A novel and injectable strontium-containing hydroxyapatite bone cement for bone substitution: A systematic evaluation.

Reconstruction of bone defects is still a challenge. In this study, we developed and systematically evaluated a novel injectable strontium-containing hydroxyapatite (Sr-HA) bone cement in which Sr-HA powder included 5% Sr and was mixed with a setting liquid that included 5% potassium citrate. This Sr-HA cement was mainly composed of HA and α-tricalcium phosphate (TCP) and exhibited favorable injectability (100%), setting times (the initial setting time was 240 s and the final setting time was 420 s), compressive strength (73.4 MPa), maximal load and maximum bending stress, and excellent radiopacity. In addition, the Sr-HA cement also had excellent biocompatibility that exhibited low cytotoxicity for cell proliferation and no obvious disturbing effect on the osteogenic differentiation of periodontal ligament stem cells (DLSCs) and dental pulp stem cells (DPSCs). However, the Sr-HA cement could slightly promote the osteogenic differentiation of MC3T3 cells, which also implied that it would promote osseointegration between the cement and surrounding bone but would not obviously disturb the biological behavior of DLSCs and DPSCs. An in vivo study further confirmed that Sr-HA cement exhibited favorable osseointegration with the maxilla and tibia. All these findings implied that the novel Sr-HA cement was a suitable bone substitution for bone defects.

Senile Lemierre syndrome complicated with descending necrotizing mediastinitis: A case report.

RATIONALE: Senile patients with LS complicated with DNM are rarely seen in clinical practice, and extensive cervical incision and drainage plus administration of effective antibiotics are the basis for treatment. Currently, the treatment controversy mainly has focused on whether mediastinal incision and drainage is necessary for patients with type I DNM, and whether anticoagulation therapy is required for jugular venous emboli and distant metastatic emboli induced by LS. PATIENT CONCERNS: A female, 76 years old, developed pain of tonsil on right side 5 days ago, and felt that the pain aggravated complicated with dysphagia and swelling pain of neck on both sides since then. DIAGNOSES: She was diagnosed with LS complicated with type I DNM. INTERVENTIONS: Tazobactam and Piperacillin 4.5 q8h and Ornidazole 100 ml q6h ivgtt were administered empirically,and secondary extensive cervical incision and drainage was performed under general anesthesia, after which low molecular weight heparin 4250 U q12h SC was administered. G test was performed 3 days later, which showed (1,3)-ß-D-glucan >1000 pg/ml. Bridging anticoagulation therapy, low molecular weight heparin 4250 U q12h SC, and Warfarin 2.5 mg qd po were given one week later. Low molecular weight heparin SC was discontinued and only Warfarin po was administered after treatment of bridging therapy for 3 days. OUTCOMES: CT of head and neck was reexamined on post-admission d24 and revealed that neck infection was improved on both sides, jugular vein distension on right side was restored to normal, abscess and pneumatosis of superior mediastinum were improved, distension of pulmonary artery on both sides was normalized, WBC was 9.94×109/L, neutrophil count was 4.43×109/L, CRP level was 9.8mg/L, D-D level was 0.81mg/L, PCT level was 0.800ng/mL and G test suggested (1,3)-ß-D-glucan pf 27.1 pg/mL. LESSONS: Concomitant use of anticoagulants on the basis of repeated cervical incision and drainage + administration of effective antibiotics can obtain excellent therapeutic efficacy in the treatment of patient with LS complicated with type I DNM.

Treatment of cryotherapy and orthotopic transplantation following chondromyxoid fibroma of zygomatic bone: A case report.

INTRODUCTION: Chondromyxoid fibrotherma (CMF) is a rare benign cartilage tumor that occurs more frequently in young males at the age of 20 to 30. It occurs more frequently on long bones, but rarely involves craniofacial bones. CASE PRESENTATION: This study mainly introduced a 30-year-old male with CMF of zygomatic bone. Single tumor excochleation was conducted initially. However, CMF reoccurred, and then the following steps were adopted: firstly, the tumor was extensively excised; secondly, in vitro tumor excochleation was conducted; thirdly, the excised tumor bone was placed in liquid nitrogen for 3 cycles of cryoablation; finally, the orthotopic transplantation was performed to reconstruct the zygomatic appearance, with satisfactory follow-up efficacy obtained. CONCLUSIONS: Orthotopic transplantation after tumorectomy and cryopreservation of tumor bone in liquid nitrogen could lead to excellent therapeutic efficacy and deserves to be widely applied in clinical practice in the treatment of a male patient with CMF of zygomatic bone, because it not only radically eliminates the tumor and kills tumor cells, but also provides bony skeleton for the growth of new bone, thus greatly promoting postoperative aesthetic degree and reducing the occurrence rates of complications.

Up-regulation of enhancer of zeste homolog 2 is associated positively with cyclin D1 overexpression and poor clinical outcome in head and neck squamous cell carcinoma.

BACKGROUND: The authors previously observed that enhancer of zeste homolog 2 (EZH2) overexpression was associated significantly with the development of oral cancer. In the current study, they investigated whether EZH2 can function as a prognostic predictor for patients with head and neck squamous cell carcinoma (HNSCC). METHODS: Expression levels of EZH2 in HNSCC cells were detected using reverse transcriptase-polymerase chain reaction (PCR) and Western blot analyses. In addition, the effects of EZH2 ablation on the proliferation and invasion of HNSCC cells were investigated through small interfering RNA (siRNA)-mediated knockdown. Real-time PCR and immunohistochemistry were used to evaluate EZH2 and cyclin D1 expression in 46 HNSCC samples, and the expression levels also were re-evaluated in 124 independent samples by immunohistochemistry. RESULTS: EZH2 expression was elevated remarkably in HNSCC specimens and cell lines. Upon EZH2 silencing, the proliferation and invasion of HNSCC cells were remarkably suppressed. EZH2 expression frequently was correlated with cyclin D1 expression (P = .034) and tumor differentiation (P = .020). In addition, both EZH2 messenger RNA levels and EZH2 protein levels were strongly associated with signs of histologic severity (P = .012 and P = .032, respectively). Univariate analysis revealed that high EZH2 expression was associated with worse overall survival (P = .001) and disease-free survival (P = .002). The combined expression of EZH2 and cyclin D1 had superior prognostic ability for patients with HNSCC than the expression of either marker alone. In multivariate analysis, EZH2 expression was identified as an independent predictor of overall and disease-free survival. CONCLUSIONS: The current results indicated that EZH2 is an independent prognostic indicator for patients with HNSCC. In addition, an analysis of the combined expression of EZH2 and cyclin D1 can serve as a more powerful prognostic predictor for patients with HNSCC.