In order to analyse the effects of flexion-extension motion of lumbar spine on the position and shape of lumbosacral dural sac, measurements were performed on 10 flexion/extension lateral myelograms of cadaver specimens of normal lumbar spine.It could be seen that from flexion to extension both sagittal diameter and length of the dural sac increased significantly, the dural sac moved caudally, and the sagittal diameter of the anterior epidural space decreased in the mid-vertebral level but increased in the inter vertebral level.The dynamic changes of the dural sac, the influence factors and the clinical relevances were discussed.

A mechanical model was constructed with three-dimensional finite element method to analyse the statusof stress distribution in the isthmus of the neural arch. It was found that the stress concentrate significantlyin the isthmus with spine upright. flexed and extended, and most obviously in extension position. The auth-ors conclude that spondylolysis is mainly the fatigue fracture due to locally increased stress and is contribut-ing most by backward extension of lumbar spine.

In the field of biomechanics, there have been many discoveries concerning the cervical spine injuries in recent years. With the help of biomechanical knowledge, we can not only judge the stability of the cervical spine and have a clear idea of the factors that may affect the stability but also conduct an appropriate classification of the injuries. In this article, we summarize the effects of the stiffness and preinjury biomechanical characteristics of the cervical spine (such as alignment, mass, inertial properties) on the injury, changes of the spinal canal during injury, and the rapidly developing research on finite element models of cervical spine injuries in the past few years.

In this paper the latest studies on the role of estrogen for the development of osteoarthritis and osteoporosis in postmenopausal women are reviewed.Estrogen can influence the pathophysiology of osteoarthritis through its interactions with the estrogen receptors,type Ⅱ collagen,cytokines and reactive oxygen species.While in the process of osteoporosis,estrogen can not only influence the estrogen receptors,cytokmes,reactive oxygen species,but also affect the sex hormone binding globulin and estrogen receptor-related receptor.

The lumber ligaments play an important role in spinal bsomechanics. The results of three-dimensional finite element analysis showed that one of functions of lumbar ligaments is transmission of the tensile load between the lumbar vertebrae. The anterior longitudinal ligament is loaded in extension of lumbar spine and the resistance to the tensile load in flexion is provided by other ligaments. These ligaments are subject to much more tension with degsneration of the intervertebral disc so that a series of pathological changes occur. Relevant significance in clinical aspect is also discussed.

Objective To investigate the diagnosis measures and treatment methods of white line hernia. Methods Analyze the clinical data of 12 cases of white line hernia who were treated by surgery. We performed peritoneal adipose tissue before resection on hernia without hernial sac type. And for those with hernial sac type, apothesis of material in hernia were firstly made, then ligated the hernia sac neck and resection were made. Then according to the white line defect size, we used pure involution suture and Onlay without tension patch repair to repair defect in the white line. Results Surgery of all the 12 cases were successful. 2 cases of them merged postoperative renal dysfunction and infection, and after hemodialysis and anti-infection treatment, they both recoverd well without recurrence. Conclusion There is no spe-cific symptoms and signs in white line hernia, but incarceration and strangulation may cause life threaten, so we should pay more attention to it. For symptomatic, large, difficult, incarcerated or strangulated white line hernia,we should take timely surgical treatment.

Objective To explore the optimum sentinel lymph node (SLN) mapping method in gastric cancer. Methods The clinical data of 59 patients who were confirmed with gastric cancer at Guangzhou General Hospital of Guangzhou Military Command from January 2004 to August 2008 were retrospectively analysed. Patent blue V dye was used in 20 patients (group A), technetium-99m sulfur colloid was used in 20 patients (group B),and a combination of patent blue V dye and technetium-99m sulfur colloid were used in 19 patients (group C).The number of SLNs detected, and accuracy and false-negative rate of SLNs in diagnosing regional lymph node metastasis were analysed by t test and chi-square test. Results The numbers of SLNs detected in groups A, B and C were 38 (1.9 per case), 31 (1.6 per case) and 56 (2.9 per case), respectively. In group C, 46 SLNs were screened out by patent blue V dye and technetium-99m sulfur colloid simultaneously, six SLNs were only detected by patent blue V dye and four only by technetium-99m sulfur colloid. There was a significant difference in the number of SLNs detected among the three groups (t = 4.35, P ＜ 0. 05 ). The number of SLNs detected in group C was significantly greater than that in groups A and B (t = 4. 21, 3. 54, P ＜ 0.05 ). The accuracy and false-negative rate of SLNs in diagnosing regional lymph node metastasis were 95% (19/20) and 5% (1/20) in group A, 90% (18/20) and 10% (2/20) in group B, and 100% (19/19) and 0 in group C. The accuracy was significantly higher (x2 = 163.01, P ＜ 0.05) and the false-negative rate was significantly lower in group C compared with those in groups A and B (x2 = 170. 14, P ＜ 0. 05). Conclusion A combination of dye and radioactive tracer is a favorable method for detecting SLNs in gastric cancer.

