54 research outputs found
Osteogenic extracellular matrix sheet for bone tissue regeneration
The application of extracellular matrix (ECM) sheets without a scaffold is not extensively reported in bone regenerative medicine. The aim of the present study was to demonstrate that an osteogenic ECM sheet (OECMS) can retain ECM integrity and growth factors to enhance bone formation in a rat non-union model. OECMS was produced from osteogenic cell sheets (OCS). Collagen and growth factor [bone morphogenetic protein 2 (BMP-2), vascular endothelial growth factors (VFGFs), basic fibroblast growth factor (bFGF) and transforming growth factor ÎČ1 (TGF-ÎČ1)] concentrations in the OECMS were quantified by enzyme-linked immunosorbent assay (ELISA). Next, hydroxyapatite (HA) constructs combined with OECMSs were implanted subcutaneously into the rats' backs to evaluate their osteoinductive capacity by histological evaluation. In addition, OECMSs were implanted in a rat femoral non-union model. 18 male Fischer 344 inbred rats were divided into OECMS and control groups. Fracture healing was evaluated by radiological and histological analyses at 2, 5 and 8 weeks and biological analysis at 8 weeks. Collagen I and growth factors were retained in the OECMSs. Osteoid formation was identified in the HA combined with OECMS at 4 weeks. Enhanced bone regeneration at the non-union of the OECMS group was confirmed at 5 and 8 weeks. Biomechanical testing revealed a significantly higher maximum bending load in the OECMS group as compared to the control group at 8 weeks. The results demonstrated that OECMS retained BMP-2 and TGF-ÎČ1 and high osteoinductive and osteoconductive capacity. As such, OECMS represents a potential new scaffold-free material for bone tissue engineering
Source potential of the MesozoicâCenozoic rocks in the South Caspian Basin and their role in forming the oil accumulations in the Lower Pliocene reservoirs
Multiple autoimmune syndrome revealed by nephrogenic diabetes insipidus and hypokalaemic paralysis
A practical and effective strategy in East Asia to prevent antiâD alloimmunization in patients by C/c phenotyping of serologic RhDânegative blood donors
Abstract Serologic RhDânegative red cells can cause antiâD alloimmunization if they carry the Asianâtype DEL or other DEL variants. RHD genotyping is a viable countermeasure if available, but inexpensive alternatives are worthy of consideration. RhDânegative blood donors in Japan were studied by antiâD adsorptionâelution and RHD genotyping. We collated published case reports of RhDânegative red cell transfusions associated with inexplicable antiâD immunization. Of 2754 serologic RhDânegative donors, 378 were genotyped D/d. AntiâD adsorptionâelution revealed 63.5% (240 of 378) to be DEL, of whom 96.7% (232 of 240) had the 1227GÂ >Â A variant, diagnostic for the Asianâtype DEL. All 240 donors also carried at least one C antigen; none had a cc phenotype. The chance of transfusing DEL red cells to genuinely RhDânegative Asian patients (based on a threeâunit transfusion) ranges from 16.7% in Korea to 69.4% in Taiwan, versus 0.6% in Germany. Among 22 RhDânegative recipients of serologic RhDânegative red cells, who produced new or increased antiâD antibody titers, all 17 from East Asia were transfused with red cells with a Câpositive phenotype or known to be Asianâtype DEL or both. Serologic RhDânegative East Asians with a cc phenotype can be red cell donors for RhDânegative recipients, especially those of childbearing potential
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