Malignant giant cell tumor of bone or soft tissue treated by surgery with or without radiotherapy.

Malignant giant cell tumor of bone or soft tissue (MGCTBS) is one of the malignant tumors associated with poor prognosis. However, it remains controversial whether the combined treatment of both surgery and radiotherapy (surgery + RT) leads to better survival outcomes than surgical treatment alone (surgery alone) does for patients diagnosed with MGCTBS. We compared the two treatment strategies using the data provided by Surveillance, Epidemiology, and End Results (SEER) program. About 357 patients with MGCTBS who received either surgery + RT or surgery alone between 1975 and 2016 in the USA were identified and then matched based on their propensity scores estimated using the patients' baseline characteristics. We also performed a subgroup analysis for patients with high-grade and regional/distant tumor extension. Unadjusted Kaplan-Meier curves suggested that the surgery alone group had a better 10-year survival profile than the surgery + RT group. After propensity score matching, there was no statistical difference between the two treatment groups with respect to the 10-year cancer-specific survival and overall survival distributions. A subsequent subgroup analysis demonstrated that the surgery alone group has a similar 10-year survival comparing with the surgery + RT group for patients with high-grade and regional/distant tumor extension. The results of our study suggest that RT should not be recommended as a regular therapeutic method for MGCTBS, even for patients with high-grade histology and distant metastasis Clinical Significance: This study may provide better decision making for surgeons dealing with malignant giant cell tumor of bone or soft tissue. Type of study: Observation study. Level of evidence: Level III.

An automated microfluidic device for time-lapse imaging of mouse embryonic stem cells.

Long-term, time-lapse imaging studies of embryonic stem cells (ESCs) require a controlled and stable culturing environment for high-resolution imaging. Microfluidics is well-suited for such studies, especially when the media composition needs to be rapidly and accurately altered without disrupting the imaging. Current studies in plates, which can only add molecules at the start of an experiment without any information on the levels of endogenous signaling before the exposure, are incompatible with continuous high-resolution imaging and cell-tracking. Here, we present a custom designed, fully automated microfluidic chip to overcome these challenges. A unique feature of our chip includes three-dimensional ports that can connect completely sealed on-chip valves for fluid control to individually addressable cell culture chambers with thin glass bottoms for high-resolution imaging. We developed a robust protocol for on-chip culturing of mouse ESCs for minimum of 3 days, to carry out experiments reliably and repeatedly. The on-chip ESC growth rate was similar to that on standard culture plates with same initial cell density. We tested the chips for high-resolution, time-lapse imaging of a sensitive reporter of ESC lineage priming, Nanog-GFP, and HHex-Venus with an H2B-mCherry nuclear marker for cell-tracking. Two color imaging of cells was possible over a 24-hr period while maintaining cell viability. Importantly, changing the media did not affect our ability to track individual cells. This system now enables long-term fluorescence imaging studies in a reliable and automated manner in a fully controlled microenvironment.