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1.
Phys Rev Lett ; 125(13): 131101, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-33034506

RESUMO

The quantum radiation pressure and the quantum shot noise in laser-interferometric gravitational wave detectors constitute a macroscopic manifestation of the Heisenberg inequality. If quantum shot noise can be easily observed, the observation of quantum radiation pressure noise has been elusive, so far, due to the technical noise competing with quantum effects. Here, we discuss the evidence of quantum radiation pressure noise in the Advanced Virgo gravitational wave detector. In our experiment, we inject squeezed vacuum states of light into the interferometer in order to manipulate the quantum backaction on the 42 kg mirrors and observe the corresponding quantum noise driven displacement at frequencies between 30 and 70 Hz. The experimental data, obtained in various interferometer configurations, is tested against the Advanced Virgo detector quantum noise model which confirmed the measured magnitude of quantum radiation pressure noise.

2.
Biochim Biophys Acta Biomembr ; 1862(2): 183055, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31487493

RESUMO

The search of antimicrobial peptides (AMP) as candidates for the development of antibiotics is an active research field. In this paper we investigated the role of charged residues in antimicrobial activity by using as a template the previously characterized crabrolin peptide. Mutant peptides in which the charge was diminished (Crabrolin Minus) or increased (Crabrolin Plus) were assayed for their ability to inhibit bacterial growth and to bind model bacterial membranes or lipopolysaccharide (LPS). Structural analysis of both peptides by means of CD, NMR and Molecular Dynamics was also performed and correlated to the biological data. Although native Crabrolin (WT) displays smaller efficacy than other antibacterial peptides with similar length, Crabrolin Plus displays a significant antimicrobial activity while Crabrolin Minus is not active, thus confirming the key role of the positive charge for interacting with the bacterial membrane. Moreover, our results show that charge position has no effect on the helical propensity of the peptides but drastically affects their antimicrobial activity. Antimicrobial activity versus Gram-positive and Gram-negative bacteria, as well as specific interaction with LPS, suggest multiple binding modes for the active peptide.


Assuntos
Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Íons/química , Venenos de Vespas/química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Sítios de Ligação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Lipopolissacarídeos , Estrutura Molecular , Engenharia de Proteínas/métodos , Isoformas de Proteínas/química , Venenos de Vespas/farmacologia
3.
Phys Rev Lett ; 123(23): 231108, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31868444

RESUMO

Current interferometric gravitational-wave detectors are limited by quantum noise over a wide range of their measurement bandwidth. One method to overcome the quantum limit is the injection of squeezed vacuum states of light into the interferometer's dark port. Here, we report on the successful application of this quantum technology to improve the shot noise limited sensitivity of the Advanced Virgo gravitational-wave detector. A sensitivity enhancement of up to 3.2±0.1 dB beyond the shot noise limit is achieved. This nonclassical improvement corresponds to a 5%-8% increase of the binary neutron star horizon. The squeezing injection was fully automated and over the first 5 months of the third joint LIGO-Virgo observation run O3 squeezing was applied for more than 99% of the science time. During this period several gravitational-wave candidates have been recorded.

4.
Dalton Trans ; 44(46): 19956-65, 2015 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-26514577

RESUMO

In this paper we show a very simple route for the incorporation of catalytically active niobium species on the surface of carbon materials, such as graphene oxide, carbon nanotubes and activated carbon. Some existing methods of incorporating a transition metal on a support have involved co-precipitation or wet impregnation, to obtain the corresponding oxides. These methods, however, cause reduction in the specific area of the support and can also form large metal oxide particles with loss of metal exposure. Therefore, here we present a novel way to add catalytically active species on the surfaces of different types of carbon through the formation of interaction complexes between the metal precursor and the functional groups of the carbon matrix. Because of the excellent catalytic properties exhibited by the niobium species we choose the NH4[NbO(C2O4)2(H2O)2]·2H2O salt as the model precursor. The characterization by XPS reveals the presence of the niobium species indicated by the displacement of the peaks between 206-212 eV related to the oxalate species according to the spectrum from pure niobium oxalate. Images obtained by TEM and SEM show the typical morphologies of carbonaceous materials without the niobium oxide formation signal, which indicates the presence of niobium complexes as isolated sites on the carbon surfaces. This new class of materials exhibited excellent properties as catalysts for pollutant oxidation. The presence of Nb promotes the catalytic activation of H2O2 generating hydroxyl radicals in situ, which allows their use in the organic compound oxidation processes. Tests for DBT oxidation indicate that Nb significantly improves the removal of such pollutants in biphasic reactions with removal around 90% under the tested conditions. Theoretical calculations showed that the most favorable adsorption model is an ionic complex presenting a ΔG = -108.7 kcal mol(-1) for the whole adsorption process.

