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61.
The genome of the gray, short-tailed opossum, Monodelphis domestica, will be the first of any marsupial to be fully sequenced. The utility of this sequence will be greatly enhanced by construction and integration of detailed genetic and physical maps. Therefore, it is important to verify the unusual recombinational characteristics that were suggested by the ‘first-generation’ M. domestica linkage map; specifically, very low levels of recombination and severely reduced female recombination, both of which are contrary to patterns in other vertebrates. We constructed a new linkage map based on a different genetic cross, using a new and much larger set of map markers, and physically anchored and oriented the linkage groups onto chromosomes via fluorescence in-situ hybridization mapping. This map includes 150 loci in eight autosomal linkage groups corresponding to the eight autosome pairs, and spans 86–89% of the autosomal genome. The sex-averaged autosomal map covers 715 cM, with a full-length estimate of 866 cM; the shortest full-length linkage map reported for any vertebrate. The sex-specific maps confirmed severely reduced female recombination in all linkage groups, and an overall F/M map ratio =  0.54. These results greatly extend earlier findings, and provide an improved microsatellite-based linkage map for this species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
62.
Explicit memory appears to be supported by medical temporal lobe structures, whereas separate neocortical regions may mediate perceptual and conceptual implicit memory. Children and adults with temporal lobe epilepsy (TLE) and matched controls were administered experimental verbal memory tests. Performance on implicit tests--word identification and word generation--was contrasted with explicit recognition and recall. Encoding conditions emphasized either conceptual or perceptual aspects of study words and were crossed with presentation modality. The priming performance of participants with TLE did not differ from controls, but participants with TLE did show deficits on recognition and recall measures. Thus, intact left temporal cortex does not appear to be necessary for normal implicit memory performance, even when conceptual processing is emphasized at study or test.  相似文献   
63.
BACKGROUND: Peanut allergy is a major health concern due to the increased prevalence, potential severity, and chronicity of the reaction. The cDNA encoding a third peanut allergen, Ara h 3, has been previously cloned and characterized. Mutational analysis of the Ara h 3 IgE-binding epitopes with synthetic peptides revealed that single amino acid changes at critical residues could diminish IgE binding. METHODS: Specific oligonucleotides were used in polymerase chain reactions to modify the cDNA encoding Ara h 3 at critical IgE binding sites. Four point mutations were introduced into the Ara h 3 cDNA at codons encoding critical amino acids in epitopes 1, 2, 3 and 4. Recombinant modified proteins were used in SDS-PAGE/Western IgE immunoblot, SDS-PAGE/Western IgE immunoblot inhibition and T cell proliferation assays to determine the effects of these changes on in vitro clinical indicators of peanut hypersensitivity. RESULTS: Higher amounts of modified Ara h 3 were required to compete with the wild-type allergen for peanut-specific serum IgE. Immunoblot analysis with individual serum IgE from Ara-h-3-allergic patients showed that IgE binding to the modified protein decreased approximately 35-85% in comparison to IgE binding to wild-type Ara h 3. Also, the modified Ara h 3 retained the ability to stimulate T cell activation in PBMCs donated by Ara-h-3-allergic patients. CONCLUSIONS: The engineered hypoallergenic Ara h 3 variant displays two characteristics essential for recombinant allergen immunotherapy; it has a reduced binding capacity for serum IgE from peanut-hypersensitive patients and it can stimulate T-cell proliferation and activation.  相似文献   
64.
65.
Development of distinct CD4+ T cell cytokine phenotypes may be conditioned by the anatomic site in which activation occurs. A double-label in situ hybridization technique was used to characterize co-expression of cytokine mRNA in antigen-specific responses of Peyer's patch (PP), lamina propria (LP), and splenic (SP) CD4+ T cells isolated from αβ T cell receptor-transgenic mice. Interleukin (IL)-2 was the dominant cytokine expressed by antigen-stimulated PP and SP populations, though it was expressed by a minority of the activated T cells. Cells that expressed interferon (IFN)-γ were less frequent, and IL-4, IL-5, and IL-10 were infrequent. In contrast, cells that expressed IFN-γ or IL-10 were most frequent in the LP population, with lower frequencies of IL-2, and few IL-4- and IL-5-positive cells. Co-expression of two cytokines by the same cell was the exception, regardless of the anatomic site from which the T cells were isolated. The surface phenotype of transgene-positive T cells isolated from each anatomic site was distinct, despite the absence of in vivo exposure to antigen for which the transgenic T cell receptor is specific. These data suggest that the cytokine responses of CD4+ T cells may be conditioned by the microenvironment, independently of specific antigen, and that the LP CD4+ T population has a distinct cytokine expression pattern with counter-regulatory properties that may be important for homeostasis in mucosal immune tissues.  相似文献   
66.
Antimicrobial peptides play an important role in host defence, particularly in the oral cavity where there is constant challenge by microorganisms. The alpha-defensin antimicrobial peptides comprise 30-50% of the total protein in the azurophilic granules of human neutrophils, the most abundant of which is human neutrophil peptide 1 (HNP-1). Despite its antimicrobial activity, a limiting factor in the potential therapeutic use of HNP-1 is its chemical synthesis with the correct disulphide topology. In the present study, we synthesised a range of truncated defensin analogues lacking disulphide bridges. All the analogues were modelled on the C-terminal region of HNP-1 and their antimicrobial activity was tested against a range of microorganisms, including oral pathogens. Although there was variability in the antimicrobial activity of the truncated analogues synthesised, a truncated peptide named 2Abz(23)S(29) displayed a broad spectrum of antibacterial activity, effectively killing all the bacterial strains tested. The finding that truncated peptides, modelled on the C-terminal beta-hairpin region of HNP-1 but lacking disulphide bridges, display antimicrobial activity could aid their potential use in therapeutic interventions.  相似文献   
67.
Background: Neural crest cells emerge by delamination from the dorsal neural tube and give rise to various components of the peripheral nervous system in vertebrate embryos. These cells change from non‐motile into highly motile cells migrating to distant areas before further differentiation. Mechanisms controlling delamination and subsequent migration of neural crest cells are not fully understood. Slit2, a chemorepellant for axonal guidance that repels and stimulates motility of trunk neural crest cells away from the gut has recently been suggested to be a tumor suppressor molecule. The goal of this study was to further investigate the role of Slit2 in trunk neural crest cell migration by constitutive expression in neural crest cells. Results: We found that Slit gain‐of‐function significantly impaired neural crest cell migration while Slit loss‐of‐function favored migration. In addition, we observed that the distribution of key cytoskeletal markers was disrupted in both gain and loss of function instances. Conclusions: These findings suggest that Slit molecules might be involved in the processes that allow neural crest cells to begin migrating and transitioning to a mesenchymal type. Developmental Dynamics 241:1274–1288, 2012. © 2012 Wiley Periodicals, Inc.  相似文献   
68.
Degree of pupil dilation has been shown to be a valid and reliable measure of cognitive load, but the effect of aural versus visual task presentation on pupil dilation is unknown. To evaluate effects of presentation mode, pupil dilation was measured in three tasks spanning a range of cognitive activities: mental multiplication, digit sequence recall, and vigilance. Stimuli were presented both aurally and visually, controlling for all known visual influences on pupil diameter. The patterns of dilation were similar for both aural and visual presentation for all three tasks, but the magnitudes of pupil response were greater for aural presentation. Accuracy was higher for visual presentation for mental arithmetic and digit recall. The findings can be accounted for in terms of dual codes in working memory and suggest that cognitive load is lower for visual than for aural presentation.  相似文献   
69.

