RESUMO
Two amphiphilic butadienyl dyes 1 and 2 form stable monolayers at the air/water interface in the presence of various salts. Dye 1 consists of the basic amphiphilic butadienyl chromophore. In dye 2, the dimethoxybenzene part of dye 1 is substituted by benzodithia-15-crown-5. The monolayers have been characterized by surface pressure-area and surface potential-area isotherms as well as Brewster angle microscopy and reflection spectroscopy. In contrast to dye 1, dye 2 interacts specifically with Hg(2+) and Ag(+) cations forming complexes. No complex formation was observed with alkali and earth alkali metal ions. The nature of the anion (Cl(-) or ClO(4)(-)) influences the monolayer behaviour of both dyes. At the air/water interface, besides monomers of the dyes, two types of associates are coexisting in the pure dye monolayers on aqueous salt solutions, attributed to dimers and aggregates, respectively. Their equilibria depend on the nature of both cations and anions in the subphase, as in the case of dye 2, or only anions, as in the case of dye 1. The dimers may be organized as head-to-tail dimers with the intermolecular distances 0.38 and 0.45nm for dye 1 and dye 2, respectively. According to the extended dipole model, we propose formation of aggregates in which the chromophores are parallel to each other with the same intermolecular distances as in the dimers, and the centers of their transition moments shifted by 0.95nm (dye 1) and 1.2nm (dye 2).
Assuntos
Derivados de Benzeno/química , Butadienos/química , Corantes/química , Éteres de Coroa/química , Sais/química , Ar , Microscopia/métodos , Soluções , Propriedades de Superfície , ÁguaRESUMO
Tetanus belongs to dangerous infection diseases, whose effective prevention can be ensured by vaccines. The acting substance of tetanus vaccines, presently in use, is a partially purified and deprived-of-lethal-action Clostridium tetani neurotoxin. The construction of a subunit preparation on the basis of toxin fragments obtained through gene engineering could be a method aimed at promoting the quality of the used tetanus vaccines. With this goal in mind, we built, within the present case study, the expressing genetic constructions and obtained, in the pure form, an extensive tetanus-vaccine chain with its C-terminal (Hc) fragment, hydride peptides, containing the Hc-fragment and C-terminal fragment of toxin B C. difficile, as well as Hc-fragment and S3 collagen-binding domain of collagenase C. histolyticum. The thus obtained proteins can be used in testing their immunogenic and protective properties, while the conducted study could be a basis for further research of a new-generation vaccine against tetanus and other human infection diseases.
Assuntos
Fragmentos de Peptídeos/genética , Proteínas Recombinantes/genética , Toxina Tetânica/genética , Vacinas Sintéticas/genética , Sítios de Ligação , Clonagem Molecular , Clostridioides difficile/genética , Clostridium/genética , Colagenases/genética , Desenho de Fármacos , Fragmentos de Peptídeos/imunologia , Plasmídeos , Engenharia de Proteínas/métodos , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Tétano/prevenção & controle , Toxina Tetânica/imunologia , Toxina Tetânica/metabolismo , Vacinas Sintéticas/imunologiaRESUMO
The novel amphiphilic benzodithia-18-crown-6 butadienyl dye (1) forms relatively stable insoluble monolayers on distilled water (collapse pressure of 41 mN/m) and on aqueous subphases containing alkali metal or heavy metal salts (collapse pressures in the range of 27-38 mN/m, respectively). The dye 1 monolayer organization depends on chromophore association and interactions (especially complex formation) with heavy and alkali metal ions as deduced from surface pressure-area and surface potential-area isotherms as well as reflection spectra and Brewster angle microscopy observations. Dye 1 undergoes specific interactions with Hg(2+) and Ag(+), respectively (formation of different complexes). Nonspecific interactions have been observed with other salts, such as KClO(4) or Pb(ClO(4))(2). Further, dye 1 monolayers on 1 mM Hg(ClO(4))(2) solution undergo reversible photoisomerization, in contrast to monolayers on water and other aqueous salt subphases.
