Modern Interpretation of Giant Cell Tumor of Bone: Predominantly Osteoclastogenic Stromal Tumor

Owing to striking features of numerous multinucleated cells and bone destruction, giant cell tumor (GCT) of bone, often called as osteoclastoma, has drawn major attractions from orthopaedic surgeons, pathologists, and radiologists. The name GCT or osteoclastoma gives a false impression of a tumor comprising of proliferating osteoclasts or osteoclast precursors. The underlying mechanisms for excessive osteoclastogenesis are intriguing and GCT has served as an exciting disease model representing a paradigm of osteoclastogenesis for bone biologists. The modern interpretation of GCT is predominantly osteoclastogenic stromal cell tumors of mesenchymal origin. A diverse array of inflammatory cytokines and chemokines disrupts osteoblastic differentiation and promotes the formation of excessive multi-nucleated osteoclastic cells. Pro-osteoclastogenic cytokines such as receptor activator of nuclear factor kappa-B ligand (RANKL), interleukin (IL)-6, and tumor necrosis factor (TNF) as well as monocyte-recruiting chemokines such as stromal cell-derived factor-1 (SDF-1) and monocyte chemoattractant protein (MCP)-1 participate in unfavorable osteoclastogenesis and bone destruction. This model represents a self-sufficient osteoclastogenic paracrine loop in a localized area. Consistent with this paradigm, a recombinant RANK-Fc protein and bisphosphonates are currently being tried for GCT treatment in addition to surgical excision and conventional topical adjuvant therapies

Ovarian cancer molecular pathology.

Peer reviewe

Topical bevacizumab treatment in aniridia

To report the results of long-term topical treatment with bevacizumab (Avastin) 5 mg/mL eyedrops in a case of aniridia-related neovacularization of the cornea. Interventional case report. A female patient with aniridia had a decrease in the best corrected visual acuity from 0.32 to 0.02 in the OS over the course of 4 years, secondary to central corneal neovascularization and epithelial breakdown. Vision in the OD was 0.2. In 2008, at age 28, a shared decision was made to start off-label treatment with bevacizumab eyedrops 0.5% in both eyes. After 9 years, the visual acuity in the OD remained stable, with stability of the macropannus and maintenance of central corneal clarity. In the OS, the central corneal neovascularization regressed, the epithelium regained its clarity, and after cataract surgery visual acuity was regained to 0.32. After 9 years of treatment with topical bevacizumab, vision acuity is comparable to the situation of 12 years previously: Visual acuity remained stable in the ODS. In a young patient with progressive corneal neovascularization secondary to aniridia, stability of central corneal neovascularization was obtained and corneal clarity was preserved by adding a daily drop of bevacizumab 5 mg/mL. No adverse events occurred. Vessel growth was inhibited, and as such, the progression of the natural history of the patient's disease was halted. More clinical study with longer follow-up is needed to investigate the applicability of treatment with topical VEGF inhibitors in aniridi

Mobile ultra-clean unidirectional airflow screen reduces air contamination in a simulated setting for intra-vitreal injection

The aim of this study is to determine whether the use of a mobile ultra-clean laminar airflow screen reduces the air-borne particle counts in the setting of a simulated procedure of an intra-vitreal injection. A mobile ultra-clean unidirectional airflow (UDF) screen was tested in a simulated procedure for intra-vitreal injections in a treatment room without mechanical ventilation. One UDF was passed over the instrument tray and the surgical area. The concentration of particles was measured in the background, over the instrument table, and next to the ocular area. The degree of protection was calculated at the instrument table and at the surgical site. Use of the UDF mobile screen reduced the mean particle concentration (particles > 0.3 microns) on the instrument table by a factor of at least 100.000 (p < 0.05), and over the patient's eye by at least a factor of 436 (p < 0.05), which in clinical practice translates into significantly reduced air contamination. Mobile UDF screen reduces the mean particle concentration substantially. The mobile UDF screen may therefore allow for a safer procedural environment for ambulatory care procedures such as intra-vitreal injections in treatment room

Uneven Power and the Pursuit of Peace: How Regional Power Transitions Motivate Integration. CES Working Paper, no. 150, 2007

This paper addresses two related puzzles confronting students of regional and international integration: Why do states willingly pool and delegate sovereignty within international institutions? What accounts for the timing and content of regional integration agreements? Most theories of integration suggest that states integrate in order to solve problems of incomplete information and reduce transaction costs and other barriers to economic growth. In contrast I argue that integration can serve to establish a credible commitment that rules out the risk of future conflict among states of unequal power. Specifically, I suggest that integration presents an alternative to preventive war as a means to preclude a rising revisionist power from establishing a regional hegemony. The implication is that it is not countries enjoying stable and peaceful relations that are most likely to pursue integration, but rather countries that find themselves caught in a regional security dilemma, which they hope to break out of by means of institutionalized cooperation. I evaluate this proposition against evidence from two historical cases of regional integration: the German Zollverein and the European Communities