Initiation of the extrinsic pathway of coagulation by human and rabbit alveolar macrophages: a kinetic study

We examined assembly and expression of the factor X activating complex on human and rabbit alveolar macrophages. Kinetic parameters of the factor X activating reaction were determined by functional titrations of factors VII and X with macrophage tissue factor (TF) added. We found rapid activation of factor X to Xa on alveolar macrophage surfaces. Detection of rapid factor Xa formation on macrophages required addition of exogenous factors VII and X. At plasma concentrations of the purified factors, factor Xa was formed on freshly isolated macrophages at approximately 5.4 pmol/min/10(6) cells. After macrophage maturation in culture for 20 hours with LPS (endotoxin) added, the factor X activation rate was increased two- to sixfold. The km' (apparent km) of TF-factor VII enzymatic complexes assembled on alveolar macrophages for factor X were (258 +/- 55 and 475 +/- 264 nmol/L for human and rabbit cells, respectively). The km' did not change during macrophage maturation in culture, but V'max (apparent Vmax) was consistently increased. The K1/2 of human factor VII (concentrations giving half maximal rates of factor X activation) for the interaction with human and rabbit alveolar macrophage TF were 0.191 +/- 0.096 and 1.7 +/- 0.7 etamol/L, respectively. The K1/2 were not significantly changed after maturation, whereas rates of Xa formation at saturation with factor VII were increased. The fast rates of factor X activation observed at physiologic concentrations of plasma-derived factors VII and X indicate that TF on alveolar macrophages is likely to provide sites for binding of factor VII and activation of factor X in vivo during clotting reactions associated with alveolar edema and inflammation.     

颈动脉粥样硬化疾病的处理——美国血管外科学会临床实践指南

美国血管外科学会（SVS）任命了一个专家委员会制定颈动脉狭窄处理的循证临床指南。在制定临床实践推荐意见过程中，该委员会使用系统评价对当前最佳的证据进行了总结，采用GRADE标准对推荐意见的强度（强烈推荐为GRADEI级，一般推荐为GRADEⅡ级）和证据的质量（高、中、低和极低）进行了分级。对于轻度颈动脉狭窄患者（有症状患者狭窄程度〈50％和无症状患者狭窄程度〈60％），推荐进行最佳的内科治疗而非血管重建术（I级推荐，高质量证据）。对于有症状中到重度狭窄患者（狭窄程度〉150％），推荐行颈动脉内膜切除术（CEA）＋最佳的内科治疗（I级推荐，高质量证据）。对于围手术期风险高的有症状中到重度狭窄患者（狭窄程度≥50％），建议采用颈动脉支架置入术作为其替代治疗手段（Ⅱ级推荐，低质量证据）。对于中到重度狭窄的无症状患者（狭窄程度≥60％），只要围手术期风险较低，就推荐行CEA＋内科治疗（I级推荐，高质量证据）。对于中到重度狭窄的无症状患者（狭窄程度≥60％），不推荐行颈动脉支架置入术（I级推荐，低质量证据）。颈动脉狭窄≥80％但存在CEA高危解剖学风险的患者可能是一个例外。     

Trends in pemphigus research over 15 years

Background Although pemphigus is a rare autoimmune blistering disease, it attracts the attention of physicians of many disciplines. Objective This study aims to assess the number of articles on pemphigus that have been published over 15 years in dermatology vs. non‐dermatology medical journals, and to evaluate the quality of available evidence. Methods PubMed was searched for articles on pemphigus published between 1 January 1993 to 31 December 2007 using the search word pemphigus. Articles were characterized by publication type and journal type per year. Regression analysis was used to determine the effect of year of publication on number of publications of each type. Results The search yielded 2032 publications on pemphigus during the evaluation period. Sixty‐one per cent were published in dermatology journals. Overall, the number of publications increased linearly with time. Most of this increase was accounted for by publications in non‐dermatology journals. There was an increase in clinical trials over the course of the study period. The number of certain publications with lower quality of evidence, mainly case reports and letters to the editor, increased significantly in the last few years. There was no increase in publications with high quality of evidence. Conclusions The increase on data from non‐dermatology disciplines is a welcome contribution. Nevertheless, high‐quality evidence on pemphigus is still lacking. We trust that the current trend towards evidence‐based dermatology will impact future research on this severe disease.     

Nasal dermoids: the significance of a midline punctum

Nasal dermoids are rare and their diagnosis is often delayed until complications occur. Signs such as a midline nasal punctum may be noted at birth but the significance of this finding frequently passes unrecognised. The cases are reported of two patients which illustrate the typical presentation of these lesions and their subsequent management is discussed.