Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Philos Trans A Math Phys Eng Sci ; 380(2231): 20210420, 2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-35858087

RESUMO

This paper reviews several leading approaches for asymptotic modelling of thin layers in elastostatics and wave propagation phenomena. The issues related to applications of the so-called 'equivalent' or 'effective' boundary conditions and their interpretations are highlighted. Comparative analysis of asymptotic models is performed for a two-dimensional elastostatic case using a novel complex variables-based modelling tool. Its implementation allows for straightforward derivations of higher order boundary conditions for problems with layers of arbitrary sufficiently smooth curvatures. Explicit expressions for the conditions up to the third order are provided. All models are tested using available benchmark solutions and the solutions for the limiting cases of the layer parameters. This article is part of the theme issue 'Wave generation and transmission in multi-scale complex media and structured metamaterials (part 1)'.

2.
Biochemistry (Mosc) ; 80(2): 180-201, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25756533

RESUMO

It was shown previously that, as differentiated from canonical proteases, abzymes against myelin basic protein (MBP) from blood of patients with multiple sclerosis and systemic lupus erythematosus effectively cleaved only MBP, while antibodies (ABs) against integrase (IN) from blood of HIV-infected patients specifically hydrolyzed only IN. In this work, all sites of effective hydrolysis by anti-IN antibodies (IgG and IgM) of 25-mer oligopeptide (OP25) corresponding to MBP were identified using reversed-phase and thin-layer chromatographies and MALDI mass spectrometry. It was found that amino acid sequences of OP25 and other oligopeptides hydrolyzed by anti-MBP abzymes were partially homologous to some fragments of the full sequence of IN. Sequences of IN oligopeptides cleavable by anti-IN abzymes were homologous to some fragments of MBP, but anti-MBP abzymes could not effectively hydrolyze OPs corresponding to IN. The common features of the cleavage sites of OP25 and other oligopeptides hydrolyzed by anti-MBP and anti-IN abzymes were revealed. The literature data on hydrolysis of specific and nonspecific proteins and oligopeptides by abzymes against different protein antigens were analyzed. Overall, the literature data suggest that short OPs, including OP25, mainly interact with light chains of polyclonal ABs, which had lower affinity and specificity to the substrate than intact ABs. However, it seems that anti-IN ABs are the only one example of abzymes capable of hydrolyzing various oligopeptides with high efficiency (within some hours but not days). Possible reasons for the efficient hydrolysis of foreign oligopeptides by anti-IN abzymes from HIV-infected patients are discussed.


Assuntos
Anticorpos Catalíticos/metabolismo , Infecções por HIV/imunologia , Integrases/imunologia , Oligopeptídeos/metabolismo , Proteólise , Proteínas Virais/imunologia , Adolescente , Adulto , Anticorpos Catalíticos/imunologia , Cromatografia em Camada Fina , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Integrases/metabolismo , Masculino , Proteínas Virais/metabolismo , Adulto Jovem
3.
Biochemistry (Mosc) ; 76(12): 1300-11, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22150275

RESUMO

It was previously shown that small fractions of IgGs and IgMs from the sera of AIDS patients specifically hydrolyze only HIV integrase (IN) but not many other tested proteins. Here we present evidence showing that these IgGs and IgMs are extreme catalytically heterogeneous. Affinity chromatography on IN-Sepharose using elution of IgGs (or IgMs) with different concentration of NaCl and acidic buffer separated catalytic antibodies (ABs) into many AB subfractions demonstrating different values of K(m) for IN and k(cat). Nonfractionated IgGs and IgMs possess serine-, thiol-, acidic-like, and metal-dependent proteolytic activity. Metal-dependent activity of abzymes increases in the presence of ions of different metals. In contrast to canonical proteases having one pH optimum, initial nonfractionated IgGs and IgMs demonstrate several optima at pH from 3 to 10. The data obtained show that IN-hydrolyzing polyclonal IgG and IgM of HIV-infected patients are cocktails of anti-IN ABs with different structure of the active centers possessing various affinity to IN, pH optima, and relative rates of the specific substrate hydrolysis.


