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51.
Multiple signal transduction cascades, consisting of multiple interacting proteins, are activated following stimulation through most cell surface receptors, including the immunoglobulin receptor of B lymphocytes. In this report, we investigated the multimolecular complexes formed following anti-Ig stimulation of a human B-lymphoma cell line, resulting in activation of phosphatidylinositol 3-kinase (PI3K). PI3K is a lipid kinase that consists of an 85-kD regulatory subunit, bound to a 110-kD catalytic subunit. CD19 is a 95-kD B-cell surface marker that contains a consensus binding motif for PI3Kp85 in the cytoplasmic domain and recruits PI3K activity in activated B cells. The protein product of the c-cbl protooncogene is a 120-kD protein that is expressed in early B-lineage cells and in myeloid cells and is phosphorylated on tyrosine following receptor-mediated signaling in T and B lymphocytes. We demonstrate here that phosphorylated c-cbl complexes with CD19 and with PI3Kp85 via its C-terminal SH2 domain, and that both c-cbl and CD19 are associated with active PI3K in anti-Ig- stimulated cells. Although we cannot differentiate between a three- component, c-cbl/CD19/p85 complex and individual two-component complexes, these studies suggest that c-cbl may function as a docking protein, possibly linking distinct signal transduction pathways. 相似文献
52.
Protein-tyrosine kinase p72syk in Fc gamma RI receptor signaling 总被引:2,自引:1,他引:2
In this report we show that gamma-interferon (IFN) induces the expression of the nonreceptor protein tyrosine kinase, p72syk, and that cross-linking the Fc gamma RI receptor in IFN-differentiated U937 cells (U937IF cells) results in the activation of syk kinase. We show that syk is tyrosine phosphorylated (12-fold increase) after Fc gamma RI cross-linking. In vitro kinase assays demonstrate that the specific kinase activity of syk increased eightfold after Fc gamma RI cross- linking. The activation of signal transduction through the Fc gamma RI receptor, as measured by the respiratory burst, is associated with the tyrosine phosphorylation and catalytic activation of the syk kinase. We show that syk coprecipitates with the gamma subunit of the Fc gamma RI, Fc gamma RI gamma. The data suggest that p72syk is involved in signal transduction through the Fc gamma RI receptor, involving the Fc gamma RI gamma subunit. 相似文献
53.
Maternal administration of granulocyte colony-stimulating factor improves neonatal rat survival after a lethal group B streptococcal infection 总被引:2,自引:0,他引:2
Novales JS; Salva AM; Modanlou HD; Kaplan DL; del Castillo J; Andersen J; Medlock ES 《Blood》1993,81(4):923-927
Maternally administered recombinant human granulocyte colony- stimulating factor (rhG-CSF) has been shown to cross the placenta and induce a peripheral neutrophilia and increases in the marrow and spleen neutrophil storage pools in fetal and newborn rats. In the present study, we have used this model system to investigate the efficacy of prenatally administered rhG-CSF on neonatal defense to a lethal challenge with Group B-beta hemolytic Streptococcus (GBS). Pregnant rats were injected with rhG-CSF twice daily beginning 6 days before parturition. At birth, all pups were infected with a dose of GBS that is lethal for 90% of infected pups (LD90). Survival was monitored daily for 5 days. Survival of infected pups from saline-treated mothers beyond 60 hours after infection was 10%. No difference in survival was observed among pups from mothers treated 2 and 4 days before parturition. In contrast, we determined that survival was 82.5% among infected pups from mothers treated for 6 days before parturition with rhG-CSF. Our results demonstrate that maternal administration of rhG- CSF augments neonatal defenses against a lethal bacterial challenge. 相似文献
54.
Persistence of the underlying malignancy remains the major obstacle limiting the success of high-dose chemoradiotherapy with allogeneic bone marrow transplantation (BMT) for lymphomas and multiple myeloma. We used the C3H 38C13 murine B-cell lymphoma, which expresses and secretes clonally derived Ig, the idiotype of which can serve as a tumor-specific antigen, to test the principle of transfer of tumor idiotype-specific immunity with BM. BALB/c marrow donors were twice immunized with 38C13-derived Ig, or with an isotype-matched control Ig, conjugated to keyhole limpet hemocyanin. Lethally irradiated C3H recipients reconstituted with marrow from idiotype immune, but not nonspecifically immune, donors demonstrated protection against subsequent lethal tumor challenge. The immunoprotective effect of immune allogeneic marrow was abrogated by T-cell depletion of the marrow graft before infusion. Low levels of serum anti-idiotypic antibody remained unaltered in recipients of T-cell-depleted immune marrow, consistent with a primary role for T-cell immunity in the cellular mechanism of this phenomenon. A modest therapeutic effect of immune allogeneic marrow was observed against 10 day, 1 cm established subcutaneous tumors, but only in combination with a booster immunization of the recipient post-BMT. These results provide the rationale for a novel strategy for enhancing the specific antitumor effect of allogeneic marrow grafts. 相似文献
55.
