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101.
Fine specificity of autoantibodies to calreticulin: epitope mapping and characterization 总被引:2,自引:0,他引:2 下载免费PDF全文
Eggleton P Ward FJ Johnson S Khamashta MA Hughes GR Hajela VA Michalak M Corbett EF Staines NA Reid KB 《Clinical and experimental immunology》2000,120(2):384-391
Extracellular calreticulin (CRT) as well as anti‐CRT antibodies have been reported in patients with various autoimmune disorders and CRT has been implicated in ‘epitope spreading’ to other autoantigens such as the Ro/SS‐A complex. In addition, antibodies against parasite forms of the endoplasmic reticulum chaperone, CRT, have been found in patients suffering from onchocerciasis and schistosomiasis. In this study, we screened sera for anti‐CRT antibodies from patients with active and inactive systemic lupus ertythematosus (SLE) and primary or secondary Sjögren’s syndrome. Approximately 40% of all SLE patients were positive for anti‐CRT antibodies. The antigenic regions of CRT were determined using full length CRT and fragments of CRT prepared in yeast and Escherichia coli, respectively. Synthetic 15mer peptides corresponding to the major autoantigenic region of CRT (amino acids 1–289), each one overlapping by 12 amino acids, were used to map the B cell epitopes on the CRT protein recognized by autoimmune sera. Major antigenic epitopes were found to be associated with the N‐terminal half of the protein in 69% of the SLE sera from active disease patients, while the C‐domain was not antigenic. Major epitopes were found to be reactive with antibodies in sera from SLE patients with both active and inactive disease, spanning different regions of the N and P‐domains. Sera from both healthy and disease controls and primary Sjögren’s syndrome patients were non‐reactive to these sequences. Limited proteolysis of CRT with two major leucocyte serine proteases, elastase and cathepsin G, demonstrated that an N‐terminal region of CRT is resistant to digestion. Interestingly, some of the epitopes with the highest reactivity belong to the fragments of the protein which bind to C1q and inhibit complement activation. Whether C1q association with CRT is a pathological or protective interaction between these two proteins is currently under investigation. 相似文献
102.
Immune-stimulating complexes containing Quil A and protein antigen prime class I MHC-restricted T lymphocytes in vivo and are immunogenic by the oral route 总被引:7,自引:0,他引:7 下载免费PDF全文
Induction of all forms of protective immunity by oral immunization with subunit vaccines is an ideal goal for the development of novel vaccines, but creates several theoretical problems from the point of view of antigen processing mechanisms. We show here that incorporation of the protein antigen ovalbumin (OVA) in lipophilic immune-stimulating complexes (ISCOMS) induces very strong primary immune responses in mice and requires very small amounts of antigen. OVA ISCOMS were particularly efficient at stimulating T-cell-mediated immunity in vivo, including delayed-type hypersensitivity (DTH) and potent class I major histocompatibility complex (MHC)-restricted cytotoxic T-cell responses. Furthermore, unlike native protein, OVA in ISCOMS was immunogenic when given orally. Thus, ISCOMS seem to allow protein to enter both the endogenous and exogenous pathways of antigen processing and overcome the usual induction of tolerance after feeding antigen. ISCOMS could provide potentially useful adjuvants for the development of oral subunit vaccines. 相似文献
103.
J. M. Reid D. J. Paterson F. M. Ashcroft D. H. Bergel 《Pflügers Archiv : European journal of physiology》1993,425(3-4):362-364
The increase in blood flow in the cerebral cortex of the anaesthetized rat during hypoxia and hypercapnia was investigated. Cerebral blood flow (CBF) was measured using the hydrogen clearance method with acutely implanted platinum electrodes. Hypoxia (PaO2 35.3±2.4 Torr) and hypercapnia (PaCO2 68.1±5.1 Torr) increased basal CBF from 76.3±9.0 ml/100g/min to 168.1±20.1 ml/100g/min and 162.4±31.9 ml/100g/min respectively. The sulphonylurea tolbutamide (1mM in 1%DMSO) had no significant effect on CBF in hyperoxia or in hypercapnia. However, it attenuated the increase of CBF during hypoxia by 66 ±11% (P<0.01). This suggests that opening of tolbutamide-sensitive potassium channels may be involved in the process of hypoxic vasodilation in the rat cerebral cortex. 相似文献
104.
The effects of antioxidant supplementation during Percoll preparation on human sperm DNA integrity 总被引:20,自引:6,他引:20
Hughes CM; Lewis SE; McKelvey-Martin VJ; Thompson W 《Human reproduction (Oxford, England)》1998,13(5):1240-1247
The integrity of sperm DNA is crucial for the maintenance of genetic
health. A major source of damage is reactive oxygen species (ROS)
generation; therefore, antioxidants may afford protection to sperm DNA. The
objectives of the study were, first, to measure the effects of antioxidant
supplementation in vitro on endogenous DNA damage in spermatozoa using the
single cell gel electrophoresis (comet) assay and, second, to assess the
effect of antioxidant supplementation given prior to X-ray irradiation on
induced DNA damage. Spermatozoa from 150 patients were prepared by Percoll
centrifugation in the presence of ascorbic acid (300, 600 microM), alpha
tocopherol (30, 60 microM), urate (200, 400 microM), or acetyl cysteine (5,
10 microM). DNA damage was induced by 30 Gy X-irradiation. DNA strand
breakage was measured using the comet assay. Sperm DNA was protected from
DNA damage by ascorbic acid (600 microM), alpha tocopherol (30 and 60
microM) and urate (400 microM). These antioxidants provided protection from
subsequent DNA damage by X-ray irradiation. In contrast, acetyl cysteine or
ascorbate and alpha tocopherol together induced further DNA damage.
