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111.
QUADAS的制定:用于系统评价中评价诊断性研究质量的工具 总被引:5,自引:0,他引:5
背景在以系统评价为基石的循证医学时代,需要有恰当的质量评价工具。对诊断性研究的评价目前尚缺乏系统开发且经过验证的评价工具。本研究的目的是采用共识决策法整合经验证据和专家意见,制定在系统评价时用于评价原始诊断性研究质量的工具。方法按照循证原则,我们在之前发表的3篇诊断性研究文献的综述的基础上,初选出一些条目形成列表,然后通过Delphi流程逐步调整列表,形成质量评价工具。参与Delphi流程的都是诊断性研究领域的专家。结果共有9位诊断学领域的专家参与Delphi流程。经过4轮Delphi流程后,专家们对哪些条目应纳入评价工具达成共识,我们把这个评价工具命名为QUADAS。纳入条目从最初的28个减少到14个,涵盖了疾病谱、金标准、疾病进展偏倚(disease progression bias)、证实偏倚(verification bias)、评价偏倚、临床评价偏倚、合并偏倚、试验的实施、病例退出以及不确定结果。QUADAS工具中的每个条目都配有评分细则。结论本研究项目开发出了用于诊断性试验系统评价的循证质量评价工具。下一步工作是确定其适用性和有效性。 相似文献
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Antibody responses to cytomegalovirus (CMV) after red cell (RBC) transfusion were studied in 84 seropositive surgery patients and 82 seropositive oncology patients. The surgery patients were randomized to receive RBCs stored either 3 to 8 or 20 to 42 days after donation. Of 38 patients receiving RBCs stored 8 days or less, 3 developed a rise in titer (4-fold increase) of IgG antibody to CMV 8 to 12 weeks after transfusion. This rate of response (8%) did not differ significantly (p = 0.23) from that (16%) in the 46 patients receiving RBCs stored 20 to 42 days. Seropositive oncology patients were randomized to receive RBCs from seronegative or random donors. Five (19%) of 27 oncology patients receiving seronegative RBCs and 13 (23%) of 55 patients receiving random RBCs (mean, 2 seropositive RBC units/patient) developed a rise in titer of antibody to CMV. No CMV morbidity occurred in either patient group. For both patient groups, a rise in titer of antibody to CMV was associated with the number of transfused RBC units. These results confirm that CMV-seronegative RBCs are unnecessary for infrequently transfused seropositive patients. They also suggest that multiple transfusions of stored RBCs are as immunosuppressive as multiple transfusions of RBCs used within a few days after donation. 相似文献
113.
Purinergic receptors on insulin-secreting cells 总被引:5,自引:0,他引:5
D. Hillaire-Buys J. Chapal G. Bertrand P. Petit and MM Loubatières-Mariani 《Fundamental & clinical pharmacology》1994,8(2):117-127
Summary— The insulin secreting B cell is fitted with the two types of purinergic receptors: P2 (for ATP and/or ADP) and P1 (for adenosine). The activation of P2 purinoceptors by ATP or ADP evokes a biphasic stimulation of insulin secretion from isolated perfused rat pancreas; this stimulation is dose-dependent between 10?6 and 10?4 M. Non hydrolysable structural analogues are also effective, and the relative potency of various agonists (2-methylthio ATP ? ATP = ADP = α, β-methylene ATP ? AMP) gave evidence for a P2y purinoceptor subtype. Proposed mechanisms include both an increased Ca2+ uptake and an increased intracellular Ca2+ mobilization via the hydrolysis of polyphosphoinositides. ATP (or ADP) potentiates physiological insulin-secreting agents (glucose and acetylcholine) and P2 purinoceptors could play a physiological role in the stimulation of insulin secretion. The activation of P1 purinoceptors (adenosine receptors) decreases insulin secretion. Using structural analogues of adenosine, the receptor was characterized as an A1 subtype; it is coupled to a pertussis toxin sensitive G protein and it inhibits adenylate cyclase. It is of physiological relevance that the B cell has the two types of purinoceptors with opposite effects. Recently, a metabolically stable structural analogue of ADP, adenosine-5′-0-(2-thiodiphosphate) or ADPßS, has been described as a potent secretory agent, effective at nanomolar concentrations on isolated perfused rat pancreas. In vivo, this substance is able to increase insulin secretion and to improve glucose tolerance after IV administration in rats and oral administration in dogs. Furthermore in streptozotocin-induced diabetes, ADPßS retains its insulin secreting effects. These results suggest that P2y purinoceptors could be a new target for antidiabetic drugs. 相似文献
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MM El-Omar BSc MRCP K Ray MRCP R Geary MB ChB 《International journal of clinical practice》1996,50(2):115-116
SUMMARY We present the case of a young female who suffered a massive intracerebral bleed following the ingestion of a small quantity of amphetamine (speed). Physicians should be aware that amphetamine abuse can lead to cerebrovascular events in young adults. 相似文献
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V Ambade MM Arora P Singh B L Somani D Basannar 《Medical Journal Armed Forces India》2009,65(3):216-220