RESUMO
Monoclonal antibodies to cholera toxin were obtained. They do not cross-react with the termolabile toxin (LT) of Escherichia coli, ricin, diphtherial toxin, staphylococcus enterotoxins of SEA, SEB, SEI, SEG, or the lethal factor and protective antigen of the anthrax toxin. Pairs of antibodies for the quantitative measurement of the cholera toxin in sandwich enzyme immunoassay (EIA) were selected. The detection limit of the toxin is 0.2 ng/ml for plate EIA and 0.44 ng/ml for microchip EIA. The presence of milk, broth, or surface water in the toxin samples does not reduce the sensitivity of EIA.
Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Toxina da Cólera/imunologia , Anticorpos Monoclonais/isolamento & purificação , Toxinas Bacterianas/imunologia , Reações Cruzadas , Proteínas de Escherichia coli/imunologia , Técnicas Imunoenzimáticas , Análise em MicrossériesRESUMO
The growth of M. tuberculosis H37RV in culture medium was studied after addition of liposomes from different lipids (phosphatidylcholine, cardiolipin, and glycosphyngolipids). Addition of phosphatidylcholine into culture medium did not modify the growth and multiplication of mycobacteria. Addition of glycosphyngolipids and their mixture with phosphatidylcholine partially inhibited the growth. Addition of cardiolipin inhibited the growth of mycobacteria and even suppressed it, depending on the dose. Presumably, high concentrations of cardiolipin added into the culture medium, can transfer the mycobacteria into an uncultivable state.
Assuntos
Metabolismo dos Lipídeos , Lipídeos/química , Lipossomos/química , Mycobacterium tuberculosis , Mycobacterium tuberculosis/química , Mycobacterium tuberculosis/fisiologia , Tamanho da PartículaRESUMO
We studied the effect of combined treatment with cisplatin, glucosaminylmuramyl dipeptide, and TNF-alpha on viability of MCF-7, U-937, B16, and L-929 tumor cells, Ehrlich ascites carcinoma cells, and normal cells (human peripheral blood lymphocytes, peritoneal macrophages, and mouse bone marrow cells). Glucosaminylmuramyl dipeptide was nontoxic for normal and tumor cells, but promoted death of tumor cells after administration in combination with cisplatin and/or TNF-alpha. At the same time, glucosaminylmuramyl dipeptide did not modulate the cytotoxic effect of individual or combined treatment with cisplatin and TNF-alpha on normal cells. Administration of glucosaminylmuramyl dipeptide to cultured MCF-7 cells 20 h before the study increased the potentiating effect of muramyl peptide.
Assuntos
Acetilmuramil-Alanil-Isoglutamina/análogos & derivados , Cisplatino/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Animais , Antineoplásicos/farmacologia , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Fatores de Tempo , Células U937RESUMO
Influence of medium composition on Mycobacterium smegmatis growth and susceptibility to antituberculosis drugs (ATD)--isoniazid and rifabutin--was studied. It was shown that addition of phospholipids (PL) in form of liposomes to meat peptone broth resulted in activation of M. smegmatis growth and decrease of its susceptibility to ATD. Growth characteristics of M. smegmatis and its susceptibility to ATD were studied using variants of modified on source of carbon synthetic medium Sauton as growth substrate. It was revealed that presence of acetate or PL in growth medium results in significant decrease of M. smegmatis susceptibility to isoniazid and rifabutin. It was suggested that this phenomenon is determined by activation of glyoxylate cycle by PL and fatty acids, which, in its turn, can stimulate expression of a number of proteins, including cell membrane pumps excreting antibiotics out of microbial cell.
Assuntos
Antituberculosos/farmacologia , Isoniazida/farmacologia , Mycobacterium smegmatis/efeitos dos fármacos , Mycobacterium smegmatis/crescimento & desenvolvimento , Rifabutina/farmacologia , Acetatos , Meios de Cultura , Glicerol , Testes de Sensibilidade Microbiana , FosfolipídeosRESUMO
The surface of the melanoma BRO cells was shown to contain binding sites for N-acetylglucosaminyl-(beta 1-4)-N-acetylmuramyl-alanyl-D-isoglutamine (GMDP). Their number (1500 +/- 200 per cell) and affinity (Kd = 10 +/- +/- 1.2 nM) were determined. The occurrence of these sites was found to correlate with the ability of the melanoma cells to react in vitro with GMDP by increasing the expression of melanoma-associated antigens (MAA). An increased number of the GMDP binding sites (5200 +/- 500 per cell) was observed upon treating the melanoma BRO cells with tumor necrosis factor alpha (TNF-alpha). The mechanism of the TNF-alpha action most likely involves the unmasking of GMDP binding sites, initially expressed on the cell surface, by activating the endogenous protease that hydrolyzes surface proteins, in particular, highly glycosylated LAMP-2 protein exposed on the melanoma cell surface.
