Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
Data Brief ; 48: 109105, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37095754

RESUMO

The data presented in this article are related to the research paper entitled "Observation of night-time emissions of the Earth in the near UV range from the International Space Station with the Mini-EUSO detector" (Remote Sensing of Environment, Volume 284, January 2023, 113336, https://doi.org/10.1016/j.rse.2022.113336). The data have been acquired with the Mini-EUSO detector, an UV telescope operating in the range 290-430 nm and located inside the International Space Station. The detector was launched in August 2019, and it has started operations from the nadir-facing UV-transparent window in the Russian Zvezda module in October 2019. The data presented here refer to 32 sessions acquired between 2019-11-19 and 2021-05-06. The instrument consists of a Fresnel-lens optical system and a focal surface composed of 36 multi-anode photomultiplier tubes, each with 64 channels, for a total of 2304 channels with single photon counting sensitivity. The telescope, with a square field-of-view of 44°, has a spatial resolution on the Earth surface of 6.3 km and saves triggered transient phenomena with a temporal resolution of 2.5 µs and 320 µs. The telescope also operates in continuous acquisition at a 40.96 ms scale. In this article, large-area night-time UV maps obtained processing the 40.96 ms data, taking averages over regions of some specific geographical areas (e.g., Europe, North America) and over the entire globe, are presented. Data are binned into 0.1° × 0.1° or 0.05° × 0.05° cells (depending on the scale of the map) over the Earth's surface. Raw data are made available in the form of tables (latitude, longitude, counts) and .kmz files (containing the .png images). These are - to the best of our knowledge - the highest sensitivity data in this wavelength range and can be of use to various disciplines.

2.
Clin Exp Dermatol ; 39(3): 385-90, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24772485

RESUMO

The differences in systemic T-cell responses between patients with psoriatic arthritis (PsA) and patients with cutaneous psoriasis (Ps) are still largely unknown. To determine differential features that could be used to distinguish PsA from Ps, we compared the cytokine secretion profile of circulating T cells in patients with PsA, patients with cutaneous Ps and control subjects. We determined Th1, Th2 and Th17 cytokine secretion of anti-CD3-stimulated peripheral blood mononuclear cells (PBMCs) using a cytokine bead array. Normality of data distribution was assessed by the Shapiro-Wilk test, and statistical significance was calculated by the Mann-Whitney test. Phenotypic characterization of circulating T cells was performed by fluorescence-activated cell sorting analysis. We found that the major systemic differences distinguishing PsA from cutaneous Ps were the increased secretion of interleukin (IL)-2 by α-CD3-stimulated PBMCs and a higher percentage of circulating CD3+ T cells expressing the proliferation marker CD71 in PsA. These results indicate IL-2 as a possible biomarker of PsA, and suggest a role of circulating T cells with high proliferative capacity in the pathogenesis of PsA.


Assuntos
Artrite Psoriásica/metabolismo , Complexo CD3/imunologia , Interleucina-2/metabolismo , Leucócitos Mononucleares/metabolismo , Psoríase/metabolismo , Adolescente , Adulto , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T Auxiliares-Indutores/metabolismo , Adulto Jovem
3.
Int J Immunopathol Pharmacol ; 25(3): 617-26, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23058012

RESUMO

We examined the effect of the protein kinase C-selective inhibitor AEB071 (sotrastaurin) on neutrophil functions in vitro. Pre-incubation with AEB071 at concentrations similar to those reached during in vivo therapy significantly reduced cell capacity to migrate toward three different chemo-attractants and to produce superoxide anions (O2⁻) in response to phorbol myristate acetate (PMA) or to N-formyl-methionyl-leucyl-phenylalanine (fMLP). AEB071 also significantly inhibited the O2⁻ overproduction induced by fMLP in neutrophils primed with tumor necrosis factor alpha (TNF-α) or granulocyte/macrophage-colony stimulating factor (GM-CSF). This inhibition was not linked to fMLP-receptor down-regulation since the drug had no effect on either fMLP-receptors or fMLP-induced CD11b membrane expression. When the activity of AEB071 was compared to that of the conventional protein kinase C (PKC) inhibitor Gö6850 (which, like sotrastaurin, inhibits classical and novel PKC isoforms), Gö6976 (an inhibitor of α and α PKC isoforms) and rottlerin (a prevailing δ PKC isoform inhibitor), AEB071 at an equimolar concentration of 3 µM (close to the maximum drug concentration reached in patients treated with AEB071) caused significantly more inhibition on both chemotactic response and superoxide production. These in vitro findings suggest that neutrophils may offer a cellular target for AEB071 activity in vivo.


