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排序方式: 共有349条查询结果,搜索用时 15 毫秒
1.
Different modulation by histamine of IL-4 and interferon-gamma (IFN-γ) release according to the phenotype of human Th0, Th1 and Th2 clones 下载免费PDF全文
Histamine, an important inflammatory mediator in allergic diseases and asthma, has been reported to have modulator effects on T cells, suggesting that the bronchial microenvironment may regulate the function of resident T cells. We examined the effect of histamine on the release of the Th2-associated cytokines IL-4 and IL-5 and the Th1-associated cytokine IFN-γ by 30 CD4+ T cell clones from peripheral blood or bronchial biopsy of one atopic subject. Based on the IL-4/IFN-γ ratio, the clones were ascribed to the Th2 (ratio >1), Th0 (ratio 0.1 and 1) or Th1 (ratio <0.1) phenotype. Histamine inhibited IFN-γ production by Th1-like cells (P<0.02, Kruskall–Wallis), especially from bronchial biopsy, but had no effect on IL-4 release. Regarding Th0 clones, histamine inhibited IL-4 production (P<0.02) in a dose-dependent manner and slightly inhibited IFN-γ production, but had no effect on Th2-like cells. Histamine had a heterogeneous and insignificant effect on IL-5 production. The H2-receptor antagonist ranitidine completely reversed the inhibition of IL-4 and IFN-γ production, whereas the agonist dimaprit mimicked this effect. In contrast, H1- and H3-receptor agonists and antagonists had no significant effect. These data demonstrate that histamine has different effects on IL-4 and IFN-γ release by T helper cells according to their phenotype via H2-receptors. This study extends the immunomodulatory effects of histamine which may contribute to the perpetuation of airway inflammation in asthma. 相似文献
2.
The role of size, sequence and haplotype in the stability of FRAXA and FRAXE alleles during transmission 总被引:2,自引:5,他引:2
Murray A; Macpherson JN; Pound MC; Sharrock A; Youings SA; Dennis NR; McKechnie N; Linehan P; Morton NE; Jacobs PA 《Human molecular genetics》1997,6(2):173-184
Factors involved in the stability of trinucleotide repeats during
transmission were studied in 139 families in which a full mutation,
premutation or intermediate allele at either FRAXA or FRAXE was
segregating. The transmission of alleles at FRAXA, FRAXE and four
microsatellite loci were recorded for all individuals. Instability within
the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for
FRAXE) was extremely rare; only one example was observed, an increased in
size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in
the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were
unstably transmitted. Instability was more frequent for FRAXA intermediate
alleles that had a tract of pure CGG greater than 37 although instability
only occurred in two of 13 such transmissions: the changes observed were
limited to only one or two repeats. Premutation FRAXA alleles over 100
repeats expanded to a full mutation during female transmission in 100% of
cases, in agreement with other published series. There was no clear
correlation between haplotype and probability of expansion of FRAXA
premutations. Instability at FRAXA or FRAXE was more often observed in
conjunction with a second instability at an independent locus suggesting
genomic instability as a possible mechanism by which at least some FRAXA
and FRAXE mutations arise.
相似文献
3.
This study evaluated the ability of five interim endodontic restorative materials to resist microleakage. Sixty extracted human molars were prepared for initial endodontic therapy via occlusal access preparations. After removal of the pulpal tissue, a cotton pellet was placed in the pulp chamber. The access preparations were sealed with one of the following materials or combinations: TERM, Cavit, IRM, Ketac-Silver, or a IRM-Cavit "sandwich" restoration. The specimens were thermocycled for 24 hours (800 cycles), immersed in methylene blue dye for 4 hours, sectioned, and evaluated under a microscope for microleakage. TERM, Cavit, and the IRM-Cavit "sandwich" had virtually no microleakage, while Ketac-Silver and IRM exhibited gross microleakage. 相似文献
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6.
JM Langley JC LeBlanc EE Wang BJ Law NE MacDonald I Mitchell D Stephens J McDonald FD Boucher S Dobson 《Pediatrics》1997,100(6):943-946
OBJECTIVE: To determine nosocomial transmission of respiratory syncytial virus (RSV) in Canadian pediatric hospitals, outcomes associated with nosocomial disease, and infection control practices. DESIGN: A prospective cohort study in the 1992 to 1994 winter respiratory seasons. SETTING: Nine Canadian pediatric university-affiliated hospitals. PARTICIPANTS: Hospitalized children with symptoms of lower respiratory tract infection (at least one of cough, wheezing, dyspnea, tachypnea, and apnea) and RSV antigen identified in a nasopharyngeal aspirate. RESULTS: Of 1516 children, 91 (6%) had nosocomial RSV (NRSV), defined as symptoms of lower respiratory tract infection and RSV antigen beginning >72 hours after admission. The nosocomial ratio (NRSV/[com-munity-acquired RSV {CARSV})] + NRSV) varied by site from 2.8% to 13%. The median length of stay attributable to RSV for community-acquired illness was 5 days, but 10 days for nosocomial illness. Four children with NRSV (4. 4%) died within 2 weeks of infection, compared with 6 (0.42%) with CARSV (relative risk = 10.4, 95% confidence interval: 3.0, 36.4). All sites isolated RSV-positive patients in single rooms or cohorted them. In a multivariate model, no particular isolation policy was associated with decreased nosocomial ratio, but gowning to enter the room was associated with increased risk of RSV transmission (incidence rate ratio 2.81; confidence interval: 1.65, 4.77). CONCLUSIONS: RSV transmission risk in Canadian pediatric hospitals is generally low. Although use of barrier methods varies, all sites cohort or isolate RSV-positive patients in single rooms. Children with risk factors for severe disease who acquire infection nosocomially have prolonged stays and excess mortality. 相似文献
7.