Choe R Durduran T Yu G Nijland MJ Chance B Yodh AG Ramanujam N 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(22):12950-12954
The feasibility of transabdominal near-infrared (NIR) spectroscopy for detecting and quantifying fetal hypoxia in utero is demonstrated in a pregnant ewe model. A frequency domain NIR spectroscopy probe, consisting of two detectors and six sources operating at three wavelengths (675, 786, and 830 nm), was placed on the maternal abdomen directly above the fetal head. Fetal hypoxia was indirectly induced through occlusion of uterine blood flow for approximately 3 min. NIR photon diffusion measurements were made during a baseline period, during hypoxia of the fetus, and during recovery. Fetal blood samples were drawn from the fetal brachial artery and jugular veins at several time points during the cycle. Seven hypoxic cycles were induced in a total of five pregnant ewes. The NIR measurements were analyzed by using a two-layer diffusion model to deconvolve the fetal blood saturation from that of the pregnant ewe. Fetal hypoxia was detected. Good agreement was found between fetal blood saturation determined by the transabdominal NIR method and arterial and venous fetal blood saturation quantified from fetal blood samples by using a hemoximeter. 相似文献
56.
Two patients with hairy cell leukemia with massive splenomegaly and severe pancytopenia were treated with recombinant alpha-A interferon (IFN-alpha-2a). There was no significant response to a trial of IFN- alpha-2a (11 and 20 weeks) with respect to blood counts or spleen size. Subsequent treatment with 2'-deoxycoformycin (dCF) for 8 consecutive weeks (4 mg/m2/wk) resulted in normalization of spleen size and a normalization of peripheral blood counts and bone marrow in one patient. The second patient demonstrated a reduction in spleen size and improved blood counts following 9 weeks of dCF therapy but eventually became refractory. This demonstrates that dCF is non-cross-resistant with interferon and confirms the efficacy of dCF in nonsplenectomized patients. 相似文献
57.
58.
雄激素对骨骼肌合成有明显影响,随着年龄增大,雄激素的下降常伴随肌量和肌力的下降。这种肌量和肌功能的下降,被称为少肌症或肌体老化,是老年人体质弱化(男性化减退)进展的关键事项。也是导致快速机能衰退及其不良后果的关键。雄激素水平下降对老年男性体质弱化(男性化减退)的潜在影响和对躯体功能的促进治疗作用无疑已经引起了相当的关注。本综述概述了近期关于肌肉老化、少肌症、老年体质弱化的概念、定义,并评估了关于雄激素和老年体质弱化的研究进展。近期源于观测性和介入性研究的证据强烈支持雄激素对老年男性肌量的作用,但雄激素对肌力和特有的躯体功能的效用并不明确。研究显示,雄激素治疗在老年男性中通常有良好的耐受性,而近期的研究则关注于雄激素的高剂量治疗和对于心血管风险较高人群的治疗。雄激素受体调节剂(SARMs)的初期试验研究显示传统雄激素治疗对于老年患者在肌量和肌功能方面有相同的效用。将来的重要研究方向包括利用这类雄激素治疗并结合适用于不同老年患者群体促进躯体功能的运动训练,同时将更多地关注近期关于激素水平、身体成分及躯体功能间关系的观测性(回顾性)研究。 相似文献
59.
Arthur F. Chance 《British Journal of Learning Disabilities》1987,15(2):74-76
The article briefly describes the staging of a highly successful musical, Joseph and the Amazing Technicolor Dreamcoat, performed by a group of people with mental handicaps, with a professional lead and the support of local school orchestras. The show, which was repeated in several towns in the North of England, highlighted the talent and skill of the performers. It demonstrated clearly that theatre is an activity in which people with mental handicaps can participate to the full, providing them with an interesting and stimulating pastime and audiences with competent and enjoyable entertainment. 相似文献
60.
Sara FL Kirk Mary Forhan Joshua Yusuf Ashly Chance Kathleen Burke Nicole Blinn Stephanie Quirke Ximena Ramos Salas Angela Alberga Shelly Russell-Mayhew 《AIMS Public Health》2022,9(1):41
BackgroundStigmatization of persons living with obesity is an important public health issue. In 2015, Obesity Canada adopted person-first language in all internal documentation produced by the organization, and, from 2017, required all authors to use person-first language in abstract submissions to Obesity Canada hosted conferences. The impact of this intentional shift in strategic focus is not known. Therefore, the aim of this study was to conduct a content analysis of proceedings at conferences hosted by Obesity Canada to identify whether or how constructs related to weight bias and obesity stigma have changed over time.MethodsOf 1790 abstracts accepted to conferences between 2008–2019, we excluded 353 abstracts that featured animal or cellular models, leaving 1437 abstracts that were reviewed for the presence of five constructs of interest and if they changed over time: 1) use of person-first versus use of disease-first terminology, 2) incorporation of lived experience of obesity, 3) weight bias and stigma, 4) aggressive or alarmist framing and 5) obesity framed as a modifiable risk factor versus as a disease. We calculated and analyzed through linear regression: 1) the overall frequency of use of each construct over time as a proportion of the total number of abstracts reviewed, and 2) the ratio of abstracts where the construct appeared at least once based on the total number of abstracts.ResultsWe found a significant positive correlation between use of person-first language in abstracts and time (R2 = 0.51, p < 0.01 for frequency, R2 = 0.65, p < 0.05 for ratio) and a corresponding negative correlation for the use of disease-first terminology (R2 = 0.48, p = 0.01 for frequency, R2 = 0.75, p < 0.001 for ratio). There was a significant positive correlation between mentions of weight bias and time (R2 = 0.53 and 0.57, p < 0.01 for frequency and ratio respectively).ConclusionUse of person-first language and attention to weight bias increased, while disease-first terminology decreased in accepted abstracts over the past 11 years since Obesity Canada began hosting conferences and particularly since more explicit actions for expectations to use person-first language were put in place in 2015 and 2017. 相似文献