Assuntos
Quimiotaxia de Leucócito/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteína Quinase C/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirróis/farmacologia , Quinazolinas/farmacologia , Superóxidos/metabolismo , Antígeno CD11b/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Interleucina-1beta/metabolismo , Interleucina-8/metabolismo , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/enzimologia , Proteína Quinase C/metabolismo , Receptores de Formil Peptídeo/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismo
4.
Rev Sci Instrum ; 80(9): 095108, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19791965

RESUMO

The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of gamma-detection based on the new device.

5.
Vaccine ; 23(22): 2909-21, 2005 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-15780740

RESUMO

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent immune stimulant when administered with different vaccines. Optimal use of GM-CSF resides in its ability to act locally to stimulate the proliferation and maturation of professional antigen-presenting cells (APCs) (i.e., Langerhans' cells) at the injection site. GM-CSF was engineered into a replication-incompetent recombinant avian (fowlpox) virus (rF-GM-CSF) and a single subcutaneous injection resulted in a sustained enrichment of activated dendritic cells within the regional draining lymph nodes. Those changes were attributed to local GM-CSF production at the injection site by rF-GM-CSF-infected cells. Studies were carried out in which mice were administered different types of beta-galactosidase (beta-gal)-based vaccines--whole protein, peptide, recombinant poxviruses--and GM-CSF was administered either as a single injection of rF-GM-CSF or four daily bolus injections of the recombinant protein. The use of rF-GM-CSF either improved the immune adjuvant effect, as observed for poxvirus-based vaccines, or was equivalent to rGM-CSF, as observed with the beta-gal protein vaccine. It is important to note that with either the replication-competent (vaccinia) or replication-incompetent (fowlpox) vaccines expressing LacZ, strong CTL responses directed against beta-gal were induced only when rF-GM-CSF was used as the immune adjuvant. Engineering GM-CSF into a recombinant fowlpox virus offers an excellent vehicle for the delivery of this cytokine as an immune adjuvant with specific vaccine platforms. In particular, delivery of GM-CSF via the rF-GM-CSF construct would be preferred over bolus injections of rGM-CSF when used as an immune adjuvant with whole protein or recombinant poxvirus-based vaccines. The study underscores the importance of defining the appropriate delivery form of an immune adjuvant, such as GM-CSF, relative to the immunization strategy to maximize the host immune responses against a specific antigen.


Assuntos
Avipoxvirus/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Animais , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/sangue , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Camundongos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Linfócitos T Citotóxicos/imunologia
6.
J Chemother ; 16(5): 491-3, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15565918

RESUMO

Photodynamic therapy (PDT) is a treatment modality using a photosensitizer, light and oxygen to cause photochemically-induced selective cell death. Topical PDT is most suitable for thin lesions such as superficial basal cell carcinoma and actinic keratoses in dermatology. Results with PDT as treatment of thicker lesions such as nodular basal cell carcinoma appear to have a limited role because the photosensitizer or the light cannot penetrate deeply enough into the thicker tumor volume. In this preliminary study we use intralesional administration of 5-aminolevulinic acid to enhance the efficacy of the photosensitivity of nodular basal cell carcinomas, thus improving clinical cure.


Assuntos
Ácido Aminolevulínico/administração & dosagem , Carcinoma Basocelular/tratamento farmacológico , Fármacos Fotossensibilizantes/administração & dosagem , Neoplasias Cutâneas/tratamento farmacológico , Adulto , Idoso , Carcinoma Basocelular/patologia , Feminino , Humanos , Injeções Intralesionais , Masculino , Pessoa de Meia-Idade , Fotoquimioterapia , Neoplasias Cutâneas/patologia , Resultado do Tratamento
7.
J Chemother ; 16(3): 306-9, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15330331

