Radiation-induced osteosarcoma of the maxilla and mandible after radiotherapy for nasopharyngeal carcinoma.

BACKGROUND: The increasing incidence of radiation-induced osteosarcoma of the maxilla and mandible (RIOSM) has become a significant problem that can limit long-term survival. The purpose of this study was to analyze the association of clinicopathologic characteristics with treatment outcomes and prognostic factors of patients who developed RIOSM after undergoing radiotherapy for nasopharyngeal carcinoma (NPC). METHODS: We reviewed the medical records of 53,760 NPC patients admitted to Sun Yat-sen University Cancer Center during the period August 1964 to August 2012. Of these patients, 47 who developed RISOM and met inclusion criteria were included in this study. Two of these 47 patients refused treatment and were then excluded. RESULTS: For all patients treated for NPC at Sun Yat-sen University Cancer Center during the study period, the total incidence of RIOSM after radiotherapy was 0.084% (47/53,760). Two patients (4.4%) had metastases at the diagnosis of RIOSM. Thirty-nine of the 45 (86.7%) patients underwent surgery for RIOSM; most patients (24/39; 61.5%) who underwent resection had gross clear margins, with 15 patients (38.5%) having either a gross or microscopic positive margin. All patients died. The 1-, 2-, and 3-year overall survival (OS) rates for the entire cohort of 45 patients were 53.3%, 35.6% and 13.5%, respectively. The independent prognostic factors associated with high OS rate were tumor size and treatment type. CONCLUSIONS: RISOM after radiotherapy for NPC is aggressive and often eludes early detection and timely intervention. Surgery combined with postoperative chemotherapy might be an effective treatment to improve patient survival.

Heat-set gels formed from easily accessible gelators of a succinamic acid derivative (SAD) and a primary alkyl amine (R-NH2).

Currently, the design and construction of an intelligent stimuli-responsive gel system is still a significant challenge. We present here a new gel system from which the formation of heat-set gels, conventional gels and irreversible heat-set gels can be achieved in aromatic solvents. This gel system is based on two-component gelators containing a succinamic acid derivative (SAD) and a primary alkyl amine (R-NH2). With the increase of temperature to 85 °C, a rarely reported reversible heat-set gel (gel formation with the increase of temperature) is afforded. Upon addition of fatty acids into two-component gelators, a conventional gel (gel formation with the decrease of temperature) is formed. When the fatty acid is replaced with dicarboxylic acid, a new heat-set gel is generated, which is irreversible and thermally super-stable. X-ray diffraction analysis reveals that the formation of a reversible heat-set gel relies on electrostatic interactions, hydrogen bonds, and hydrophobic interactions. These two-component gelators show a perfect gel system for the formation of diverse gels including heat-set gels, conventional gels and irreversible heat-set gels. The tunable strategy demonstrated in this letter may provide a new way for creation of more functional gels in gel science.

A rare (3,4,5)-connected metal-organic framework featuring an unprecedented 1D + 2D → 3D self-interpenetrated array and an O-atom lined pore surface: structure and controlled drug release.

A rare (3,4,5)-connected self-interpenetrated metal-organic framework with an O-atom lined pore surface has been constructed from Zn(II) and H4L (H4L = 5,5'-(1,3,6,8-tetraoxobenzo[lmn][3,8]phenanthroline-2,7(1H,3H,6H,8H)diyl)-diisophthalic acid), which features an unprecedented 1D + 2D → 3D self-interpenetrated array and shows good controlled drug release properties.