全文获取类型
收费全文 | 66665篇 |
免费 | 5375篇 |
国内免费 | 42篇 |
专业分类
72082篇 |
出版年
2023年 | 354篇 |
2022年 | 689篇 |
2021年 | 1254篇 |
2020年 | 948篇 |
2019年 | 1035篇 |
2018年 | 1551篇 |
2017年 | 1358篇 |
2016年 | 2114篇 |
2015年 | 3006篇 |
2014年 | 3030篇 |
2013年 | 3761篇 |
2012年 | 4441篇 |
2011年 | 4069篇 |
2010年 | 2530篇 |
2009年 | 2303篇 |
2008年 | 3002篇 |
2007年 | 2888篇 |
2006年 | 2663篇 |
2005年 | 2895篇 |
2004年 | 2829篇 |
2003年 | 2370篇 |
2002年 | 1984篇 |
2001年 | 1667篇 |
2000年 | 1573篇 |
1999年 | 1374篇 |
1998年 | 660篇 |
1997年 | 590篇 |
1996年 | 652篇 |
1995年 | 520篇 |
1994年 | 503篇 |
1993年 | 478篇 |
1992年 | 1011篇 |
1991年 | 897篇 |
1990年 | 821篇 |
1989年 | 802篇 |
1988年 | 794篇 |
1987年 | 734篇 |
1986年 | 677篇 |
1985年 | 673篇 |
1984年 | 623篇 |
1983年 | 463篇 |
1982年 | 365篇 |
1981年 | 358篇 |
1980年 | 341篇 |
1979年 | 459篇 |
1978年 | 382篇 |
1977年 | 319篇 |
1975年 | 318篇 |
1974年 | 319篇 |
1973年 | 316篇 |
排序方式: 共有10000条查询结果,搜索用时 26 毫秒
931.
Benjamin Marty Alexandre Vignaud Andreas Greiser Benjamin Robert Paulo Loureiro de Sousa Pierre G. Carlier 《PloS one》2015,10(5)
Modified Look-Locker Inversion recovery (MOLLI) sequence is increasingly performed for myocardial T1 mapping but is known to underestimate T1 values. The aim of the study was to quantitatively analyze several sources of errors when T1 maps are derived using standard post-processing of the sequence and to propose a reconstruction approach that takes into account inversion efficacy (η), T2 relaxation during balanced steady-state free-precession readouts and B1+ inhomogeneities. Contributions of the different sources of error were analyzed using Bloch equations simulations of MOLLI sequence. Bloch simulations were then combined with the acquisition of fast B1+ and T2 maps to derive more accurate T1 maps. This novel approach was evaluated on phantoms and on five healthy volunteers. Simulations show that T2 variations, B1+ heterogeneities and inversion efficiency represent major confounders for T1 mapping when MOLLI is processed with standard 3-parameters fitting. In vitro data indicate that T1 values are accurately derived with the simulation approach and in vivo data suggest that myocardium T1 are 15% underestimated when processed with the standard 3-parameters fitting. At the cost of additional acquisitions, this method might be suitable in clinical research protocols for precise tissue characterization as it decorrelates T1 and T2 effects on parametric maps provided by MOLLI sequence and avoids inaccuracies when B1+ is not homogenous throughout the myocardium. 相似文献
932.
Carry‐over Effects of Size at Metamorphosis in Red‐eyed Treefrogs: Higher Survival but Slower Growth of Larger Metamorphs 下载免费PDF全文
Rebecca D. Tarvin Catalina Silva Bermúdez Venetia S. Briggs Karen M. Warkentin 《Biotropica》2015,47(2):218-226
Most animals have complex life histories, composed of a series of ecologically distinct stages, and the transitions between stages are often plastic. Anurans are models for research on complex life cycles. Many species exhibit plastic timing of and size at metamorphosis, due to both environmental constraints on larval growth and development and adaptive plastic responses to environmental variation. Models predicting optimal timing of metamorphosis balance cost/benefit ratios across stages, assuming that size affects growth and mortality rates in each stage. Much research has documented such effects in the larval period, but we lack an equal understanding of juvenile growth and mortality. Here, we examine how variation in size at metamorphosis in the Neotropical red‐eyed treefrog, Agalychnis callidryas, affects post‐metamorphic growth, foraging, and behavior in the lab as well as growth and survival in the field. Surprisingly, many individuals lost mass for weeks after metamorphosis. In the lab, larger metamorphs lost more mass following metamorphosis, ate similar amounts, had lower food conversion efficiencies, and grew more slowly after mass loss ceased than did smaller ones. In field cages larger metamorphs were more likely to survive than smaller ones; just one froglet died in the lab. Our data suggest that size‐specific differences in physiology and behavior influence these trends. Comparing across species and studies, large size at metamorphosis generally confers higher survival; size effects on growth rates vary substantially among species, in both magnitude and direction, but may be stronger in the tropics. 相似文献
933.
