BACKGROUND: Platelet-rich plasma containing various high-concentration growth factors can promote new bone formation and accelerate bone healing. But its effects on distraction osteogenesis remain unclear. OBJECTIVE: To observe the effects of autologous platelet-dch plasma on premaxillary distraction osteogeaesis in rabbits. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Laboratory of Physiology, North Campus,Sun Yat-sen University between July and August 2007. MATERIALS: Sixteen healthy rabbits, the same number for male and female, aged 3-5 months,weighing 1. 4-1.7 kg,were randomly and evenly divided into an experimental group and a control group. Premaxillary incisor band,outside front distraction mask, and distraction rubber band were self-made.Coagulant was prepared by dissolving 1000 u bovine thrombin in 1 mL of 10% calcium chloride.METHODS: Titanium nails (1.5 mm in diameter) were separately inserted on two sides of left premaxillary suture in rabbits. A self-made distraction device was used. Gelatum-like substance [Vplatelet-rich plasma: V coagulant=9:1] was injected into the left premaxillary suture of experimental group rabbits immediately prior to distraction.In each group, one-week sustained distraction was performed in 4 rabbits,and three-week sustained distraction was performed in another rabbits. MAIN OUTCOME MEASURES: The increase of nail-nail distance on the two sides and histological results following distraction osteogenesis.RESULLTS: Rabbit premaxillary bone moved anterior in the two groups. The experimental group showed greater increase of nail-nail distance, faster bone formation and mineralization, more blood vessels, and thicker and more mature bone trabecula in the distraction interspace in comparison with the control group. CONCLUSION: Platelet-rich plasma will help bone tissue regeneration and promote premaxillary distraction osteogenesis.

Objective To investigate the safety and short-term effectiveness of the hybrid operation for the treatment of intracranial complex ruptured aneurysms.Methods From December 2014 to March 2017,14 consecutive patients with complex ruptured aneurysm treated with hybrid operation at the Department of Neurosurgery,Nanfang Hospital,Southern Medical University were enrolled retrospectively,including 13 with acute spontaneous aneurismal subarachnoid hemorrhage and 1 with hemorrhage in the recurrent aneurysm embolization.Twelve aneurysms were treated with shape clipping.Digital subtraction angiography (DSA) was used to evaluate the clipping effect of aneurysms.Two patients with aneurysm were treated with extracranial-intracranial (EC-IC) bypass and aneurysm trapping.Endovascular balloon occlusion for trapping aneurysms was performed after DSA evaluation of the patency of bridge vessel.Results Of the 14 patients,11 were treated with emergency hybrid operation after angiography,2 were treated with elective surgery,and 1 with emergency surgery for rescue because of bleeding during embolization.DSA revealed that the aneurysm clips in 3 of 12 patients needed to be adjusted,including 2 parent artery stenosis and 1 with incomplete clipping.After adjustment,the clipping was satisfactory.In intracranial and extracranial bypass surgery,angiography revealed that the blood vessels were patent.Trapping of the aneurysms was performed in the one-stage operation.One patient discharged voluntarily after procedure because of serious vasospasm.Onepatient had perfusion pressure breakthrough after surgery and received hematoma evacuation and decompression.The Glasgow outcome scale (GOS) score was 3 at discharge.Other patients had no new neurological dysfunction after operation.Thirteen patients were followed up for 3-24 months after operation.There were no new neurological dysfunction,including GOS 5 in 8 cases and 4 in 5 cases.Six patients underwent DSA examination,in 4 of them the aneurysm clipping did not show aneurysm recurrence,and the parent arteries were patent.Two patients treated with vascular bypass.There were no recurrence of aneurysms,and the parent arteries and anastomotic vessels were patent.Conclusion After preliminary observation,using hybrid operation for the treatment of complicated intracranial ruptured aneurysms was safe and effective.

Objective: To evaluate the anti-tumor activity of mouse multi-subtype heat shock protein/peptide (mHSP/P) vaccine in combination with a programmed death ligand 1 (PD-L1) inhibitor in mouse sarcoma. Methods: Immunohistochemical staining and en-zyme-linked immunosorbent assay (Elisa) was used to quantitatively identify the expression of heat shock proteins (HSP70, HSP90, Grp94) in the sarcoma cell line MCA207. From the protein suspension prepared, mHSP/P and Grp94/peptide (Grp94/P) sarcoma vac-cines were isolated using chromatography and were identified by Western blot (WB). Flow cytometry was used to determine their cy-totoxic effects. The levels of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) produced upon mHSP/P and Grp94/P stimulation were measured by Elisa. The effect of sarcoma vaccines on the growth and survival of sarcoma was evaluated in mice. The expression of PD-L1 on the surface of MCA207 sarcoma cells was evaluated by immunofluorescent staining. The effect of IFN-γ treatment on the expression of PD-L1 was determined by WB. Animal experiments explored the effects of PD-L1 inhibitor in combination with mHSP/P treatment on tumors. Results: Tumor tissue carries a variety of HSP subtypes (HSP70, HSP90, Grp94). We successfully isolated sarco-ma tissue-derived mHSP/P and Grp94/P tumor vaccines, which were identified by WB; flow cytometry analysis demonstrated their cy-totoxicity. The levels of IFN-γ and TNF-α cytokines upon mHSP/P stimulation were significantly higher than that observed upon Grp94/P stimulation (P<0.05). The expression of PD-L1 on the surface of sarcoma cells increased with IFN-γ treatment. Animal experiments demonstrated that PD-L1 inhibitor in combination with mHSP/P significantly increased the immune response against tumor (P<0.05). Conclusions: Tumor-derived mHSP/P and Grp94/P can be used as tumor vaccines in animal models. The mHSP/P can elicit a stronger anti-tumor immune response than Grp94/P. IFN-γ stimulates the expression of PD-L1 in sarcoma cells, which results in immune eva-sion. The PD-L1 inhibitor in combination with mHSP/P increased the anti-tumor effect in the tumor microenvironment.