5.
Cytokine ; 48(3): 212-7, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19682920

RESUMO

The gene polymorphisms interferon-gamma (IFN-gamma) +874 T/A and interleukin (IL)-4 -590 C/T have been associated with the altered production of cytokines. Therefore, they might be indicative of the occurrence of Paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. The analysis of single nucleotide polymorphism (SNP) at position+874 IFN-gamma showed an increase occurrence of A/T genotype in both PCM patients and healthy individuals as control (HIC) (56% and 45%, respectively), while the allelic distribution showed 82% of A allele in the patients and 80% in the controls. The SNP of -590 IL-4 showed that C/T genotype was significantly (p<0.05) more prevalent (39%) in PCM group compared to the HIC group (19%), while IL-4 C/C genotype was significantly less frequent (59%) in the patient group compared to the control group (81%). Otherwise, 41% of PCM patients and 19% of HIC individuals carried the IL-4 T allele. Stimulation of peripheral blood mononuclear cells (PBMC) from PCM patients with cell extract antigenic preparations (PbAg) as well as secreted and surface antigens (MEXO) of P. brasiliensis evidenced that there is no difference in the IFN-gamma production related to A and T alleles between PCM and HIC individuals. However, with IL-4 production, PCM patients classified as C phenotype showed two times more IL-4 production than PCM patients classified as T phenotype and HIC controls. In conclusion, our results suggest that functional genetic variants in the IL-4 promoter could influence the production of IL-4 in PCM.


Assuntos
Interferon gama/genética , Interleucina-4/genética , Paracoccidioidomicose/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Antígenos de Fungos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença , Humanos , Imunidade Inata , Interferon gama/metabolismo , Interleucina-4/metabolismo , Masculino , Pessoa de Meia-Idade , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Paracoccidioidomicose/fisiopatologia , Adulto Jovem
6.
Biocell ; 32(2): 175-83, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18825911

RESUMO

4', 6-diamidino-2-phenylindole dihydrochloride (DAPI) is a DNA dye widely used to mark and trace stem cells in therapy. We here studied the effect of DAPI staining on the behavior of mesenchymal stem cells cultured in either a control, non-osteogenic medium or in an osteogenic differentiation medium. In the control medium, the number of stem cells/field, as well as the number of fluorescent cells/field increased up to the sixth day in both control and DAPI-treated cultures. Afterwards, both the number of fluorescent cells and their fluorescence intensity decreased. Control cells were fusiform and with some long extensions that apparently linked them to neighboring cells, while DAPI-treated cells were mostly round cells with fine and short extensions. The trypan-blue exclusion method showed 99% cell viability in both groups, however, both alkaline phosphatase activity and the thiazolyl blue formazan assay (indicative of mitochondrial metabolism) gave significantly lower values in DAPI-marked cells. The mitochondrial mass, as indicated by specific staining and flow cytometry, showed no differences between groups. Mesenchymal stem cells gave origin to mineralized nodules in the osteogenic differentiation medium and there were not DAPI-marked cells on the ninth day of culture. Alkaline phosphatase activity, viability assay and number of cells/field and of mineralized nodules/field were similar in both groups. So, DAPI treatment did not change cell viability and proliferation during osteogenic differentiation of mesenchymal stem cells. However, since these cells loose DAPI marking after 9 days in osteogenic cultures suggests that DAPI may not be an effective marker for mesenchymal stem cells implanted in bone tissue for long periods.


