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321.
Pantoja-Hernández MA Muñoz-Sánchez CI Guevara-González RG Botello-Alvarez E González-Chavira MM Torres-Pacheco I Guevara-Olvera L 《Biotechnology letters》2004,26(1):75-78
Ornithine decarboxylase from respiratory fungal pathogen, Coccidioides immitis, cloned in the pETCiODC plasmid under control of T7lac promoter, was produced in E. coli BL21(DE3), BL21(DE3)pLysS, BLR(DE3) and EWH319 transformant strains. E. coli BL21(DE3)pLysS-pETCiODC expressed the highest specific activity of ODC, suggesting that this strain could be successfully used for protein structure and drug testing studies. 相似文献
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Valle MR Mèndez L Valdez M Redondo M Espinosa CM Vargas M Cruz RL Barrios HP Seoane G Ramirez ES Boue O Vigil JL Machado H Nordelo CB Piñeiro MJ 《Experimental & applied acarology》2004,34(3-4):375-382
Boophilus microplus has developed resistance against a range of chemical acaricides which has stimulated the development of alternative methods such as vaccination against ticks. In Cuba, the Bm86-based recombinant vaccine GavacTM has been successfully used in a number of controlled laboratory and field trials in cattle against B. microplus. In this paper, we have evaluated GavacTM in a large scale field trial wherein 588,573 dairy cattle were vaccinated with the aim to reduce the number of acaricidal treatments. It was found that the number of acaricidal treatments could be reduced by 87% over a period of 8 years (1995–2003). Prior to the introduction of the vaccine, 54 clinical cases of babesiosis and six fatal cases were reported per 1000 animals. Six years later, the incidence of babesiosis was reduced to 1.9 cases per 1000 cattle and mortality reduced to 0.18 per 1000. The national consumption of acaricides in Cuba could be reduced by 82% after the implementation of the integrated anti-B. microplus control program. 相似文献
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Structural and functional characterization of N-terminally blocked peptides isolated from the venom of the social wasp Polybia paulista 总被引:2,自引:0,他引:2
Ribeiro SP Mendes MA Dos Santos LD de Souza BM Marques MR de Azevedo WF Palma MS 《Peptides》2004,25(12):2069-2078
Two novel peptides were isolated from the crude venom of the social wasp Polybia paulista, by using RP-HPLC under a gradient of MeCN from 5 to 60% (v/v) and named Polybine-I and -II. Further purification of these peptides under normal phase chromatography, rendered pure enough preparations to be sequenced by Edman degradation chemistry. However, both peptides did not interact with phenylisothiocyanate reagent, suggesting the existence of a chemically blocked N-terminus. Therefore, the sequences of both peptides were assigned by ESI-MS/MS under CID conditions, as follows: Polybine-I Ac-SADLVKKIWDNPAL-NH2 (Mr 1610 Da) and Polybine-II Ac-SVDMVMKGLKIWPL-NH2 (Mr 1657 Da). During the tandem mass spectrometry experiments, a loss of 43 a.m.u. was observed from the N-terminal residue of each peptide, suggesting the acetylation of the N-terminus. Subsequently, the peptides with and without acetylation were synthesized on solid phase and submitted to functional characterizations; the biological activities investigated were: hemolysis, chemotaxis of polymorphonucleated leukocytes (PMNL), mast cell degranulation and antibiosis. The results revealed that the acetylated peptides exhibited more pronounced chemotaxis of PMNL cells and mast cell degranulation than the respective non-acetylated congeners; no hemolytic and antibiotic activities were observed, irrespective to the blockage or not of the -amino groups of the N-terminal residues of each peptide. Therefore, the N-terminal acetylation may be related to the increase of the inflammatory activity of both peptides. 相似文献
326.
Manni V Lisi A Rieti S Serafino A Ledda M Giuliani L Sacco D D'Emilia E Grimaldi S 《Bioelectromagnetics》2004,25(2):118-126
This work concerns the effect of low frequency electromagnetic fields (ELF) on biochemical properties of human oral keratinocytes (HOK). Cells exposed to a 2 mT, 50 Hz, magnetic field, showed by scanning electron microscopy (SEM) modification in shape and morphology; these modifications were also associated with different actin distribution, revealed by phalloidin fluorescence analysis. Moreover, exposed cells had a smaller clonogenic capacity, and decreased cellular growth. Indirect immunofluorescence with fluorescent antibodies against involucrin and beta-catenin, both differentiation and adhesion markers, revealed an increase in involucrin and beta-catenin expression. The advance in differentiation was confirmed by a decrease of expression of epidermal growth factor (EGF) receptor in exposed cells, supporting the idea that exposure to electromagnetic field carries keratinocytes to higher differentiation level. These observations support the hypothesis that 50 Hz electromagnetic fields may modify cell morphology and interfere in differentiation and cellular adhesion of normal keratinocytes. 相似文献
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329.
Yueh-Hsin Ping Chia-ying Chu Hong Cao Jean-Marc Jacque Mario Stevenson Tariq M Rana 《Retrovirology》2004,1(1):1-13
Background
Dendritic cell (DC) transmission of human immunodeficiency virus (HIV) to CD4+ T cells occurs across a point of cell-cell contact referred to as the infectious synapse. The relationship between the infectious synapse and the classically defined immunological synapse is not currently understood. We have recently demonstrated that human B cells expressing exogenous DC-SIGN, DC-specific intercellular adhesion molecule-3 (ICAM-3)-grabbing nonintegrin, efficiently transmit captured HIV type 1 (HIV-1) to CD4+ T cells. K562, another human cell line of hematopoietic origin that has been extensively used in functional analyses of DC-SIGN and related molecules, lacks the principal molecules involved in the formation of immunological synaptic junctions, namely major histocompatibility complex (MHC) class II molecules and leukocyte function-associated antigen-1 (LFA-1). We thus examined whether K562 erythroleukemic cells could recapitulate efficient DC-SIGN-mediated HIV-1 transmission (DMHT).Results
Here we demonstrate that DMHT requires cell-cell contact. Despite similar expression of functional DC-SIGN, K562/DC-SIGN cells were inefficient in the transmission of HIV-1 to CD4+ T cells when compared with Raji/DC-SIGN cells. Expression of MHC class II molecules or LFA-1 on K562/DC-SIGN cells was insufficient to rescue HIV-1 transmission efficiency. Strikingly, we observed that co-culture of K562 cells with Raji/DC-SIGN cells impaired DMHT to CD4+ T cells. The K562 cell inhibition of transmission was not directly exerted on the CD4+ T cell targets and required contact between K562 and Raji/DC-SIGN cells.Conclusions
DMHT is cell type dependent and requires cell-cell contact. We also find that the cellular milieu can negatively regulate DC-SIGN transmission of HIV-1 in trans. 相似文献330.
Drago M Chessa M Gianfranco B Bossone E Carminati M 《International journal of cardiovascular interventions》2004,6(3-4):156-159
We describe a case of a congenital coronary artery fistula of the right coronary artery draining into the left atrium in an eight-year-old boy. The initial diagnosis was made after the detection of a continuous cardiac murmur at the age of six years. Transthoracic echocardiography showed the right coronaric ostium dilatation, the site of drainage in the left atrium and left ventricle volume overload. Catheterization confirmed the diagnosis. The patient underwent percutaneous closure by PDA occluder device. Immediate post-closure angiograms showed complete occlusion of the fistula. The patient showed transient ischemic changes on ECG associated to an increase of plasmatic levels of the cardiac enzyme. ECG and cardiac enzyme were normal one week after the procedure. 相似文献