Cultured, unprimed spleen cells suppress the generation of cytolytic T lymphocytes when added to mixed lymphocyte culture of cells disparate at minor histocompatibility (H) loci. Cells cultured for 2 to 3 days inhibit cell-mediated lympholysis specifically in that they suppress only when they carry the same H antigen by which the stimulators activate the responding cells. However, culturing of cells for more than 3 days results also in the generation of nonspecific suppressor cells which inhibit the cell-mediated lympholysis regardless whether they carry the stimulating antigens. The specific suppressor cells are T lymphocytes of the Lyt-1+Lyt-2+ type. Fresh, uncultured spleen cells, although ineffective in vitro, can prevent the in vivo priming of minor H-specific cytotoxic T lymphocyte precursors when injected i.v. into mice incompatible at minor H loci. This suppressive effect of the immunizing inoculum is abolished by irradiation (3300 rds) or by treatment with a monoclonal Thy-1-specific antibody and complement. Thus the suppressor T cell demonstrated here is of the "veto" cell type; that is, it probably suppresses minor H-specific cells when the latter recognize the stimulating antigen on the surface of the suppressor cell itself. 相似文献
Combining cell surface phenotyping with functional analysis, human CD8+ T cells have been divided into several subsets which are being studied extensively in diverse physiological situations, such as viral infection, cancer and ageing. In particular, so-called terminally differentiated effector cells possess a CD45RA+ CCR7- CD27- CD28- phenotype, contain perforin and, in different models, have been shown to exert direct ex vivo killing and to release interleukins upon both antigen-nonspecific and -specific stimulation. Using HLA class I multimers, we have identified a high frequency of peripheral CD8+ T cells that recognize a peptide derived from the self protein cytokeratin 18 presented by the HLA-A*0201 molecule. These cells can be detected in approximately 15% of the HLA-A2-positive healthy donors tested. A detailed analysis revealed that they must have divided extensively in vivo, have an effector cell phenotype and express various natural killer cell-associated receptors. Interestingly, however, they remained unresponsive to antigen-specific stimulation in vitro in terms of cytotoxicity and cytokine secretion. Thus, cytokeratin 18-specific cells constitute a frequently encountered, new CD8+ T lymphocyte subpopulation without classical effector status and with so far unknown function. 相似文献
The extent of reaction of functional groups (pA), the extent of conversion of monomer molecules (qM), the true relative polymer yield (yp), the constitutional repeating unit-based apparent relative polymer yield (y), and the monomer-based apparent relative polymer yield (y) are defined and their interrelationships given. The use of y instead of yp overestimates the true yield, except in the limit of high degrees of polymerization. Use of y, on the other hand, always underestimates the true yield, especially at infinite degrees of polymerization. The correct expression for the calculation of the mass fraction of i-mers in reactants with a Schulz-Flory “most probable” distribution is given and shown to become identical with the usual approximation in the limit of vanishingly small mass of the leaving molecule. 相似文献
We reported that RNA condensed on protamine is protected from RNase-mediated degradation and can be used for vaccination. Here, we show that such complexes are also danger signals that activate mouse cells through a MyD88-dependent pathway. Moreover, mRNA-protamine complexes stimulate human blood cells. They strongly activate DC and monocytes, leading to TNF-alpha and IFN-alpha secretion. In addition, protamine-RNA complexes directly activate B cells, NK cells and granulocytes. The detailed analysis of the activated cell types, the study of the cytokines released from PBMC cultured with protamine-RNA complexes and recently published results suggest that TLR-7 and TLR-8 may be involved in the recognition of protamine-stabilized RNA. Our data indicate that protamine-stabilized RNA, which may be similar to RNA condensed in the nucleocapsids of RNA viruses, is a strong danger signal. Thus, similarly to plasmid DNA, protamine-RNA combines antigen production and non-specific immunostimulation. The studies presented here explain the capacity of protamine-RNA to act as a vaccine, and pave the way towards the development of safe and efficient mRNA-based immunotherapies. 相似文献
The numerical value of K0 = [η]0/M of a sample of poly(tetrahydrofuran), which is proporational to the unperturbed dimensions, was determined in different solvents by three methods at 25°C. The resulting value of K0 = 0.202 ml./g. was compared with the corresponding data for polyethylene, poly(ethylene oxide) and polyoxymethylene. 相似文献