Objective To explore the efficiency of prophylactic intravesical chemotherapy after nephroureterectomy for primary upper tract urothelial carcinoma.Methods Forty-seven patients with primary upper tract urothelial carcinoma who underwent nephroureterectomy were retrospectively analyzed.There were 25 male and 22 female patients with mean age of 68 years.Patients were divided into intravesical chemotherapy group (n =32) and non-intravesical chemotherapy group (n =15).In the intravesical chemotherapy group, there were 14 male and 18 female patients with mean age of 70.3 years;20 cases located at left side while 12 at the right side.In non-intravesical chemotherapy group, There were 11 male and 4 female patients with mean age of 65.0 years;10 cases located at left side while 5 at the right side.The age, gender, side of the two groups were not statistical different.The two groups were followed up, and the tumor stage, grade, recurrence rate, cancer-free survival time were compared.Results The pathology results of all cases were urothelial carcinoma.In the intravesical chemotherapy group, 23 cases were high grade tumors with 9 low grade tumors.There were 15 cases of Ta-T1 stage, 8 cases of T2 stage and 9 cases of T3 stage;the tumor of 19 cases located at pelvis, 12 located at ureter, 1 located at pelvis and ureter;the mean size of the tumors was (2.75 ± 1.49) cm;8 cases were multiple while 24 were single.In the non-intravesical chemotherapy group, 12 cases were high grade tumors with 3 low grade tumors, there were 6 cases of Ta-T1 stage, 4 cases of T2 stage and 5 cases of T3 stage;the tumor of 11 cases located at pelvis, 3 located at ureter, 1 located at pelvis and ureter;the mean size of the tumors was (3.11 ± 1.48) cm;6 cases were multiple while 9 were single.The items mentioned above did not reach statistical difference between the two groups(P ＞0.05).6 patients relapsed in intravesical chemotherapy group while 7 in non-intravesical chemotherapy group.The recurrence rate of bladder cancer of intravesical chemotherapy group was lower than that of non-intravesical chemotherapy group (18.75％ vs.46.67％, χ2 =3.978, P =0.046).Compared with non-intravesical chemotherapy group, intravesical chemotherapy group had longer cancer-free survival, but it did not reach statistical difference (36.5months vs.29.6months, t =1.079, P =0.286).The age and tumor grade were risk factors of bladder cancer recurrence, meanwhile the gender, tumor side, tumor stage, voided urine cytology, tumor size, and location were not.Conclusion Prophylactic intravesical chemotherapy after nephroureterectomy for primary upper tract urothelial carcinoma could reduce the recurrence rate of bladder cancer.

Objective To investigate the relationship of serum adiponectin (APN) gene promoter region single nucleotide polymorphism (SNP) frequency and type 2 diabetes mellitus (T2DM).Methods 120 cases of T2DM were divided into Yin Deficiency Syndromes(n=42), Yin hot (n=38), yin and yang (n=40) and 50 cases of normal volunteers were select as the control group. The diponectin gene (aPM1) promoter polymorphisms of each group were detected with polymerase chain reaction amplification (PCR).Results Serum APN Yin hot levels in patients with T2DM (6.98 ± 1.23 μg/ml) were lower than Qi and yin (2.55 ± 0.78 μg/ml) and yang group (3.48 ± 0.22 μg/ml) (P<0.05), and TG, LDL-C, TC (4.48 ± 0.87 mmol/L, 4.98 ± 0.42 mmol/L, 5.36 ± 0.79 mmol/L) were higher than Qi and yin (3.25 ± 0.75 mmol/L, 4.02 ± 0.69 mmol/L, 3.12 ± 0.52 mmol/L) and yang group (3.18 ± 0.69 mmol/L, 4.09 ± 0.71 mmol/L, 3.22 ± 0.78 mmol/L)(P<0.05). Yin hot type aPM1-11377G/C genotype of the GG genotype was significantly higher than the proportion of Qi and yin and yang group (P<0.05), while the yin and yang and yin and yang group aPM1-11377G/C genotype the proportion was higher in GG genotype (P<0.05). GG genotype was significantly lower than serum APN type CG and CC genotype (P<0.05), whereas no significantdifference in other indexes (P>0.05).Conclusion T2DM patients Yin hot type inherent relationship with aPM1-11377G/C polymorphism, aPM1-11377G/C polymorphism may reflect R2DM Disease Syndromes typing a certain extent, and by influence insulin resistance in patients with arterial plaque and serum APN levels, thereby affecting T2DM disease occurrence and progression.

OBJECTIVETo investigate the mechanism associated with thoracolumbar burst fractures.

METHODSStress distribution of the spine in the upright, flexion and extension positions was analyzed using a three-dimensional finite element model of the spinal motion segment.

RESULTSStress concentration was noted at the pedicle and posterosuperior part of the vertebral body near the pedicle.

CONCLUSIONStress concentration of the spine may be implicated in the biomechanical mechanism underlying thoracolumbar burst fractures.