RESUMO

The ocular tissues can be the site of a number of malignant tumors in adults. Approximately 5% to 10% of all skin tumors occur in the eyelid. Incidence studies indicate that basal cell carcinoma is the most frequent malignant eyelid tumor (90%) followed by squamous cell carcinoma (9%). A 55-year-old man presented a squamous cell carcinoma (SCC) of 8 mm diameter, localized in the middle third of the lower eyelid, 3 mm under the eyelid margin on the eyelids. The histopathologic examination of a biopsy specimen showed the typical features of squamous cell carcinoma. Photodynamic therapy (PDT) with topical 5-aminolevulic acid (ALA) after Frost suture was employed. Very good results were obtained with rapid healing, without invasiveness, and without anesthesia. There was no evidence of scar formation and no signs of recurrence at 6 months follow-up. Many therapeutic methods have been suggested for squamous cell carcinoma of the eyelid. We consider photodynamic treatment of eyelid skin malignancies to be of great interest and it may represent an interesting future perspective for their management especially when surgical intervention cannot be tolerated by the patient.


Assuntos
Ácido Aminolevulínico/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Neoplasias Palpebrais/tratamento farmacológico , Neoplasias Palpebrais/patologia , Fotoquimioterapia/métodos , Biópsia por Agulha , Seguimentos , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Medição de Risco , Resultado do Tratamento
8.
Adv Space Res ; 33(8): 1352-7, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15803627

RESUMO

The ALTEA project investigates the risks of functional brain damage induced by particle radiation in space. A modular facility (the ALTEA facility) is being implemented and will be operated in the International Space Station (ISS) to record electrophysiological and behavioral descriptors of brain function and to monitor their time dynamics and correlation with particles and space environment. The focus of the program will be on abnormal visual perceptions (often reported as "light flashes" by astronauts) and the impact on retinal and brain visual structures of particle in microgravity conditions. The facility will be made available to the international scientific community for human neurophysiological, electrophysiological and psychophysics experiments, studies on particle fluxes, and dosimetry. A precursor of ALTEA (the 'Alteino' project) helps set the experimental baseline for the ALTEA experiments, while providing novel information on the radiation environment onboard the ISS and on the brain electrophysiology of the astronauts during orbital flights. Alteino was flown to the ISS on the Soyuz TM34 as part of mission Marco Polo. Controlled ground experiments using mice and accelerator beams complete the experimental strategy of ALTEA. We present here the status of progress of the ALTEA project and preliminary results of the Alteino study on brain dynamics, particle fluxes and abnormal visual perceptions.


Assuntos
Encéfalo/efeitos da radiação , Radiação Cósmica , Luz , Retina/efeitos da radiação , Voo Espacial/instrumentação , Percepção Visual/efeitos da radiação , Ausência de Peso , Adaptação à Escuridão , Eletrofisiologia , Desenho de Equipamento , Meio Ambiente Extraterreno , Humanos , Monitorização Fisiológica , Fosfenos , Estimulação Luminosa , Monitoramento de Radiação , Pesquisa
10.
Adv Space Res ; 31(1): 135-40, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12577986

RESUMO

In this work we present preliminary results of nuclear composition measurements on board space station MIR obtained with SILEYE-2 particle telescope. SILEYE-2 was placed on MIR in 1997 and has been working since then. It consists of an array of 6 active silicon strip detectors which allow nuclear and energetic identification of cosmic rays in the energy range between approximately 30 and 200 MeV/n. The device is attached to an helmet and connected to an eye mask which shields the cosmonaut eyes from light and allow studies of the Light Flashes (LF) phenomenon. In addition to the study of the causes of LF, the device is used to perform real time long term radiation environment monitoring inside the MIR, performing measurements in solar quiet and active days.


Assuntos
Radiação Cósmica , Fosfenos , Monitoramento de Radiação/instrumentação , Atividade Solar , Voo Espacial/instrumentação , Relação Dose-Resposta à Radiação , Desenho de Equipamento , Meio Ambiente Extraterreno , Olho/efeitos da radiação , Dispositivos de Proteção da Cabeça , Humanos , Luz , Estimulação Luminosa , Silício , Astronave/instrumentação
11.
Adv Space Res ; 31(1): 141-6, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12577991

RESUMO

The ALTEA project participates to the quest for increasing the safety of manned space flights. It addresses the problems related to possible functional damage to neural cells and circuits due to particle radiation in space environment. Specifically it aims at studying the functionality of the astronauts' Central Nervous Systems (CNS) during long space flights and relating it to the peculiar environments in space, with a particular focus on the particle flux impinging in the head. The project is a large international and multidisciplinary collaboration. Competences in particle physics, neurophysiology, psychophysiology, electronics, space environment, data analyses will work together to construct the fully integrated vision electrophysiology and particle analyser system which is the core device of the project: an helmet-shaped multi-sensor device that will measure concurrently the dynamics of the functional status of the visual system and passage of each particle through the brain within a pre-determined energy window. ALTEA is scheduled to fly in the International Space Station in late 2002. One part of the multi-sensor device, one of the advanced silicon telescopes, will be launched in the ISS in early 2002 and serve as test for the final device and as discriminating dosimeter for the particle fluences within the ISS.


