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501.
502.
BACKGROUND: Two severe birth defects, congenital diaphragmatic hernia (CDH) and esophageal atresia (EA) with or without tracheoesophageal fistula (TEF), have traditionally been analyzed separately in epidemiological studies. Lung hypoplasia (LH), part of the CDH spectrum, is not usually associated with EA/TEF, yet both are foregut malformations. METHODS: We conducted an epidemiological study of two combinations of the defects in the population of 3,318,966 live births and stillbirths monitored from 1983 to 1996 by the California Birth Defects Monitoring Program (CBDMP). RESULTS: A total of 433 cases had a Bochdalek type CDH/LH (0.13 per 1000 births), 893 had EA/TEF (0.27 per 1000 births), and 646 had LH (0.19 per 1000 births). Among them, 18 cases had CDH/LH with EA/TEF (0.005 per 1000 births), and 53 had EA/TEF and LH (0.02 per 1000 births); both prevalences are significantly higher than expected. Sixteen of 17 cases of CDH/LH with EA/TEF, and 34 of 40 cases of EA/TEF with LH were stillborn or died; 72% and 74%, respectively, had an autopsy. The male to female sex ratios were 1.43 and 1.13, respectively. In both groups, infants had similar proportions of additional severe defects, except for genitourinary and anal defects and syndromes/associations, which were more prevalent in the EA/TEF with LH group. We reviewed human studies and experimental animal models for factors reported to cause any combination of the defects. CONCLUSIONS: Several genetic and environmental factors could affect the significant co-occurrence of the defects. Future studies should include storage of patients' biological materials for DNA analysis, karyotyping, and environmental exposure evaluation.  相似文献   
503.
CD4(+) Th cells play an important role in the induction and maintenance of adequate CD8(+) T cell-mediated antitumor responses. Therefore, identification of MHC class II-restricted tumor antigenic epitopes is of major importance for the development of effective immunotherapies with synthetic peptides. CAMEL and NY-ESO-ORF2 are tumor Ags translated in an alternative open reading frame from the highly homologous LAGE-1 and NY-ESO-1 genes, respectively. In this study, we investigated whether CD4(+) T cell responses could be induced in vitro by autologous, mature dendritic cells pulsed with recombinant CAMEL protein. The data show efficient induction of CAMEL-specific CD4(+) T cells with mixed Th1/Th2 phenotype in two healthy donors. Isolation of CD4(+) T cell clones from the T cell cultures of both donors led to the identification of four naturally processed HLA-DR-binding CAMEL epitopes: CAMEL(1-20), CAMEL(14-33), CAMEL(46-65), and CAMEL(81-102). Two peptides (CAMEL(1-20) and CAMEL(14-33)) also contain previously identified HLA class I-binding CD8(+) T cell epitopes shared by CAMEL and NY-ESO-ORF2 and are therefore interesting tools to explore for immunotherapy. Furthermore, two CD4(+) T cell clones that recognized the CAMEL(14-33) peptide with similar affinities were shown to differ in recognition of tumor cells. These CD4(+) T cell clones recognized the same minimal epitope and expressed similar levels of adhesion, costimulatory, and inhibitory molecules. TCR analysis demonstrated that these clones expressed identical TCR beta-chains, but different complementarity-determining region 3 loops of the TCR alpha-chains. Introduction of the TCRs into proper recipient cells should reveal whether the different complementarity-determining region 3 alpha loops are important for tumor cell recognition.  相似文献   
504.
The role of highlighting in visual search through maps   总被引:1,自引:0,他引:1  
Two experiments were conducted in which participants performed a vehicle dispatching task. The intensity of one information source (vehicles in Experiment 1, destinations in Experiment 2) was varied to examine the effects of salience and discrimination on both searching for and processing the information in a cluttered display. Response times were recorded for questions either requiring focused attention on or divided attention between the different information domains in the map. The results of the present experiments indicate that it is possible to declutter a display without erasing any information. By 'lowlighting' one information domain and keeping the other domain at a fairly high intensity level, dividing attention between the information sources is optimal, as is focusing attention on either of the information domains exclusively. These results are discussed in conjunction with a computational model of confusion and salience which serves to predict search and integration performance in a cluttered display with separate domains of information displayed at different intensities.  相似文献   
505.
The antimicrobial activity of bovine lactoferrin is attributed to lactoferricin, situated in the N1-domain. Based on common features of antimicrobial peptides, a second putative antimicrobial domain was identified in the N1-domain of lactoferrin, designated lactoferrampin. This novel peptide exhibited candidacidal activity, which was substantially higher than the activity of lactoferrin. Furthermore, lactoferrampin was active against Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa, but not against the fermenting bacteria Actinomyces naeslundii, Porphyromonas gingivalis, Streptococcus mutans and Streptococcus sanguis. Notably, lactoferrampin is located in the N1-domain in close proximity to lactoferricin, which plays a crucial role in membrane-mediated activities of lactoferrin.  相似文献   
506.