934.
Luiz Henrique Soares de Andrade Wilson Max Almeida Monteiro de Moraes Eduardo Hiroshi Matsuo Junior Elizabeth de Orleans Carvalho de Moura Hanna Karen Moreira Antunes Jairo Montemor Ednei Luiz Antonio Danilo Sales Bocalini Andrey Jorge Serra Paulo José Ferreira Tucci Patricia Chakur Brum Alessandra Medeiros 《Molecular and cellular biochemistry》2015,402(1-2):193-202
935.
Fabián Casas Ana Benítez‐López Jesús T. García Carlos A. Martín Javier Viñuela Francois Mougeot 《Ibis》2015,157(1):115-124
Capturing and marking free‐living birds permits the study of important aspects of their biology but may have undesirable effects. Bird welfare should be a primary concern, so it is necessary to evaluate and minimize any adverse effects of procedures used. We assess short‐term effects associated with the capture, handling and tagging with backpack‐mounted transmitters of Pin‐tailed Pterocles alchata and Black‐bellied Pterocles orientalis Sandgrouse, steppe birds of conservation concern. There was a significantly higher mortality (15%) during the first week after capture than during the following weeks (< 2.5%) in Pin‐tailed Sandgrouse, but no significant temporal mortality pattern in Black‐bellied Sandgrouse. In Pin‐tailed Sandgrouse, mortality rate during the first week increased with increasing relative transmitter and harness weight regardless of season, and with increasing handling time during the breeding season. There were no significant differences in mortality rate between study areas, type of tag, sex or age or an effect of restraint time. These results suggest the use of lighter transmitters (< 3% of the bird's weight) and a reduction of handling time (< 20 min), particularly during the breeding season, as essential improvements in procedure to reduce the mortality risk associated with the capture, handling and tagging of these vulnerable species. 相似文献
936.
Elena López‐Villar Gabriel Á. Martos‐Moreno Julie A. Chowen Shigeru Okada John J. Kopchick Jesús Argente 《Journal of cellular and molecular medicine》2015,19(7):1455-1470
The incidence of obesity and type diabetes 2 has increased dramatically resulting in an increased interest in its biomedical relevance. However, the mechanisms that trigger the development of diabetes type 2 in obese patients remain largely unknown. Scientific, clinical and pharmaceutical communities are dedicating vast resources to unravel this issue by applying different omics tools. During the last decade, the advances in proteomic approaches and the Human Proteome Organization have opened and are opening a new door that may be helpful in the identification of patients at risk and to improve current therapies. Here, we briefly review some of the advances in our understanding of type 2 diabetes that have occurred through the application of proteomics. We also review, in detail, the current improvements in proteomic methodologies and new strategies that could be employed to further advance our understanding of this pathology. By applying these new proteomic advances, novel therapeutic and/or diagnostic protein targets will be discovered in the obesity/Type 2 diabetes area. 相似文献
937.
