BACKGROUND:Silk fibroin, as a kind of high-performance biomaterial, has been widely used to construct scaffolds in bone tissue engineering. However, whether silk fibroin itself holds osteoinductive ability has not been reported yet. OBJECTIVE:To investigate the impact of different concentrations of silk fibroin solution on the proliferation and differentiation of rat bone marrow mesenchymal stem cel s (BMSCs) in vitro. METHODS:Silk fibroin and BMSCs were respectively isolated from silkworm cocoon and rat tibia, and were identified. Then, BMSCs were cultured in different concentrations of silk fibroin solution (0.01%, 0.05%and 0.1%), and the cell proliferation and the alkaline phosphatase activity were detected at different time points. RESULTS AND CONCLUSION:FTIR spectra of the sample extracted from silkworm cocoon showed distinct absorption peaks at 1 653 (amide I), 1 530.5 (amide II) and 1 212.3 cm-1 (amide III), which could be confirmed to be silk fibroin. Thus generated BMSCs showed long fusiform or astral morphology, positive for representative markers (CD29, CD44 and CD90) relating to mesenchymal stem cells, and could differentiate into osteocytes, chondrocytes and adipocytes under specific induction conditions, which further confirmed the extracted cells were BMSCs. Compared with the control group (without silk fibroin), 0.05% silk fibroin not only significantly promoted the cell adhesion, migration and proliferation, but also enhanced the alkaline phosphatase activity (P<0.01). With the increasing of the silk fibroin concentrations, the osteodifferentiation capacity of the BMSCs was progressively improved within the range of 0-0.05%and then declined at 0.01%of silk fibroin solutions. These results suggest that silk fibroin can promote osteogenesis, thus providing scientific evidence for developing silk fibroin-based tissue-engineered scaffolds.

OBJECTIVETo investigate the complications and conversions in myeloproliferative disorders (MPD).

METHODSThree hundred and fifty six patients with MPD were reviewed, including 78 with etiologic thrombocythemia (ET), 93 with primary myelofibrosis (MF), 185 with polythythemia vera (PV). The clinical observation, follow-up, analysis with SPSS statistic software were performed.

RESULTSOut of the 356 cases, 101 (28.5%) developed thromboembolic events, 81 (22.8%) hemorrhage, 60 (16.9%) hypertension, 20 (5.6%) coronary heart disease, 3 (0.8%) hemolysis and 1 (0.3%) gastrointestinal ulcer, 2 (0.6%) calculus and 1 (0.3%) bone marrow necrosis. Twenty four patients (6.7%) developed MF (9 in ET, 15 in PV), 2 (0.6%) erythrocytosis (1 in ET, 1 in MF), 3 (0.8%) thrombocythemia (all in PV), 5 (1.4%) acute leukemia (2 in ET, 3 in MF) and 1 (0.3%) multiple myeloma (in ET). Eleven cases (3.1%) died, 5 (1.4%) from acute leukemia, 2 (0.6%) fatal hemorrhages, 1 (0.3%) each myocardial infarction and infectious shock, 2 (0.6%) unknown causes.

CONCLUSIONEmbolism and bleeding were the main complications in MPD. Conversions among ET, MF and PV hematological malignancies could occur.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Female ; Humans ; Male ; Middle Aged ; Myeloproliferative Disorders ; complications ; mortality