Assuntos
Células da Medula Óssea/fisiologia , Corantes Fluorescentes/metabolismo , Indóis/metabolismo , Células-Tronco Mesenquimais/fisiologia , Osteogênese/fisiologia , Animais , Células da Medula Óssea/citologia , Diferenciação Celular , Forma Celular , Células Cultivadas , Meios de Cultura/química , Masculino , Células-Tronco Mesenquimais/citologia , Mitocôndrias/metabolismo , Ratos
7.
Biocell ; 32(2): 175-183, Aug. 2008. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-541112

RESUMO

4', 6-diamidino-2-phenylindole dihydrochloride (DAPI) is a DNA dye widely used to mark and trace stem cells in therapy. We here studied the effect of DAPI staining on the behavior of mesenchymal stem cells cultured in either a control, non-osteogenic medium or in an osteogenic differentiation medium. In the control medium, the number of stem cells/field, as well as the number of fluorescent cells/field increased up to the sixth day in both control and DAPI-treated cultures. Afterwards, both the number of fluorescent cells and their fluorescence intensity decreased. Control cells were fusiform and with some long extensions that apparently linked them to neighboring cells, while DAPI-treated cells were mostly round cells with fine and short extensions. The trypan-blue exclusion method showed 99% cell viability in both groups, however, both alkaline phosphatase activity and the thiazolyl blue formazan assay (indicative of mitochondrial metabolism) gave significantly lower values in DAPI-marked cells The mitochondrial mass, as indicated by specific staining and flow cytometry, showed no differences between groups. Mesenchymal stem cells gave origin to mineralized nodules in the osteogenic differentiation medium and there were not DAPI-marked cells on the ninth day of culture. Alkaline phosphatase activity, viability assay and number of cells/field and of mineralized nodules/field were similar in both groups. So, DAPI treatment did not change cell viability and proliferation during osteogenic differentiation of mesenchymal stem cells. However, since these cells loose DAPI marking after 9 days in osteogenic cultures suggests that DAPI may not be an effective marker for mesenchymal stem cells implanted in bone tissue for long periods.


Assuntos
Masculino , Animais , Ratos , Diferenciação Celular , Células Cultivadas , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Corantes Fluorescentes/metabolismo , Células-Tronco Mesenquimais , Indóis/metabolismo , Meios de Cultura/química , Mitocôndrias/metabolismo , Osteogênese/fisiologia
8.
Biocell ; 32(2): 175-183, Aug. 2008. ilus, tab, graf
Artigo em Inglês | BINACIS | ID: bin-127194

RESUMO

4, 6-diamidino-2-phenylindole dihydrochloride (DAPI) is a DNA dye widely used to mark and trace stem cells in therapy. We here studied the effect of DAPI staining on the behavior of mesenchymal stem cells cultured in either a control, non-osteogenic medium or in an osteogenic differentiation medium. In the control medium, the number of stem cells/field, as well as the number of fluorescent cells/field increased up to the sixth day in both control and DAPI-treated cultures. Afterwards, both the number of fluorescent cells and their fluorescence intensity decreased. Control cells were fusiform and with some long extensions that apparently linked them to neighboring cells, while DAPI-treated cells were mostly round cells with fine and short extensions. The trypan-blue exclusion method showed 99% cell viability in both groups, however, both alkaline phosphatase activity and the thiazolyl blue formazan assay (indicative of mitochondrial metabolism) gave significantly lower values in DAPI-marked cells The mitochondrial mass, as indicated by specific staining and flow cytometry, showed no differences between groups. Mesenchymal stem cells gave origin to mineralized nodules in the osteogenic differentiation medium and there were not DAPI-marked cells on the ninth day of culture. Alkaline phosphatase activity, viability assay and number of cells/field and of mineralized nodules/field were similar in both groups. So, DAPI treatment did not change cell viability and proliferation during osteogenic differentiation of mesenchymal stem cells. However, since these cells loose DAPI marking after 9 days in osteogenic cultures suggests that DAPI may not be an effective marker for mesenchymal stem cells implanted in bone tissue for long periods.(AU)


Assuntos
Masculino , Animais , Ratos , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Diferenciação Celular , Células Cultivadas , Corantes Fluorescentes/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Meios de Cultura/química , Indóis/metabolismo , Mitocôndrias/metabolismo , Osteogênese/fisiologia
9.
Cell Mol Life Sci ; 65(16): 2450-60, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18661101