RESUMO
New amphiphilic photochromic benzo-15(18)-crown-5(6) ethers (APC) differing in the position of the octadecyl substituent and the size of the crown cavity were synthesized. The compounds form stable monolayers in the air/water and air/alkaline metal salt solution interfaces. The results of the pressure isotherm measurements, atomic force microscopy (AFM), and electronic spectroscopy show that the structure of the monolayers formed depends on the structure of the parent APC and the nature of the cation in salt solutions. The area per molecule of APC in the monolayer (specific area) is the smallest on the water surface and increases by 20-40% on the aqueous subphase surface with an increasing concentration of salts therein to indicate the formation of APC complexes with the metal cations. When the hydrophobic aliphatic substituent is displaced from position 3 to position 5 of the benzothiazole ring, the specific area on the surface of water and subphases decreases twofold, which indicates the compactization of the monolayer on this modification. A reversible E-Z-photoisomerization of APC was found in the monolayers formed in the salt solution/air interface. The features of the reaction are defined by the specific organization of the amphiphilic molecules in the monolayer and by the nature of the cation.
Assuntos
Corantes/síntese química , Éteres Cíclicos/síntese química , Luz , Tensoativos/síntese química , Ar , Álcalis , Corantes/química , Corantes/efeitos da radiação , Éteres Cíclicos/química , Éteres Cíclicos/efeitos da radiação , Espectroscopia de Ressonância Magnética , Microscopia de Força Atômica , Microscopia Eletrônica , Soluções , Estereoisomerismo , Propriedades de Superfície , Tensoativos/química , Tensoativos/efeitos da radiação , ÁguaRESUMO
Polymerase chain reaction (PCR) was used for detection of pathogenic Clostridium botulinum, Clostridium perfringens, Clostridium difficile, and Escherichia coli. With this aim in view, primers to botulinic toxins types A, B, C1, D, E, F, and G, perfringens enterotoxin, difficile toxin, and types 1 and 2 Shigella-like toxins were chosen and synthesized. Optimal amplification conditions were selected for each pair of primers, with DNA and the respective agent as the reaction mixture matrices. PCR was highly specific and sensitive in all cases. Its sensitivity was 10-100 cells/sample. Among the tested C. botulinum, C. perfringens, C. difficile, and E. coli strains, specific amplification products of expected size were observed only in the strains containing the respective toxin genes. These findings recommend the use of these methods in clinical microbiology. Strains containing type 2 Shigella-like toxin gene were detected among E. coli strains isolated from patients with the hemolytic uremic syndrome, which for the first time indicates that the problem with E. coli epidemic strain O157 is valid for Russia. As a result of our studies, test systems for detection of types A, B, C, D, E, F, and G C. botulinum strains, C. perfringens and C. difficile, and E. coli O157 strains are now available.
Assuntos
Toxinas Bacterianas/genética , Clostridium/isolamento & purificação , Escherichia coli/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Toxinas Botulínicas/genética , Clostridioides difficile/isolamento & purificação , Clostridioides difficile/patogenicidade , Clostridium/patogenicidade , Clostridium botulinum/isolamento & purificação , Clostridium botulinum/patogenicidade , Clostridium perfringens/isolamento & purificação , Clostridium perfringens/patogenicidade , Primers do DNA , DNA Bacteriano/análise , Escherichia coli/patogenicidade , Infecções por Escherichia coli/diagnóstico , Amplificação de Genes , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , Sensibilidade e Especificidade , Toxina Shiga I/genética , Toxina Shiga II/genéticaAssuntos
Cateterismo/métodos , Ligamentos , Fígado , Anestésicos Locais , Cateterismo/instrumentação , Humanos , Agulhas , Procaína , Punções/instrumentação , Punções/métodosRESUMO
The effectiveness, both immunological (by an increase in the titers of antitoxins) and protective (by resistance to the inoculation of the absolute lethal dose of infective agents), of the regional (wound) revaccination with tetratoxoid (Clostridium perfringens, C. oedematiens, C. septicum, C. histolyticum) was demonstrated on the experimental model of wound infection (gas gangrene) of guinea pigs. The schedule of rapid immunization with tetratoxoid was developed, which made it possible to create good immunological preparedness (basic immunity) for subsequent revaccination in case of traumas within 6 days. The effectiveness of rapid immunization by the application of tetratoxoid on the wound was shown. This immunization ensured a considered increase in the titers of antitoxins within the first 6 days, which increased the protection of the animals from infection with each of the four causative agents of gas gangrene.
