950 resultados para REACTIVE-SITE
Resumo:
To defend the host from malignancies, the immune system can spontaneously raise CD8(+) T-cell responses against tumor antigens. Investigating the functional state of tumor-reactive cytolytic T cells in cancer patients is a key step for understanding the role of these cells in tumor immunosurveillance and for evaluating the potential of immunotherapeutic approaches of vaccination against cancer. In this study we identified a subset of circulating tumor-reactive CD8(+) T lymphocytes, which specifically secreted IFN-gamma after exposition to autologous tumor cell lines in stage IV metastatic melanoma patients. Additional phenotypic characterization using multicolor flow cytometry revealed that a significant fraction of these cells were CD45RA(+)CCR7(-), a phenotype that has been proposed recently to characterize cytolytic effectors potentially able to home into inflamed tissues. In the case of an HLA-A2-expressing patient, the antigen specificity of this population was identified by using HLA-A2/peptide multimers incorporating a tyrosinase-derived peptide. Consistently with their phenotypic characteristics, A2/tyrosinase peptide multimer(+) CD8(+) T cells, isolated by cell sorting, were directly lytic ex vivo and able to specifically recognize tyrosinase-expressing tumor cells. Overall, these results provide the first evidence that a proportion of melanoma patients have circulating tumor-reactive T cells, which are lytic effectors cells.
Resumo:
BACKGROUND: The present study was designed to evaluate surgeons' strategies and adherence to preventive measures against surgical site infections (SSIs). MATERIALS AND METHODS: All surgeons participating in a prospective Swiss multicentric surveillance program for SSIs received a questionnaire developed from the 2008 National (United Kingdom) Institute for Health and Clinical Excellence (NICE) clinical guidelines on prevention and treatment of SSIs. We focused on perioperative management and surgical technique in hernia surgery, cholecystectomy, appendectomy, and colon surgery (COL). RESULTS: Forty-five of 50 surgeons contacted (90%) responded. Smoking cessation and nutritional screening are regularly propagated by 1/3 and 1/2 of surgeons, respectively. Thirty-eight percent practice bowel preparation before COL. Preoperative hair removal is routinely (90%) performed in the operating room with electric clippers. About 50% administer antibiotic prophylaxis within 30 min before incision. Intra-abdominal drains are common after COL (43%). Two thirds of respondents apply nonocclusive wound dressings that are manipulated after hand disinfection (87%). Dressings are usually changed on postoperative day (POD) 2 (75%), and wounds remain undressed on POD 2-3 or 4-5 (36% each). CONCLUSIONS: Surgeons' strategies to prevent SSIs still differ widely. The adherence to the current NICE guidelines is low for many procedures regardless of the available level of evidence. Further research should provide convincing data in order to justify standardization of perioperative management.
A Survey on Detection Techniques to Prevent Cross-Site Scripting Attacks on Current Web Applications
Resumo:
The epithelial sodium channel ENaC is physiologically important in the kidney for the regulation of the extracellular fluid volume, and in the lungs for the maintenance of the appropriate airway surface liquid volume that lines the pulmonary epithelium. Besides the regulation of ENaC by hormones, intracellular factors such as Na(+) ions, pH, or Ca(2+) are responsible for fast adaptive responses of ENaC activity to changes in the intracellular milieu. In this study, we show that ENaC is rapidly and reversibly inhibited by internal sulfhydryl-reactive molecules such as methanethiosulfonate derivatives of different sizes, the metal cations Cd(2+) and Zn(2+), or copper(II) phenanthroline, a mild oxidizing agent that promotes the formation of disulfide bonds. At the single channel level, these agents applied intracellularly induce the appearance of long channel closures, suggesting an effect on ENaC gating. The intracellular reducing agent dithiothreitol fully reverses the rundown of ENaC activity in inside-out patches. Our observations suggest that changes in intracellular redox potential modulate ENaC activity and may regulate ENaC-mediated Na(+) transport in epithelia. Finally, substitution experiments reveal that multiple cysteine residues in the amino and carboxyl termini of ENaC subunits are responsible for this thiol-mediated inhibition of ENaC.
Resumo:
Some cancer patients mount spontaneous T- and B-cell responses against their tumor cells. Autologous tumor reactive CD8 cytolytic T lymphocyte (CTL) and CD4 T-cell clones as well as antibodies from these patients have been used for the identification of genes encoding the target antigens. This knowledge opened the way for new approaches to the immunotherapy of cancer. In this review, we describe the characterization of the structure-function properties of the melanocyte/melanoma tumor antigen Melan-A/MART-1, the assessment of the T-cell repertoire available against this antigen in healthy individuals, and the analysis of naturally acquired and/or vaccine-induced CTL responses to this antigen in patients with metastatic melanoma.
