Easier node dissection after chemoradiotherapy for lung cancer with collagen insertion at mediastinoscopy

Objective: Induction chemoradiotherapy followed by anatomical resection is a current therapeutic strategy for non-small-cell lung cancer with mediastinal node involvement. Dense peritracheal fibrosis and sclerosis after chemoradiotherapy cause difficult mediastinal node dissection. We evaluated a novel technique to make the mediastinal node dissection easier after induction therapy. Methods: At the end of mediastinoscopic node biopsy for staging of lung cancer, cotton-type collagen was inserted anterior and lateral to the trachea in patients with pathologically confirmed mediastinal node involve-ment (n=45). The induction therapy consisted of concurrent use of platinum-based chemotherapy and hyperfractionated radiotherapy. After the chemoradiotherapy all patients underwent a pulmonary resection with complete mediastinal node dissection 7–12 weeks after the collagen insertion. Surgical findings of the mediastinum and the time for node dissection were compared with those without collagen insertion at mediastinoscopy after chemoradiotherapy (n=5). Results: All five patients without collagen insertion showed sclerotic and fibrotic change of mediastinal nodes with severe adhesion to the trachea. In 42 of 45 patients with collagen insertion (93.3%) the collagen remained unabsorbed and separated the mediastinal nodes from the trachea. Mediastinal node dissection was easily accomplished by removing mediastinal tissues lateral and anterior to the collagen. The rate of mediastinal node separation was significantly higher with collagen insertion than without (p< 0.0001). The times for node dissection in patients with and without collagen insertion showed no significant difference. Conclusion: Cotton-type collagen insertion at staging mediastinoscopy for lung cancer separates the mediastinal nodes from the trachea and makes the node dissection easier after induction chemoradiotherapy.     

Prevention of Restenosis after Coronary Angioplasty with Low-Density Lipoprotein Apheresis

Abstract: A prospective study was performed to determine whether low-density lipoprotein (LDL) apheresis, when performed only immediately before and after percutaneous transluminal coronary angioplasty (PTCA), is effective in preventing restenosis of coronary artery lesions following PTCA. Thirty-six patients with coronary heart disease (CHD) and hypercholesterolemia were divided into 2 groups. The 9 patients in the LDL group underwent LDL-apheresis 1 day before and 5 days after PTCA while the 27 patients of the control group underwent PTCA but did not undergo LDL-apheresis. Follow-up coronary angiography (CAG) was performed 4 months after PTCA. The rate of restenosis of coronary artery lesions was significantly lower in the LDL group (0%) than in the control group (30%). These findings suggest that LDL-apheresis, when performed before and after PTCA, is effective in preventing restenosis of coronary artery lesions in patients with CHD and hypercholesterolemia.     

syk kinase activation by a src kinase-initiated activation loop phosphorylation chain reaction

Activation of the syk tyrosine kinase occurs almost immediately following engagement of many types of antigen receptors, including Fc receptors, but the mechanism through which syk is activated is currently unclear. Here we demonstrate that Fc receptor-induced syk activation occurs as the result of phosphorylation of the syk activation loop by both src family kinases and other molecules of activated syk, suggesting that syk activation occurs as the result of a src kinase-initiated activation loop phosphorylation chain reaction. This type of activation mechanism predicts that syk activation would exhibit exponential kinetics, providing a potential explanation for its rapid and robust activation by even weak antigen receptor stimuli. We propose that a similar mechanism may be responsible for generating rapid activation of other cytoplasmic tyrosine kinases, such as those of the Bruton tyrosine kinase/tec family, as well.     

Immediate changes in subcellular structures of transplanted tumors following photodynamic and laser hyperthermic therapy

Background and Objective: To further understand the precise process of the tumor cell degeneration after photodynamic therapy (PDT), laser hyperthermic therapy (LH), and combined treatments using an Nd:YAG laser. It is important to examine initial morphological alteration of tumor cells after these treatments. Study Design/Materials and Methods: In this study, nude mice bearing HeLa cell tumors were treated with PDT, LH, and combined treatments of the two. Tumor tissues obtained immediately after these treatments were analyzed using electron microscopy and morphometry. Results: In the combined treatments, which produced more severe effects on tumor cells, morphological features of apoptosis such as cytoplasmic condensation, blebs, and apoptotic bodies appeared in the cells, although the typical alteration in the nuclear chromatin was not seen. Conclusion: Cytoplasmic alterations may proceed more rapidly than nuclear alterations in the cellular degeneration induced by the single or combined treatments of PDT and LH.