Assuntos
Clostridium perfringens/imunologia , Clostridium/imunologia , Gangrena Gasosa/prevenção & controle , Toxoides/uso terapêutico , Animais , Antitoxinas/sangue , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Emergências , Gangrena Gasosa/imunologia , Gangrena Gasosa/mortalidade , Cobaias , Imunização Secundária , Camundongos , Coelhos , Fatores de Tempo , Infecção dos Ferimentos/imunologia , Infecção dos Ferimentos/mortalidade , Infecção dos Ferimentos/prevenção & controleAssuntos
Vacinas Bacterianas/imunologia , Clostridium perfringens/imunologia , Gangrena Gasosa/imunologia , Leucócitos Mononucleares/imunologia , Fagócitos/imunologia , Toxoides/imunologia , Infecção dos Ferimentos/imunologia , Animais , Gangrena Gasosa/prevenção & controle , Cobaias , Imunização Secundária , Linfonodos/imunologia , Infecção dos Ferimentos/prevenção & controleAssuntos
Infecções por Clostridium/prevenção & controle , Infecção dos Ferimentos/prevenção & controle , Infecções por Clostridium/imunologia , Gangrena Gasosa/imunologia , Gangrena Gasosa/prevenção & controle , Humanos , Imunização Passiva , Tétano/imunologia , Tétano/prevenção & controle , Vacinação , Infecção dos Ferimentos/imunologiaRESUMO
Carcinogenesis in mice induced by the tryptophane derivative 3-hydroxyanthranilic acid was studied after administration of synthetic beta-carotene and ascorbic acid. The incidence of induced hemoblastoses and hepatomas was decreased 2-fold, while the latent period of their development was, increased in mice on a lifetime feed containing 15 mg/kg of beta-carotene. The anticarcinogenic effect of ascorbic acid added to drinking water was similar to that of beta-carotene. The additive inhibitory influence of beta-carotene and ascorbic acid on endogenous blastomogenesis was not found in mice.
Assuntos
Ácido Ascórbico/uso terapêutico , Carotenoides/uso terapêutico , Neoplasias Hepáticas Experimentais/prevenção & controle , Ácido 3-Hidroxiantranílico , Animais , Neoplasias Hepáticas Experimentais/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL , beta CarotenoRESUMO
Preventive effects of artificial beta-carotene on the development of rat mammary gland adenocarcinomas induced by DMBA were studied in rats maintained on a diet containing beta-carotene at a dose of 2.5 mg per animal within 10 weeks, which was initiated after the carcinogen administration. The carotenoid treatment course caused the following effects: manifestation of adenocarcinomas induced by DMBA was decreased, latent period of neoplasm development as well as the rate of tumor differentiation were increased and metastatic spreading into the regional lymph nodes was inhibited.
Assuntos
Carotenoides/uso terapêutico , Neoplasias Mamárias Experimentais/prevenção & controle , 9,10-Dimetil-1,2-benzantraceno , Animais , Metástase Linfática , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Ratos , beta CarotenoRESUMO
Development of spontaneous hepatomas was studied in CBA mice, which were maintained on a diet containing the carotenoid drug lipochromine in a dose of 25 mg/kg during their life beginning at the age of 3 months twice a week. Concentrations of vitamin A (as retinol) and beta-carotene were estimated in mice blood and liver tissue by means of HPLC. Decrease in occurrence of spontaneous tumors in liver tissue as well as distinct increase in periods of their development were detected in the animals treated with the drug. The phenomenon observed correlated positively with an increase in concentration of beta-carotene in liver tissue of tumor-bearing mice, thus indicating the preventive effect of lipochromine on spontaneous carcinogenesis in mice CBA strain.