Resumo:
The objective of this work was to evaluate the use of multispectral remote sensing for site-specific nitrogen fertilizer management. Satellite imagery from the advanced spaceborne thermal emission and reflection radiometer (Aster) was acquired in a 23 ha corn-planted area in Iran. For the collection of field samples, a total of 53 pixels were selected by systematic randomized sampling. The total nitrogen content in corn leaf tissues in these pixels was evaluated. To predict corn canopy nitrogen content, different vegetation indices, such as normalized difference vegetation index (NDVI), soil-adjusted vegetation index (Savi), optimized soil-adjusted vegetation index (Osavi), modified chlorophyll absorption ratio index 2 (MCARI2), and modified triangle vegetation index 2 (MTVI2), were investigated. The supervised classification technique using the spectral angle mapper classifier (SAM) was performed to generate a nitrogen fertilization map. The MTVI2 presented the highest correlation (R²=0.87) and is a good predictor of corn canopy nitrogen content in the V13 stage, at 60 days after cultivating. Aster imagery can be used to predict nitrogen status in corn canopy. Classification results indicate three levels of required nitrogen per pixel: low (0-2.5 kg), medium (2.5-3 kg), and high (3-3.3 kg).
Resumo:
Expression of tissue-specific homing molecules directs antigen-experienced T cells to particular peripheral tissues. In studies using soluble antigens that focused on skin and gut, antigen-presenting cells (APCs) within regional lymphoid tissues were proposed to be responsible for imprinting homing phenotypes. Whether this occurs in other sites and after physiologic antigen processing and presentation is unknown. We define in vivo imprinting of distinct homing phenotypes on monospecific T cells responding to antigens expressed by tumors in intracerebral, subcutaneous, and intraperitoneal sites with efficient brain-tropism of CD8 T cells crossprimed in the cervical lymph nodes (LNs). Multiple imprinting programs could occur simultaneously in the same LN when tumors were present in more than one site. Thus, the identity of the LN is not paramount in determining the homing phenotype; this critical functional parameter is dictated upstream at the site of antigen capture by crosspresenting APCs.
Resumo:
NK cell self-tolerance is maintained by inhibitory receptors specific for MHC class I molecules. Inhibitory NK receptors are also expressed on memory CD8 T cells but their biological relevance on T cells is unclear. In this study, we describe the expression of the Ly49A receptor on a subset of autoreactive T cells which persist in mice double-transgenic for the lymphocytic choriomeningitis virus-derived peptide gp33 and a TCRalphabeta specific for the gp33. No Ly49A-expressing cells are found in TCRalphabeta single-transgenic mice, indicating that the presence of the autoantigen is required for Ly49A induction. Direct evidence for an Ag-specific initiation of Ly49A expression has been obtained in vitro after stimulation of autoreactive TCRalphabeta T cells with the cognate self-Ag. This expression of Ly49A substantially reduces Ag-specific activation of autoreactive T cells. These findings thus suggest that autoantigen-specific induction of inhibitory NK cell receptors on T cells may contribute to peripheral self-tolerance.
Resumo:
Diplomityö muodostuu kahdesta kokonaisuudesta. Työn teoriaosa kertoo mitä ympäristöjohtaminen on, millaisia ovat multi-site -organisaatio ja multi-site -johtamisjärjestelmä sekä mitä vaatimuksia nämä asettavat yritykselle. Työssä esitetään malli, jota käyttämällä kansainvälisten johtamisjärjestelmästandardien mukaan rakennetut laatu-, ympäristö-, terveys- ja turvallisuusjärjestelmät voidaan yhdistää yhdeksi kokonaisuudeksi, multi-site - johtamisjärjestelmäksi. Malli rakentuu kolmesta tasosta, joita ovat paikallinen, maakohtainen ja konsernitaso. Esimerkkien avulla kerrotaan miteneri lähtökohdista voidaan näiden tasojen kautta edetä kohti yhtä johtamiskokonaisuutta. Esille tuodaan myös multi-site -johtamisjärjestelmän käyttöönottoa puoltavat ja vastustavat näkökohdat. Työn konkreettinen osa on johtamisjärjestelmämallin paikallisen tason toteuttaminen. Ympäristöjohtamisjärjestelmän rakentaminen standardin EN ISO 14001:2004 vaatimusten mukaiseksi Kvaerner Power Oy:n Suomen toimipaikoille sekä tämän järjestelmän yhdistäminen sertifioituun EN ISO 9001 -standardin mukaiseen laatujärjestelmään. Työssä kerrotaan miten ympäristöjohtamisjärjestelmä on rakennettu ja miten laatu- ja ympäristöjärjestelmät on liitetty yhdeksi kokonaisuudeksi. Työn tuloksena syntyi malli johtamisjärjestelmien yhdistämisestä sekä sertifioitu ympäristöjohtamisjärjestelmä, jonka yhdistäminen laatujärjestelmään toteutettiin tavoitteiden mukaisesti.
Resumo:
This contribution presents the LRCW.net a website with a virtual laboratory intranet devoted to the study of coarse and cooking wares in the late Antique Mediterranean. It is designed as a public website with a virtual laboratory intranet. There, all institutions and researchers interested in the subject can work together towards a specific purpose such as the creation of an on-line ‘encyclopedia’ for these categories of ceramics. The LRCW.net website and the associated virtual laboratory are just a small part of a wider initiative that aims to create an on-line Encyclopedia for Ancient Ceramics in the Mediterranean.