Assuntos
Sistema Nervoso Central/efeitos da radiação , Radiação Cósmica , Fosfenos , Monitoramento de Radiação/instrumentação , Voo Espacial/instrumentação , Ausência de Peso , Adaptação Fisiológica , Medicina Aeroespacial/instrumentação , Sistema Nervoso Central/fisiologia , Eletroencefalografia , Desenho de Equipamento , Dispositivos de Proteção da Cabeça , Humanos , Monitorização Fisiológica/instrumentação , Estimulação Luminosa , Doses de Radiação , Retina/fisiologia , Retina/efeitos da radiação
12.
Acta Astronaut ; 50(8): 511-25, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11962526

RESUMO

The phenomenon of light flashes (LF) in eyes for people in space has been investigated onboard Mir. Data on particles hitting the eye have been collected with the SilEye detectors, and correlated with human observations. It is found that a nucleus in the radiation environment of Mir has roughly a 1% probability to cause an LF, whereas the proton probability is almost three orders of magnitude less. As a function of LET, the LF probability increases above 10 keV/micrometer, reaching about 5% at around 50 keV/micrometer.


Assuntos
Radiação Cósmica , Olho/efeitos da radiação , Luz , Monitoramento de Radiação/instrumentação , Voo Espacial , Percepção Visual/efeitos da radiação , Medicina Aeroespacial , Astronautas , Íons Pesados , Humanos , Transferência Linear de Energia , Masculino , Fosfenos , Prótons , Radiometria , Silício , Atividade Solar , Fatores de Tempo , Visão Ocular/efeitos da radiação , Ausência de Peso
13.
Cancer Res ; 61(14): 5517-22, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11454701

RESUMO

Surface-bound IgE play a central role in antiparasite immunity; to exploit IgE-driven immune mechanisms in tumor prevention and control, monoclonal IgEs of irrelevant specificity were loaded through biotin-avidin bridging onto tumor cells, either by systemic administration to tumor-bearing mice or pre-loading of tumor cells before inoculation. Here we show that systemic administration of biotinylated IgEs to mice bearing tumors pre-targeted with biotinylated antibodies and avidin significantly decreased tumor growth rate. In addition, as compared with IgG-loaded control cells, inoculation of suboptimal doses of IgE-loaded tumor cells suppressed tumor formation in a fraction of animals and induced protective host immunity by eliciting tumor-specific T-cell responses. Similarly, tumor vaccination experiments showed that irradiated tumor cells (IgE loaded by biotin-avidin bridging) conferred protective immunity at doses 100-fold lower than the corresponding control cells without IgE. Finally, in vivo depletion of eosinophils or T cells abrogated IgE-driven tumor growth inhibition. These results demonstrate that IgEs targeted on tumor cells not only possess a curative potential but also confer long-term antitumor immunity and that IgE-driven antitumor activity is not restricted to the activation of innate immunity effector mechanisms but also results from eosinophil-dependent priming of a T-cell-mediated adaptive immune response. This suggests a potential role for IgEs in the design of new cell-based tumor vaccines.


Assuntos
Anticorpos Monoclonais/farmacologia , Imunoglobulina E/imunologia , Animais , Anticorpos Monoclonais/uso terapêutico , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/uso terapêutico , Divisão Celular/efeitos dos fármacos , Eosinófilos/citologia , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Feminino , Interleucina-5/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Neoplasias Experimentais/prevenção & controle , Análise de Sobrevida , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Células Tumorais Cultivadas/imunologia , Células Tumorais Cultivadas/efeitos da radiação
14.
Phys Med ; 17 Suppl 1: 255-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11776990

RESUMO

The ALTEA project studies the problems related to possible functional damage to the Central Nervous System (CNS) due to particle radiation in space environment. The project is a large international and multi-disciplinary collaboration. The ALTEA instrumentation is an helmet-shaped multi-sensor device that will measure concurrently the dynamics of the functional status of the visual system and the passage of each particle through the brain within a pre-determined energy window. ALTEA is scheduled to fly in the International Space Station in February 2003. One part of the multi-sensor device, one of the advanced silicon telescopes, will be launched in the ISS in early 2002 and serve as test for the final device and as discriminating dosimeter for the particle fluences within the ISS.