Meißner Lisa Schürmann Peter Dörk Thilo Hagemeier Lars Klintschar Michael 《International journal of legal medicine》2021,135(1):143-151
International Journal of Legal Medicine - Pulmonary embolism (PE) is a complex multi-factorial disease and represents one manifestation of venous thromboembolism (VTE). Most commonly PE constitutes... 相似文献
8.
David Stewart Peter Panus Nicholas Hagemeier Jim Thigpen Lauren Brooks 《American journal of pharmaceutical education》2014,78(2)
Objectives. To determine if student self-testing improves performance during a doctor of pharmacy course.Methods. Students were given access to online quizzes with a large pool of randomly selected questions specific to upcoming examination content. Quizzes were electronically scored immediately upon completion and students were provided corrective feedback.Results. Examination scores following implementation of the practice quizzes were significantly higher in all but the last testing period. The upper fiftieth percentile of students scored higher on both the practice quizzes and subsequent examinations in all but the fourth testing period.Conclusions. Providing pharmacy students with self-testing opportunities could increase their retention of course material and provide feedback to both students and educators regarding learning, as well as provide students with a measure of their metacognition. 相似文献
9.
Carsten V. Dalchow K. C. Hagemeier A. Muenscher R. Knecht F. Kameier 《European archives of oto-rhino-laryngology》2013,270(2):505-510
Drilling during temporal bone surgery may result in temporary or permanent noise-induced hearing loss or tinnitus. This has practical implications for both the patient and the surgeon. Different surgical drill devices, routinely used in temporal bone surgery, are examined referring to their emitted sound levels and sound transport. Two surgical drills were used on a brass tubing and a steel wire to simulate sound generation during temporal bone surgery. Overview measurements were performed on human cadaver in a medical laboratory. A set-up in a silent chamber was chosen to exclude external sound sources. The noise emissions and the vibration generated by a silver diamond bur and a cutting drill (Rose bur) were registered when used on a brass tubing and a solid steel wire with sound level meter and a non-contact laser vibrometer. The highest sound rate generated by the diamond burr did not exceed 63 dB(A) when used on a solid steel wire, whereas the cutting burr emitted 76 dB(A). Both drills produced lower sound levels on the brass tubing. Again the cutting burr topped the diamond burr with 68 dB(A) against 56 dB(A). The sound emission did not exceed 76 dB(A) outside a radius 4 cm around the drill location. In conclusion, sound emission generated by different surgical burs routinely used in temporal bone surgery is lower than expected. Still, within a small radius around those burs high sound pressure levels may be induced into surrounding structures such as ossicles, labyrinth, and cochlear. Still damage is feasible when using surgical drills for a longer time period close to sensitive structures. 相似文献
10.
HABIB BOUKERCHE MARIE-HéLèNE RUCHAUD-SPARAGANO CHRISTINE R OUEN JEAN BROCH IER CéCILE KAPLAN & JOHN LOUIS MCGREGOR 《British journal of haematology》1996,92(2):442-451
P-selectin (also called CD62, GMP-140, PADGEM, CD62P) is a recently described member of a family of vascular adhesion receptors expressed by activated platelets and endothelial cells that are involved in leucocyte cell adhesion. The aim of this study was to characterize a new monoclonal antibody (LYP7) directed against activated human blood platelets that inhibits ristocetin-induced platelet aggregation. Immunoadsorbent affinity chromatography and immunoprecipitation studies showed that LYP7 (IgG1) bound a surface-labelled glycoprotein (GP) which changed its apparent molecular mass (Mr) on reduction from 138 kD (situated below GPIIb) to 148 kD (above GPIIbα). LYP7 and S12, a monoclonal antibody directed against P-selectin immunoprecipitated the same band. Using ELISA assay, purified P-selectin was shown to bind LYP7 and S12 monoclonal antibodies. Binding sites of 125I-labelled LYP7, which was greatly increased on thrombin-stimulated (2 U/ml) washed platelets (10825±2886, mean ±SD) (Kd=1.5±0.5 nm ) compared to resting platelets (2801±1278, mean ±SD) (Kd=1.5±0.6 nm ), was found to be normal on thrombin-stimulated platelets taken from a patient with grey platelet syndrome or a patient with Glanzmann thrombasthenia. LYP7 (IgG1, F(ab′)2 or Fab fragments) inhibited ristocetin-induced platelet aggregation of platelets in a dose-dependent fashion without affecting the binding of von Willebrand (vWf ) factor. However, agglutination of formaldehyde-fixed platelets induced by ristocetin was not affected by monoclonal antibody LYP7. In addition, the binding of thrombin-activated platelets to neutrophils was inhibited by monoclonal antibody LYP7. These results strongly suggest that P-selectin, by promoting cell–cell contact, may play an active role in platelet–platelet interactions. 相似文献