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排序方式: 共有143条查询结果,搜索用时 15 毫秒
41.
Radiation dosimetry for electron beam CT 总被引:3,自引:0,他引:3
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The West Midlands Regional Health Authority Department of Nursing funded a 1-year study to look at 'Implementation aspects of the lecturer-practitioner role (in nursing)'. A feasibility study was carried out from November 1992 to October 1993 to address the issue and highlight areas requiring more in-depth study. Twenty-nine subjects working as or with lecturer-practitioners were interviewed using a semi-structured questionnaire. The interview was divided into two discrete parts. The first section contained a mixture of open and closed questions and the second section adopted a modified repertory grid technique. This paper provides the main results from the first half of the interview. The study describes in practical terms how managers need to plan for the introduction of a lecturer-practitioner post; the key responsibilities of the role; and a person specification. The work identifies clear prerequisite criteria for job role and gives guidance on lecturer-practitioner management and function. 相似文献
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The level of Hb C in the erythrocytes of individuals with Hb C trait decreases significantly in the presence of coexisting alpha- thalassemia. This relationship may result from the higher affinity of beta A than beta C for limiting amounts of alpha-globin during hemoglobin assembly. This mechanism would predict that the beta A and beta C synthetic capacity in alpha-thalassemic individuals with Hb C trait should be balanced despite the low levels of Hb C in their circulating erythrocytes. To directly test this prediction, we have measured the beta A and beta C synthetic capacity of reticulocyte RNA isolated from two individuals with Hb C trait, one with a normal alpha- globin genotype and one with alpha-thalassemia. The balanced expression of beta A and beta C in both cases supports the proposed posttranslational control over Hb C expression. 相似文献
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A prospective study of NAT2 acetylation genotype, cigarette smoking, and risk of breast cancer 总被引:4,自引:1,他引:3
Hunter DJ; Hankinson SE; Hough H; Gertig DM; Garcia-Closas M; Spiegelman D; Manson JE; Colditz GA; Willett WC; Speizer FE; Kelsey K 《Carcinogenesis》1997,18(11):2127-2132
Polymorphisms in the N-acetyltransferase 2 (NAT2) gene are determinants of
the rate of metabolic activation of carcinogenic compounds such as aryl
aromatic amines. Homozygosity for any combination of three variant alleles
in Caucasians defines 'slow' acetylators; presence of one or two wild-type
alleles characterizes 'rapid' acetylators. Although most previous studies
have not observed an overall elevation in risk of breast cancer among slow
acetylators, a recent study observed that cigarette smoking was associated
with a large increase in risk of breast cancer among slow acetylators. We
assessed the relation between NAT2 acetylation status and breast cancer
risk, and its interaction with smoking, in a prospective study of mainly
Caucasian US women. Four hundred and sixty-six incident cases who were
diagnosed with breast cancer after giving a blood specimen in 1989-90 were
matched to 466 controls in a nested case-control study. NAT2 genotype was
determined using PCR-RFLP assays. The multivariate relative risk (RR)
comparing slow with rapid acetylators was 0.9 (95% CI 0.7-1.2). Among slow
acetylators, current smoking immediately prior to diagnosis was not
associated with a significant elevation in risk compared with never smoking
rapid acetylators (RR = 1.4, 95% CI 0.7-2.6). No significant association
was seen between pack-years of smoking and risk of breast cancer among
either slow or fast acetylators. A non-significant elevation in risk was
observed among women who smoked for > or = 5 years prior to first
pregnancy and were rapid acetylators, compared with never smoking rapid
acetylators (RR = 1.5, 95% CI 0.9-2.6). In analyses limited to 706
post-menopausal women, the elevated risks for current smokers immediately
prior to diagnosis who were slow acetylators compared with never smokers
who were fast acetylators were slightly stronger but still not
statistically significant. In summary, we observed little evidence of an
association between NAT2 genotype and breast cancer. In this prospective
study, cigarette smoking was not appreciably associated with breast cancer
among either slow or fast NAT2 acetylators.
相似文献
48.
Suzanne Elizabeth Reed RGN DipNptA FE Teacher''s Cert. RCNT Cert.Ed RNT BEd MSc 《Journal of advanced nursing》1988,13(3):383-395
The study compares team and primary nursing modes of organization of nursing care on three related variables, namely: nurse-related behaviour and quality of care, philosophy of care and job satisfaction for nurses. The historical dimension and evolution of modes of care, quality of care, philosophy of care and theories of job satisfaction are discussed within the context of the study. The literature and previous research studies conducted on team and primary nursing are reviewed and comparisons of the two are made. Analysis of data collected yielded results which are compared for differences and benefits between team and primary nursing. The results of the study suggest that when compared to team nursing mode of organization of care, primary nursing affords increased quality of care, a more coherent philosophy of nursing and increased job satisfaction for nurses. Methodological problems are examined and implications for policy explored. 相似文献
49.