Objective

Unfavorable histology endometrial carcinomas confer worse prognosis. We determined the association of adjuvant radiation on local recurrence and survival for unfavorable, early stage endometrial cancer.

Methods

We retrospectively identified 125 patients who had a hysterectomy for early stage (FIGO IA), unfavorable histology (clear cell, papillary serous or grade 3 endometrioid), endometrial carcinoma treated between 1992 and 2011. Patients were restaged according to current FIGO 2009 guidelines. Primary endpoint was local control and secondary endpoints were distant recurrence and overall survival.

Results

The median age of the cohort was 67 years old with a mean follow up 152 months. Adjuvant radiation was delivered in 60 patients (48%). There were a total of 24 recurrences; 5 had local–regional recurrences, 4 local and distant recurrence, 12 distant only recurrences, and 3 had unspecified recurrences. The 5-year local–regional control was 97.8% in patients who received radiation and 80.1% in patients who did not receive radiation (p = 0.018). The 5-year overall survival rate was 68.1% if patients did not receive radiation and 84.9% if they did receive radiation (p = 0.0062). On univariate analysis, only radiation (HR 0.12, 95% CI: 0.03 to 0.49, p-value = 0.018) was associated with a significant increase in local relapse free survival.

Conclusions

Adjuvant radiation therapy was significantly associated with an improvement in local–regional control and overall survival in patients with unfavorable histology, early stage endometrial cancer.  相似文献   
70.

Background  

Complementary and Alternative Medicine (CAM) is increasingly popular with cancer patients and yet information provision or discussion about CAM by health professionals remains low. Previous research suggests that patients may fear clinicians' 'disapproval' if they raise the subject of CAM, and turn to other sources to acquire information about CAM. However, little empirical research has been conducted into how cancer patients acquire, and, more importantly evaluate CAM information before deciding which CAM therapies to try.  相似文献   
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