Tissue factor (TF) is an essential enzyme activator that forms a catalytic complex with FVII(a) and initiates coagulation by activating FIX and FX, ultimately resulting in thrombin formation. TF is found in adventitia of blood vessels and the lipid core of atherosclerotic plaques. In unstable coronary syndromes, plaque rupture initiates coagulation by exposing TF to blood. Biologically active TF has been detected in vessel walls and circulating blood. Elevated intravascular TF has been reported in diverse pro-thrombotic syndromes such as myocardial infarction, sepsis, anti-phospholipid syndrome and sickle-cell disease. It is unclear how TF circulates, although it may be present in pro-coagulant microparticles. We now report identification of a form of human TF generated by alternative splicing. Our studies indicate that alternatively spliced human tissue factor (asHTF) contains most of the extracellular domain of TF but lacks a transmembrane domain and terminates with a unique peptide sequence. asHTF is soluble, circulates in blood, exhibits pro-coagulant activity when exposed to phospholipids, and is incorporated into thrombi. We propose that binding of asHTF to the edge of thrombi contributes to thrombus growth by creating a surface that both initiates and propagates coagulation.

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BACKGROUND: Subtyping of lung carcinoma with immunohistochemistry is essential for diagnosis, whereas molecular testing (MT) is required for therapy guidance. In the current study, the authors report on MT performed on fine-needle aspiration specimens at the study institution over a 2-year period preceding the April 2013 College of American Patholo- and 11 had insufficient material for any MT. Anaplastic lymphoma kinase (ALK) testing was performed in 9 cases in which DNA was insufficient for epidermal growth factor receptor (EGFR) testing. In addition, 13 cases of adenocarcinoma=non-small cell lung carcinoma had at least 1 MT canceled because of insufficient DNA, but at the same time had an average of 3.46 immunohistochemical stains performed. CONCLUSIONS: Of all the cytology specimens, 10.6% featured limited material; however, no universally accepted testing sequence priority was available at the time the study was performed. As per the MTG, MT should take precedence over immunohistochemistry in cases of adenocarcinoma=non-small cell lung carcinoma. Approximately 5.3% of the specimens in the current study had insufficient material for MT while having multiple stains performed instead. The MTG also recommend performing EGFR before ALK testing; the authors found 9 cases with insufficient material for EGFR testing that had ALK testing performed. The results of the current study underscore the need for a testing prioritization algorithm in view of the MTG publication to serve as reference for both clinicians and pathologists. Cancer (Cancer Cytopathol) 2014;122:454-8.

The advent of molecular diagnostic assays for hereditary hearing loss permits earlier detection of the underlying causes, facilitates appropriate interventions, and is expected to generate the data necessary for more specific genotype-phenotype correlations.

SummaryThe presence of thrombogenic blood-borne or circulating tissue factor (cTF) has recently been demonstrated. These observations have implicated cTF to be a key determinant of thrombus propagation by depositing on platelets in nascent thrombi. Previously, we detected cTF by detergent solubilization and addition of phospholipids. We now report the direct demonstration of TF activity in ex-vivo thrombi. Collagen-coated substrates were exposed to native blood at shear rates of 0, 650, and 2000 s-1 for 10 min in a modified rotating Teflon cone and plate viscometer. Substrates were then gently rinsed to remove ‘loose’ (unadherent) components of blood. cTF activity was measured by adding a solution containing 10 nM FVIIa, 100 nM FX, and 5 mM CaCl2 to the substrates exposed to blood. Samples of this mixture were obtained at intervals for 30 min and the amount of Xa generated was quantified by adding a chromogenic substrate, Spectrozyme Xa, and measuring the increase in OD at 405 nm. Our studies show that a minimal amount of generated Xa (∼ 1nM) can be measured from ex-vivo thrombi. Static and shear samples generated the same amount of Xa, with the exception of blood subjected to 650 s-1 shear. At 650 s-1 shear rate, the amount of Xa generated reached a maximum of 4 nM at 5 min and then decreased to ∼1 nM. Immunohistological stains and fluorescent images demonstrate the presence of cTF antigen at 650 s-1 wall shear rate.