Ian Ford Vladimir Bezlyak David J Stott Naveed Sattar Chris J Packard Ivan Perry Brendan M Buckley J. Wouter Jukema Anton J. M de Craen Rudi G. J Westendorp James Shepherd 《PLoS medicine》2009,6(1)
Background
Reduced glomerular filtration rate (GFR) is associated with increased cardiovascular risk in young and middle aged individuals. Associations with cardiovascular disease and mortality in older people are less clearly established. We aimed to determine the predictive value of the GFR for mortality and morbidity using data from the 5,804 participants randomized in the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER).Methods and Findings
Glomerular filtration rate was estimated (eGFR) using the Modification of Diet in Renal Disease equation and was categorized in the ranges ([20–40], [40–50], [50–60]) ≥ 60 ml/min/1.73 m2. Baseline risk factors were analysed by category of eGFR, with and without adjustment for other risk factors. The associations between baseline eGFR and morbidity and mortality outcomes, accrued after an average of 3.2 y, were investigated using Cox proportional hazard models adjusting for traditional risk factors. We tested for evidence of an interaction between the benefit of statin treatment and baseline eGFR status. Age, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, C-reactive protein (CRP), body mass index, fasting glucose, female sex, histories of hypertension and vascular disease were associated with eGFR (p = 0.001 or less) after adjustment for other risk factors. Low eGFR was independently associated with risk of all cause mortality, vascular mortality, and other noncancer mortality and with fatal and nonfatal coronary and heart failure events (hazard ratios adjusted for CRP and other risk factors (95% confidence intervals [CIs]) for eGFR < 40 ml/min/1.73m2 relative to eGFR ≥ 60 ml/min/1.73m2 respectively 2.04 (1.48–2.80), 2.37 (1.53–3.67), 3.52 (1.78–6.96), 1.64 (1.18–2.27), 3.31 (2.03–5.41). There were no nominally statistically significant interactions (p < 0.05) between randomized treatment allocation and eGFR for clinical outcomes, with the exception of the outcome of coronary heart disease death or nonfatal myocardial infarction (p = 0.021), with the interaction suggesting increased benefit of statin treatment in subjects with impaired GFRs.Conclusions
We have established that, in an elderly population over the age of 70 y, impaired GFR is associated with female sex, with presence of vascular disease, and with levels of other risk factors that would be associated with increased risk of vascular disease. Further, impaired GFR is independently associated with significant levels of increased risk of all cause mortality and fatal vascular events and with composite fatal and nonfatal coronary and heart failure outcomes. Our analyses of the benefits of statin treatment in relation to baseline GFR suggest that there is no reason to exclude elderly patients with impaired renal function from treatment with a statin. 相似文献938.
Identification of Varicella-Zoster Virus-Specific CD8 T Cells in Patients after T-Cell-Depleted Allogeneic Stem Cell Transplantation 下载免费PDF全文
Pim L. J. van der Heiden Renate de Boer Dirk M. van der Steen Michel G. D. Kester Menno W. A. G. van der Hoorn Wilmy M. E. Haarman Helen E. Barnby-Porritt Jeremy W. Fry C. E. Napper Erik W. A. Marijt Roel Willemze J. H. Frederik Falkenburg Mirjam H. M. Heemskerk 《Journal of virology》2009,83(14):7361-7364
To study the role of CD8 T cells in the control of varicella-zoster virus (VZV) reactivation, we developed multimeric major histocompatibility complexes to identify VZV-specific CD8 T cells. Potential HLA-A2 binding peptides from the putative immediate-early 62 protein (IE62) of VZV were tested for binding, and peptides with sufficient binding capacity were used to generate pentamers. Patients with VZV reactivation following stem cell transplantation were screened with these pentamers, leading to the identification of the first validated class I-restricted epitope of VZV. In 42% of HLA-A2 patients following VZV reactivation, these IE62-ALW-A2 T cells could be detected ex vivo.Varicella-zoster virus (VZV) infects about 95% of the population, persists throughout life, and may lead to herpes zoster when the virus reactivates. After T-cell-depleted allogeneic stem cell transplantation (TCD alloSCT), reactivation of the virus leads to considerable morbidity (10). Primary infection elicits both humoral and cellular responses, but cellular immunity is essential for preventing herpes zoster. The VZV genome comprises more than 70 unique open reading frames that encode proteins that are coordinately expressed during replication. The product of open reading frame 62, the