Assuntos
Acetilmuramil-Alanil-Isoglutamina/análogos & derivados , Acetilmuramil-Alanil-Isoglutamina/metabolismo , Melanoma/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Antígenos CD/metabolismo , Antígenos de Neoplasias/metabolismo , Sítios de Ligação , Humanos , Hidrólise , Proteínas de Membrana Lisossomal , Glicoproteínas de Membrana/metabolismo , Ligação Proteica , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Flow cytometry was used to demonstrate that cultured human melanoma BRO cells expressed membrane-bound tumour necrosis factor-alpha (TNF-alpha) and were able to release TNF-alpha upon treatment with glucosaminylmuramyl dipeptide (GMDP). The released TNF-alpha was shown to prime melanoma cells, previously unable to respond to GMDP by increasing expression of melanoma-associated antigens, making them sensitive to GMDP treatment.
Assuntos
Acetilmuramil-Alanil-Isoglutamina/análogos & derivados , Adjuvantes Imunológicos/farmacologia , Melanoma/metabolismo , Fator de Necrose Tumoral alfa/fisiologia , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Animais , Antígenos de Neoplasias/biossíntese , Antígenos de Neoplasias/efeitos dos fármacos , Sistema Livre de Células/fisiologia , Meios de Cultivo Condicionados/farmacologia , Citometria de Fluxo , Humanos , Melanoma/imunologia , Camundongos , Células Tumorais CultivadasAssuntos
Acetilmuramil-Alanil-Isoglutamina/farmacologia , Adjuvantes Imunológicos/farmacologia , Melanoma Experimental/genética , Metástase Neoplásica/genética , Fenótipo , Animais , Antígenos de Neoplasias/imunologia , Antígenos de Superfície/imunologia , Citotoxicidade Imunológica , Humanos , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Nus , Metástase Neoplásica/imunologia , Transplante de Neoplasias , Transplante Heterólogo , Células Tumorais Cultivadas , Evasão TumoralRESUMO
Albumin-like glycoprotein (Gp66) with a molecular mass of 66 kDa has been isolated from human fetal tissue by size-exclusion, ion-exchange chromatography and reverse-phase HPLC. Reactivity of Gp66 with antiserum raised against the major protein components fraction of human fetal serum was observed. The N-terminal 35 amino acid residues of Gp66 were identical to human serum albumin. Meanwhile Gp66 differed from albumin by a/ the presence of 3-5 Trp residues instead of 1 according to fluorescence and UV-spectra, b/ the glycosylation pattern: bi-, tri-, and tetraantennary sialooligosaccharides of a complex type were present. Isoelectric focusing revealed 4 isoforms (pI ranging within 4.8 to 5.1) of Gp66. Gp66 (but not asialo-Gp66) was able to inhibit the cytotoxic effect of TNF against the tumor cell line L929. Inhibition of WEHI-3 and L929 tumor cells proliferation by Gp66 was similar to that of albumin.
Assuntos
Glicoproteínas/química , Albumina Sérica/química , Animais , Sequência de Carboidratos , Divisão Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Glicoproteínas/metabolismo , Glicoproteínas/farmacologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Peso Molecular , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/toxicidade , VitronectinaRESUMO
Analysis of the findings of ultrasonic examinations of the fetal heart in pregnant women with antibodies to phospholipids has shown changes in this parameter in 42% of the examinees, in 3 cases antenatal fetal death was revealed. The detected changes were of different nature, but in the majority of cases they were of a compensatory type. Marked hypertrophy of the right ventricular myocardium, whose work in the antenatal period is largely responsible for the viability of the fetus, was found.
Assuntos
Síndrome Antifosfolipídica/diagnóstico por imagem , Coração Fetal/diagnóstico por imagem , Complicações na Gravidez/diagnóstico por imagem , Ultrassonografia Pré-Natal , Adulto , Peso ao Nascer , Feminino , Doenças Fetais/diagnóstico por imagem , Humanos , Hipertrofia Ventricular Direita/diagnóstico por imagem , Recém-Nascido , GravidezRESUMO
Proton signals for nine synthetic peptide fragments of human interleukin-2 (region 59-78) were assigned for aqueous solutions both of pure peptides and their mixtures with LNKB-2 monoclonal antibody. The nonspecific magnetization transfer (NOE) between the antibody or its Fab-fragment and the peptides was studied upon large excess of free peptide over bound peptide. NOE spectra using modified pulse sequence, enabling to eliminate broad signals and achieve higher (peptide signal)/noise ratio were obtained. The saturation transfer experiments indicated that methyl groups of amino acid residues corresponding to Leu66,70,72, Val69 and Ala73 in interleukin-2 contact with the antibody binding site. Thus, the hydrophobic interactions are of major importance for the LNKB-2-IL-2 peptide complexes. The minimal IL-2 fragment which can still bind to LNKB-2 monoclonal antibody is -Leu70-Asn71-Leu72-.