RESUMO

The innate immunity of multicellular organisms relies in large part on the action of antimicrobial peptides (AMPs) to resist microbial invasion. Crafted by evolution into an extremely diversified array of sequences and folds, AMPs do share a common amphiphilic 3-D arrangement. This feature is directly linked with a common mechanism of action that predominantly (although not exclusively) develops upon interaction of peptides with cell membranes of target cells. This minireview reports on current understanding of the modes of interaction of AMPs with biological and model membranes, especially focusing on recent insights into the folding and oligomerization requirements of peptides to bind and insert into lipid membranes and exert their antibiotic effects. Given the potential of AMPs to be developed into a new class of anti-infective agents, emphasis is placed on how the information on peptide-membrane interactions could direct the design and selection of improved biomimetic synthetic peptides with antibiotic properties.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/química , Materiais Biomiméticos/química , Humanos , Dobramento de Proteína
10.
Immunol Lett ; 114(1): 23-30, 2007 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-17897724

RESUMO

Memory T cell populations in patients with paracoccidioidomycosis (PCM) were analyzed before and after chemotherapy treatment. Peripheral blood mononuclear cells (PBMC) collected from patients infected by Paracoccidioides brasiliensis or from non-infected individuals were stimulated in vitro with either membrane and extra-cellular antigens (MEXO) or yeast cell antigen preparation (PbAg) of P. brasiliensis. An increase in the level of CD4(+) memory T cells was determined in PBMC from PCM patients before (NT) and after treatment (TR) and in those with PCM relapsed (RE) compared to that from non-infected controls (NINF). The CD8(+) memory T cells were increased in PBMC from RE patients stimulated with MEXO, but not in NT or TR. The distribution of memory B cells did not differ between NT and TR patients, while a significant elevation was determined in RE patients and higher antibody levels were also detected. The cytokine analysis showed low production of IFN-gamma by cells from RE patients compared with NT or TR patients. In contrast, high production of IL-4 was detected in NT and RE patients, and moderate levels were produced by RE patients. These results suggest that IFN-gamma production may participate in the maintenance of immunological memory in the acquired protection against P. brasiliensis infection and this data can contribute to future development of successful treatment of PCM to avoid relapsing.


Assuntos
Antifúngicos/uso terapêutico , Memória Imunológica , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Subpopulações de Linfócitos T/imunologia , Adolescente , Adulto , Idoso , Anticorpos Antifúngicos/sangue , Anticorpos Antifúngicos/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Interferon gama/sangue , Interferon gama/imunologia , Interleucina-4/sangue , Interleucina-4/imunologia , Leucócitos Mononucleares/imunologia , Pessoa de Meia-Idade , Paracoccidioidomicose/tratamento farmacológico , Paracoccidioidomicose/microbiologia
11.
Biopolymers ; 87(1): 85-92, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17554783

RESUMO

The synthetic peptide Vitr-p-13 (YPIVGQELLGAIK-NH(2)), derived from the bacterial dimeric Vitreoscilla haemoglobin (VHb) in the position 95-107, is characterized by a pre-eminent "statistical coil" conformation in water as demonstrated by CD experiments and long time-scale MD simulations. In particular, Vitr-p-13 does not spontaneously adopt an alpha-helix folding in water, but it is rather preferentially found in beta-hairpin-like conformations. Long time-scale MD simulations have also shown that Vitr-p-13 displays a "topological-trigger" which initiates alpha-helix folding within residues 7-10, exactly like seen in the temporins, a group of linear, membrane-active antimicrobial peptides of similar length. At variance with temporins, in Vitr-p-13 such a process is energetically very demanding (+10 kJ/mol) in water at 300 K, and the peptide was found to be unable to bind model membranes in vitro and was devoid of antimicrobial activity. The present results, compared with previous studies on similar systems, strengthen the hypothesis of the requirement of a partial folding when still in aqueous environment to allow a peptide to interact with cell-membranes and eventually exert membrane perturbation-related antibiotic effects on target microbial cells.


