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Background: There is a critical need for the management of large bone defects. The purpose of this study was to engineer a biomimetic periosteum and to combine this with a macroporous ß-tricalcium phosphate (ß-TCP) scaffold for bone tissue regeneration. Methods: Rat bone marrow-derived mesenchymal stem cells (rBMSCs) were harvested and cultured in different culture media to form undifferentiated rBMSC sheets (undifferentiated medium (UM)) and osteogenic cell sheets (osteogenic medium (OM)). Simultaneously, rBMSCs were differentiated to induced endothelial-like cells (iECs), and the iECs were further cultured on a UM to form a vascularized cell sheet. At the same time, flow cytometry was used to detect the conversion rates of rBMSCs to iECs. The pre-vascularized cell sheet (iECs/UM) and the osteogenic cell sheet (OM) were stacked together to form a biomimetic periosteum with two distinct layers, which mimicked the fibrous layer and cambium layer of native periosteum. The biomimetic periostea were wrapped onto porous ß-TCP scaffolds (BP/ß-TCP) and implanted in the calvarial bone defects of rats. As controls, autologous periostea with ß-TCP (AP/ß-TCP) and ß-TCP alone were implanted in the calvarial defects of rats, with a no implantation group as another control. At 2, 4, and 8 weeks post-surgery, implants were retrieved and X-ray, microcomputed tomography (micro-CT), histology, and immunohistochemistry staining analyses were performed. Results: Flow cytometry results showed that rBMSCs were partially differentiated into iECs with a 35.1% conversion rate in terms of CD31. There were still 20.97% rBMSCs expressing CD90. Scanning electron microscopy (SEM) results indicated that cells from the wrapped cell sheet on the ß-TCP scaffold apparently migrated into the pores of the ß-TCP scaffold. The histology and immunohistochemistry staining results from in vivo implantation indicated that the BP/ß-TCP and AP/ß-TCP groups promoted the formation of blood vessels and new bone tissues in the bone defects more than the other two control groups. In addition, micro-CT showed that more new bone tissue formed in the BP/ß-TCP and AP/ß-TCP groups than the other groups. Conclusions: Inducing rBMSCs to iECs could be a good strategy to obtain an endothelial cell source for prevascularization. Our findings indicate that the biomimetic periosteum with porous ß-TCP scaffold has a similar ability to promote osteogenesis and angiogenesis in vivo compared to the autologous periosteum. This function could result from the double layers of biomimetic periosteum. The prevascularized cell sheet served a mimetic fibrous layer and the osteogenic cell sheet served a cambium layer of native periosteum. The biomimetic periosteum with a porous ceramic scaffold provides a new promising method for bone healing. [ABSTRACT FROM AUTHOR]

Background: Various treatments of giant cell tumor of bone (GCTB) included in curettages and resections and with adjuvant are exerted, but the best treatment is controversial. The aim of the study was the identification of individual risk factors after various treatments in GCTB. Methods: A total of 179 patients treated for GCTB between 1998 and 2010 were concluded in the retrospective study. All patients were treated with intralesional curettage, extensive curettage, or wide resection. Mean follow-up was 60.2 ± 18.7 months (36~112 months). Age, gender, tumor location, Campanacci grade, soft tissue extension, pathological features, and surgical methods were performed to univariate Kaplan-Meier survival analysis and multivariate Cox regression analysis. Results: The local recurrence rates of intralesional curettage (41.9 %) and extensive curettage (19.0 %) were significantly higher than that of wide resection (7.7 %). The higher risk of local recurrence was found for soft tissue extension (hazard = 7.921, 95 % CI 1.107~56.671), compared with no statistical significances between gender, location, Campanacci grade, pathologic fracture, and local recurrences, which were shown by Kaplan-Meier analysis. However, recurrence-free survival (RFS) of patients younger than 30 was significantly lower than that of patients older than 30. The RFS of pathologic fracture patients with soft tissue extension was significantly lower than that of pathologic fracture patients without soft tissue extension. Multivariate Cox regression analysis indicated that the independent variable that contributed to recurrence-free survival was soft tissue extension and surgical methods. The RFS of extensive curettage had no statistically significant difference with wide resection and was significantly higher than that of intralesional curettage. Use of high-speed burring and bone cement significantly decreased the local recurrence rate. Conclusions: Age (below 30 years), gender, tumor location, Campanacci grade, and pathologic fracture have no statistically significant influence on local recurrences. Soft tissue extension and intralesional curettage of surgical methods increased the RFS. The results of the present study suggested that compared with curettage and wide section, treatment of GCTB by extensive curettage could provide the favorable local control and functional recovery. [ABSTRACT FROM AUTHOR]