A pilot randomized trial comparing symptomatic vs. hemoglobin-level- driven red blood cell transfusions following hip fracture 总被引:5,自引:1,他引:5
JL Carson ; ML Terrin ; FB Barton ; R Aaron ; AG Greenburg ; DA Heck ; J Magaziner ; FE Merlino ; G Bunce ; B McClelland ; A Duff ; H Noveck 《Transfusion》1998,38(6):522-529
BACKGROUND: The indications for transfusion have never been evaluated in an adequately sized clinical trial. A pilot study was conducted to plan larger clinical trials. STUDY DESIGN AND METHODS: Hip fracture patients undergoing surgical repair who had postoperative hemoglobin levels less than 10 g per dL were randomly assigned to receive 1) symptomatic transfusion: that is, transfusion for symptoms of anemia or for a hemoglobin level that dropped below 8 g per dL or 2) threshold transfusion: that is, patients receive 1 unit of packed RBCs at the time of random assignment and as much blood as necessary to keep the hemoglobin level above 10 g per dL. Outcomes were 60-day mortality, morbidity, functional status, and place of residence. RESULTS: Among 84 eligible patients enrolled, mean (± SD) prerandomization hemoglobin was 9.1 (± 0.6) g/ dL. The median number of units transfused in the threshold transfusion group was 2 (interquartile range, = 1–2), and that in the symptomatic transfusion group was 0 (6; interquartile range, = 0–2) (p < 0.001). Mean hemoglobin levels were approximately 1 g per dL higher in the threshold group than in the symptomatic group: for example, on Day 2, 10.3 (± 0.9) g per dL versus 9.3 (± 1.2) g per dL, respectively (p < 0.001). At 60 days, death or inability to walk across the room without assistance occurred in 16 (39.0%) of the symptomatic transfusion group and 19 (45.2%) of the threshold transfusion group. Death occurred by 60 days in 5 (11.9%) of the symptomatic transfusion group and 2 (4.8%) in the threshold transfusion group (relative risk = 2.5; 95% CI, 0.5–12.2). Other outcomes were similar for the two groups. CONCLUSIONS: Symptomatic transfusion may be an effective blood-sparing protocol associated with the transfusion of appreciably fewer units of RBCs and lower mean hemoglobin levels than are associated with the threshold transfusion policy. However, it is unknown whether these two clinical strategies have comparable mortality, morbidity, or functional status. A definitive trial is needed. 相似文献
50.
Understanding deregulated cellular and molecular dynamics in the haematopoietic stem cell niche to develop novel therapeutics for bone marrow fibrosis 下载免费PDF全文
Bone marrow fibrosis is the continuous replacement of blood‐forming cells in the bone marrow with excessive scar tissue, leading to failure of the body to produce blood cells and ultimately to death. Myofibroblasts are fibrosis‐driving cells and are well characterized in solid organ fibrosis, but their role and cellular origin in bone marrow fibrosis have remained obscure. Recent work has demonstrated that Gli1+ and leptin receptor+ mesenchymal stromal cells are progenitors of fibrosis‐causing myofibroblasts in the bone marrow. Genetic ablation or pharmacological inhibition of Gli1+ mesenchymal stromal cells ameliorated fibrosis in mouse models of myelofibrosis. Conditional deletion of the platelet‐derived growth factor (PDGF) receptor‐α (PDGFRA) gene (Pdgfra) and inhibition of PDGFRA by imatinib in leptin receptor+ stromal cells suppressed their expansion and ameliorated bone marrow fibrosis. Understanding the cellular and molecular mechanisms in the haematopoietic stem cell niche that govern the mesenchymal stromal cell‐to‐myofibroblast transition and myofibroblast expansion will be critical to understand the pathogenesis of bone marrow fibrosis in both malignant and non‐malignant conditions, and will guide the development of novel therapeutics. In this review, we summarize recent discoveries of mesenchymal stromal cells as part of the haematopoietic niche and as myofibroblast precursors, and discuss potential therapeutic strategies in the specific targeting of fibrotic transformation in bone marrow fibrosis. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. 相似文献