immediate-early 62 (IE62) protein, is required for the initiation of VZV replication (9) and is expressed at high levels before viral replication has occurred (8). Previous research has demonstrated that IE62-specific T cells were detected after primary VZV infection and in immune subjects (2, 4). In addition, T cells recognizing various other IE proteins and glycoproteins of VZV, as demonstrated by gamma interferon (IFN-γ) production upon stimulation with peptides or lysate derived from these proteins, have been described (1, 6, 13). The VZV-specific memory T cells found in these studies were predominantly CD4 T cells, while no VZV-specific CD8 T cells were demonstrated without prior in vitro expansion, possibly due to the low frequency of VZV-specific CD8 T cells or to the low sensitivity of the screening methods used to detect CD8 T cells by IFN-γ production upon stimulation. Frey et al. described CD8 epitopes of IE62 detected following in vitro restimulation. However, the HLA restriction and specificity of these T cells were not confirmed (4). Due to the lack of validated VZV-derived immunodominant peptides for major histocompatibility complex (MHC) class I, the analysis of VZV-specific CD8 T-cell responses is hampered (14). To be able to analyze the role of CD8 T cells in VZV reactivation, we therefore set out to identify epitopes for VZV by using VZV-IE62-specific MHC class I peptide complexes.The predictive algorithms BIMAS (11) and SYFPEITHI (12) were used to select potential HLA-A2 binding peptides from the IE62 protein. Peptides with a score of ≥3 (BIMAS) or ≥20 (SYFPEITHI) were considered to have potentially significant binding affinity. The 81 resulting 9-mer peptides were synthesized and tested for binding affinity with the REVEAL MHC-peptide binding assay (ProImmune, Oxford, United Kingdom). HLA-A2 binding affinity was determined by the ability of the peptides to stabilize the HLA-peptide complex. Based on the binding affinity measurements, 34 high- to medium-affinity HLA-A2 binding peptides were selected and used to generate ProVE MHC pentamers (ProImmune, Oxford, United Kingdom). To enable screening of this large number of pentamers, the pentamers were divided into five pools, each containing six or seven pentamers. In the initial screening with pooled pentamers, four HLA-A2-positive patients were screened after a clinical diagnosis of VZV reactivation after TCD alloSCT. The presence of viral DNA in plasma at the time of clinical observations of VZV reactivation was confirmed by real-time PCR on plasma samples as previously described (7). After informed consent was obtained, peripheral blood mononuclear cells (PBMCs) were cryopreserved and thawed and 0.5 × 106 cells were incubated with pentamers at a concentration of 0.03 mg/ml for 10 min at room temperature in RPMI medium supplemented with 2% fetal bovine serum. After the cells were washed twice, 8 μl of FluoroTag-phycoerythrin (PE) was added for 20 min of incubation at 4°C and the cells were counterstained with CD4, CD40, and CD19-fluorescein isothiocyanate (FITC). Flow cytometric analysis was performed on a FACScalibur fluorescence-activated cell sorter (FACS; Becton-Dickinson [BD], San Jose, CA). In one of four patients, pentamer pool 6, containing pentamers 61, 62, 64, 65, 66, and 67, was positive (0.06% of CD8 T cells); no other positive signals were observed. Staining with the individual pentamers revealed that pentamer 66, containing the epitope ALWALPHAA derived from the IE62 protein of VZV (IE62-ALW-A2) was responsible for the positive signal (0.06% of CD8 T cells, Fig. Fig.1B1B).Open in a separate windowFIG. 1.Screening with pentamers containing VZV-derived immunogenic epitopes. PBMCs of a patient after VZV reactivation following TCD alloSCT were incubated with pentamers and then stained with FluoroTag-PE to detect the pentamer-positive cells (A and B) and counterstained with CD4-, CD40-, and CD19-FITC. Pentamer staining of the CD4-, CD40-, and CD19-negative cells is shown. (A) PBMCs stained with pentamer 67 containing the epitope ALPHAAAAV, showing no specific staining. (B) PBMCs stained with pentamer 66 containing the epitope ALWALPHAA, showing specific staining. IE62-ALW-A2-specific T-cell clones were sorted into a single cell per well and expanded nonspecifically. The clones were stained with an irrelevant tetramer (C) and the IE62-ALW-A2 tetramer (D) in combination with CD8-FITC. Clones 1 and 2 were stained with a Vβ kit (BD) to demonstrate that clone 1 (E) and clone 2 (F) express different T-cell receptors. The results demonstrate that we isolated different T-cell clones that specifically stain with the IE62-ALW-A2 tetramer.To confirm the specificity of the IE62-ALW-A2-specific T cells, the pentamer-positive T cells were sorted into a single cell per well with a FACSDiva (BD) and expanded as previously described (5). The expanded T-cell clones were labeled specifically with the IE62-ALW-A2 PE-conjugated tetramer that was constructed as previously described (3) (Fig. (Fig.1D),1D), and Vβ analysis with the T-cell receptor Vβ repertoire kit (BD) showed that at least two different T-cell clones were isolated, demonstrating the oligoclonal origin of IE62-ALW-A2-positive T cells (Fig. 1E and F). To assess the cytolytic capacity of IE62-ALW-A2 T cells, chromium release assays were performed as described earlier (5). 