Assuntos
Anticorpos Catalíticos/química , Anticorpos Antivirais/química , Infecções por HIV/imunologia , Integrase de HIV/química , HIV-1/enzimologia , Imunoglobulina G/química , Imunoglobulina M/química , Anticorpos Catalíticos/sangue , Anticorpos Catalíticos/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Infecções por HIV/sangue , Integrase de HIV/imunologia , HIV-1/imunologia , Humanos , Hidrólise , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Cinética , Conformação Proteica
4.
Nucleic Acids Res ; 36(22): 7043-58, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18987001

RESUMO

HIV-1 integrase (IN) oligomerization and DNA recognition are crucial steps for the subsequent events of the integration reaction. Recent advances described the involvement of stable intermediary complexes including dimers and tetramers in the in vitro integration processes, but the initial attachment events and IN positioning on viral ends are not clearly understood. In order to determine the role of the different IN oligomeric complexes in these early steps, we performed in vitro functional analysis comparing IN preparations having different oligomerization properties. We demonstrate that in vitro IN concerted integration activity on a long DNA substrate containing both specific viral and nonspecific DNA sequences is highly dependent on binding of preformed dimers to viral ends. In addition, we show that IN monomers bound to nonspecific DNA can also fold into functionally different oligomeric complexes displaying nonspecific double-strand DNA break activity in contrast to the well known single strand cut catalyzed by associated IN. Our results imply that the efficient formation of the active integration complex highly requires the early correct positioning of monomeric integrase or the direct binding of preformed dimers on the viral ends. Taken together the data indicates that IN oligomerization controls both the enzyme specificity and activity.


Assuntos
DNA Viral/metabolismo , Integrase de HIV/metabolismo , Desoxirribonucleases/metabolismo , Integrase de HIV/isolamento & purificação , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/metabolismo , Ligação Proteica
5.
Artigo em Russo | MEDLINE | ID: mdl-18467993

RESUMO

One of the key elements in epidemiologic control for infectious diseases is timely and active identification of contacts, which results in in-time hospitalization of patients that are needed it and allows to conduct educational work with the public. Measures for outpatient medical and preventive help in Legionella infection which were developed on the experience of termination of outbreak of pneumonia caused by Legionella in town Verkhnyaya Pyshma in July-August, 2007 are presented.


Assuntos
Surtos de Doenças , Legionelose/prevenção & controle , Atenção à Saúde/organização & administração , Conhecimentos, Atitudes e Prática em Saúde , Hospitalização , Humanos , Controle de Infecções , Legionella , Federação Russa/epidemiologia , População Urbana
6.
Artigo em Russo | MEDLINE | ID: mdl-18464556

RESUMO

Data on organization of medical care during outbreak of Legionnaires' disease in July-August, 2007 in town Verkhnyaya Pyshma in Sverdlovsk region are presented. Special feature of this outbreak was spreading of infection in boundaries of the town with total population of 70,600 people. Results of organizational work of health authorities in order to provide timely and adequate medical care for patients with Legionnaires' disease on both outpatient and inpatient levels of care, conduction of preventive measures in foci of infection, coordination of interaction between different medical organizations and services are summarized in the article.


Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Surtos de Doenças , Hospitais Urbanos/organização & administração , Doença dos Legionários/epidemiologia , Adulto , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/microbiologia , Notificação de Doenças , Desinfecção , Humanos , Legionella pneumophila/classificação , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/diagnóstico , Quarentena , Federação Russa/epidemiologia
7.
Neurosci Behav Physiol ; 38(2): 145-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18197380

RESUMO

Administration of singe doses of lead citrate (200 mg/kg) to pregnant rats (on day 18 of pregnancy) was followed by the appearance of destructive changes in brains at age 40 days, with cysts, foci of gliocyte proliferation, pyknotic neurons, and decreases in NADH and NADPH diaphorase activities in neocortical and hippocampal neurons. Decreases in the density of neurons in the cortex and decreases in cortical thickness were also observed. The intensity of free-radical oxidation in the cortex increased three-fold, along with a 3.9-fold increase in the concentration of lipid peroxides, providing evidence of oxidative stress. The possible mechanisms by which these alterations develop are analyzed.


Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/patologia , Intoxicação do Sistema Nervoso por Chumbo/patologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Animais , Proliferação de Células/efeitos dos fármacos , Feminino , Radicais Livres/metabolismo , Hipocampo/crescimento & desenvolvimento , Hipocampo/patologia , Peróxidos Lipídicos/metabolismo , Luminescência , NADH NADPH Oxirredutases/metabolismo , Neocórtex/crescimento & desenvolvimento , Neocórtex/patologia , Neurônios/metabolismo , Tamanho do Órgão/fisiologia , Estresse Oxidativo/fisiologia , Gravidez , RNA/biossíntese , RNA/genética , Ratos
8.
Morfologiia ; 131(1): 27-31, 2007.
Artigo em Russo | MEDLINE | ID: mdl-17526259

RESUMO

Administration of a single dose of lead nitrate (200 mg/kg) to pregnant rats (Day 18 of gestation) resulted in the appearance of destructive brain changes in their offspring on postnatal Day 40, including the cysts, foci of glial cell proliferation, pyknosis of neurons, decrease of NADH- and NADPH-diaphorase activity in neocortical and hippocampal neurons. The reduction of both neuronal density in the cortex and cortical thickness was also demonstrated. The intensity of free radical oxidation in the cortex was increased 3-fold, while the concentration of lipid hydroperoxides was increased 3.9 times, and the resistance to peroxidation was decreased by a factor of 3, which is indicative of oxidative stress. Possible mechanisms of the pathological changes development are discussed.


Assuntos
Córtex Cerebral/patologia , Hipocampo/patologia , Chumbo/toxicidade , Exposição Materna , Neurônios/patologia , Nitratos/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Animais , Córtex Cerebral/crescimento & desenvolvimento , Córtex Cerebral/metabolismo , Di-Hidrolipoamida Desidrogenase/metabolismo , Feminino , Radicais Livres/metabolismo , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Peroxidação de Lipídeos , NADPH Desidrogenase/metabolismo , Neocórtex/crescimento & desenvolvimento , Neocórtex/metabolismo , Neocórtex/patologia , Neurônios/metabolismo , Gravidez , Ratos
9.
Bull Exp Biol Med ; 143(3): 376-80, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18225768

RESUMO

We studied the relationship between parameters of brain development, elevated plus-maze behavior, and the status of the endocrine glands in the progeny of 4.5-5- and 8-9-month-old females after litter reduction by removal of one uterine tube. The progeny of young experimental females differed from the progeny of control animals by brain weight (at the age of 1 day), morphometrical characteristics of the cortex and its neurons, activity of 3beta-hydroxysteroid dehydrogenase in the adrenal cortex (at the age of 1 and 40 days), and behavioral reactions in the elevated plus-maze (at the age of 30 days). The differences in these parameters between the progeny from old females with experimentally reduced litter size and control females were significantly less pronounced.


Assuntos
Encéfalo/embriologia , Glândulas Endócrinas/embriologia , Tamanho da Ninhada de Vivíparos/fisiologia , Envelhecimento/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/crescimento & desenvolvimento , Glândulas Endócrinas/crescimento & desenvolvimento , Feminino , Troca Materno-Fetal , Aprendizagem em Labirinto , Gravidez , Ratos
10.
Mol Biol (Mosk) ; 39(3): 477-87, 2005.
Artigo em Russo | MEDLINE | ID: mdl-15981577

RESUMO

The influence of new non-natural regular minor groove binders (MGB), containing 2-4 imidazole, pyrrole or thiazole residues, and their conjugates with oligonucleotides, on the polymerization reaction catalyzed by HIV-1 reverse transcriptase was analyzed. Various model template-primer complexes: poly(A)-oligo(U), poly(A)-oligo(dT), poly(dA)-oligo(U), poly(dA)-oligo(dT) and activated DNA were used. The concentration of oligopeptides, giving 50% inhibition (I50) of the RT-dependent polymerization reaction, was shown to depend strongly on the structure of template-primer complexes, number and type of the heterocycle rings in the MGBs analyzed. The range of I50 for the most of the compounds studied is 7.7 x 10(-3)-1.0 x 10(-5) M. The affinity of MGB is minimal for poly(A)-oligo(U). However, some of imidazole and pyrrole-containing MGBs demonstrated unusually high affinity (I50 = 3 x 10(-9)-4 x 10(-8) M) to the above template-primer in complex with RT. The affinity of conjugates of thiazolecarboxamides with oligonucleotides complementary or partially complementary to the template, is 1-4 orders higher compared to free thiazolecarboxamides. The possible reasons of the dependence of I50 values upon the structure of the template-primer complexes, the structure of MGB, and their conjugates with oligonucleotides are discussed.