Assuntos
Proteínas de Bactérias/química , Hemoglobinas/química , Modelos Moleculares , Peptídeos/química , Dobramento de Proteína , Vitreoscilla/química , Proteínas de Bactérias/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Hemoglobinas/metabolismo , Peptídeos/metabolismo , Ligação Proteica , Estrutura Secundária de Proteína , Relação Estrutura-Atividade , Hemoglobinas Truncadas , Vitreoscilla/metabolismo
12.
Hum Immunol ; 67(11): 931-9, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17145373

RESUMO

Allelic variants of cytokine genes seem to be involved in mechanisms of resistance or susceptibility to several diseases. The aim of this study was to investigate the frequency of genotypes with the tumor necrosis factor-alpha TNF-alpha gene polymorphism G/A at position -308 and the IL-10 gene polymorphism G/A at position -1082, and to verify a possible association of these polymorphisms with paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. Genotyping was performed by allele-specific polymerase chain reaction (ASPCR) and restriction fragment length polymorphism (RFLP) on genomic DNA isolated of granulocytes from 54 PCM patients and 31 noninfected individuals. The analysis of SNP at position -1082 IL-10 showed a high frequency of GA genotype in both patients and controls (51% and 55%, respectively), while the allelic frequency showed 54% of G allele in the patients and 66% of A allele in the controls. The GG genotype was more frequent in patients (85%) and controls (68%) when we analyze the SNP at position -308 of TNF-alpha gene. Otherwise, 91% of PCM patients and 84% of noninfected individuals carried the G allele in -308 TNF-alpha SNP. Stimulation of cells from individuals with PCM phenotyped as A+ (GA or AA genotypes) presented elevation of TNF-alpha producing cells when compared with IL-10-producer cells. These findings reinforce the critical role of IL-10 and TNF-alpha in the paracoccidioidomycosis and can strongly suggest that the genetic screening of the -308G/A and -1082G/A polymorphisms may be a valid tool for identification of subjects needing a more appropriate therapy.


Assuntos
Interleucina-10/genética , Paracoccidioides , Paracoccidioidomicose/genética , Polimorfismo de Nucleotídeo Único/genética , Fator de Necrose Tumoral alfa/genética , Adolescente , Adulto , Idoso , Frequência do Gene , Genótipo , Granulócitos/imunologia , Humanos , Pessoa de Meia-Idade , Paracoccidioidomicose/imunologia
13.
Biopolymers ; 81(3): 215-24, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-16261508

RESUMO

Molecular dynamics (MD) simulations and circular dichroism (CD) experiments were carried out on aqueous temporin A and L, two short peptides belonging to an interesting class of natural substances known to be active mainly against Gram-positive/negative bacteria and fungi. Experimental results indicate the higher propensity of temporin L, with respect to temporin A, in forming alpha-helical structures. These results were revisited by long-timescale MD simulations, in which their alpha-helical propensity was investigated in the absence of trifluoroethanol. Results clearly show the higher stability of alpha-helix conformations in temporin L; moreover, an interestingly strong mechanical analogy emerges since both temporins show the same residue interval (from 7 to 10) as the most energetically accessible for alpha-helix formation. Such studies provide some intriguing structural and mechanical evidence that may help in better understanding and rationalizing the conformational behaviour of temporins in water solution and, ultimately, the inner principles of their microbial targets selectivity and mechanism of action at the level of cell membranes.


Assuntos
Modelos Químicos , Peptídeos/química , Proteínas/química , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos , Dicroísmo Circular , Simulação por Computador , Dados de Sequência Molecular , Conformação Proteica , Soluções/química , Termodinâmica , Água/química
14.
J Immunol Methods ; 307(1-2): 118-26, 2005 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-16269152

RESUMO

In this work, we analyzed serological responses of paracoccidioidomycosis (PCM) patients to membrane and extracellular antigens (Mexo) of Paracoccidioides brasiliensis by ELISA, immunoblot technique and immunofluorescence assays to identify a specific antigen profile. Among 140 PCM serum samples analyzed, a homogeneous IgG response to Mexo was observed. The specificity of this antigen was 96.6% in relation to control sera and 81.2% to sera from patients with diverse infections. Patients undergoing treatment for more than 1 year showed a reduced antibody response against Mexo. These results suggest that the presence of anti-Mexo antibodies might be an indicator of active disease. A protein from Mexo with a molecular weight of 28 kDa (Pb28) was the most specific antigen in humoral immune responses to PCM, since it reacted with 100% of patient sera and did not react with heterologous serum samples tested. This protein was purified by molecular filtration chromatography in FPLC system and, when tested by immunoblotting, it maintained its reactivity and specificity of 100% with PCM sera. The Pb28 N-terminal amino acid sequence comparison analysis in the non-redundant GenBank database at NCBI revealed no significant homology to known PCM proteins or to other fungal proteins of known function. Since the 28-kDa protein of P. brasiliensis seems to be specific for PCM, it can be used as an alternative antigen in immunoblotting diagnostic methods.