51Cr-labeled Epstein-Barr virus (EBV) lymphoblastoid cell lines (LCLs) loaded with the IE62-ALW peptide were incubated with IE62-ALW-A2 T cells for 4 h. As demonstrated in Fig. Fig.2A,2A, HLA-A2-positive EBV LCLs loaded with the IE62-ALW-A2 peptide were lysed by both T-cell clones, whereas unloaded EBV LCLs were not lysed. To determine the avidity of the T-cell clones, the IE62-ALW-A2 peptide was titrated on EBV LCLs, and after 24 h of coculture, supernatants were harvested and used to determine the IFN-γ production of the stimulated T cells by standard enzyme-linked immunosorbent assay. Half-maximum IFN-γ production of the T-cell clones was observed when the stimulator cells were loaded with 10 ng/ml peptide, indicative of high-avidity T-cell clones (Fig. (Fig.2B).2B). To determine whether the T cells recognized cells endogenously expressing the IE-62-encoding gene, COS-A2 cells were transfected with Lipofectamine (Invitrogen, Carlsbad, CA) by using pcDNA vectors coding for different VZV genes, which were kindly provided by E. Wiertz (Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands). The transfected COS-A2 cells were used 24 h after transfection as stimulator cells in this assay. After 24 h of coculture, supernatants were harvested and used to determine the IFN-γ production of the stimulated T cells. IE62-ALW-A2 T-cell clones produced IFN-γ in response to COS-A2 cells endogenously expressing the IE62 protein, as well as COS-A2 cells pulsed with the IE62-ALW-A2 peptide. No IFN-γ was produced when the COS-A2 cells were transfected with the IE63-encoding gene of VZV or pulsed with an irrelevant peptide (Fig. (Fig.2C2C).Open in a separate windowFIG. 2.IE62-ALW-A2 T cells recognize IE62-ALW-A2 peptide-loaded target cells and target cells endogenously expressing IE62. (A) The cytolytic activity of IE62-ALW-A2-positive T-cell clones 1 and 2 was analyzed with the 51Cr release assay. T cells were incubated for 4 h with IE62-ALW-A2 peptide (pep)-loaded or unloaded, HLA-A2-positive EBV LCLs at an effector-to-target ratio of 10:1. (B) IE62-ALW-A2 T-cell clone 1 was stimulated with HLA-A2-positive EBV LCLs loaded with different concentrations of the IE62-ALW-A2 peptide. Release of IFN-γ (pg/ml) after 24 h of stimulation is shown. (C) IE62-ALW-A2 T-cell clones 1 and 2 were stimulated with HLA-A2-positive COS-A2 cells, left untreated, or loaded with the IE62-ALW-A2 peptide or with the IE4-ALR-B8 peptide as an irrelevant peptide or transfected with the IE63-encoding gene (COS-A2-IE63) or the IE62-encoding gene (COS-A2-IE62). Release of IFN-γ (picograms per milliliter) after 24 h of stimulation is shown.To determine whether IE62-ALW-A2-specific T cells were present in healthy individuals, cryopreserved PBMCs from 18 healthy, VZV-seropositive, HLA-A2-positive individuals were screened with the PE-conjugated VZV tetramer. PBMCs were labeled with tetramers for 15 min at 37°C in RPMI medium without phenol supplemented with 2% fetal bovine serum, washed, and analyzed with a FACScalibur. In 3 of these 18 serologically VZV-positive individuals, IE62-ALW-A2 tetramer-positive T cells could be detected (range, 0.01 to 0.02% of CD8 T cells). These data demonstrate that IE62-ALW-A2-specific T cells can be observed and that the frequency of these T cells is low under steady-state conditions in immunocompetent persons.To assess the frequency of IE62-ALW-A2-specific T cells in a cohort of patient who suffered from VZV reactivation following TCD alloSCT, 19 HLA-A2-positive patients after VZV reactivation following TCD alloSCT were screened by using the IE62-ALW-A2 tetramer. We screened these patients at a median of 47 days after the clinical diagnosis of VZV reactivation. In 8 of these 19 patients, IE62-ALW-A2-specific T cells could be directly detected ex vivo (mean, 0.04% [range, 0.01 to 0.11%] of CD8 T cells), indicating that this epitope is recognized in 42% of the HLA-A2-positive patients during VZV reactivation (Table (Table1).1). In VZV-seronegative patients (six screened), no IE62-ALW-A2 tetramer-positive cells could be detected.
