Biomechanical properties of cervical traction under neck muscle force / 医用生物力学

Objective To establish a three-dimensional(3D) finite element model of cervical vertebrae (C1-7),and study its biomechanical properties under muscle force by cervical traction,so as to provide references for clinical treatment.Methods On the basis of nonlinear finite element model of normal cervical vertebrae and combined with clinical traction methods,cervical traction at the extension angle of 0°,10°,20°,30°,40° under the same traction weight,was simulated by finite element analysis (FEA) software to obtain and select the joint force and muscle force that were appropriate for FEA on the model.Results In the process of cervical extension by traction,under the muscle force,the average maximum equivalent stress of cervical vertebrae,intervertebral disc and uncovertebral joints increased by 4.86,1.79,0.69 MPa,respectively,and the average maximum relative displacement of cervical vertebrae in sagittal and vertical axis direction increased by 1 1.1,1.26 mm,respectively.The biomechanical properties of cervical traction were similar to the FEA results reported in the literature.Conclusions Neck muscles play an active role in promoting the stress and displacement of cervical vertebrae,intervertebral discs and uncovertebral joints and it should be taken into consideration when performing cervical traction in clinic.In addition,the traction angle should not be too large:0.-20. is generally recommended as a relatively safe angle range at the initial stage.

Biomechanical analysis of a finite element model of rotator cuff / 中华创伤骨科杂志

Objective To establish a finite element model of rotator cuff which can be used to simulate the rotator cuff injury and to evaluate the biomechanical effects of rotator cuff surgery.Methods The Dicom CT images of the right shoulder of a Chinese healthy volunteer were used to establish models of the scapula,humerus and clavicle.The rotator cuff structures were separated and modeled based on the MRI images and anatomical knowledge.After the rotator cuff model was introduced into the finite element analysis software Abaqus 6.12,the anatomical positions were simulated when the shoulder was at 30° internal rotation,30° external rotation,30° abduction,30° adduction,30° flexion and 30° extension.Results When the shoulder was in 30° flexion,the average stress was 52.2 kPa on the supraspinatus,223.0 kPa on the inffaspinatus and the teres minor,and 90.4 kPa on the subscapularis.When the shoulder was in 30° extension,the average stress was 105.0 kPa on the supraspinatus,78.2 kPa on the infraspinatus and the teres minor,and 55.7 kPa on the subscapularis,indicating that the muscle and tendon of the supraspinatus was subjected to greater stress and the humerus and the scapula produced less stress compared with the shoulder in 30° flexion.Conclusion Since our finite element model of the rotator cuff can simulate common activities of the shoulder joint and obtain stress values of the corresponding rotator cuff muscles,it can be used in simulation of rotator cuff injury and its surgery.

Diffusional kurtosis imaging value for assessment of liver cancer and tumoral cell invasion of peritumoral zone / 中华放射学杂志

Objective Study the apply of diffusional kurtosis imaging(DKI) value to assess liver cancer and tumoral cell invasion of peritumoral liver zone. Methods This research belonging to prospective study which included 24 patients with liver cancer and confirmed by clinical history and imaging features(liver cancer group), 10 healthy volunteers as control group. The liver cancer group underwent MRI plain and contrast enhanced scan, and DKI examination, while control group underwent MRI plain scan and DKI scan. The signal features of liver parenchyma and liver cancer lesion could be observed from the routine MRI and DKI. Fractional anisotropy (FA), mean diffusion (MD), axial diffusivity (Da), radial diffusivity (Dr), fractional anisotropy kurtosis (Fak), mean kurtosis (MK), kurtosis anisotropy (Ka) and radial kurtosis (Kr) value of four groups, the distant liver parenchyma(far away from the tumor>2 cm), peritumoral liver parenchyma(the distance≤2 cm around the tumor) and liver cancer were recorded. The differences of DKI parameters were evaluated using one-way analysis of variance (ANOVA). Results The signal of liver cancer in MR plain scan showed mild long T1 and mild long T2 signal, fast in and fast out enhanced feature of the neoplasms could be observed from the enhanced MRI and signal of liver cancer would not lower in DKI with b value up to top. The difference of DKI parameters including FA, MD, Da, Dr and Ka value had statistical significance in these four groups excepted for MK and Kr value. MD, Da and Dr value of normal parenchyma were higher than that of peritumoral parenchyma and liver cancer,while the Ka value was reverse. The differences of MD, Da, Dr and Ka value only had no statistical significance between the distant liver parenchyma and peritumoral liver parenchyma(P>0.05),and the differences of them had statistical significance among the rest group(P<0.05). Conclusion The DKI quantitative parameters can reflect the differences of different tissue, meaning that they can provide molecular imaging information for evaluating liver cancer and peritumoral zone.