Supplementation in vitro with the antioxidants ascorbate, urate and alpha
tocopherol separately has beneficial effects for sperm DNA integrity.
相似文献
105.
Tissue sections and cultured lymphocytes from rabbits clinically affected following experimental infection with Alcelaphine herpesvirus-1 (AHV-1) were assessed for the presence of viral DNA by in situ hybridization with the cloned major HindII repeat sequence of this virus. Small numbers of virus-infected cells were consistently detected only in submandibular lymph nodes, while other tissues showed no evidence of viral DNA. Virus titration in culture suggested that there were higher titres of virus in the lymph nodes, spleen and lung of infected animals than in the kidney or peripheral blood lymphocytes and confirmed the low level of virus in these animals. Substantially more viral DNA was detected by in situ hybridization in lymphocytes following at least 24 h of culture, suggesting that viral replication is normally repressed by the host. 相似文献
106.
Evaluation of PCR testing of ethanol-fixed nasal swab specimens as an augmented surveillance strategy for influenza virus and adenovirus identification 下载免费PDF全文
Krafft AE Russell KL Hawksworth AW McCall S Irvine M Daum LT Connoly JL Reid AH Gaydos JC Taubenberger JK 《Journal of clinical microbiology》2005,43(4):1768-1775
Viral culture isolation has been widely accepted as the "gold standard" for laboratory confirmation of viral infection; however, it requires ultralow temperature specimen storage. Storage of specimens in ethanol at room temperature could expand our ability to conduct active surveillance and retrospective screenings of viruses with rapid and inexpensive real-time PCR tests, including isolates from remote regions where freezing specimens for culture is not feasible. Molecular methods allow for rapid identification of viral pathogens without the need to maintain viability. We hypothesized that ethanol, while inactivating viruses, can preserve DNA and RNA for PCR-based methods. To evaluate the use of ethanol-stored specimens for augmenting surveillance for detection of influenza viruses A and B and adenoviruses (AdV), paired nasal swab specimens were collected from 384 recruits with febrile respiratory illness at Fort Jackson, S.C., in a 2-year study. One swab was stored at ambient temperature in 100% ethanol for up to 6 months, and the other swab was stored at -70 degrees C in viral medium. For viral detection, frozen specimens were cultured for a variety of respiratory viruses, and ethanol-fixed specimens were tested with TaqMan (TM) probe and LightCycler SYBR green (SG) melting curve assays with at least two different PCR targets for each virus. The sensitivities of the TM and SG assays on specimens stored in ethanol for 1 month were 75% and 58% for influenza A, 89% and 67% for influenza B, and 93 to 98% and 57% for AdV, respectively. Lower specificities of the real-time assays corresponded to the increased detection of PCR-positive but culture-negative specimens. Influenza virus RNA was detected as well or better after 6 months of storage in ethanol. 相似文献
107.
Samuels ME Forbey KC Reid JE Abkevich V Bulka K Wardell BR Bowen BR Hopkins PN Hunt SC Ballinger DG Skolnick MH Wagner S 《Clinical genetics》2001,59(2):88-98
Defects in the lipoprotein lipase (LPL) gene are associated with dyslipidemia in the general population. Several rare mutations in the gene, as well as two common coding region polymorphisms, D9N and N291S, exhibit deleterious effects on circulating lipid levels. Using a linkage-based approach, we have identified a large Utah kindred segregating the D9N variant in the LPL gene. The kindred was ascertained for premature coronary heart disease and was expanded based on familial dyslipidemia. A genomic scan identified a region of linkage including LPL, and mutation screening identified the segregating variant. In the kindred, the variant shows high penetrance for a hypoalphalipoproteinemia phenotype, but is also associated with hypertriglyceridemia and elevated insulin levels. The strength of linkage was dependent on the combination of phenotype definition and model parameters, favoring the use of a MOD score approach. Most other studies of LPL have proceeded by mutation screening of randomly chosen individuals or selected affected probands; this is the first example identifying a segregating LPL mutation using direct linkage. 相似文献
108.
bcl-2 rearrangement in Hodgkin's disease. Results of polymerase chain reaction, flow cytometry, and sequencing on formalin-fixed, paraffin-embedded tissue. 总被引:2,自引:0,他引:2 下载免费PDF全文
A. H. Reid R. E. Cunningham G. Frizzera T. J. O'Leary 《The American journal of pathology》1993,142(2):395-402
We examined 81 cases of Hodgkin's disease for evidence of the t(14;18) translocation, using the polymerase chain reaction assay on lysates of formalin-fixed, paraffin-embedded tissue. Seven of 74 amplifiable cases (9%) were positive for the translocation, which involves the bcl-2 oncogene and the immunoglobulin heavy chain gene. Two of these cases were sequenced and the breakpoints had the same pattern found in follicular lymphoma. The nuclei from one of the cases were sorted into large and small subpopulations. The t(14;18) signal was more intense in the large nucleus subpopulation, which contained a greater proportion of Reed-Sternberg-like nuclei. These results are consistent with the hypothesis that Reed-Sternberg cells carry the translocation, but they do not exclude the possibility that the translocation is found in cells representing the reactive component of Hodgkin's disease. The results also demonstrate that routinely processed material is suitable for polymerase chain reaction-based analysis of translocations, although the sensitivity is reduced 10- to 100-fold, compared with fresh tissue. 相似文献
109.
110.
Complement fixing antibody responses to virus infection in children with acute lymphoblastic leukaemia. 下载免费PDF全文
Thirty children with acute lymphoblastic leukaemia (ALL) were studied and had a virus isolated. Only 50% produced a significant rise in complement fixing (CF) antibody titre compared to 100% of normal children. The failure to produce antibodies was unpredictable. CF antibodies are not a reliable guide to virus infections in children with ALL. 相似文献