Open in a separate windowaMean percentages of IE62-ALW-A2 tetramer-positive cells of CD8 T cells of three tetramer stainings performed on different days are shown.bPBMCs were in vitro stimulated (IVS) for 7 days with IE62-ALW-A2 peptide, and the mean percentages of tetramer-positive cells of three to six stimulations are shown. A negative result was defined as <0.01% of CD8+ T cells.cND, no PBMCs were available to do the analysis.To verify the presence of the IE62-ALW-A2-specific T cells in the patient and donor cohort and to investigate whether individuals negative for IE62-ALW-A2-specific T cells were unable to mount a response against the epitope or whether the frequency of IE62-ALW-A2-specific T cells was too low to detect by FACS, the presence of these T cells was further measured after in vitro stimulation. PBMCs were cultured at a concentration of 1 × 106/ml in 24-well plates in Iscove''s modified Dulbecco''s medium supplemented with 10% human serum in the presence of IE62-ALW peptide (1 μg/ml), interleukin-2 (IL-2; 50 IU/ml), and IL-15 (10 ng/ml). After stimulation for 7 days, the presence of IE62-ALW-A2-specific T cells was reassessed by tetramer labeling. These in vitro stimulations demonstrated that IE62-ALW-A2 CD8 T cells were detectable in another four patients and confirmed the presence of IE62-ALW-A2-specific T cells in eight patients and three healthy, VZV-seropositive individuals with ex vivo-detectable IE62-ALW-A2-specific T cells (Table (Table1;1; Fig. 3A to D). Thus, in 12 (63%) of 19 patients, IE62-ALW-A2 CD8 T cells could be detected either by direct tetramer labeling or after in vitro expansion, indicating that this HLA-A2-restricted epitope is commonly used in HLA-A2-positive individuals.Open in a separate windowFIG. 3.Detection and kinetics of IE62-ALW-A2-specific T cells. PBMCs with detectable IE62-ALW-A2 T cells (A, left side), a low level of detectable tetramer-positive cells (B, left side), or no detectable tetramer-positive cells (C and D, left side) were in vitro stimulated for 7 days with IE62-ALW-A2 peptide (I μg/ml) in the presence of IL-2 and IL-15 (A to D, right side). Cells were stained with CD4-FITC, CD40-FITC, and IE62-ALW-A2 tetramer, and the percentages of CD8+ T cells that were IE62-ALW-A2 tetramer positive are indicated. CD8+ T cells are defined as CD4− CD40− lymphocytes. (E) PBMCs of a patient during the course of VZV reactivation following TCD alloSCT were stained with the IE62-ALW-A2 tetramer in combination with CD8-FITC. The percentages of IE62-ALW-A2-specific CD8 T cells before, during, and after VZV reactivation are shown. In the box, the presence of viral DNA in peripheral blood is shown as measured by real-time PCR at various time points. The bold line illustrates the use of valaciclovir to treat the VZV reactivation.To study whether the immune response against the IE62-ALW-A2 epitope correlated with clinical reactivation, the percentage of IE62-ALW-A2-positive T cells was analyzed during the course of VZV reactivation in one patient. To determine the presence of viral DNA in plasma before and during the course of VZV reactivation, real-time PCR was performed on plasma samples derived at different time points. Six days prior to clinical signs of VZV reactivation, only 0.03% of the CD8 T cells were IE62-ALW-A2 specific. At 42 days after the onset of VZV reactivation, 0.23% of the CD8 T cells were IE62-ALW-A2 specific. After the VZV infection resolved, the percentage of IE62-ALW-A2-specific CD8 T cells declined to 0.09% at day 49 and 0.03% at day 145 after reactivation (Fig. (Fig.3D).3D). The T cells present at the peak of the response were predominantly HLA-DR positive, CD45RA negative, CCR7 negative, CD28 negative, and CD27 positive, consistent with an activated effector memory phenotype.In this study, we demonstrate that CD8 T cells specific for VZV are detectable without prior in vitro stimulation in patients with VZV reactivation following TCD alloSCT. We identified the ALWALPHAA peptide derived from the IE62-encoding gene of VZV as the first validated VZV-specific HLA class I-restricted immunogenic epitope by a pentamer-based epitope discovery method. The detection of the IE62-ALW peptide as an immunogenic peptide for VZV-specific CD8 T cells demonstrates the usefulness of this procedure for discovering new immunogenic virus- or tumor-specific epitopes. We demonstrated that, despite the low frequency, it is possible to detect VZV-specific CD8 T cells, allowing ex vivo analysis of the immune response to VZV infection, reactivation, and possibly VZV vaccination. 相似文献
TABLE 1.