Expression of DEK Protein in the Tissue and Voided Urine of Patients with Bladder Urothelial Carcinoma and Its Clinical Significance / 中国医科大学学报

Objective To detect the presence of DEK protein in the tissue and voided urine of patients with bladder urothelial carcinoma ,and an?alyze the relationship between DEK protein and clinical pathological classification of bladder cancer. Methods The expression of DEK protein was examined by immunohistochemistry in 48 bladder cancer tissues and 18 adjacent normal tissues(control group). The presence of DEK protein in voided urine was analyzed by western blot in 28 bladder cancer patients and 6 healthy individuals(control group). Results The positive ex?pression of DEK protein in bladder tumor tissues(73%)is higher than in adjacent normal tissues(33%,P<0.05). The expression of DEK in su?perficial bladder cancer(86%)was found higher than invasive bladder cancer(55%)with significant differences(P<0.05). The expression of DEK in urine samples of bladder cancer patients(0.834)was found higher than control group(0.242,P<0.05);Compared with the DEK expres?sion of control group,the sensitivity of diagnosis of bladder cancer with voided urine could be 82.1%. Conclusion DEK protein positive ex?pressed in tissues and voided urine of patients with bladder urothelial carcinoma. The expression was correlated with pathological classification of bladder cancer. The positive rate of DEK expression in early stage of tumor tissues is higher than late stage. The presence of DEK protein in tissues and voided urine can be considered as a suitable biomarker for bladder cancer potentially.

Expression and significance of VEGF-C and VEGF-D in differentiated thyroid carcinoma / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#VEGF-C,D are known to be capable of inducing proliferation of lymphatic endothelia cell and development of lymphatic vessels, so we investigated the expression of VEGF-C,D in the differentiated thyroid carcinoma tissues microarray in order to understand the significance mechanism of cervix lymphatic metastasis of thyroid cancer.@*METHOD@#A tissue microarray containing 71 specimens was constructed, including normal thyroid tissues, thyroid adenoma, papillary thyroid carcinoma with and without lymphatic metastasis, follicular thyroid carcinoma. VEGF-C, D protein expression was detected with immunohistochemistry.@*RESULT@#The expression of VEGF-C,D were not observed in normal thyroid tissues and adenoma tissues. The expression of VEGF-C,D in papillary thyroid carcinoma was significantly higher than those in follicular thyroid carcinoma (P < 0.05) and adeno ma tissues (P < 0.01). The expression of VEGF-C,D in papillary thyroid carcinoma with lymphatic metastasis was significantly higher than those in papillary thyroid carcinoma without lymphatic metastasis (P < 0.05).@*CONCLUSION@#By inducing proliferation of lymphatic endothelia cell and development of lymphatic vessels, VEGF-C,D contributed to lymphatic metastasis of papillary thyroid carcinoma.

The relationship between sleep episode and hypoxemia which following it in patients with obstructive sleep apnea-hypopnea syndrome and its clinical significance / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the relationship between sleep respiratory events and hypoxemia following obstructive sleep apnea-hypopnea syndrome (OSAHS) and its clinical significance.@*METHOD@#Forty-five patients suffered from snoring and suspected of sleep breathing disorders were measured by a Chinese version of Epworth Sleepiness Scale and tested by polysomnography all night long. Some ordinary polysomnographic parameters were recorded in all cases as well as the delay period of desaturation which means the duration from the beginning of sleep respiratory events to the beginning of the following desaturation.@*RESULT@#Forty-five patients were all suffered from obstructive sleep respiratory events. The mean delay period of desaturation in group of middle OSAHS was longer than that in group of normal snorers (P0.05), and the difference between patients with middle OSAHS and patients with severe OSAHS as well (P>0.05). The mean delay period of desaturation had a positive relationship with AHI (r = 0.608, P<0.01) and a negative relationship with lowest SaO2 (LSaO2) (r = - 0.543, P<0.01). The relationship between total scores of the 7 questions of Epworth sleepiness scale (ESS7) with the mean delay period of desaturation (r = 0.689, P<0.01) was significantly higher than that with AHI and LSaO2 (r = 0.486, P<0.01; r = - 0.422, P<0.01).@*CONCLUSION@#The delay period of desaturation is a sensitive parameter which describe oxygen desaturation following obstructive sleep respiratory events. The mean delay period of desaturation in group of middle and severe OSAHS was much longer than that in group of normal snorers as well as mild OSAHS. Furthermore, the mean delay period of desaturation has a closely relationship with AHI and LSaO2. And it was highly associated with ESS7 than AHI and LSaO2. Based on it, the mean delay period of desaturation may provide valuable information in evaluating the severity of the patients with OSAHS. It may evaluate the severity of daytime sleepiness better than AHI and LSaO2.