Assuntos
Antígenos de Fungos/imunologia , Paracoccidioides/imunologia , Paracoccidioidomicose/diagnóstico , Adolescente , Adulto , Idoso , Sequência de Aminoácidos , Anticorpos Antifúngicos/sangue , Especificidade de Anticorpos/imunologia , Antígenos de Fungos/química , Antígenos de Fungos/isolamento & purificação , Western Blotting , Encéfalo/patologia , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/sangue , Testes Imunológicos/métodos , Fígado/patologia , Pessoa de Meia-Idade , Paracoccidioidomicose/sangue , Paracoccidioidomicose/patologia , Análise de Sequência de Proteína , Pele/patologia
15.
Biochem Pharmacol ; 70(4): 560-9, 2005 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15982641

RESUMO

This study deals with the combination of chloroquine (CQ, an anti-malaric drug) and 3'-azido-3'-deoxythymidine (AZT, anti-human immuno-deficiency virus (HIV) drug) with a chimeric toxin (TS) obtained by chemical linking of saporin (a ribosome inactivating protein from the plant Saponaria officinalis) and human transferrin, in the intoxication of the human chronic myeloid leukaemia cells (K562). Our data demonstrate that AZT, at concentrations comparable to those reached in the blood of HIV-infected patients under pharmacological treatment with this drug, can increase the toxicity of TS in cooperation with CQ inducing an increased effect on protein synthesis in K562 cells ( approximately 50% inhibition of protein synthesis for TS alone, and TS with AZT and approximately 70% with both AZT and CQ). Furthermore, pre-treatment of cells with AZT alone can induce an increase of apoptosis in K562 cells intoxicated with TS. By comparing data obtained with the model toxin ricin, we get indications that the two toxins partially differ in their intracellular routes, also suggesting that chimeric constructs containing ricin-like toxins (i.e. immunotoxins) could be coupled with the use of common and cheap drugs for the treatment of cancer in HIV-infected patients.


Assuntos
Cloroquina/farmacologia , Imunotoxinas/química , N-Glicosil Hidrolases/química , Proteínas de Plantas/química , Proteínas Recombinantes de Fusão/toxicidade , Transferrina/química , Zidovudina/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Microscopia Confocal , Proteínas Recombinantes de Fusão/química , Proteínas Inativadoras de Ribossomos Tipo 1 , Saporinas
16.
Water Res ; 39(8): 1441-50, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15878015

RESUMO

This study addresses the pre-treatment of toxic and recalcitrant compounds found in the waste waters arriving at a treating station for industrial effluents containing chlorinated aromatics and non-aromatic compounds, anilines, phenols, methyl-tert-butyl-ether (MTBE). By reducing the total organic carbon (TOC) of these waste waters the hydraulic load for the further bacterial processing in the secondary biological treatment is decreased. The TOC decrease and discoloration of the waste waters was observed only under light irradiation in the reactor by immobilized Fenton processes on Fe/C-fabrics but not in the dark. The energy of activation for the degradation of the waste waters was of 4.2 kcal/mol. The degradation of the waste waters was studied in the reactor as a function of (a) the amount of oxidant used (H2O2), (b) the recirculation rate, (c) the solution pH and (d) the applied temperature. With these parameters taken as input factors, statistical modeling allows one to estimate the most economic use of the oxidant and electrical energy to degrade these waste waters. The concentration of the most abundant organic pollutants during waste waters degradation was followed by gas chromatography/mass spectrometry (GC-MS). The ratio of the biological oxygen demand to the total organic carbon BOD5/TOC increased significantly due to the Fe/C-fabric catalyzed treatment from an initial value of 2.03 to 2.71 (2 h). The reactor results show that the recirculation rate has no influence on the TOC decrease of the treated waters but affects the BOD increase of these solutions.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água , Purificação da Água/métodos , Compostos de Anilina , Carbono/química , Concentração de Íons de Hidrogênio , Resíduos Industriais , Éteres Metílicos/química , Compostos Orgânicos , Fenóis/química , Temperatura , Água/química
17.
Scand J Immunol ; 60(5): 500-5, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15541043