Presence of IE62-ALW-A2-specific T cells in HLA-A2 patients after VZV reactivation following TCD alloSCTPatient | No. of days after:
| % IE62-ALW-A2+ T cells (SD)
| ||
---|---|---|---|---|
TCD alloSCT | VZV reactivation | Before IVSa | After IVSb | |
1 | 180 | 46 | Negative | 0.22 (0.15) |
2 | 190 | 38 | 0.03 (0.01) | 0.51 (0.21) |
3 | 545 | 31 | Negative | Negative |
4 | 294 | 52 | Negative | 0.12 (0.06) |
5 | 82 | 38 | Negative | Negative |
6 | 183 | 16 | Negative | 0.01 (0.01) |
7 | 176 | 81 | 0.02 (0.01) | 0.44 (0.06) |
8 | 99 | 35 | 0.11 (0.02) | 0.22 (0.04) |
9 | 601 | 88 | Negative | 0.01 (0.01) |
10 | 95 | 63 | Negative | Negative |
11 | 90 | 83 | Negative | Negative |
12 | 179 | 48 | Negative | Negative |
13 | 1,224 | 62 | Negative | Negative |
14 | 173 | 20 | 0.03 (0.01) | 0.22 (0.12) |
15 | 514 | 21 | 0.03 (0.01) | NDc |
16 | 635 | 40 | 0.02 (0.01) | ND |
17 | 161 | 8 | Negative | Negative |
18 | 174 | 48 | 0.01 (0.00) | 0.02 (0.01) |
19 | 92 | 49 | 0.04 (0.01) | 0.06 (0.02) |
939.
Y Vazquez Maritza Pupo-Antúnez S V Vazquez Capó G Torres Y Caballero A Sánchez D Limonta M Alvarez MG Guzmán 《MABS-AUSTIN》2009,1(2):157-162
Dengue fever (DF) and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) are considered the most important arthropod-borne viral diseases in terms of morbidity and mortality. The emergency and severity of dengue (Den) infections increase the necessity of an early, quick and effective dengue laboratory diagnostic. Viral isolation is considered a gold standard for diagnosis of dengue infection using monoclonal antibodies (mAbs) as a tool for determining serotype specificity. Alternatives have been used to improve sensitivity and time to dengue diagnosis. Based on the early expression of dengue C protein in the life cycle, we focused our study on the application of an anti-dengue 2 virus capsid protein mAb in dengue diagnosis. The kinetic expression of dengue-2 capsid in mosquito cells and its immuno-localization in experimentally infected suckling albin Swiss (OF-1) mice brain tissues was established. The results demonstrate the possible utility of this mAb in early dengue diagnosis versus traditional isolation. In addition, a preliminary study of an enzyme immunoassay method using 8H8 mAb for specific detection of dengue C protein antigen was performed, making possible recombinant C protein quantification. The results suggest that detection of dengue capsid protein could be useful in the diagnosis of early dengue infection.Key words: monoclonal antibodies, capsid protein, dengue virus, diagnosis, immunoassays 相似文献
940.
Ritha JA Njau Don de Savigny Lucy Gilson Eleuther Mwageni Franklin W Mosha 《Malaria journal》2009,8(1):1-27