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应用分子生物学方法确定同期性多灶性肺癌的克隆来源 ,为肺癌的分期提供依据。方法 :对 2例肺部同期多灶性肺癌患者的每个病灶都用石蜡切片做显微解剖及蛋白酶K消化 ,提取基因组DNA ,先后两次PCR扩增K -ras第 1外显子和 p5 3外显子 5~ 9,用微型凝胶做非同位素性SSCP电泳 ,银染色后观察。对有变异电泳图型的样本用DNA序列测定去证实点突变。结果 :例 1的两个肺癌结节 ,仅 1个表现K -ras第 1外显子 12密码子突变 (GGT→TGT) ;例 2的 3个肺癌结节 ,1个表现K -ras第 1外显子 12密码子突变 (GGT→TGT) ,另 1个表现 p5 3第 5外显子 48密码子突变 (GTG→TTG) ,第 3个无突变发现。结论 :此 2例的多灶性肺癌均为不同的克隆来源。因此 ,提出应用非同位素PCR -SSCP分析 ,检测K -ras和p5 3点突变是鉴别多发性肺癌克隆起源的有效方法。  相似文献   
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1. Thirteen strains of hemolytic streptococci isolated from patients with acute rheumatic fever did not show any evidence of being related serologically. 2. Strains of hemolytic streptococci exist which, although identical by the agglutination test, do not show complete reciprocal agglutinin absorption. Sera prepared from such related strains may show some protective power in mice against another member of the group. 3. Some strains of hemolytic streptococci may absorb agglutinins from a serum prepared against another strain, and yet may fail to be agglutinated by that serum. 4. None of 20 strains of hemolytic streptococci isolated in New York City in 1924, and 1925, corresponded serologically with Dochez, Avery, and Lancefield''s 4 type strains or with Gordon''s Type I strain.  相似文献   
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The retrograde aortic (RA) route is a widely used access route for mapping and ablation of ventricular tachycardias (VT) arising from the left ventricular endocardium. With the expanding role of VT ablation in patients with significant comorbidity, the choice between the RA and transseptal access routes is an increasingly important consideration. An individualized decision based on the location of the arrhythmogenic substrate, vascular anatomy, aortic valve morphology, and operator experience is necessary when deciding on the optimal access route. Among patients with challenging vascular anatomy, growing experience from structural interventions such as transcatheter aortic valve replacements and peripheral vascular interventions has provided valuable insights into techniques for safe retrograde access. The present review focuses on patient selection for RA access, potential complications associated with the technique, and optimal approaches for access in patients with challenging vascular or aortic valve anatomy.  相似文献   
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OBJECTIVE: To describe a new model of the adaptation process following acquired brain injury, based on the patient's goals, the patient's abilities and the emotional response to the changes and the possible discrepancy between goals and achievements. BACKGROUND: The process of adaptation after acquired brain injury is characterized by a continuous interaction of two processes: achieving maximal restoration of function and adjusting to the alterations and losses that occur in the various domains of functioning. Consequently, adaptation requires a balanced mix of restoration-oriented coping and loss-oriented coping. The commonly used framework to explain adaptation and coping, 'The Theory of Stress and Coping' of Lazarus and Folkman, does not capture this interactive duality. RELEVANT THEORIES: This model additionally considers theories concerned with self-regulation of behaviour, self-awareness and self-efficacy, and with the setting and achievement of goals. THE TWO-DIMENSIONAL MODEL: Our model proposes the simultaneous and continuous interaction of two pathways; goal pursuit (short term and long term) or revision as a result of success and failure in reducing distance between current state and expected future state and an affective response that is generated by the experienced goal-performance discrepancies. This affective response, in turn, influences the goals set. This two-dimensional representation covers the processes mentioned above: restoration of function and consideration of long-term limitations. We propose that adaptation centres on readjustment of long-term goals to new achievable but desired and important goals, and that this adjustment underlies re-establishing emotional stability. We discuss how the proposed model is related to actual rehabilitation practice.  相似文献   
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Research exploring how scanning affects judgments of spatial extent has produced conflicting results. We conducted four experiments on line bisection judgments measuring ocular and pointing behavior, with line length, position, speed, acceleration, and direction of scanning manipulated. Ocular and pointing judgments produced distinct patterns. For static judgments (i.e., no scanning), the eyes were sensitive to position and line length with pointing much less sensitive to these factors. For dynamic judgments (i.e., scanning the line), bisection biases were influenced by the speed of scanning but not acceleration, while both ocular and pointing results varied with scan direction. We suggest that static and dynamic probes of spatial judgments are different. Furthermore, the substantial differences seen between static and dynamic bisection suggest the two invoke different neural processes for computing spatial extent for ocular and pointing judgments.  相似文献   
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