Assuntos
Anticarcinógenos/uso terapêutico , Carotenoides/uso terapêutico , Neoplasias Hepáticas Experimentais/prevenção & controle , Animais , Carotenoides/análise , Carotenoides/sangue , Cromatografia Líquida de Alta Pressão , Feminino , Fígado/química , Masculino , Camundongos , Camundongos Endogâmicos CBA , Extratos Vegetais/uso terapêutico , Vitamina A/análise , Vitamina A/sangue , beta CarotenoRESUMO
The study made with the use of complex methods established that the local (wound) application of tetanus toxoid rapidly made the manifestation of the lysosomal apparatus more pronounced, increased the oxidizing activity (determined in the nitro blue tetrazolium test) and phagocytic activity of the mononuclear phagocytizing system in the wound and in the regional lymph nodes. The wound application of tetanus toxoid significantly increased blast transformation of T lymphocytes in guinea pigs simultaneously with tetanus wound infection. The study confirmed the pathogenetic expediency of the proposed method for the stimulation of anti-tetanus immunity by the application of tetanus toxoid on the wound which specifically inhibited the primary stage of the infectious process.
Assuntos
Fagócitos/imunologia , Toxoide Tetânico/administração & dosagem , Vacinação , Ferimentos e Lesões/terapia , Administração Tópica , Animais , Cobaias , Linfonodos/imunologia , Linfócitos T/imunologia , Ferimentos e Lesões/imunologiaRESUMO
The efficacy of eremomycin, a new glycopeptide antibiotic, was studied on a model of antibiotic-associated colitis in golden hamsters. The colitis was induced by intraperitoneal or intragastric administration of lincomycin. In a dose of 100 mg/kg administered orally once a day for 5 days eremomycin protected the animals from the lincomycin-induced colitis: some animals survived, the others died in later periods. When the animals were infected with a pathogenetic strain of Clostridium difficile followed by exposure to lincomycin the use of eremomycin produced the similar effect.
Assuntos
Antibacterianos/uso terapêutico , Clostridioides difficile/patogenicidade , Modelos Animais de Doenças , Enterocolite Pseudomembranosa/tratamento farmacológico , Lincomicina/efeitos adversos , Administração Oral , Animais , Clostridioides difficile/efeitos dos fármacos , Cricetinae , Enterocolite Pseudomembranosa/induzido quimicamente , Enterocolite Pseudomembranosa/microbiologia , Glicopeptídeos/uso terapêutico , Injeções Intraperitoneais , Lincomicina/administração & dosagem , Masculino , Mesocricetus , Fatores de TempoRESUMO
Antibacterial activity of eremomycin, a novel glycopeptide antibiotic, against obligate anaerobic Gram-positive++ bacteria was studied. Eremomycin was shown to inhibit the growth of obligate anaerobic Gram-positive++ cocci and bacteria belonging to Clostridium in rather low concentrations and within narrow ranges of the MIC which was indicative of the antibiotic undoubted advantages. The antibacterial activity of eremomycin was 2 times as high as that of vancomycin and 8 times as high as that of ristomycin with respect to Gram-positive++ anaerobic cocci. Pathogenic strains of Clostridium spp. were 2 to 4 times more sensitive to eremomycin than to vancomycin. A significant property of the novel glycopeptide antibiotic was shown to be its capacity for inhibiting the growth of Gram-positive++ aerobic and obligate anaerobic cocci within the same concentration ranges which might be of importance in monotherapy of mixed aerobic and anaerobic infections.