Knowledge of the opinions of physicians with regard to preconceptional cystic fibrosis (CF) carrier screening and the possible factors that are associated with their opinions is important for the implementation of such a screening program. Data were obtained from a study in which genetic knowledge, opinions with regard to genetic testing and related skills were investigated. A questionnaire, developed and used by American researchers, was adapted to the Dutch health care situation, and sent to randomly selected general practitioners (GPs) (n = 200), gynecologists (GYNs) (n = 300), and pediatricians (PEDs) (n = 265). In this part of the study, their opinions with regard to genetic preconceptional CF carrier screening in different situations were assessed. The response rate for the GPs, GYNs, and PEDs was 64%, 69%, and 72%, respectively. In total, 63% of the GPs, 69% of the GYNs and 72% of the PEDs supported preconceptional CF carrier testing if a couple requested a test. Sixteen percent, 19% and 25%, respectively, were in favor of actively offering a test with 95% test sensitivity to all couples who were planning a pregnancy. A positive opinion on preconceptional CF carrier screening was associated with the following variables: "considering the test sensitivity as less important" (GPs, GYNs), "high perceived risk of having a child with CF" (GYNs), "providing genetic counselling in their own practice" (PEDs) and "reassurance when both partners test negative" (PEDs). Physicians are sympathetic toward preconceptional CF carrier screening if the couples themselves request a test. Physicians had reservations about routinely offering a CF carrier test.  相似文献   
507.

Introduction  

The glucocorticoid receptor (GR) plays an important regulatory role in the immune system. Four polymorphisms in the GR gene are associated with differences in glucocorticoid (GC) sensitivity; the minor alleles of the polymorphisms N363 S and BclI are associated with relative hypersensitivity to GCs, while those of the polymorphisms ER22/23EK and 9β are associated with relative GC resistance. Because differences in GC sensitivity may influence immune effector functions, we examined whether these polymorphisms are associated with the susceptibility to develop Rheumatoid Arthritis (RA) and RA disease severity.  相似文献   
508.
Foam cell formation due to excessive accumulation of cholesterol by macrophages is a pathological hallmark of atherosclerosis. Macrophages cannot limit the uptake of cholesterol and therefore depend on cholesterol efflux pathways for preventing their transformation into foam cells. Several ABC-transporters, including ABCA1 and ABCG1, facilitate the efflux of cholesterol from macrophages. These transporters, however, also affect membrane lipid asymmetry which may have important implications for cellular endocytotic pathways. We propose that in addition to the generally accepted role of these ABC-transporters in the prevention of foam cell formation by induction of cholesterol efflux from macrophages, they also influence the macrophage endocytotic uptake.  相似文献   
509.
Vaults are ribonucleoproteins that may function in intracellular transport processes. We investigated the intracellular distribution and dynamics of vaults in non-small cell lung cancer cells in which vaults are labeled with the green fluorescent protein. Immunofluorescence experiments showed that vaults are dispersed throughout the cytoplasm; a small fraction is found in close proximity to microtubules. Immunoprecipitation experiments corroborated these results showing co-precipitation of MVP and beta-tubulin. Using quantitative fluorescence-recovery after photobleaching (FRAP), we demonstrated that vault mobility over longer distances in part depends on intact microtubules; vaults moving slower when microtubules are depolymerized by nocodazole. Biochemical fractionation indicated a small fraction of MVP associated with the nucleus, however, no GFP-tagged vaults could be observed inside the nucleus. We observed an accumulation of vaults at the nuclear envelope upon treatment of cells with the protein synthesis inhibitor cycloheximide. Analysis of nucleo-cytoplasmic transport using a fluorescent substrate containing a classical NLS and NES expressed in MVP+/+ and MVP-/- mouse embryonic fibroblasts indicated no differences in nuclear import/export kinetics, suggesting no role for vaults in these processes. We hypothesize that a subset of vaults moves directionally via microtubules, possibly towards the nucleus.  相似文献   
510.
Kinesin-3 motors have been shown to transport cellular cargo along microtubules and to function according to mechanisms that differ from the conventional hand-over-hand mechanism. To find out whether the mechanisms described for Kif1A and CeUnc104 cover the full spectrum of Kinesin-3 motors, we characterize here NcKin3, a novel member of the Kinesin-3 family that localizes to mitochondria of ascomycetes. We show that NcKin3 does not move in a K-loop-dependent way as Kif1A or in a cluster-dependent way as CeUnc104. Its in vitro gliding velocity ranges between 0.30 and 0.64 mum/s and correlates positively with motor density. The processivity index (k(bi,ratio)) of approximately 3 reveals that not more than three ATP molecules are hydrolyzed per productive microtubule encounter. The NcKin3 duty ratio of 0.03 indicates that the motor spends only a minute fraction of the ATPase cycle attached to the filament. Unlike other Kinesin-3 family members, NcKin3 forms stable dimers, but only one subunit releases ADP in a microtubule-dependent fashion. Together, these data exclude a processive hand-over-hand mechanism of movement and suggest a power-stroke mechanism where nucleotide-dependent structural changes in a single motor domain lead to displacement of the motor along the filament. Thus, NcKin3 is the first plus end-directed kinesin motor that is dimeric but moves in a nonprocessive fashion to its destination.  相似文献   
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