Objective　To explore the possibility of telomerase as tumor marker of lung cancer and to evaluate its value on early diagnosis of lung cancer. Methods　Telomerase activity was measured in 40 resected specimens of lung cancer and 40 preoperative fibro-optic bronchoscope biopsied specimens of suspected lung cancer by PCR based silver staining telomeric repeat amplification protocal (TRAP) respectively. Results　The positive rate of telomerase was 100％ in SCLC, but 84.8％ in resected samples and 95.7％ in biopsied samples in NSCLC. The positive rate of telomerase was 87.5％(35／40) in resected lung cancer tissues, 7.5％(3／40) in paracancerous tissues and 0％(0／40) in normal lung tissues (P＜0.01). 82.5％ (34／40) biopsied specimens of suspected lung cancer were detected with telomerase activity. Its sensitivity, specificity， and accurate rate was 96.4％, 71.4％, and 91.4％ respectively for detection of lung cancer, Youden’s Index (J)＝0.678，and SE（J）＝0.174. Conclusion　Telomerase may be a sensitive tumor marker of lung cancer. Detecting telomerase activity in preoperative fibro-optic bronchoscope biopsied specimens may contribute to early diagnosis of lung cancer.

BACKGROUNDCalcaneal fractures are relatively common but complex, while the treatment of these fractures is still controversial. The objective of this study was to compare the biomechanical stability of minimally invasive, locking, and non-locking plating systems used for fixing Sanders type II and type III calcaneal fractures. Finite element analysis was used for comparing the three types of plating systems. This study helped in guiding the clinical management of calcaneal fractures.

METHODSThe CT data acquired from a volunteer was used to construct a finite element model of calcaneus. The fracture lines were made according to Sanders type II (A, B, C) and type III (AB, AC, BC) and six calcaneal fractures models were constructed accordingly. Three fixation methods used in clinical treatment were simulated by design tools (minimally invasive plating with percutaneous screws, Y-size non-locking plating, and locking plating) and then fixed to these fracture models with the help of clinical principles. The single minimally invasive plating fixation was also tested to compare the function of percutaneous screws. Then, the neutral force was applied on established methods. The displacement and presses distribution condition in various plating models were analyzed and compared.

RESULTSThe levels of displacement and compressive press on the bone around fixation or strains on plating were within the physiological limit, indicating that the three methods were suitable for application. Compared with the locked and unlocked plates, the minimally invasive plating caused a relatively lower displacement without the high stress in bone or fixation. The minimum stress in fixation was observed in locking plate as the distribution of stress was concentrated in the anterior part of locking plate.

CONCLUSIONSThe minimally invasive plating method could be a better alternative method in treating Sanders type II and type III calcaneal fractures. The observed stiffness of locking plate was not obviously stronger than unlocked plate.

Adult ; Ankle Injuries ; surgery ; Bone Plates ; Calcaneus ; injuries ; surgery ; Finite Element Analysis ; Fracture Fixation, Internal ; Fractures, Bone ; surgery ; Humans ; Male ; Young Adult