Objective Bone defect repair remains a challenge in regenerative medicine, which has triggered a research upsurge on improving the bone repairing effect using heterogeneous bone combined with growth factors.The aim of this study was to evaluate local bone formation following surgical implantation of coralline hydroxyapatite (CHA), a heterogeneous bone, in combination with the concentrated growth factor (CGF).Methods This randomized prospective study included 24 New Zealand rabbits, which were equally divided into a CHA/CGF+CHA, a CHA/CGF+autograft and a CHA+autograft group.A defect 10 mm in diameter was made in the parietal bone of each animal and filled with CHA/CGF, CHA or autograft.At 6 and12 weeks after the operation, we observed the bone formation by micro-CT and histological examination.Results The bone volume (BV) was significantly higher in the CHA/CGF+CHA than in the CHA+autograft group both at 6 weeks ([39.00±7.61] vs [32.12±6.55] mm3, P<0.05) and at 12 weeks after the operation ([49.75±2.36] vs [39.45±7.02] mm3, P<0.05), and so was the bone mineral density (BMD) ([308.30±29.82] vs [256.85±151.25] mg/mL, P<0.05;[389.00±31.87] vs [302.53±127.05] mg/mL, P<0.05).Histological examination showed that the new bone was distributed throughout the CHA scaffold in the CGF/CHA group at 6 weeks, and the new bone was observed only in the periphery region of the CHA scaffold in the CHA group.The bone defects in the CGF/CHA group were fully repaired at 12 weeks, while those in the CHA group were partly repaired with bone and fibrous tissue in the central region of the defects.Conclusion Combination of CHA with CGF could effectively enhance bone healing.CHA/CGF compound artificial bone is an ideal substitute in bone transplantation.

Objective This study was to evaluate the clinical outcomes of orbital blowout fracture repair using the individual titanium mesh bent by computer-aided rapid prototyping . Methods The CT imaging data of 11 cases of orbital blowout fracture were analyzed.The subciliary approach was used for the exposure of the fractures .An appropriate 3D-printed titanium mesh pre-bent by computer-aided rapid prototyping was selected and implanted according to the characteristics of a given defect .The surgical results were analyzed by evaluating diplopia , eyeball movement , enophthalmos , and the position of the titanium mesh and comparing the orbital vol-ume before and after surgery . Results All the operations were successfully accomplished .No remolding or trimming was needed for the pre-bent titanium mesh and implanted titanium mesh was tightly fixed to the orbital wall .The patients were followed up for 3 -12 months, which revealed no symptoms of diplopia in any of the patients . Volumetric analysis showed a significantly reduced orbital volume difference from (2.60 ±0.43) mL preoperatively to (-0.07 ±0.62) mL postoperatively (P<0.01).Enophthalmos was desirably correc-ted, with the enophthalmos difference decreased from (2.35 ±0.81)mm preoperatively to (-0.10 ±0.52) mm postoperatively (P<0.01).No extra-ocular muscle limitation was observed . Conclusion The individual titanium mesh bent with computer-aided rapid prototyping technology can be applied to orbital blowout fracture repair , which may achieve a high success rate of anatomic restoration of the orbital volume and effective prevention of enophthalmos .

Objective:To investigate the pathological characteristics and the clinical significance of novel coronavirus (2019-nCoV)-infected pneumonia (termed by WHO as coronavirus disease 2019, COVID-19).Methods:Minimally invasive autopsies from lung, heart, kidney, spleen, bone marrow, liver, pancreas, stomach, intestine, thyroid and skin were performed on three patients died of novel coronavirus pneumonia in Chongqing, China. Hematoxylin and eosin staining (HE), transmission electron microcopy, and histochemical staining were performed to investigate the pathological changes of indicated organs or tissues. Immunohistochemical staining was conducted to evaluate the infiltration of immune cells as well as the expression of 2019-nCoV proteins. Real time PCR was carried out to detect the RNA of 2019-nCoV.Results:Various damages were observed in the alveolar structure, with minor serous exudation and fibrin exudation. Hyaline membrane formation was observed in some alveoli. The infiltrated immune cells in alveoli were majorly macrophages and monocytes. Moderate multinucleated giant cells, minimal lymphocytes, eosinophils and neutrophils were also observed. Most of infiltrated lymphocytes were CD4-positive T cells. Significant proliferation of type Ⅱ alveolar epithelia and focal desquamation of alveolar epithelia were also indicated. The blood vessels of alveolar septum were congested, edematous and widened, with modest infiltration of monocytes and lymphocytes. Hyaline thrombi were found in a minority of microvessels. Focal hemorrhage in lung tissue, organization of exudates in some alveolar cavities, and pulmonary interstitial fibrosis were observed. Part of the bronchial epithelia were exfoliated. Coronavirus particles in bronchial mucosal epithelia and type Ⅱ alveolar epithelia were observed under electron microscope. Immunohistochemical staining showed that part of the alveolar epithelia and macrophages were positive for 2019-nCoV antigen. Real time PCR analyses identified positive signals for 2019-nCoV nucleic acid. Decreased numbers of lymphocyte, cell degeneration and necrosis were observed in spleen. Furthermore, degeneration and necrosis of parenchymal cells, formation of hyaline thrombus in small vessels, and pathological changes of chronic diseases were observed in other organs and tissues, while no evidence of coronavirus infection was observed in these organs.Conclusions:The lungs from novel coronavirus pneumonia patients manifest significant pathological lesions, including the alveolar exudative inflammation and interstitial inflammation, alveolar epithelium proliferation and hyaline membrane formation. While the 2019-nCoV is mainly distributed in lung, the infection also involves in the damages of heart, vessels, liver, kidney and other organs. Further studies are warranted to investigate the mechanism underlying pathological changes of this disease.