Assuntos
Transcriptase Reversa do HIV/antagonistas & inibidores , Oligonucleotídeos/química , Inibidores da Transcriptase Reversa/química , Tiazóis/química , Transcriptase Reversa do HIV/química , Ligantes
11.
Bull Exp Biol Med ; 140(6): 736-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16848240

RESUMO

A direct relationship between the weights of the brain and hemisphere and parameters characterizing the development of the cortex and its neurons in intact newborn rats was revealed. Parameters of brain development in newborn rats correlate with 3beta-hydroxysteroid dehydrogenase activity in the adrenal zona glomerulosa.


Assuntos
Córtex Suprarrenal/patologia , Encéfalo/patologia , 3-Hidroxiesteroide Desidrogenases/metabolismo , Córtex Suprarrenal/anatomia & histologia , Córtex Suprarrenal/ultraestrutura , Animais , Animais Recém-Nascidos , Peso Corporal , Encéfalo/anatomia & histologia , Encéfalo/ultraestrutura , Feminino , Masculino , Modelos Estatísticos , Neurônios/metabolismo , Tamanho do Órgão , Ratos , Zona Glomerulosa/metabolismo
12.
Antibiot Khimioter ; 49(8-9): 25-8, 2004.
Artigo em Russo | MEDLINE | ID: mdl-15727142

RESUMO

One foreign and two Russian recombinant enzyme immunoassay test-systems were comparatively investigated under conditions of an encoded experiment. Sensitivity in the experiment with the Russian test-systems Borreliosis-ELISA-IgG and Lyme Best was 63.8 and 68.8% respectively. As for the test-system Borrelia IgG Recombinant, it was 47.5%. All the test-systems were highly specific (94.4 to 99.5%). The test-systems Lyme Best and Borrelia IgG Recombinant revealed partial cross reactions with sera from patients with systemic lupus erythematosus and leptospirosis.


Assuntos
Grupo Borrelia Burgdorferi/imunologia , Doença de Lyme/diagnóstico , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Imunoglobulina G/sangue , Doença de Lyme/sangue , Kit de Reagentes para Diagnóstico , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Testes Sorológicos/métodos
13.
Vopr Virusol ; 41(1): 19-21, 1996.
Artigo em Russo | MEDLINE | ID: mdl-8669139

RESUMO

Morphologic study of the lungs, liver, spleen, and kidneys of ferrets infected with canine distemper virus has been carried out. Electron microscopy revealed virus reproduction in bronchial epithelial cells, types I and II alveolocytes, bile duct epitheliocytes, and hepatocytes. Mononuclear phagocyte system cells infected with the virus were found in all the examined organs. The most expressed pathological changes were observed in the lungs.


Assuntos
Cinomose/patologia , Animais , Vírus da Cinomose Canina/isolamento & purificação , Vírus da Cinomose Canina/fisiologia , Furões , Rim/ultraestrutura , Rim/virologia , Fígado/ultraestrutura , Fígado/virologia , Pulmão/ultraestrutura , Pulmão/virologia , Microscopia Eletrônica , Fagócitos/virologia , Baço/ultraestrutura , Baço/virologia , Replicação Viral
14.
Arch Virol ; 141(5): 909-21, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8678836

RESUMO

An approach combining virology with light and electron microscopy was used to study the organs of guinea pigs during nine serial passages of Ebola virus, strain Zaire. It was observed that the wild type of Ebola virus causes severe granulomatous inflammation in the liver and reproduces in the cells of the mononuclear phagocyte system (MPS). Based on morphological characterization, two types of virus-cell interactions were demonstrated. The obtained data evidenced for heterogeneity of the population of wild type of Ebola virus. The virus accumulated in the liver of the infected animals, and the lesions became more pronounced with passage. Degenerative changes appeared, and their severity was increased with passage in the other organs as well. The set of target cells diversified and, as a result, not only the MPS cells, but also hepatocytes, spongiocytes, endotheliocytes and fibroblasts became involved in the reproduction of Ebola virus. The possible role of granulomatous inflammation in the development of the adaptive mechanism of Ebola virus to guinea pigs is discussed.


Assuntos
Granuloma/patologia , Doença pelo Vírus Ebola/patologia , Inflamação/patologia , Animais , Chlorocebus aethiops , Ebolavirus/patogenicidade , Cobaias , Fígado/patologia , Fígado/virologia , Masculino , Camundongos , Coelhos , Células Vero
15.
Vopr Virusol ; 38(4): 176-9, 1993.
Artigo em Russo | MEDLINE | ID: mdl-8236944

RESUMO

Ebola virus reproduction and morphological lesions were investigated in infected guinea pigs by electron microscopy. The liver was found to be the main target organ, whereas in other internal organs the pathological changes were insignificant. Ebola virus reproduction was demonstrated only in cells of the mononuclear phagocyte system.