Assuntos
Radiação Cósmica , Olho/efeitos da radiação , Luz , Fosfenos , Voo Espacial/instrumentação , Percepção Visual/efeitos da radiação , Medicina Aeroespacial/instrumentação , Adaptação à Escuridão/efeitos da radiação , Eletroencefalografia , Desenho de Equipamento , Meio Ambiente Extraterreno , Humanos , Estimulação Luminosa/instrumentação , Astronave
15.
Cancer Res ; 60(15): 4211-5, 2000 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-10945632

RESUMO

We have shown previously that T cells, tagged with biotinylated anti-CD3 antibody fragments, can exert avidin-dependent cytolytic activity on suitably biotinylated tumor cells in vitro. In this study, we demonstrate that avidin-driven CTL-tumor bridging in vivo leads to growth inhibition of murine tumors WEHI-164 fibrosarcoma and RMA lymphoma. The biodistribution of biotin-tagged 111In-labeled T cells demonstrated a selective avidin-dependent and time-dependent accumulation of radioactivity at tumor sites. The specificity of lymphocyte tumor localization was demonstrated by the concurrent time-dependent decrease of radioactivity in the blood and in all other organs. Furthermore, we documented a therapeutic effect of the adoptively transferred T cells, i.e., a significant delay of tumor growth at early stages. All of the experiments included a control group of mice, which received all of the reagents, except avidin. These avidin-minus mice showed no specific localization and no delay in tumor growth, indicating that avidin bridging was essential for T-cell activity at tumor sites.


Assuntos
Avidina/metabolismo , Biotina/metabolismo , Imunoterapia Adotiva/métodos , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Animais , Anticorpos/imunologia , Anticorpos/metabolismo , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/metabolismo , Biotinilação , Complexo CD3/imunologia , Citotoxicidade Imunológica , Feminino , Fibrossarcoma/imunologia , Fibrossarcoma/metabolismo , Fibrossarcoma/terapia , Linfoma de Células T/imunologia , Linfoma de Células T/metabolismo , Linfoma de Células T/terapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transplante de Neoplasias
16.
Adv Space Res ; 25(10): 2075-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11542859

RESUMO

The SilEye experiment aims to study the cause and processes related to the anomalous Light Flashes (LF) perceived by astronauts in orbit and their relation with Cosmic Rays. These observations will be also useful in the study of the long duration manned space flight environment. Two PC-driven silicon detector telescopes have been built and placed aboard Space Station MIR. SilEye-1 was launched in 1995 and provided particles track and LF information; the data gathered indicate a linear dependence of FLF(Hz) ( 4 2) 10(3) 5.3 1.7 10(4) Fpart(Hz) if South Atlantic Anomaly fluxes are not included. Even though higher statistic is required, this is an indication that heavy ion interactions with the eye are the main LF cause. To improve quality and quantity of measurements, a second apparatus, SilEye-2, was placed on MIR in 1997, and started work from August 1998. This instrument provides energetic information, which allows nuclear identification in selected energy ranges; we present preliminary measurements of the radiation field inside MIR performed with SilEye-2 detector in June 1998.


Assuntos
Radiação Cósmica , Luz , Prótons , Voo Espacial/instrumentação , Percepção Visual/efeitos da radiação , Adaptação à Escuridão , Interpretação Estatística de Dados , Humanos , Estimulação Luminosa , Doses de Radiação , Silício , Astronave/instrumentação
17.
J Immunol ; 162(1): 106-13, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9886375