Assuntos
Antibacterianos/farmacologia , Clostridium/efeitos dos fármacos , Glicopeptídeos/farmacologia , Clostridium/crescimento & desenvolvimento , Meios de Cultura , Avaliação Pré-Clínica de Medicamentos , Resistência Microbiana a Medicamentos , Técnicas In Vitro , Testes de Sensibilidade Microbiana , Ristocetina/farmacologia , Vancomicina/farmacologiaRESUMO
A method for isolation of the ribosomal fraction (RF) from the cytoplasm of type-A C. perfringens strain BP6K was developed and its chemical and antigenic properties characterized. RF has been found to possess protective properties: two subcutaneous immunizations of mice with RF preparations adsorbed on Al(OH)3 in doses of 250 and 500 micrograms (dry weight) has ensured, on the average, the protection of 41.9% of the immunized animals from 1 DCL of type-A C. perfringens strain BP6K culture.
Assuntos
Clostridium perfringens/isolamento & purificação , Proteínas Ribossômicas/isolamento & purificação , Animais , Fracionamento Celular/métodos , Clostridium perfringens/imunologia , Relação Dose-Resposta Imunológica , Avaliação Pré-Clínica de Medicamentos , Gangrena Gasosa/imunologia , Gangrena Gasosa/terapia , Imunização , Camundongos , Proteínas Ribossômicas/imunologia , Proteínas Ribossômicas/uso terapêuticoRESUMO
Sensitivity of the main microbial species causing gas gangrene to 21 antibacterial drugs was studied. The pathogens included 28 strains of Clostridium perfringens, 21 strains of C. oedematiens, 31 strains of C. septicum and 19 strains of C. histolyticum. Antibiotics having a bactericidal effect on the Clostridia were determined. The findings of the study were indicative of a variety of the antibiotic sensitivity spectra of the Clostridium spp., which accentuated the importance of antibiotic sensitivity assay in every particular case of gas gangrene.
Assuntos
Antibacterianos/farmacologia , Clostridium/efeitos dos fármacos , Gangrena Gasosa/microbiologia , Clostridium perfringens/efeitos dos fármacos , Meios de Cultura , Resistência Microbiana a Medicamentos , Gangrena Gasosa/etiologia , Técnicas In Vitro , Testes de Sensibilidade MicrobianaRESUMO
The immunomorphological reaction of regional lymphoid organs, the pathomorphology of wound tissues, humoral antitoxic response and a protective effect after local (wound) booster immunization with tetanus toxoid have been studied in observations on 100 guinea pigs with experimental wound infection. The study has shown that the local application of tetanus toxoid, besides stimulating humoral response, induces a more rapid effect aimed at the primary elements of the infectious process (the germination of spores, the adhesion, colonization and toxin formation of the causative agent), thus facilitating the localization of the focus of infection, the development of reparative processes in the wound and the arresting of the infection.
Assuntos
Imunização Secundária , Toxoide Tetânico/imunologia , Tétano/imunologia , Ferimentos Penetrantes/imunologia , Animais , Formação de Anticorpos/imunologia , Cobaias , Imunidade Celular/imunologia , Linfonodos/imunologia , Linfonodos/patologia , Tétano/patologia , Tétano/prevenção & controle , Toxoide Tetânico/administração & dosagem , Fatores de Tempo , Ferimentos Penetrantes/complicações , Ferimentos Penetrantes/patologiaRESUMO
The results of the studies on the preparation of diagnostic antitoxic sera to C. difficile, intended for use in biological assays with the aim of the laboratory diagnosis of clostridial enteric infections, are presented. The conditions for the detoxification of C. difficile native toxin have been established, the optimum schedules for the immunization of rabbits have been selected and specific antitoxic sera to C. difficile have been obtained. The neutralizing activity of these sera has been evaluated in the lethality test and in the cytotoxic test on human embryo dermo-muscular fibroblast cells M-19.