RESUMO

Paracoccidioides brasiliensis, a thermo-dimorphic fungus, is the ethiologic agent of paracoccidioidomycosis (PCM). The recidive is the greatest obstacle of this disease, because the yeast usually returns after the long treatment period. In the present work, we have investigated the cellular immune response of cells from peripheral blood drawn from patients with different duration of PCM. The classification of patients ranged from nontreated to those with long-standing disease over 5 years. Unstimulated as well as cells stimulated with phytohemaglutinin or two different antigen preparations, secreted (MEXO) or somatic (PbAg) of P. brasiliensis, were characterized. We found that cells from patients with disease proliferate considerably upon stimulation with the antigen preparations and that cells from patients with disease of long duration does not proliferate that vigorously as from patients with more recent diagnosis. Both interferon (IFN)-gamma and interleukin (IL)-4 appear to be increased in patients, but IFN-gamma tended to increase upon treatment while IL-4-secretion decreased. With respect to CD28 and CD86, we found that the subset of CD28 positive CD8 cells are decreased in all stages of the disease as compared to control individuals. A subset of CD86 positive CD19 cells appeared to be considerably increased compared to the controls. Indeed, our results demonstrated that the treatment of PCM patients promoted a regulation of IFN-gamma, IL-4 levels and CD28, CD86 expression bringing new insight to the cellular immune response in PCM.


Assuntos
Antígenos CD/imunologia , Antígenos CD28/imunologia , Glicoproteínas de Membrana/imunologia , Paracoccidioidomicose/imunologia , Adolescente , Adulto , Idoso , Antígenos/imunologia , Antígenos CD/metabolismo , Antígeno B7-2 , Biomarcadores , Antígenos CD28/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Glicoproteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Paracoccidioides/imunologia , Paracoccidioidomicose/metabolismo
18.
J Clin Virol ; 25 Suppl 1: S71-8, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12091084

RESUMO

BACKGROUND: Infections of the central nervous system (CNS) are a difficult diagnostic problem for both clinicians and microbiologists. Various clinical signs, such as encephalitis, myelitis, meningitis, may be associated with herpesviruses. The use of multiplex 'Herpes Consensus' polymerase chain reaction (HC-PCR) in association with nested PCR (nPCR), in addition to classical techniques, made it possible to optimise the management of cerebrospinal fluid (CSF) and serum samples from patients affected by these viral diseases of the CNS. OBJECTIVES: To test by HC-PCR by nPCR and cell culture the CSF and sera from patients with viral infections of the CNS. STUDY DESIGN: We analysed 320 CFS, 154 serum samples and 11 various samples from 286 patients with clinically suspected encephalitis, meningitis or other diseases of the CNS by HC-PCR, nPCR and traditional investigations (cell culture and serological tests). RESULTS: On molecular analysis with the HC-PCR test, 51 CFS samples (15.9%) were positive for at least one of the six target Herpes viruses: fourteen for Herpes simplex 1 (HSV-1), seven for HSV-2, 12 for Cytomegalovirus (CMV; one of which was from an HIV-positive patient), five for Epstein-Barr virus (EBV; four of which were from HIV-positive patients), three for Varicella-Zoster virus (VZV), five for Human Herpes virus type 6 (HHV-6), three for HSV-1 with HHV-6 co-infection (two cases) and HSV-2 co-infection (one case), and two for HHV-6 with CMV or EBV co-infection (both from patients with immune deficiency). A further 12 samples were positive in nPCR for HHV-7 (8), ADV (1), Enterovirus (1), HSV-1 (1), EBV (1). Of the 154 serum samples, 17 (11.0%) tested positive by HC-PCR for HSV-1 (4), HSV-2 (1), CMV(1), EBV(1), VZV(3) or HHV-6(6), 1 with co-HSV-2/VZV infection. A further five samples tested positive for HHV-7 in nPCR. Culture and tests for antibodies did not supply sufficiently sensitive and specific data. CONCLUSIONS: Our laboratory experience shows that herpesviruses play a central aetiological role in viral infections of the CNS. PCR analysis, especially the HC-PCR test, have revolutionised the diagnostic approach to such infections, making possible rapid, specific and highly sensitive baseline screening. In this way, microbiological investigations can lead to prompt diagnosis, which was limited in the past to a very small number of cases.