Background: Killer cell immunoglobulin-like receptors (KIRs) show extensive variation in genetic content and allelic polymorphisms among different populations. Materials and methods: We analyzed the distribution of KIR genes in the Tibetan ethnic minority of Lhasa city, the Uyghur and Kazakh ethnic minorities of Urumqi city populations in China. Genotyping of 16 KIR genes was tested in 479 randomly selected individuals using the multiple PCR-SSP method. Results: A total of 42 KIR genotypes were detected, of which, 29 were predicted to be AB genotypes, 12 were BB genotypes and one was AA genotypes. 27 KIR genotypes were identified in Kazakhs, 30 KIR genotypes were identified in Uyghurs and 20 KIR genotypes were identified in Tibetans. The predominant genotype 1(AA genotypes) occurred most frequently in Tibetans (52.7%, 118/224), Kazakhs (43.2%, 54/125) and Uyghurs (34.9%, 45/130). Not only the four framework genes were present in all individuals, but the pseudogene 2DP1 could also be detected in all Uyghur individuals. Tibetans were different from Kazakh and Uyghur groups in KIR genetic content and KIR allelic variation. Intriguingly, Tibetans (29.5%, 66/224) had lower frequencies of 2DS4-v when compared with Uyghurs (60.8%, 79/130) and Kazakhs (59.2%, 74/125). Uyghurs (25.4%, 33/130) displayed higher frequencies of Bx genotypes with C4Tx (absence of KIR3DS1-2DL5-2DS5-2DS1) than both Kazakhs (11.2%, 14/125) and Tibetans (3.6%, 8/224). Conclusions: The study showed that profile of KIR genotypes in three ethnic minority populations in China displayed ethnic diversity. It could be valuable for enriching the ethnical information resources for KIR gene, as well as facilitating further research on KIR-related diseases. [ABSTRACT FROM AUTHOR]

Background Rhynchocypris oxycephalus is a cold water fish with a wide geographic distribution including the relatively warm temperate regions of southern China. It also occurs in second- and thirdstep geomorphic areas in China. Previous studies have postulated that high-altitude populations of R. oxycephalus in southern China are Quaternary glacial relics. In this study, we used the mitochondrial gene Cytb and the nuclear gene RAG2 to investigate the species phylogeographical patterns and to test two biogeographic hypotheses: (1) that divergence between lineages supports the three-step model and (2) climatic fluctuations during the Quaternary resulted in the present distribution in southern China. Results Phylogenetic analysis detected three major matrilines (A, B, and C); with matrilines B and C being further subdivided into two submatrilines. Based on genetic distances and morphological differences, matriline A potentially represents a cryptic subspecies. The geographic division between matrilines B and C coincided with the division of the second and third geomorphic steps in China, suggesting a historical vicariance event. Pliocene climatic fluctuations might have facilitated the southwards dispersal of R. oxycephalus in matriline C, with the subsequent warming resulting in its split into submatrilines C1 and C2, leaving submatriline C2 as a relic in southern China. Conclusions Our study demonstrates that geological events (three steps orogenesis) and climate fluctuations during the Pliocene were important factors in shaping phylogeographical patterns in R. oxycephalus. Notably, no genetic diversity was detected in several populations, all of which possessed unique genotypes. This indicates the uniqueness of local populations and calls for a special conservation plan for the whole species at the population level. [ABSTRACT FROM AUTHOR]

Background Leukemia is the most common malignant proliferative disease in children. Our previous study found that miR-99a was up-regulated in pediatric primary AML using microRNA expression profiles. Up to date, although there is a certain number of reports on microRNA expression features and functions in pediatric acute myeloid leukemia (AML) and chronic myeloid leukemia (CML), the expression and function of miR-99a in these diseases remain to be investigated. Methods qRT-PCR was performed to measure the expression level of miR-99a in 88 samples including 68 pediatric acute myeloid leukemia patients, 8 chronic myeloid leukemia patients and 12 pediatric controls. MTT assay, apoptosis assay, dual-luciferase reporter transfection assay and western blot analysis were used to investigate the function of miR-99a. Results MiR-99a was highly expressed in pediatric-onset AML (M1-M5) and CML, while significantly lowly expressed during complete remission of these diseases. MTT assay indicated that the proliferations of K562 and HL60 cells were significantly promoted by miR- 99a, and apoptosis assessment by Annexin V/propidium iodide staining demonstrated that the apoptosis of these cells was inhibited by miR-99a. Additionally, dual-luciferase reporter transfection assay and western blot analysis indicated that miR-99a may target CTDSPL and TRIB2, which are two tumor suppressor genes. Conclusions This study revealed that miR-99a may play a potential oncogenic role in pediatric myeloid leukemia including AML and CML via regulating tumor suppressors CTDSPL and TRIB2, suggesting that these two leukemias might share some common biological pathways involved in the generation and development of disease and miR-99a could be a common therapeutic target for myeloid leukemias treatment. [ABSTRACT FROM AUTHOR]

Four sect. of seed-like Fruits (including 14 species) of Subg. Sclarea of Salvia of Labiatae in China were systematically observed and researched by using both biological anatomical lens and scanning electron microscope (98 photographs were attached). Their shapes were ovoid, elliptical and fusiform and so on; the sizes were large, medium and small; the surface ultrastructures of seed-like Fruits were ranged from plain, stripes, reticulate to convex meshes and the like. The relationships among them and the position of evolution and the relationships among three Ser. of Sect. Drymosphace were discussed. According to the surface ornamentation types analysis of seed-like Fruits, their evolution was from plain, stripes, reticulate, convex meshes to reticulate and convex meshes, and both reticulate and convex meshes appeared on dorsal and ventral surfaces of seed-like Fruits of one species at the same time. The plain was an original type; the stripes, reticulate and convex meshes were intermediate types; and both reticulate and convex meshes appeared on seed-like Fruits of one species was regarded as an evolution type. This was a rare phenomenon in other Family and Genus of angiosperms, which was worthy of an in-depth study. According to types of the ornamentation characteristics, they had intra-specific stabilities, but significant inter-specific difference in both the macro morphology features and the ultrastructure ornamentation, which provided evidences for classification identification, discussion on their genetic relationships, introduction and cultivation and genetics and breeding. [ABSTRACT FROM AUTHOR]