BACKGROUND:A selection of treatment for thoracolumbar fracture is very important.OBJECTIVE:To develop and validate three-dimensional finite element models of human thoracolumbar fracture using varying fixation methods,and to compare biomechanical characteristics of fixation method.DESIGN TIME AND SETTING:A contrast observation was performed at the Mechanical Experiment Center of Tongji University from August to October 2008.MATERIALS:64-slice spiral CT (Siemens,Germany) was used to scan T_(11)-L_1 segments of an adult male,and the slice thickness was 0.6 mm.based on Boolean operation,the lower half of T_(12) segment was resected,and the structure of posterior part was reserved to establish finite element model of thoracolumbar fracture.METHODS:There were five groups in this study,including 4 pedicle screws+2 rods (group 1),5 pedicle screws+2 rods at one side (group 2),6 pedicle screws+2 rods at both sides (group 3),anterior fixation (group 4),and anterior plus posterior fixation (group 5).Forces of axial compressive,anterior bending,posterior extension,left bending,and right rotation were loaded to compare the biochemical characteristics.MAIN OUTCOM MEASURES:vonMises stress and displacement at different directions.RESULTS:The stresses of all the fixation screws increased from the anterior part to posterior part in all movement tests,and the strongest stress was measured in the joint position.The stress of proximal screw was stronger than that of the distal screw.Additionally,the stress in group 1 was significantly stronger than in groups 2,3,and 5 (P<0.01).The group 5 was the most stable,but the group 1 was the poorest.CONCLUSION:T_(12) bursting fracture models were established using varying fixation methods,and the results verified that short segment plus fracture vertebral segmental fixation has more superior biomechanics.

[Objective]To assess the clinical outcome of pedicle screw fixation plus bone graft of vertebral body via pedicle for thoracolumbar fractures.[Method]Ninety-six patients treated from 2003-2007 were reviewed.Twenty-eight were treated by short segment fixation(group1).Sixty-eight were treated by short-segment pedicle instrumentation combined with trans-pedicular intracorporeal bone grafting and fixation at the level of the fracture(38 artificial bone as group 2,30 autogenous bone as group 3).Preoperative TLISS(thoracolumbar injury severity score) was evaluated.Radiological evaluation was made for measuring Cobb′s angle,the percentage of the anterior and posterior height of injured vertebra and SI after operation and during the follow-up.[Result]All the patients achieved fracture union during the follow-up with a mean period of 16.8 months(range 12-20 months).All of the fractures were reduced satisfactorily.The height of the injured vertebra,Cobb′s angle correctivity were better in group 2 and 3.There was no difference between those of group 2 and 3.[Conclusion]Short segment plus fracture vertebral segmental fixation can restore the height of vetebra.It is an effcient method for thoracolumbar fracture.

Objective: To intensively investigate sporadic CMT patients, we have analyzed the LMNA gene in this study in a series of 32 unrelated CMT patients. Methods: Twelve exons of the LMNA gene were amplified from genetomic DNA. PCR products of each exon were analyzed by single strand conformational polymorphism (SSCP). Results: No abnormal SSCP pattern, suggesting no mutation in our CMT patients, was detected. Conclusion: The CMT diseases resulted from the mutations of LMNA gene were rare.

Objective: To evaluate the effect of pure titanium modified by bioadhesive RGD peptide on the early attachment, growth and proliferation of osteoblasts. Methods: The titanium samples were hydroxylated by alkali/hot water aging and sol-gel layer-by-layer deposition technique. Afterwards, the terminal -NH_2 group was introduced to the titanium surface by organosilane APTMS self-assembled monolayers and the functional group -NH_2 was further reacted with EDC/NHS by which RGD peptides was covalently immobilized to titanium. The efficiency of this bioreactive surface in promoting cell attachment and the competitive inhibition effect of RGD peptide with different concentrations were observed by calculating the amount of osteoblasts attached on the modified titanium. The growth and proliferation were observed by MTT method and scanning electronic microscopy. Results: The cell adhesion percentage of the RGD modified titanium group was much higher than that of the other groups. The RGD peptide solutions with higher concentration had stronger inhibitory impact on the cell adhesion onto the titanium surface. The cell growth, morphology and proliferation on the RGD peptide modified titanium were better than other groups. Conclusion: Bioadhesive peptide can be chemically grafted onto the titanium surface by means of self-assembled monolayers technique. The cells′ biological behaviors on the surface of RGD immobilized titanium are greatly improved in vitro.

Objectives To detect the cord blood vitamin D level in neonates and to determine the association between the cord blood vitamin D level and neonatal outcomes. Methods A total of 223 eligible mother-and-singleton-offspring pairs were recruited. The information of mothers' pregnancy was collected by questionnaires. The weight, length, and head circumference of neonates were measured. The levels of 25(OH)D in cord blood of neonates and in blood of late pregnancy mothers were determined by chemiluminescence immunoassay. Results The median concentration of 25(OH)D in cord blood was 20.7 nmol/L, and 82.1% of neonate had vitamin D deficiency, and 12.1% had severe vitamin D deficiency (<10 nmol/L). The concentration of 25(OH)D in cord blood was consistent with that in blood of late pregnancy mother. The distribution of concentration of 25(OH)D in cord blood was significantly different in neonates in different seasons of birth (P<0.05). There were more cases <10 nmol/L in winter and spring. The concentration of 25(OH)D in cord blood had no significant associations with the incidences of low birth weight (LBW) and small for gestational age (SGA) (P>0.05). After the variables of sex, gestational age and birth season are controlled, the birth weight and head circumference were significantly different in neonates with different concentrations of 25(OH)D in cord blood (P<0.05). Conclusions The concentration of 25(OH)D in cord blood in term neonates was generally lower. The vitamin D status in neonates was consistet with that in their late pregnancy mothers. Cord blood 25(OH) D levels were associated with neonates' birth weight and head circumference, but it should be confirmed by larger sample size in the future.

bThis study explored whether the transplantation of modified marrow stromal cells (MSCs) has angiogenic effects in a left middle cerebral artery occlusion infarction/reperfusion (MCAO I/R) rat model and preliminarily examined the mechanism of angiogenesis following cerebral infarction. MSCs were isolated by using a direct adherent method and cultured. Vascular endothelial growth factor (VEGF) was transfected into MSCs by employing the liposome transfection. The transfection efficiency was measured by the optical density method. The protein expression of VEGF gene before and after transfection was measured by Western blotting. SD rat model of transient occlusion of the left middle cerebral artery was established by using an approach of intra-luminal occlusion. Tetrazolium (TTC) and HE staining were performed to observe the cerebral infarction. ELISAs were used to measure the levels of VEGF in the rat cerebral tissues. The expression patterns of angiopoietin-2 (Ang-2) and CD34 in cells surrounding the area of infarction were immunohistochemistrically observed. Ang-2 protein expression in the tissue surrounding the area of infarction was measured by Western blotting. VEGF expression in the MSCs increased after transfection at a rate of approximately 28%±3.4%. ELISA showed that the expression of VEGF in the cerebral tissue was significantly increased after induction of infarction, peaking on the 4th day and decreasing to the levels of the sham surgery group (normal) within 7 to 10 days. The VEGF level was significantly higher at each time point in the VEGF-MSC and MSC groups compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than in the MSC group and stayed relatively high until the 10th day. The immunohistochemical results showed that 10 days after the infarction, the number of Ang-2 and CD34-expressing cells in the area surrounding the infarction was significantly higher in the VEGF-MSC group and the MSC group compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than the MSC group. A similar trend in Ang-2 protein expression was revealed by Western blotting. In the MCAO rat model transfected with modified MSCs over-expressing VEGF, compared to the MSC transplantation group, the concentration of VEGF was significantly increased in the brain tissue after cerebral infarction. In addition, the level of Ang-2 was up-regulated, with angiogenesis promoted, the blood supply to the areas surrounding the cerebral infarction increased, and neurological function improved. We are led to speculate that the synergistic effects of VEGF and Ang-2 may be responsible for the angiogenesis following cerebral infarction.

