Biomechanical analysis of four internal fixations for Pauwels Ⅲ femoral neck fractures with defects / 中国骨伤

OBJECTIVE@#To investigate the biomechanical characteristics of different internal fixations for Pauwels type Ⅲ femoral neck fracture with defect, and provide reference for the treatment of femoral neck fracture.@*METHODS@#Three-dimensional (3D) finite element models of femoral neck fractures were established based on CT images, including fracture and fracture with defects. Four internal fixations were simulated, namely, inverted cannulated screw(ICS), ICS combined with medial buttress plate, the femoral neck system (FNS) and FNS combined with medial buttress plate. The von Mises stress, model stiffness and fracture displacements of fracture models under 2 100 N axial loads were measured and compared.@*RESULTS@#When femoral neck fracture was fixed by ICS and FNS, the peak stress was mainly concentrated on the surface of the screw near the fracture line, and the peak stress of FNS is higher than that of ICS;When the medial buttress plate was combined, the peak stress was increased and transferred to medial buttress plate, with more obvious of ICS fixation. For the same fracture model, the stiffness of FNS was higher than that of ICS. Compared with femoral neck fracture with defects, fracture model showed higher stiffness in the same internal fixation. The use of medial buttress plate increased model stiffness, but ICS increased more than FNS. The fracture displacement of ICS model exceeded that of FNS.@*CONCLUSION@#For Pauwels type Ⅲ femoral neck fracture with defects, FNS had better biomechanical properties than ICS. ICS combined with medial buttress plate can better enhance fixation stability and non-locking plate is recommended. FNS had the capability of shear resistance and needn't combine with medial buttress plate.

Risk factors for elevated serum total bile acid in preterm infants / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the risk factors for elevated serum total bile acid (TBA) in preterm infants.</p><p><b>METHODS</b>A retrospective analysis was performed for the clinical data of 216 preterm infants who were admitted to the neonatal intensive care unit. According to the presence or absence of elevated TBA (TBA >24.8 μmol/L), the preterm infants were divided into elevated TBA group with 53 infants and non-elevated TBA group with 163 infants. A univariate analysis and an unconditional multivariate logistic regression analysis were used to investigate the risk factors for elevated TBA.</p><p><b>RESULTS</b>The univariate analysis showed that there were significant differences between the elevated TBA group and the non-elevated TBA group in gestational age at birth, birth weight, proportion of small-for-gestational-age infants, proportion of infants undergoing ventilator-assisted ventilation, fasting time, parenteral nutrition time, and incidence of neonatal respiratory failure and sepsis (P<0.05). The unconditional multivariate logistic regression analysis showed that low birth weight (OR=3.84, 95%CI: 1.53-9.64) and neonatal sepsis (OR=2.56, 95%CI: 1.01-6.47) were independent risk factors for elevated TBA in preterm infants.</p><p><b>CONCLUSIONS</b>Low birth weight and neonatal sepsis may lead to elevated TBA in preterm infants.</p>

Diagnostic value and influencing factors for amplitude-integrated EEG in brain injury in preterm infants / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the diagnostic value and influencing factors for amplitude-integrated EEG (aEEG) in brain injury in preterm infants.</p><p><b>METHODS</b>One hundred and sixteen preterm infants with a gestational age (GA) between 27 weeks and 36(+6) weeks were enrolled as subjects. The aEEG scores of all preterm infants were obtained within 6 hours after birth. According to the diagnostic results, the 116 preterm infants were divided into two groups: brain injury (n=63) and non-brain injury (n=53). The risk factors for brain injury were evaluated using logistic regression analysis. According to the aEEG results, the 116 preterm infants were divided into two groups: normal aEEG (n=58) and abnormal aEEG (n=58). The influencing factors for aEEG results in preterm infants were determined using univariate analysis.</p><p><b>RESULTS</b>The brain injury group had a significantly higher rate of abnormal aEEG than the non-brain injury group (83% vs 11%; P<0.05). The infants in the brain injury group from two different GA subgroups (27-33(+6) weeks and 34-36(+6) weeks) had significantly lower aEEG scores than the non-brain injury group from corresponding GA subgroups (P<0.01). Logistic regression analysis showed that low GA (<32 weeks), low birth weight (<1 500 g), abnormal placenta, fetal membranes, and umbilical cord, and hypertension during pregnancy were high-risk factors for brain injury (P<0.05). There were significant differences in GA, birth weight, abnormal placenta, fetal membranes, and umbilical cord, and hypertension during pregnancy between the normal and abnormal aEEG groups (P<0.05).</p><p><b>CONCLUSIONS</b>The risk factors for brain injury are consistent with the influencing factors for aEEG results in preterm infants, suggesting that aEEG contributes to the early diagnosis of brain injury.</p>

