗
PubMed1999

[Infection in burn patients: the problems of pathogenesis, prevention and treatment].

Urgent issues of pathogenesis, prophylaxis and treatment of infection in patients with thermal injuries are considered. Analysis of the results of multifactorial dynamic examinations of immunological reactivity and nonspecific resistance of 198 burnet patients is presented. For the first time a substantial decrease of B-lymphocytes count in normal or elevated level of immunoglobulins of the main classes is shown as well as a decrease in plasma fibronectin content. Lowering of T-lymphocytes content and polymorphonuclear leucocytes function disturbances, dominant role of St. aureus and P. aeruginosa in etiology of infections in burnt patients and high antibiotic resistance of these microorganisms are demonstrated. Pathogenetic substantiation of combined therapeutic usage of thymus and interferon preparations and when indicated--immunoglobulines is recorded. Positive experience in application of recombinant interleukine-2 (Ronkoleukine) is outlined. The data are provided on advisability of application of new cephalosporines and fluorine-quinolones for antibiotic therapy and prophylaxis in the burnet. In complicated forms of gram-negative infections the combination of aminoglycosides with ureidopenicillines or cyprofloxacine is recommended, in infections provoked by polyresistant strains of S. aureus vancomycin is indicated. With prophylactic aim in case of early surgical treatment it is recommended to apply modern antibacterial preparations with broad spectrum of action. Prophylaxis of hospital infections inpatients of specialised clinics for the burnt is discussed.

Anti-Bacterial Agents↗
PubMed1998

[Clinical and laboratory study of cefodizime (Modivid) in prophylaxis and treatment of surgical patients].

The results of the clinical and laboratory study of the efficacy of the prophylactic and therapeutic use of cefodizime (modivid) in patients with chronic calculous cholecystitis and burns are presented. Expediency of the preoperative prophylactic use of the drug and its significance in the treatment of infectious complications of the burn disease were verified. The immunological investigation gave evidence of an increase of the phagocytosis functional activity when cefodizime (modivid) was used prophylactically in cholecystectomy.

Adolescent↗
PubMed1998

[Efficacy of lomefloxacin and ofloxacin in complex therapy of infections in patients with burns].

The experience with lomefloxacin and ofloxacin respectively in the complex therapy of 26 and 40 patients with burns is described. The drugs were shown to be highly active in the treatment of burn wound infections and infectious complications of burn disease. The clinical efficacy of lomefloxacin and ofloxacin amounted to 88 and 77.5 per cent and the bacteriological efficacy amounted to 81 and 80 per cent respectively.

Adolescent↗
PubMed1997

[Bronchoscopy in inhalation burns].

The treatment of burns of various depth and location which are combined with thermoinhalation affections of the respiratory organs is a serious problem during the entire course of burn disease. Despite advances in modern treatment of burns, the death rate of pulmonary complications is still high. Pulmonary disorders encountered in inhalation of chemical toxic products of burning, smoke and its finely divided components increase the fatal outcomes by 30-100% in different periods of the burn disease. Until recently, thermoinhalation affections were not often taken into account in analysis of the causes of death of patients with burns, and the diagnosis was based on scanty historical data and late clinical symptoms. In works published from the beginning of the eighties, bronchoscopy was assigned secondary significance. Evaluation of the character of the lesion, the extent and depth of pathological changes in the tracheobronchial tree in thermoinhalation affections is based in most cases on the post-mortem findings. The purpose of this work was to evaluate clinically and by laboratory studies the role and significance of bronchoscopy in establishing the diagnosis in individuals with burns and thermoinhalation damage during life, in the treatment and prevention of the expected complications in the respiratory organs, and to promote wide use of a bronchoscope in this category of seriously ill patients. On the basis of the study, the authors revealed a close correlation between respiratory insufficiency of various degree and extent and the depth of the affection of the tracheobronchial tree. They also substantiated indications for systemic bronchoscopic treatment of thermoinhalation lesions.

Adolescent↗