bThis study explored whether the transplantation of modified marrow stromal cells (MSCs) has angiogenic effects in a left middle cerebral artery occlusion infarction/reperfusion (MCAO I/R) rat model and preliminarily examined the mechanism of angiogenesis following cerebral infarction. MSCs were isolated by using a direct adherent method and cultured. Vascular endothelial growth factor (VEGF) was transfected into MSCs by employing the liposome transfection. The transfection efficiency was measured by the optical density method. The protein expression of VEGF gene before and after transfection was measured by Western blotting. SD rat model of transient occlusion of the left middle cerebral artery was established by using an approach of intra-luminal occlusion. Tetrazolium (TTC) and HE staining were performed to observe the cerebral infarction. ELISAs were used to measure the levels of VEGF in the rat cerebral tissues. The expression patterns of angiopoietin-2 (Ang-2) and CD34 in cells surrounding the area of infarction were immunohistochemistrically observed. Ang-2 protein expression in the tissue surrounding the area of infarction was measured by Western blotting. VEGF expression in the MSCs increased after transfection at a rate of approximately 28%±3.4%. ELISA showed that the expression of VEGF in the cerebral tissue was significantly increased after induction of infarction, peaking on the 4th day and decreasing to the levels of the sham surgery group (normal) within 7 to 10 days. The VEGF level was significantly higher at each time point in the VEGF-MSC and MSC groups compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than in the MSC group and stayed relatively high until the 10th day. The immunohistochemical results showed that 10 days after the infarction, the number of Ang-2 and CD34-expressing cells in the area surrounding the infarction was significantly higher in the VEGF-MSC group and the MSC group compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than the MSC group. A similar trend in Ang-2 protein expression was revealed by Western blotting. In the MCAO rat model transfected with modified MSCs over-expressing VEGF, compared to the MSC transplantation group, the concentration of VEGF was significantly increased in the brain tissue after cerebral infarction. In addition, the level of Ang-2 was up-regulated, with angiogenesis promoted, the blood supply to the areas surrounding the cerebral infarction increased, and neurological function improved. We are led to speculate that the synergistic effects of VEGF and Ang-2 may be responsible for the angiogenesis following cerebral infarction.
Angiopoietin-2 ; genetics ; metabolism ; Animals ; Bone Marrow ; metabolism ; pathology ; Cerebral Infarction ; genetics ; metabolism ; pathology ; Male ; Neovascularization, Pathologic ; genetics ; pathology ; Rats ; Rats, Sprague-Dawley ; Stromal Cells ; metabolism ; pathology ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

Objective To explore the role of night waking in the cognitive development of infants and young toddlers. Method A total of 116 infants aged 2 to 30 months were randomly selected in Yiwu, Zhejiang from December 2011 to February 2013. Social-demographic factors were investigated through questionnaire;sleep information were collected via the Brief Infant Sleep Questionnaire (BISQ);Cognitive development was assessed in all infants using Baley development scale. Results The mean age was 12.99 month-old. 50.86%(59/116) were males. Ocassional night waking was reported in 5.26%, one night waking in 29.82%, multiple night waking accounted in 64.91%of children under one year old. Ocassional night waking was reported in 32.20%, one night waking in 45.76%, multiple night waking in 22.03%of children over one year old. The frequency of night waking was signiifcantly different between children under one year old and children over one year old (P<0.01). The average duration of waking was 0.49±0.31 h in children under one year old, and 0.31±0.48 h in children older than one year old, and the difference was signiifcantly different (Z=4.35, P<0.001). In children over one year old, the more frequent night waking, the lowered MDI scores (F=3.98, P=0.024). The waking duration was negatively correlated with MDI scores in children over one year old (r=-0.26, P=0.035). Neither night waking duration nor night waking frequency had signiifcant correlation with MDI scores in children under one year old. Multivariable linear regression conifrmed that night waking was an independent inlfuential factor of MDI and PDI scores in children over one year old. Conclusions Persistent night waking should warrant attention.

OBJECTIVEThe term "premature thelarche" refers to isolated breast development before 8 years of age in female, without any other signs of sexual maturation, while "gynecomastia" is the presence of breast tissue in males. This study aimed to investigate the prevalence of premature thelarche and gynecomastia in Chinese infants and toddlers, identify the potential risk factors, and explore the influence of early breast development on physical growth, mental development and psychomotor development.

METHODA total of 1 510 full term and healthy children at the age of 0-48 months were sampled by stratified cluster random sampling method from 8 provinces from 2011-2012. Weight, height and breast development were assessed by senior primary pediatricians, while Bayley Scale of Infant Development-I (BSID-I) was used to measure the mental developmental index (MDI) and psychomotor developmental index (PDI) for children aged 2-30 months. Social-demographic Questionnaires were completed by the caregivers.

RESULTThe combined prevalence of premature thelarche and gynecomastia was 1.6% (23/1 475), girls 2.2% (15/695), boys 1.0% (8/780), all within 2 years of age. The birth weight, feeding patterns in first 4 months, delivery mode, weaning time and social economic status were not significantly associated with the breast development. However, lower father's education level (OR = 3.632, 95%CI = 1.565-8.432) as well as smoking mother (OR = 18.960, 95%CI = 1.590-226.304) were significantly related to breast development even after adjusting for potential confounders. Lower weight (-0.479 ± 0.648 vs. 0.005 ± 0.987, P < 0.05) and height (-0.602 ± 1.042 vs. 0.008 ± 0.986, P < 0.05) Z score were found in breast development group, even after adjusting for age, gender and father' education level. Neither mental development (t = -0.082, P > 0.05) nor psychomotor development (t = 1.054, P > 0.05) was associated with breast development.

CONCLUSIONWe showed a similar prevalence of premature thelarche with the data reported in similar studies reported from other countries. Among the 0-48 months old infants and toddlers, Father's education level and smoking mother were both related to breast development. Breast development was significantly associated with physical growth, but had no correlation with the mental or psychomotor development.

African Continental Ancestry Group ; Body Height ; Body Weight ; Breast ; growth & development ; Child Development ; Child, Preschool ; Cross-Sectional Studies ; Environmental Exposure ; Female ; Gynecomastia ; epidemiology ; etiology ; Humans ; Infant ; Infant, Newborn ; Male ; Multivariate Analysis ; Prevalence ; Puberty, Precocious ; epidemiology ; etiology

Objective: To investigate the current bedtime routine among Chinese children less than 3 years of age and explore its dose-dependent association with sleep duration and sleep quality. Method: Healthy full-term born children aged 0-35 months were selected by stratified cluster random sampling method from 8 provinces in China following the "Hospital of Province-City-County" sampling technical route during 2012-2013.Brief Infant Sleep Questionnaire(BISQ) was used to assess sleep conditions of these children.Children′s personal and family information was obtained by Shanghai Children′s Medical Center Socio-demographic Questionnaire.Both of these questionnaires were filled in by parents. The effects of bedtime routine on children′s sleep duration and quality were analyzed by multivariate analysis of variance. Result: The children′s average age was(12±10) months(n=1 304), of whom 689 were males (52.8%, 689/1 304). There were 48.5%(632/1 304)of the parents reported that their children had not established regular sleep routines. There was a consistent dose-dependent association between bedtime routine and sleep duration, as well as other indicators for sleep quality (all P<0.05). The more regular the sleep routines, the longer the sleep duration, the earlier the children went to sleep, the shorter the sleep onset latency, the fewer the nighttime wakeup and the shorter the nighttime waking.The nighttime sleep duration was significantly longer for those with a bedtime routine 'every night’ than those who 'never’ had a bedtime routine (9.5(95%CI: 9.4-9.6)vs. 8.9(95%CI: 8.6-9.3)h, t=3.345, P=0.001). Compared with children who never had bedtime routines, children with regular bedtime routines had fewer night wakeup (1.3(95%CI: 1.2-1.4) vs. 2.4( 95%CI: 2.0-2.9), t=3.182, P=0.001) and shorter night waking duration(16.6(95%CI: 14.6-18.8) vs. 59.2 (95%CI: 47.0-72.7)min, t=6.383, P<0.01). Conclusion The percentage of children who have established regular bedtime routine is low in China. There is significant dose-dependent association between regular bedtime routine and sleep outcomes, especially sleep quality. The more regular the sleep routines, the better the sleep quality.