Assuntos
Viroses do Sistema Nervoso Central/diagnóstico , Infecções por Herpesviridae/diagnóstico , Herpesviridae/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Anticorpos Antivirais/análise , Viroses do Sistema Nervoso Central/sangue , Viroses do Sistema Nervoso Central/líquido cefalorraquidiano , DNA Viral/análise , Herpesviridae/genética , Herpesviridae/crescimento & desenvolvimento , Infecções por Herpesviridae/sangue , Infecções por Herpesviridae/líquido cefalorraquidiano , Humanos , Controle de Qualidade , Kit de Reagentes para Diagnóstico , Cultura de Vírus
19.
Ann Ig ; 14(6): 487-94, 2002.
Artigo em Italiano | MEDLINE | ID: mdl-12638352

RESUMO

Surveillance of acute flaccid paralysis (AFP) is the milestone to monitor the progress toward poliomyelitis eradication aim, fixed by WHA in 1988. Active AFP surveillance started in Apulia in 1997; this work evaluates five-year period activities. In this period, the total number of cases notified was 48, 7 of which were resident out of Apulia. Twenty-five were males and 23 females; the age ranged between 1 month and 15 years. Any collected serum specimens showed protective antibody levels against polioviruses. Polioviruses type 1 and type 2 Sabin-like were isolated from stool samples collected from two AFP patients. AFP surveillance targets improved in the years, with only exception, in 2001, of second serum specimen collected within 14 days because of children were discharged earlier form the hospitals. Apulia experience demonstrates the achievement of good levels of AFP surveillance targets. System sensitivity has been optimal in 2001 with a number of notified cases threefold the expected value and adequate specimen sampling (80%). Additional involved hospitals and availability of increased and dedicated human resources contributed to this outcome. The effort to achieve WHO targets for AFP surveillance needs to be maintained in next years until global certification of eradication will be declared.


Assuntos
Paralisia/epidemiologia , Vigilância da População , Doença Aguda , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Itália/epidemiologia , Masculino , Hipotonia Muscular , Paralisia/diagnóstico , Fatores de Tempo
20.
J Pept Res ; 58(3): 213-20, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11576327

RESUMO

Temporins are a novel family of small (10-13 residues) cationic antimicrobial peptides recently isolated from the skin of the European red frog Rana temporaria. Although recently acquired evidence shows that temporins have the potential to kill bacteria by permeabilizing the cytoplasmic membrane, the molecular mechanisms of membrane selectivity and permeabilization are largely unknown. In this study, it was found that temporins cause the release of fluorescent markers entrapped in phosphatidylcholine liposomes in a manner that depends significantly on the size of the solute. Temporins were also shown to lack a detergent-like effect on lipid vesicles, indicating that marker leakage caused by these peptides is not due to total membrane disruption but to perturbation of bilayer organization on a local scale. Binding of temporins to liposomes did lead to a small increase in lipid hydrocarbon chain mobility, as revealed by EPR spectroscopy of nitroxide-labeled fatty acids incorporated in the bilayer. Reference experiments were conducted using the bee venom peptide melittin, whose properties and behavior in natural and model membrane systems are well known. Our findings for temporins are discussed in relation to the models proposed to date to account for the action of antimicrobial peptides on membranes.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacocinética , Meliteno/farmacocinética , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Proteínas/farmacocinética , Peptídeos Catiônicos Antimicrobianos/química , Permeabilidade da Membrana Celular , Dextranos/análise , Espectroscopia de Ressonância de Spin Eletrônica , Fluoresceínas/análise , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Lipossomos/química , Lipossomos/metabolismo , Meliteno/química , Modelos Químicos , Tamanho da Partícula , Permeabilidade , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Proteínas/química
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