Assuntos
Ebolavirus , Febres Hemorrágicas Virais/patologia , Animais , Ebolavirus/fisiologia , Cobaias , Febres Hemorrágicas Virais/microbiologia , Fígado/microbiologia , Fígado/ultraestrutura , Microscopia Eletrônica , Fatores de Tempo , Replicação Viral
16.
Artigo em Inglês | MEDLINE | ID: mdl-6128178

RESUMO

1. The cytostatic and antimicrobial activity of triterpene glycosides of 19 holothurian species of the Pacific tropical zone has been studied. 2. It has been demonstrated that yeast and tumor cells display a comparable sensibility to the action of triterpene oligosides of sea cucumbers. 3. Gram-positive and Gram-negative bacteria are not sensible to the action of glycosides in doses to 500 mkg/ml. 4. Triterpene glycosides-stichoposides, thelothurins and oligosides of Holothuria of genus Bohadschia are the most active in relation to fungal, yeast microflora and tumor cells.


Assuntos
Equinodermos/análise , Glicosídeos/farmacologia , Pepinos-do-Mar/análise , Animais , Antibacterianos , Antifúngicos , Bactérias/efeitos dos fármacos , Glicosídeos/isolamento & purificação , Triterpenos/isolamento & purificação , Triterpenos/farmacologia
17.
Antibiotiki ; 24(4): 270-3, 1979 Apr.
Artigo em Russo | MEDLINE | ID: mdl-443789

RESUMO

Antimicrobial activity of 9 triterpene glycosides of the plant and animal origin was studied. It was found that saponins inhibited the fungal growth to different extents and had no activity against grampositive and gramnegative bacteria. Triterpene glycosides of the animal origin, i.e. holoturins A and B, stichoposids A and C had the most pronounced antifungal activity as compared to the saponins isolated from plants. Changes in the length of the carbon chain from 2 to 6 monosugars had no significant effect on the activity of the triterpeneglycosides studied.


Assuntos
Glicosídeos/farmacologia , Esteroides , Triterpenos , Animais , Antibacterianos , Antifúngicos , Equinodermos , Testes de Sensibilidade Microbiana , Plantas Medicinais
18.
Antibiotiki ; 22(9): 837-41, 1977 Sep.
Artigo em Russo | MEDLINE | ID: mdl-911157

RESUMO

The effect of triterpen glycosides of cauloside C from Caulophyllum robustum, theasaponine from Thea sinensis ahd stichoposide A from Stichopus japonicus on multiplication and biosynthesis of RNA in the cells of a 7-hour culture of Saccharomyces carlsbergensis was studied. It was shown that cauloside C, theasaponine and stichoposide A in concentrations of 7.5 gamma/ml inhibited multiplication of the yeast cells by 65, 10 and 90 per cent respectively. The summation RNA of the yeast cells is divided into 3 zones on Sephadex G-100. The glycosides induced no pronounced changes in the chromotographic profile of RNA. Biosynthesis of the transport and ribosomal RNA were inhibited to the same extent. Triterpen glycosides inhibited the biosynthesis of RNA at the stage of 14C-uridine in corporation into the nucleotide pool of the yeast cells.


Assuntos
Glicosídeos/farmacologia , RNA/biossíntese , Saccharomyces/efeitos dos fármacos , Triterpenos , Células Cultivadas , Meios de Cultura , Relação Dose-Resposta a Droga , Fungicidas Industriais , RNA/antagonistas & inibidores , Saccharomyces/metabolismo , Fatores de Tempo
20.
Mikrobiologiia ; 44(5): 825-7, 1975.
Artigo em Russo | MEDLINE | ID: mdl-1207501

RESUMO

The concentration of RNA in the cells of Saccharamyces carlsbergensis was found to vary from 3.51 to 7.54% with aging. A high content of RNA, a high rate of the incorporation of 14C-uridine into RNA and the acid-soluble fraction are typical of the cells in the logarithmic phase of growth. The total RNA can be separated into three zones on Sephadex G-100. No changes in the chromatographic profile were detected with aging.


Assuntos
RNA/análise , Saccharomyces/crescimento & desenvolvimento , Fatores Etários , Cromatografia em Gel , Meios de Cultura , RNA/biossíntese , Saccharomyces/análise , Saccharomyces/metabolismo , Espectrofotometria
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA