BACKGROUND: Defatting is to reduce the special cell surface antigens by clearing fat and lipoprotein, so as to decrease immunological rejection, improve the biocompatibility of allograft bone, and increase osteogenic potential. However, the effect of defatting on biomechanical performance of bone remains controversial.OBJECTIVE: To explore the influence of defatting on the biomechanics of bovine cortical bone samples.DESIGN, TIME AND SETTING: Randomized, self-controlled observation was performed in Futian People's Hospital of Guangdong Medical College between 2006 and 2008.MATERIALS: Eight pairs of healthy adult bovine femora were used. Bone blocks, 50 mm long and 10 mm wide, were selected from each pair of femora, and burnished into 24 pairs of 7 mm×7 mm×40 mm rectangular bovine cortical bone samples.METHODS: The 24 pairs of cortical bone samples were randomly divided into two groups (n=12). One of each pair was selected as test group sample, and the other as control group sample. The samples of test group were defatted In 500 mL chloroform and methanol mixture (1:1) for 24 hours, while control samples were immerged in deionized water for 24 hours. Six samples from each group were selected for axial compressive test and three-point bending test.MAIN OUTCOME MEASURES: Load and deflection of every sample.RESULTS: Axial compressive test showed that the maximum load and the maximum strain of defatted samples were significantly decreased compared with control group, but the fragility and elastic modulus were increased (P < 0.05). In three-point bending test, the maximum load and the maximum stress of defatted sampled were significantly decreased, the maximum deflection was decreased, and the elastic modulus was increased (P < 0.05).CONCLUSION: The mechanical strength of cortical bone decreased but the fragility increased after defatting.

OBJECTIVE To study the gene chip joint pyrosequencing technology in the newborn genetic deafness gene mutation screening, and provide a theoretical basis for the early diagnosis and prevention of genetic deafness. METHODS 2000 Neonatal EDTA umbilical cord blood was collected and genomic DNA (gDNA) was extracted. Microarray chip was used to detect four deafness gene at 9 mutation sites. And the positive result of gene chip detection was verified by pyrosequencing.RESULTS Among the GJB2 mutations, there were 1 case of 35delG mutation type, 3 cases of 176 del16 mutation type, 57 cases of 235del C mutation type, 9 cases of 299 del AT mutation type, 6 cases of GJB3 gene 538C>T mutation type. There were 5 cases of 1555A>G mutations and 1 case of 1494C>T mutations in mitochondrial 12S rRNA. There were 6 cases of 2168A>G mutation type and 23 cases of IVS7-2A>G mutations in SLC26A4. 103 cases of newborns carry the mutated gene in 2,000, the gene mutation rate is 5.15%. CONCLUSION All the four genes mutation at nine mutation sites are found in newborns with family history of non-hereditary deafness, and GJB2 gene mutation is common. The screening of genetic deafness in newborns is very important for early diagnosis and prevention of hereditary hearing loss. In particular, the diagnosis of mitochondrial 12S rRNA gene mutation can prevent the occurrence of deafness caused by drug use, for the genetic mutation of these carriers' health is of great significance.

ObjectiveTo investigate the feasibility of decreasing radiation dose and contrast media dose of abdominal CTA using low tube voltage setting combined with personalized contrast media application.MethodsOne hundred and twenty patients were randomly divided into 3 groups,and there were 40 patients in each group.120 kV tube voltage was used in group A,and 100 kV tube voltage was used in group B and C.Personalized injection flow rate of contrast media which determined according to patient's body mass (injection flow rate =λ × body mass) was used for all groups,and the λ values for group A,B and C were 0.07,0.07 and 0.06 ml · kg-1· s- 1 respectively. CT dose index volume ( CTDIvol ) effective dose(ED) and contrast media dose were evaluated,and these parameters were all analyzed using one-way ANOVA analysis.Image quality of abdominal aorta and branch arteries was rated using a three-point ordinal for all 3 groups,and image quality score was analyzed using Kruskal-Wallis test.ResultsCTDIvol were (8.2±0.8),(6.0 ±1.0) and (6.1 ±1.1)mGy for group A,B and C,ED were (5.2 ±0.8),(3.5 ± 0.7) and ( 3.6 ± 0.6) mSv,and contrast media dose were (72.3 ± 10.3 ),(73.5 ± 11.3 ) and (61.6 ±9.4) ml,respectively.There were significant differences in CTDlvol,ED and contrast media dose among 3 groups ( F =66.094,77.812,15.919 ; P =0.000).Compare with group A,the ED of group B was decreased 32.7％,and the ED and contrast media dose of group C were decreased 30.8％ and 14.8％,respectively.Image quality was rated as excellent,good,and general for 20,19 and 1 patients in group A,25,15 and 0 patients in group B,and 23,17 and 0 patients in group C,respectively.There was no significant difference in image quality score among 3 groups ( x2 =1.492,P =0.474 ).ConclusionsThe radiation dose and contrast media dose can be decreased in abdominal CTA using low tube voltage and personalized contrast media apolication while image quality can be preserved.

Objective To observe the application and efficacy of dynamic condylar screw (DCS) in treating intertrochanteric fractures of the femur and discuss the fixation principle, feasibility, advanta-ges and related issues. Methods A retrospective analysis was done on 23 patients with intertrochanter-ic fractures of the femur treated with DCS from January 2000 to December 2006. Of all, there were 10 elderly patients with different levels of various kinds of internal diseases and 13 young patients injuried by high-energy such as traffic accidents. According to Boyd' s classfication, there was one patient with type Ⅰ fracture, five with type Ⅱ , nine with type Ⅲ and eight with type Ⅳ. After a detailed pre-operative physical examination and targeted treatment, DCS fixation was employed for intertrochanteric fractures of the femur. Results A follow-up for average 18 months showed no death. Early complications occurred in three patients including two with pulmonary infection and one with urinary tract infection, who got cured after proper treatment. There was one patient with long-term complication, post-traumatic arthritis. All 23 patients got bone healing, with excellenee rate of 96% according to Harris criteria. There were no complications like breakage of nails, nonunion, eoxa yarn deformity, shortening or external rotation of the lower limb. Conclusions DCS has advantages of simple operation, reliable fixation and coincidence with biomechanical characteristics and hence is one of ideal methods for treatment of intertrochanteric frac-ture of the femur, especially for subtrochanteric fracture, contrary chanteric fractur, fracture involving large pyriform troehanteric and comminuted fractures of sub-trochanteric lateral os integumentale.

Objective To investigate the correlation of plasma matrix metalloproteinase-3 (MMP-3)levels and MMP-3 Lys45Glu (rs679620) polyrnorphism with ischemic stroke and its TOAST subtypes.Methods The patients with large artery atherosclerotic stroke (LAA) and small artery occlusion stroke (SAO)according to TOAST etiological typing (ischemic stroke group) and healthy subjects (control group) were enrolled.The enzyme-linked immunosorbent assay was used to detect plasma MMP-3 level.The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the genotypes of MMP-3 Lys45Glu.Results A total of 233 patients with ischemic stroke were enrolled,in which 162 were LAA and 71 were SAO; 200 healthy subjects were taken as controls.The plasma MMP-3 level in the ischernic stroke group was significantly higher than that in the control goup (253.99 ± 75.02 ng/ml vs.196.38 ± 78.17 ng/ml;t =7.813,P=0.000).The plasma MMP-3 level in the LAA group (262.81 ±69.23 ng/ml) was significantly higher than those in thegroups of SAO (233.85 ± 83.90 ng/ml,P =0.008) and control (P =0.000),and the plasma MMP-3 level in the SAO was also significantly higher than that in the control group (P =0.000).Multivariate logistic regression analysis showed that the increased serum MMP-3 level was an independent risk factor for ischemic stroke (odds ratio [OR] 1.012,95％ confidence interval [CI] 1.008-1.015; P =0.000).There was no significant difference in the frequencies of genotype (x2 =2.085,P =0.353) and allele (x2 =2.29,P =0.130) of MMP-3 Lys45Glu between the ischemic stroke group and the control group.However,there were significant difference in MMP-3 Lys45Glu genotype frequencies among.the groups of LAA,SAO and control (x2 =10.39,P=0.034).The AA + GA genotype frequency in the LAA group was significant higher than those in the groups of SAO (65.4％ vs.49.3％ ;x2 =5.375,P =0.020) and control (65.4％ vs.54.0％ ;x2 =4.84,P =0.028).There was no significant difference in the allele frequencies among the groups of LAA,SAO and control (x2 =3.887,P =0.143).Multivariate logistic regression analysis showed that MMP-3 Lys45Glu polymorphism was an independent risk factor for LAA (OR 1.783,95％ CI 1.183-2.688; P =0.006).The plasma MMP-3 level in patients with the genotypes AA (n =73),GA (n =176) and GG (n =184)were 235.70 ± 70.85 ng/ml,(244.20 ± 85.90 ng/ml and 207.98 ± 77.61 ng/ml.There were significant difference in the plasma MMP-3 levels among the patients with the genotypes AA,GA and GG (F=9.682,P =0.000).The plasma MMP-3 level in the patients with the genotype AA + GA was significantly higher than that in patients with genotype GG (241.71 ± 81.73 ng/ml vs.207.98 ± 77.61 ng/ml; t =4.336,P =0.000).Conclusions The plasma MMP-3 level increased in patients with LAA or SAO,especially in the patients with LAA.The MMP-3 Lys45Glu polymorphism might be associated with the plasma MMP-3 level and LAA.

Objective To investigate the relationship between estrogen levels and tenosynovitis in postm-enopausal women. Methods 74 cases of postmenopausal women,including 32 cases of tenesynovitis (group A),42 cases healthy postrnenopausal women for the control group (group B) were observed. 42 cases of normal menstruation women were taken as control group (group C). Results The estrogen level was (89.7066±126.7458) pmol/L in group A,(45.6768±30.6342) pmol/L in group B,and (626.7384±361.5348)pmol/L in group C,There is statistical difference between group A and group C (P<0.05). Conclusions Tenosynovitis incidence in postmeno-pausal women has no significant relationship with the level of estrogen change.

Objective To investigate the risk factors for clinical poor outcome after microsurgical treatment of ruptured middle cerebral artery aneurysms (MCAA).Methods The patients with ruptured MCAA treated with microsurgery were enrolled retrospectively.The data of demography,medical history,Hunt-Hess grade,imaging characteristics,surgery-related factors,and postoperative complications were collected.Glasgow Outcome Scale (GOS) was used to assess the outcomes.GOS 4-5 was defined as a good outcome and 1-3 was defined as a poor outcome.Results A total of 44 patients with ruptured MCAA were enrolled,including 26 (59.1％) females and 18 (40.9％) males,aged 36-75 years old (mean 58.5 years).The aneurysms were clipped in 42 cases (95.5％) and wrapped in 2 eases (4.5％).They were followed up for 3-6 months,33 (75.0％) had good outcome and 11 (25.0％) had poor outcome.Univariate analysis showed that there were significant differences in the proportions of Hunt-Hess grade,midline shift degree,hematoma volume,intraoperative rupture,decompressive craniectomy,and postoperative pulmonary infection between the good outcome group and the poor outcome group.Multivariatelogistic regression analysis showed that Hunt-Hess grade Ⅳ-Ⅴ (odds ratio [OR] 20.885,95％ confilence interval [CI] 1.342-38.696;P =0.001),intraoperative anenrysm rupture (OR 18.906,95％ CI 2.918-20.915;P=0.011),and complicated with pulmonary infection (OR 38.865,95％ CI 18.718-40.509;P =0.001) were the independent risk factors for poor outcomes.Conclusion The high Hunt-Hess grade,intraoperative aneurysm rupture,and complicated with pulmonary infection after surgery are the independent risk factors for poor outcomes after microsurgical treatment in patients with ruptured MCAA.

Problem-based learning (PBL) has been applied in many teaching fields and achieved satisfying effect. Dermatovenology is a special secondary discipline of clinical medicine which includes dermatosurgery, dermatopathology, laser cosmetology and other different sub-professional subjects, and it covers a wide variety of diseases and it is difficult to identify skin lesions. However, the teaching time for graduate students is limited and the traditional teaching mode can't meet the needs of learning for them. In this paper, the application of PBL method in the teaching of medical graduate students and the application of PBL combined with other teaching methods have been expounded through the analysis of domestic and foreign literature, and its role in the teaching of dermatology graduate students will be discussed.

With the development of modern medical technology,accurate resection of tumor and timely repair and repair of defective tissues and organs are important concerns in the field of tumor research.The precise excision of tumor,refers to the preoperative assessment of systemic and local detection based on detailed to personalized surgical planning,the use of precise operation in operation,ensure as much as possible while minimizing surgical trauma to patients after removal of the lesions,creating the optimal conditions of recovery for trauma patients.Repair and regeneration of defective tissues and organs refers to the deletion or damage of tissues and organs,and gradually resume its anatomical structure and function process under the action of a variety of cells,extracellular mechanisms and related regulatory factors.Then from the tumor resection,tumor resection and accurate regeneration after three point repair technology to change rapidly in the tissue of tumor plastic organ regeneration in tissue of origin.

Objective To compare the effect of the bipolar electric coagulation and unipolar electric coagulation on cranioplasty of scalp separation. Methods The clinical data of 67 patients who underwent unilateral frontotemporal cranioplasty from 2014 to 2017 were retrospectively analyzed. According to coagulation method during operation, these patients were divided into two groups, unipolar electric coagulation group (32 cases) and bipolar electric coagulation group (35 cases). The operation time, postoperative intracranial hemorrhage, infection, epilepsy and subcutaneous effusion were compared between two groups. Results The operation time of two groups had no significant difference (P > 0.05). The incidence of intracranial hemorrhage, infection and epilepsy of two groups had no significant differences (P > 0.05). But the incidence of subcutaneous effusion in unipolar electric coagulation group was significantly higher than that in bipolar electric coagulation group: 28.1%(9/32) vs. 5.7%(2/35), P<0.05. Conclusions The use of unipolar electric coagulation during the scalp separation in cranioplasty can reduce operation time in a certain extent, but significantly increase the incidence of postoperative subcutaneous effusion.