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41.
A central paradigm of immunology is clonal selection: lymphocytes displaying clonally distributed antigen receptors are generated and subsequently selected by antigen for growth or elimination. Here we show that in mice transgenic for anti-H-2Kk,b antibody genes, in which a homogeneous clone of developing B cells can be analyzed for the outcome of autoantigen encounter, surface immunoglobulin M+/idiotype+ immature B cells binding to self-antigens in the bone marrow are induced to alter the specificity of their antigen receptors. Transgenic bone marrow B cells encountering membrane-bound Kb or Kk proteins modify their receptors by expressing the V(D)J recombinase activator genes and assembling endogenously encoded immunoglobulin light chain variable genes. This (auto)antigen-directed change in the specificity of newly generated lymphocytes is termed receptor editing. 相似文献
42.
KW Sax SM Strakowski PE Keck SL McElroy SA West SP Stanton 《Canadian Metallurgical Quarterly》1998,44(8):784-786
BACKGROUND: This study examined patients with a first-episode of affective psychosis during acute and compensated states in order to determine whether changes in attentional functioning over time were accompanied by changes in the severity of psychotic or affective symptoms. METHODS: Attentional performance was measured in patients (n = 27) using the degraded-stimulus continuous Performance Test (CPT) and symptoms were assessed at the time of index hospitalization, and 2 months after discharge. A comparison group of normal volunteers (n = 31) also performed the CPT two months apart. RESULTS: Patients performed significantly worse than controls at the initial testing but not at follow-up. The improvement in attentional performance significantly correlated with decreased severity of manic symptoms. CONCLUSIONS: Results suggest attentional dysfunction is a state-dependent characteristic of mania, and may provide an additional measure of clinical improvement following treatment. 相似文献
43.
Crack growth and residual strength tests have been conducted on both Glare 3 and Glare 4 material. Results have been compared with those for 2024-T3 monolithic aluminium alloy showing improvements in fatigue life of up to 100 times and improvements in residual strengths of up to 40%. The potential weight savings and general structural performance improvements of the Glare material make it most attractive for future aerospace vehicle design, despite its current higher manufacturing costs. 相似文献
44.
This study demonstrates that the use of high field 1H NMR spectroscopy permits individual detection of phosphatidylcholine and sphingomyelin molecules at the surface of native low density lipoprotein (LDL) particles. Distinct behaviour was observed for the choline head group -N(CH3)3 resonances of these different phospholipids revealing preferential immobilisation for phosphatidylcholine. This suggests the existence of reversible and irreversible phosphatidylcholine-apolipoprotein B interactions and is consistent with microdomain formation at the surface monolayer of LDL. The novel resonance assignment and results show that 1H NMR can provide efficient and practical means for future studies on the structure and dynamics at the LDL surface. 相似文献
45.
Integrating principles from a variety of theory has led to the development of a conceptual framework for reengineering in a clinical care delivery setting to improve the value of services provided to the customer. A conceptual framework involving the identification of three high level core processes to reengineer can provide clarity and focus for clinicians to begin directing reengineering efforts. Those core processes are: clinical management of the patient's medical needs, patient operational processes to support the clinical processes, and administrative decision-making processes to support the implementation of the clinical and operational processes. Improvement in any one of these areas has the potential to increase value, but the concurrent targeting of these core processes for reengineering has provided a synergy that has accelerated the achievement of the desired outcomes in the area of surgical services. 相似文献
46.
47.
Identification of a gene that causes primary open angle glaucoma 总被引:3,自引:0,他引:3
EM Stone JH Fingert WL Alward TD Nguyen JR Polansky SL Sunden D Nishimura AF Clark A Nystuen BE Nichols DA Mackey R Ritch JW Kalenak ER Craven VC Sheffield 《Canadian Metallurgical Quarterly》1997,275(5300):668-670
Glaucoma is a major cause of blindness and is characterized by progressive degeneration of the optic nerve and is usually associated with elevated intraocular pressure. Analyses of sequence tagged site (STS) content and haplotype sharing between families affected with chromosome 1q-linked open angle glaucoma (GLC1A) were used to prioritize candidate genes for mutation screening. A gene encoding a trabecular meshwork protein (TIGR) mapped to the narrowest disease interval by STS content and radiation hybrid mapping. Thirteen glaucoma patients were found to have one of three mutations in this gene (3.9 percent of the population studied). One of these mutations was also found in a control individual (0.2 percent). Identification of these mutations will aid in early diagnosis, which is essential for optimal application of existing therapies. 相似文献
48.
Advances in genetic engineering and expression systems have led to a rapid progress in the development of immunoglobulins fused to other proteins. These 'antibody fusion proteins' have novel properties and include antibodies fused to the cytokine interleukin-2. In the present review we describe strategies for construction of these antibody-interleukin-2 fusion proteins and discuss their in vitro and in vivo properties. Antibody-interleukin-2 fusion proteins retain both antibody associated functions such as antigen binding, complement activation and Fc gamma receptor binding as well as interleukin-2 associated functions such as the stimulation of proliferation of CTLL2 cells. In vivo, they produce strong potentiation of the host immune response against any associated antigen. In addition, these novel molecules are able to target tumor cells and produce a specific and effective T cell response capable of eliminating the tumor. These properties suggest that antibody-interleukin-2 fusion proteins will be useful in the diagnosis and/or treatment of human cancer as well as in the potentiation of human response against any associated antigen. 相似文献
49.
SL Kamholz RJ Brewer G Grijalva J Burack MJ Del Rio M Vaynblatt N Lawson S Squinto WL Fodor AJ Norin 《Canadian Metallurgical Quarterly》1997,21(9):951-955
The lack of sufficient suitable human donor lungs for the many patients requiring pulmonary transplantation as life-saving therapy for end-stage lung diseases has generated extensive interest in cross-species lung transplantation. Ethical concerns and those of animal rights advocates have prompted studies of nonprimate species as potential solid organ donors for humans. This paper provides an overview of some of the laboratory studies of cross-species pulmonary transplantation performed over the past 20 years and focuses, in particular, on more recent work (from our laboratory and others) in the area of porcine-to-primate pulmonary xenotransplantation. 相似文献
50.
RB Petersen H Goren M Cohen SL Richardson N Tresser A Lynn M Gali M Estes P Gambetti 《Canadian Metallurgical Quarterly》1997,41(3):307-313
NaCl-tolerant lactic acid bacteria (LAB) strains LC-10 (Lactobacillus casei) and LP-15 (Lact. plantarum) and NaCl were used as additives to sorghun (Sorghum bicolor). Numbers of LAB were significantly (P < 0.05) higher in all the additive-treated silages than in the control silage at an early stage of ensiling. During the fermentation process, addition of NaCl or LAB effectively inhibited the growth of aerobic bacteria and clostridia, but not yeasts. All the additive-treated silages had significantly (P < 0.05) lower pH, ammonia nitrogen content, dry matter loss and gas production but significantly (P < 0.05) higher lactic acid content and residual water soluble carbohydrates compared with the control silage. The improvement in silage quality was in the order: LAB > NaCl > control. Yeast counts were high in all additive-based silages and they increased during the exposure of the silages to air. As a result, these silages suffered aerobic deterioration, whereas the control silage was stable. The results confirmed that the NaCl or LAB improved fermentation quality but did not prevent aerobic deterioration of the silage. 相似文献