Resumo:
Kuparipinnan hapettuminen on viimevuosina ollut suosittu tutkimuskohde materiaalitieteissä kuparin laajan teollisuuskäytön vuoksi. Teollisuussovellusten, kuten suojaavien pintaoksidien kehittäminen vaatii kuitenkin syvällistä tuntemusta hapettumisprosessista ja toisaalta myös normaaliolosuhteissa materiaalissa esiintyvien hilavirheiden vaikutuksesta siihen. Tässä työssä keskitytäänkin tutkimaan juuri niitä mekanismeja, joilla erilaiset pintavirheet ja porrastettu pintarakenne vaikuttavathapen adsorptioprosessiin kuparipinnalla. Tutkimus on tehty käyttämällä laskennallisia menetelmiä sekä VASP- ja SIESTA-ohjelmistoja. Työssätutkittiin kemiallisia ja rakenteellisia virheitä Cu(100)-pinnalla, joka on reaktiivisin matalanMillerin indeksin pinta ja porrastetun pinnan tutkimuksessa käytettiin Cu(211)-pintaa, joka puolestaan on yksinkertainen, stabiili ja aiemmissa tutkimuksissa usein käytetty pintarakenne. Työssä tutkitut hilavirheet, adatomit, vähentävät molekyylin dissosiaatiota kuparipinnalla, kun taas vakanssit toimivat dissosiaation keskuksina. Kemiallisena epäpuhtautena käytetty hopeakerros ei estä kuparin hapettumista, sillä happi aiheuttaa mielenkiintoisen segregaatioilmiön, jossa hopeatyöntyy syvemmälle pinnassa jättäen kuparipinnan suojaamattomaksi. Porrastetulla pinnalla (100)-hollow on todennäköisin paikka molekyylin dissosiaatiolle, kun taas portaan bridge-paikka on suotuisin molekulaariselle adsorptiolle. Lisäksi kuparin steppipinnan todettiin olevan reaktiivisempi kuin tasaiset kuparipinnat.
Resumo:
A series of 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridines differently substituted at positions 1, 5, and 9 have been designed from the pyrano[3,2-c]quinoline derivative 1, a weak inhibitor of acetylcholinesterase (AChE) with predicted ability to bind to the AChE peripheral anionic site (PAS), at the entrance of the catalytic gorge. Fourteen novel benzonaphthyridines have been synthesized through synthetic sequences involving as the key step a multicomponent Povarov reaction between an aldehyde, an aniline and an enamine or an enamide as the activated alkene. The novel compounds have been tested against Electrophorus electricus AChE (EeAChE), human recombinant AChE (hAChE), and human serum butyrylcholinesterase (hBChE), and their brain penetration has been assessed using the PAMPA-BBB assay. Also, the mechanism of AChE inhibition of the most potent compounds has been thoroughly studied by kinetic studies, a propidium displacement assay, and molecular modelling. We have found that a seemingly small structural change such as a double O → NH bioisosteric replacement from the hit 1 to 16a results in a dramatic increase of EeAChE and hAChE inhibitory activities (>217- and >154-fold, respectively), and in a notable increase in hBChE inhibitory activity (> 11-fold), as well. An optimized binding at the PAS besides additional interactions with AChE midgorge residues seem to account for the high hAChE inhibitory potency of 16a (IC50 = 65 nM), which emerges as an interesting anti-Alzheimer lead compound with potent dual AChE and BChE inhibitory activities.
Resumo:
A series of 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridines differently substituted at positions 1, 5, and 9 have been designed from the pyrano[3,2-c]quinoline derivative 1, a weak inhibitor of acetylcholinesterase (AChE) with predicted ability to bind to the AChE peripheral anionic site (PAS), at the entrance of the catalytic gorge. Fourteen novel benzonaphthyridines have been synthesized through synthetic sequences involving as the key step a multicomponent Povarov reaction between an aldehyde, an aniline and an enamine or an enamide as the activated alkene. The novel compounds have been tested against Electrophorus electricus AChE (EeAChE), human recombinant AChE (hAChE), and human serum butyrylcholinesterase (hBChE), and their brain penetration has been assessed using the PAMPA-BBB assay. Also, the mechanism of AChE inhibition of the most potent compounds has been thoroughly studied by kinetic studies, a propidium displacement assay, and molecular modelling. We have found that a seemingly small structural change such as a double O → NH bioisosteric replacement from the hit 1 to 16a results in a dramatic increase of EeAChE and hAChE inhibitory activities (>217- and >154-fold, respectively), and in a notable increase in hBChE inhibitory activity (> 11-fold), as well. An optimized binding at the PAS besides additional interactions with AChE midgorge residues seem to account for the high hAChE inhibitory potency of 16a (IC50 = 65 nM), which emerges as an interesting anti-Alzheimer lead compound with potent dual AChE and BChE inhibitory activities.