Adenoid cystic carcinoma (ACC) is a slowly growing tumor with a particular tendency to infiltrate the surrounding tissue by perineural spread. The clinical diagnosis may prove difficult due to the submucons extension of the tumor, especially at the skull base. This article outlines the clinical characteristics, diagnostics, and treatment modalities in a series of 56 patients with an ACC in the head and neck diagnosed between 1970 and 1998 in 32 females and 24 males. The youngest patient was aged 24 years, the oldest 77 years. The average age was 54 years. In 16 patients the tumor originated in the paranasal sinuses or the nasopharynx and involved the skull base. As a rule, several months passed between the manifestation of the first symptoms such as pain, blocked nose, epistaxis, or diplopia and the initial clinical diagnosis. All patients received surgical treatment, however, complete microscopical resection could only be achieved in approximately one third of the cases. Therefore, nine patients were postoperatively treated with radiotherapy. The average survival rates of the patients with an ACC of the skull base were only 99 months as compared to 144 months in the patients without skull base involvement. 相似文献
This study identifies instability of MHC class I/peptide complexes and intermolecular competition for MHC class I presentation as factors responsible for the subdominance of cyto toxic T lymphocyte (CTL) epitopes. This evidence is based on the characterization of a new CTL epitope derived from the glycoprotein (GP) of lymphocytic choriomeningitis virus (LCMV). This epitope, peptide GP117-125 (GP117) is presented to T cells by the mouse MHC class I molecule, H-2Db. In short-term experiments induction of GP117-specific CTL by vaccination rendered C57BL/6 mice only partially resistant to infection with wild-type LCMV (LCMV-WE) but completely resistant to challenge with a previously described LCMV variant. The variant virus, LCMV-8.7B23, bears point mutations within both known LCMV-GP, H-2 Db-restricted epitopes GP33-41 (GP33) and GP276-286 (GP276) resulting in a valine to leucine change at position 35 in peptide GP33 (V35L) and an asparagine to serine change at position 280 in peptide GP276 (N280S). Although variant peptide GP33/V35L stimulates a weak CTL response, GP276/N280S does not. Elution of peptide GP117 from both LCMV-WE- and LCMV-8.7B23-infected cells revealed that the difference in the capacity of GP117-specific CTL to protect against LCMV-WE and the virus variant LCMV-8.7B23 was due to differences in the level of GP117 presentation on the surface of both types of cells. Thus, it appears that the protective capacity of CTL specific for the subdominant epitope GP117 is influenced by the extent of presentation of other immunodominant peptide epitopes present within infected cells. 相似文献
Objective: To investigate the efficacy and safety of a recently developed ibuprofen medicated plaster in the treatment of acute sports impact injuries/contusions.
Methods: In this double-blind, multi-center, placebo-controlled, parallel group, phase 3 study (EudraCT Number: 2012–003257-2) patients (n = 132; ages 18 to 60 years) diagnosed with acute sports-related traumatic blunt soft tissue injury/contusion to the upper or lower limbs were randomized to receive either ibuprofen 200 mg plaster (n = 64) or placebo plaster (n = 68). Plasters were administered once daily for five consecutive days. The primary assessment was the area under the curve (AUC) of the visual analogue scale (VAS) of pain on movement (POM) over 0 to 72 h (VAS0-72).
Results: The ibuprofen medicated plaster was associated with a reduction in pain on movement (POM) based on lower VAS AUC0-72h (2399.4 mm*h) compared with placebo (4078.9 mm*h) (least squares mean difference: – 1679.5 mm*h; P < 0.0001). The reduction in AUC of POM was also significantly greater for the ibuprofen medicated plaster compared with placebo at 12, 48, 24, and 120 h (P < 0.0001). Algometry/tenderness measurements found that the ibuprofen medicated plaster was associated with greater reduction in tenderness/pain than placebo at each timepoint (P values <0.0001). Seven patients experienced drug-related adverse events (n = 1 [1.6%] for the ibuprofen plaster, and n = 6 [8.8%] for placebo). All drug-related AEs were administration site reactions and were mild in intensity.
Conclusions: The results of this study indicate that ibuprofen medicated plaster results in rapid and clinically relevant reduction of pain in patients suffering from blunt musculoskeletal injuries or recurrent pain. The ibuprofen medicated plaster was well tolerated. 相似文献
Acylureas (ureides) are valued for their important biological activities. Whereas cyclic acylureas have frequently been the object of solid-phase chemistry, only few reports have focused on the solid-supported preparation of acyclic representatives. We have prepared different types of acylureas on Rink amide resin in three or four steps. The products are either N-acylated (9, 18), N-acylated-N'-alkylated (10, 19), or N-acylated-N-alkylated (22). Characteristic NMR parameters of isomeric acylureas 10, 19, and 22 are discussed. 相似文献