SUDHL-4 cell culture in vitro and establishment of mouse tumor model / 中国实验血液学杂志

This study was designed to investigate the biological and immunological characteristics of a human diffuse large B-cell lymphoma (DLBCL) cell line SUDHL-4, and to establish a mouse model for human DLBCL. SUDHL-4 cells were cultured under different conditions. The morphology and in vitro expression of B-cell and tumor-related markers were detected by microscopy and flow cytometry respectively. To establish the transplanted tumor, the cells were injected subcutaneously into SCID mice. Tumor formation and its histomorphology were analyzed. The results showed that the expression of B cell/tumor-related markers was found on cultured SUDHL-4 cells. A stable mouse model of human DLBCL was successfully established in SCID mice by subcutaneous injection of 10(7) SUDHL-4 cells. Tumor tissue from mice exhibited similar histologic manifestation to those of human DLBCL. It is concluded that the SUDHL-4 cells represent a high consistency in immunological characteristics with human DLBCL. Transplantation of SUDHL-4 cells provides a syngeneic mouse model for the study of human DLBCL.

Risk factors for Tourette syndrome / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To identify the risk factors for Tourette syndrome (TS) in children.</p><p><b>METHODS</b>Through a genetic epidemiologic case control study, segregation ratio was estimated using the method of Li-Manted-Gart in 80 children with TS. Heritability for the first- and second-degree relatives was estimated using the Falconer regression method. In addition, the 80 children and 80 controls with other diseases were evaluated using the Family Environment Scale and a self-designed questionnaire. Risk factors for TS were investigated using single factor and multifactor regression analysis.</p><p><b>RESULTS</b>The segregation ratio of TS was 0.1176. Heritabilities for the first- and second-degree relatives were (49.7±2.6)% and (21.5±3.4)% respectively. The weighted mean heritability of the first-degree and second-degree relatives was (39.5±2.1)%. Significantly decreased scores were noted in independence, active-recreational orientation and organization and increased scores were noted in the conflict and control in the TS group compared with the control group (P<0.01). Single factor analysis indicated that the risk factors for TS included family history, type of home education, maternal smoking, family conflict, low level of parental education, family control and fetal anoxia. Multifactor regression analysis indicated that there were five important risk factors for TS: family history, family conflict, type of family education, low level of parental education and maternal smoking.</p><p><b>CONCLUSIONS</b>Both heredity and environment are involved in the pathogenesis of TS. The mode of inheritance for TS is polygenic. Improving the living environments of children with a family history of TS is of prime importance.</p>

Relationship of variation 3057 G-->A of exon 20 of leptin receptor gene to lipid metabolism and fat distribution of children with obesity / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the relationship of the variation of exon 20 of leptin receptor (LEPR) gene to the lipid metabolism and fat distribution of the children with obesity.</p><p><b>METHODS</b>Polymerase chain reaction-restriction fragment length polymorphism(RFLP) and polyacrylamide gel electrophoresis were used to analyze the variation of exon 20 of the LEPR gene of the obesity group(72 obesity children) and the control group(60 healthy children). At the same time, all childrens' serum triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C), low density lipoprotein cholesterol(LDL-C), height and weight were measured, and their body mass index(BMI) and fat percent(%fat) were calculated.</p><p><b>RESULTS</b>Three genotypes of exon 20 of LEPR gene were detected in this study. Compared with the control, the frequency of gene variation at 3057 nucleotide G-->A transversion was higher(P<0.05). The concentration of serum TG and the BMI and %fat of the A/A genotype obesity children were higher than those of the G/G genotype ones(P<0.01) but the level of serum HDL of the A/A children were lower than that of the G/G children (P<0.01). As to the G/A genotype children, only their serum TG level was higher than that of the G/G genotype ones(P<0.05).</p><p><b>CONCLUSION</b>The above findings indicated there were polymorphisms in the children with obesity, and those polymorphisms might remarkably affect their lipid metabolism and fat distribution.</p>