Recyclable, malleable and intrinsically flame-retardant epoxy resin with catalytic transesterification.

Flame retardancy and recyclability are two important issues in the research field of thermosets, particularly for epoxy resin (EP) with the biggest market share. It is of great importance, but rarely achievable, to integrate these properties simultaneously into EP. Herein, we report a facile way to prepare intrinsically flame-retardant epoxy vitrimers combining rapid recycling and multiple shape memory effects by introducing dynamic ester-linkages with catalytic transesterification activity into the crosslinking networks of EP. The flame-retardant epoxy vitrimers exhibited high Tg (∼110.7 °C), desirable thermal stability and excellent flame retardancy with UL-94 V-0 rating, and high LOI of ∼34%. Also, the value of the peak heat release rate (PHRR) and the total heat release (THR) showed 63% and 32% reduction, respectively. Meanwhile, flame-retardant epoxy vitrimers showed high malleability that could be reprocessed in 15 min at 200 °C without sacrificing the mechanical properties and flame retardancy. Moreover, the dynamic transesterification network allowed flame-retardant EP to access multiple shape memory effect. The design of flame-retardant epoxy vitrimers provide a prime example to foster the cyclic utilization of flame-retardant thermosetting polymers.

[Prognostic significance of clinicopathologic parameters in gastrointestinal stromal tumor: a study of 156 cases].

OBJECTIVE: To evaluate the prognostic significance of various clinicopathologic parameters in gastrointestinal stromal tumor (GIST), and to study the frequency of c-kit exon 11 mutations in this tumor. METHODS: One hundred and fifty-six cases of gastric or small intestinal GIST were retrieved from the archival files of the Department of Pathology, Chinese PLA General Hospital. The clinical features, site of occurrence, tumor diameter, mitotic index, coagulative tumor necrosis, and risk grade were studied and analyzed statistically. Tumor DNA was extracted and c-kit exon 11 was amplified. Upon detection by denaturing high-performance liquid chromatography, the amplified exon 11 was sequenced. RESULTS: For the 83 cases of gastric GIST studied, the mean age of patients was 55.4 years. Follow-up information was available in 62 cases, with 17 cases having local recurrence or distant metastasis. The 5-year survival rate was 66.5% +/- 17.1%. For the 73 cases of small intestinal GIST studied, the mean age of patients was 50.6 years. Follow-up information was available in 43 cases, with 22 cases having local recurrence or distant metastasis. The 5-year survival rate was 61.8% +/- 18.3%. In general, for gastric GIST, age younger than 50 years (P = 0.046), advanced clinical stage (P = 0.0001), large tumor size (P = 0.0001), high mitotic index (P = 0.0001), presence of coagulative tumor necrosis (P = 0.0001), and high risk grade (P = 0.004) were associated with lower survival rate. COX hazard proportional model revealed that advanced clinical stage (P = 0.001), large tumor size (P = 0.001), high mitotic index (P = 0.002) and high risk grade (P = 0.018) indicated worse prognosi. For small intestinal GIST, advanced clinical stage (P = 0.010) and presence of coagulative tumor necrosis (P = 0.036) were associated with lower survival rate. Advanced clinical stage was an independent prognostic factor. A total of 25 cases harbored c-kit mutations. The frequency of c-kit mutations was 32% and 22.5% for gastric and small intestinal GIST respectively. For gastric GIST, c-kit mutations occurred mainly in patients older than 50 years. In contrast, c-kit mutations in small intestinal GIST occurred in the age group of 40 to 49 years. CONCLUSIONS: For gastric GIST, advanced clinical stage, tumor diameter, mitotic index and risk grade are the main prognostic indicators. For small intestinal GIST, advanced clinical stage and presence of coagulative tumor necrosis indicate poor prognosis. In general, small intestinal GIST is more frequently associated with metastasis and tumor relapse than gastric GIST. The occurrence of c-kit mutations also correlates with age of patients.

Aberrant FHIT protein expression in classical Hodgkin's lymphoma: a potential marker.

AIMS: The fragile histidine triad (FHIT) gene is frequently inactivated in human cancers; however, the FHIT gene remains unexplored in Hodgkin's lymphoma. The aim of this study was to investigate the role of FHIT expression in classical Hodgkin's lymphoma. METHODS: Classical Hodgkin's lymphomas were analysed for FHIT gene expression by two-step non-biotin immunohistochemical method and Western blotting. RESULTS: Thirty of the 33 (91%) cases of Hodgkin's lymphoma tested were positive for FHIT protein by immuohistochemistry. The expression of FHIT was mainly located in cytoplasm of Reed-Sternberg (HRS) cells. The protein expression was also documented by Western blotting. The non-Hodgkin's lymphomas were negative for FHIT protein. CONCLUSIONS: The results indicate that abnormal FHIT expression is noted frequently in classical Hodgkin's lymphoma and the expression can give insight into the pathogenesis of the disease. The protein may serve as a marker to localise HRS cells in classical Hodgkin's lymphoma.

[Expression of fragile histidine triad (FHIT) protein and its significance in diagnosing classical Hodgkin lymphoma].

OBJECTIVE: To study the expression of FHIT protein and its potential application in diagnosing classic Hodgkin lymphoma. METHODS: Immunohistochemical study using EnVision method for FHIT tumor suppressor protein, hematopoietic stem cell markers CD133/AC133 and CD34, B-cell marker CD20, T-cell marker CD3 and oncoprotein c-erbB2 was performed on 33 cases of classic Hodgkin lymphoma. RESULTS: Thirty-three of the Hodgkin lymphoma cases (90.9%) expressed FHIT protein. The antigen was mainly located in the cytoplasm, nucleus and membrane of classic Reed-Sternberg and Reed-Sternberg-like cells. Normal B and T lymphocytes, as well as their malignant counterparts, were negative for FHIT protein; whereas monocytes, histiocytes and dendritic cells were positive. All the cases studied were negative for CD133/AC133, CD34, CD3 and c-erbB-2. Two of the 33 cases showed positive staining for CD20 in some of the Reed-Sternberg cells. CONCLUSION: The expression of FHIT protein can be used as a useful adjunct in diagnosing classic Hodgkin lymphoma.