RESUMO

In the present study, we examined the structural requirements of peptide Ags for productive interactions with the TCR of CTL. For this purpose, we used as a model a previously identified immunodominant epitope that represents the target of EBV-specific HLA-A11-restricted CTL responses. By the use of peptides having minimal sequence homology with the wild-type epitope, we demonstrated that it is possible to selectively expand and reactivate memory CTL precursors without triggering the lytic mechanisms of wild-type specific effectors. In fact, stimulation of PBL from EBV-seropositive donors by polyalanine analogues, sharing only the putative TCR contact residue with the natural epitope, exclusively induced clonal expansion and reactivation of EBV-specific memory CTL precursors. Interestingly, these polyalanine peptides failed to trigger the cytotoxic function of CTLs specific for the wild-type viral epitope. This clearly indicates that reactivation of memory CTL precursors and triggering of the cytotoxic function have different requirements. The same phenomenon was observed using as stimulators naturally occurring peptides carrying the appropriate TCR contact residue. These data strongly suggest that cross-reactive peptides may play an important role in the expansion and reactivation of CTL clones from the memory T cell pool, and may be involved in long-term maintenance of T cell memory.


Assuntos
Aminoácidos/imunologia , Antígenos Nucleares do Vírus Epstein-Barr/imunologia , Memória Imunológica , Ativação Linfocitária , Oligopeptídeos/imunologia , Linfócitos T Citotóxicos/imunologia , Substituição de Aminoácidos , Aminoácidos/isolamento & purificação , Linhagem Celular Transformada , Reações Cruzadas , Citotoxicidade Imunológica/efeitos dos fármacos , Epitopos de Linfócito T/química , Antígenos Nucleares do Vírus Epstein-Barr/química , Produtos do Gene pol/química , HIV/imunologia , Antígenos HLA-A/química , Antígeno HLA-A11 , Humanos , Memória Imunológica/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Peptídeos/química , Peptídeos/imunologia , Peptídeos/farmacologia , Receptores de Antígenos de Linfócitos T/antagonistas & inibidores , Homologia de Sequência de Aminoácidos , Subpopulações de Linfócitos T/imunologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/química
18.
Acta Otolaryngol ; 118(4): 557-62, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9726683

RESUMO

In this multicentre study we evaluated the prevalence and risk factors of otitis media with effusion (OME) in Italian school-children and the effectiveness of medical treatment of chronic OME with a new cephalosporin, ceftibuten. During two winter periods, 3413 children, aged 5 to 7 years, were examined for the presence of OME by means of pneumotoscopy and a portable, hand-held tympanometer. The prevalence of asymptomatic OME was 14.2%, with no difference as regards sex, age, month of examination or geographic area. Younger children had significantly more bilateral than unilateral effusion. A recent episode of acute otitis media and previous tonsillectomy or adenoidectomy were associated with an increased risk of OME in multivariate logistic regression models. The presence of OME was unrelated to such factors as birthweight, prematurity, sibling or parental history of allergy, duration of daycare attendance, family history of ear infections. After 12 weeks, 26.6% of children with OME still had middle-ear fluid: 52 were randomized to ceftibuten (9 mg/kg q.d. for 14 days) and 59 to no treatment (nasal saline drops allowed). Children treated with ceftibuten had a significantly better resolution of middle-ear effusion after 4 and 8 weeks. As mass screening programmes for OME in the year of school entry are questioned, a focus only on children with known risk factors seems advisable. Ceftibuten can be useful in reducing the duration of middle-ear effusion.


Assuntos
Cefalosporinas/uso terapêutico , Otite Média com Derrame/tratamento farmacológico , Otite Média com Derrame/epidemiologia , Ceftibuteno , Criança , Pré-Escolar , Feminino , Humanos , Itália/epidemiologia , Modelos Logísticos , Masculino , Prevalência , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
20.
Arzneimittelforschung ; 46(10): 964-6, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8931889

RESUMO

The synthesis and biological activity on human neutrophils of for-Met-(gamma-lactam)-Leu-Phe-OMe [fM(gamma l)LP-OMe], an analogue of the chemotactic fMLP-OMe, are reported. The tetrapeptide evidences chemotactic activity as well as superoxide anion production and lysozyme release, although with lower efficacy when compared with the parent tripeptide.


Assuntos
Fatores Quimiotáticos/síntese química , Peptídeos/síntese química , Fatores Quimiotáticos/química , Fatores Quimiotáticos/farmacologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/enzimologia , Dextranos/química , Humanos , Técnicas In Vitro , Conformação Molecular , Muramidase/metabolismo , Neutrófilos/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , Superóxidos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA