ObjectiveTo review the research progress of cementless intercalary prosthesis stem. MethodsThe literature about the cementless intercalary prosthesis in treatment of bone defects of extremities was reviewed, and the designing and application of prosthesis stem were analyzed. ResultsCementless intercalary prosthesis has the advantages of good biocompatibility. However, there are also some disadvantages, including the multiple factors affecting the fixation of the prosthesis stem and individual differences in the stability of the prosthesis. The methods to improve the fixation stability of prosthesis stem mainly include the optimization of prosthesis stem shape, addition of auxiliary fixation, and improvement of coating materials on the stem surface as well as porous structure of the stem surface. Among these methods, augment with auxiliary fixation has the most satisfactory effect on improving the stability of prosthesis. However, the deficiency of the method is the increasing risk of the larger incision exposure and surgical trauma. ConclusionImproving the design and fixation method of the cementless intercalary prosthesis stem can further improve the stability of the prosthesis. Under the premise of avoiding increasing surgical trauma as much as possible, addition of the auxiliary fixation can be a feasible choice to improve the fixation stability of prosthesis.
ObjectiveTo observe the changes of macular microvascular structure in eyes with macular edema secondary to branch retinal vein occlusion (BRVO-ME) after intravitreal injection of conbercept and analyze its relationship with visual function and central retinal thickness (CRT).MethodsA prospective clinical study. From July 2018 to June 2019, 21 eyes of 21 patients with unilateral temporal BRVO-ME diagnosed in the Department of Ophthalmology of Peking Union Medical College Hospital were included in the study. Among them, there were 14 eyes of 14 males and 7 eyes of 7 females; the average age was 58.0±8.3 years. There were 13 eyes and 8 eyes with occlusion of the superior temporal and inferior temporal branches of the retinal vein, respectively. The affected area was defined as the side of the venous obstruction. All the affected eyes underwent best-corrected visual acuity (BCVA) and optical coherence tomography angiography (OCTA) examination. The BCVA was tested using the international standard logarithmic visual acuity chart, which was converted into the logarithmic minimum angle of resolution (logMAR) visual acuity during statistical analysis. All the eyes were treated with intravitreal injection of conbercept once a month for 3 months, and then treated as needed. A 3 mm × 3 mm scan centered on fovea was obtained and the vascular density of superficial capillary plexus (SCP) and deep capillary plexus (DCP), fovea avascular zone (FAZ) area, perimeter of FAZ (PERIM), acircularity index (AI), foveal vascular density in a 300 μm wide region around FAZ (FD-300) and central retinal thickness (CRT) were measured. The follow-up time after treatment was 6 months. The vascular density and FAZ parameters were compared before and after treatment by paired t test. The correlations of BCVA, CRT and vascular density, FAZ area and the other parameters at 6 months after treatment were analyzed by linear regression analysis. ResultsBefore treatment, the logMAR BCVA of the eyes was 0.506±0.159, and the CRT was 375.4±81.3 μm; 6 months after treatment, the logMAR BCVA of the eyes was 0.294±0.097, and the CRT was 266.3±46.7 μm. There was a statistically significant difference of logMAR BCVA and CRT between the eyes before and after treatment (t=8.503, 9.843; P＜0.05). There was no statistically significant difference in the overall vascular density of SCP and DCP before and 6 months after treatment (t=－0.091, －0.320; P＞0.05). The foveal vascular density decreased, and the difference was statistically significant (t=8.801, 3.936; P＜0.05). The vascular density of DCP of the affected area increased, and the difference was statistically significant (t=－2.198, P＜0.05). Compared with those before treatment, the FAZ area and PERIM of the affected eyes had an increasing trend, while AI and FD-300 had a decreasing trend, and the differences were statistically significant (t=－18.071, －12.835, 2.555, 8.610; P＜0.05). The linear regression analysis showed that BCVA and FAZ area 6 months after treatment have significant correlation (t=2.532, P=0.024). ConclusionCRT decreased and BCVA increased after intravitreal injection of conbercept in BRVO-ME eyes. After treatment, the foveal vascular density of SCP and DCP decreased while the vascular density of DCP of the affected area increased. The FAZ increased and the PERIM and AI decreased during follow-up. The BCVA was significantly correlated with the FAZ area 6 months after treatment.
This study explored the variation of bursting force of multi-chamber infusion bag with different geometry size, providing guidance for its optimal design. Models of single-chamber infusion bag with different size were established. The finite element based on fluid cavity method was adopted to calculate the fluid-solid coupling deformation process of infusion bag to obtain corresponding critical bursting force. As a result, we proposed an empirical formula predicting the critical bursting force of one chamber infusion bag with specified geometry size. Besides, a theoretical analysis, which determines the force condition of three chamber infusion bag when falling from high altitude, was conducted. The proportion of force loaded on different chamber was gained. The results indicated that critical bursting force is positively related to the length and width of the chamber, and negatively related to the height of the chamber. While the infusion bag falling, the impact force loaded on each chamber is proportional to the total liquid within it. To raise the critical bursting force of in fusion bag, a greater length and width corresponding to reduced height are recommended considering the volume of liquid needed to be filled in.
Objective Poly (propylene carbonate) (PPC), a newly reported polymer, has good biodegradabil ity and biocompatibil ity. To explore the feasibil ity of using electrospinning PPC materials in nerve tissue engineering, and to observe the effect of al igned and random PPC materials on axonal growth of rat dorsal root gangl ions (DRGs) in vitro. Methods Either al igned or randomly oriented sub-micron scale polymeric fiber was prepared with an electrospinning process. DRGs were harvested from 3 newborn Sprague-Dawley rats (female or male, weighing 4-6 g), and were incubated into 12-pore plate containing either al igned (the experimental group, n=6) or randomly oriented sub-micron scale polymeric fiber (the control group, n=6). The DRGs growth was observed with an inverted microscope; at 7 days immunofluorescent staining and scanning electronic microscope (SEM) observation were performed to quantify the extent of neurite growth andSchwann cells (SCs) migration. Results Either al igned or random fibers were fabricated by an electrospinning process. The diameter of the individual fiber ranged between 800 nm and 1 200 nm. In al igned PPC material, 90% fibers arranged in long axis direction, but the fibers in random PPC material arranged in all directions. The DRGs grew well in 2 PPC materials. Onthe al igned fiber film, the majority of neurite growth and SCs migration from the DRGs extended unidirectionally, parallel to the al igned fibers; however, neurite growth and SCs migration on the random fiber films oriented randomly. The extents of neurite growth were (2 684.7 ± 994.8) μm on the al igned fiber film and (504.7 ± 52.8) μm on the random fiber films, showing significant difference (t= —5.360, P=0.000). The distances of SCs migration were (2 770.6 ± 978.4) μm on the al igned fiber film and (610.2 ± 56.3) μm on the random fiber films, showing significant difference (t= —5.400, P=0.000). The extent of neurite growth was fewer than the distances of SCs migration in 2 groups. Conclusion The orientation structure of sub-micron scalefibers determines the orientation and extent of DRGs neurite growth and SCs migration. Al igned electrospinning PPC fiber is proved to be a promising biomaterial for nerve regeneration.
In view of the evaluation of fundus image segmentation, a new evaluation method was proposed to make up insufficiency of the traditional evaluation method which only considers the overlap of pixels and neglects topology structure of the retinal vessel. Mathematical morphology and thinning algorithm were used to obtain the retinal vascular topology structure. Then three features of retinal vessel, including mutual information, correlation coefficient and ratio of nodes, were calculated. The features of the thinned images taken as topology structure of blood vessel were used to evaluate retinal image segmentation. The manually-labeled images and their eroded ones of STARE database were used in the experiment. The result showed that these features, including mutual information, correlation coefficient and ratio of nodes, could be used to evaluate the segmentation quality of retinal vessel on fundus image through topology structure, and the algorithm was simple. The method is of significance to the supplement of traditional segmentation evaluation of retinal vessel on fundus image.
Objective To observe the morphological changes of dendrite and soma in retinal ganglion cells (RGCs) which subsisted in early diabetic rats. Methods The RGCs of 3-months-course diabetic rats and coeval normal rats were marked by gene gun techniques. To collect RGCs photographs by Leica microscope with Z axis and CCD camera；to observe the changes of diameter, variance of structural features in dendritic field and somata after classification which according to the size and morphology. Thy-1 antibody marks on the retinal RGCs, taking a photograph under fluorescent microscope, counting the changes of retinal RGCs density in early diabetic rat. Results In three-month diabetic rats,the density of retinal RGCs was decreased obviously. Morphological changes of RGCs in the dendritic fields were observed with gene gun technique. There was no severe variation in all kinds of the bole of cell dendrite, in which some only showed crispation partially and sparseness also twisting in the dendritic ramus. The mean diameter of dendritic field and soma in class A of diabetic rats was (401plusmn;86) mu;m, the mean diameter of dendritic field in control group was (315plusmn;72) mu;m,compared with each other, there is statistically significant differences (t=21.249，Plt;0.001); the mean diameter of soma in class A of diabetic rats was (24plusmn;6) mu;m, the mean diameter of soma in control group was (22plusmn;5) mu;m, compared with each other, there is no statistically significant differences (t=0.927，Pgt;0.05); the mean diameter of dendritic field and soma in class B of diabetic rats were (170plusmn;36)、(14plusmn;2) mu;m respectively, in control group were (165plusmn;36)、(16plusmn;2) mu;m, the mean diameter of dendritic field and soma in class C of diabetic group were(265plusmn;78)、(17plusmn;5) mu;m respectively, in control group were (251plusmn;57)、(17plusmn;4) mu;m , compared with each other, there are on statistically significant differences(t=1.357，0.798，0.835，1.104，Pgt;0.05). Conclusions In short-term diabetes, the survived RGCs show good plasticity in adult diabetic rats, especially in class A. The changes of dendrites were more sensitive than the soma, which could be the leading index of the morphologic changes of RGCs in the early stage. The good plasticity showed by the RGCs and the time window from changing in dendrite to cell death provide us many evidences not only for the research but also for the nerve protection in clinic. (Chin J Ocul Fundus Dis,2008,24:249-254)
Objective To review the progress in influence of bony structure of glenohumeral joint on the shoulder joint stabil ity. Methods Recent l iterature, concerning the influence factors of the shoulder joint stabil ity and the action of bony structure of the glenohumeral joint in the stabil ity of shoulder joint, was extensively reviewed and summarized. Results The specific factors which the bony structure of the glenohumeral joint influences the stabil ity of the shoulder joint are the conformity index, the shape of the glenohumeral joint, version angle, incl ination angle, and head shaft angle, etc. Conclusion Although the predecessor’s research experience and cl inical reports have prel iminarily determined therelationship between the bony structure of the glenohumeral joint and the stabil ity of the shoulder joint, it is necessary to further study in various aspects (including anatomy, biomechanics, and cl inical practice).
In order to investigate the effect of nerve compression on neurons, the commonly used model of chronic nerve compression was produced in 48 SD rats. The rats were sacrificed in 1, 2, 3, 4, 5 and 6 months after compression, respectively. The number of neuron and ultrashruchure of alpha-motor neurons and ganglion cells of the corresponding spinal segment were examined. The results showed as following: After the sciatic nerve were crushed, the number of neuron and ultrastructure of alpha-motor neurons and ganglion cells might undergo ultrastructural changes, and even the death might occur. These changes might be aggravated as the time of crushing was prolonged and the compression force was increased. It was concluded that for nerve compression, decompression should be done as early as possible in order to avoid or minimize the ultructural changes of the neuron.
ObjectiveTo investigate the changes and clinical significance of cardiac structure and function evaluation by cardiac magnetic resonance imaging (CMR) for patients with pectus excavatum deformity at preoperation. MethodsWe retrospectively analyzed 54 patients (24 children and 30 adults) who underwent pectus excavatum surgery from June 2012 to June 2014. There were 48 males and 6 females at age of 7-33 (19.08±5.17) years. All the patients underwent CMR using 1.5 Tesla scanner for evaluation of compressing and displacement of the heart. The major and minor dimensions of right ventricle were measured. The right ventricle end-diastole volume (RVEDV), right ventricle end-systolic volume (RVESV), and right ventricle ejection fraction (RVEF) were also recorded and analyzed. ResultsThe heart compression and displacement occurred in 83.3% of the children group and 90.0% of the adults group. The extent of heart displacement in the adults was more serious than that in the children (76.86%±13.30% vs. 67.99%±8.15%, P<0.05). The structure of right ventricle were striking distorted because right atrum or right ventricule below valve ring was compressed locally, with the major dimension of right ventricle obviously increased, and the minor dimension of right ventricle obviously decreased. The indices of right ventricle major dimension and right ventricle minor dimension were 61.14±0.44 mm/m2 and 14.82±2.52 mm/m2 in the children, 49.54±15.40 mm/m2 and 18.90 ±3.14 mm/m2 in the adults. The RVEDV and RVESV were significantly higher in the adults than those in the children (139.09±29.08 ml vs. 121.50±31.27 ml; 73.61±16.05 ml vs. 64.92±19.28 ml; P<0.05). RVEF was similar between the children and the adults (45.29%±4.14% vs. 46.30±6.09%). The patients' symptoms disappeared after correction of pectus excavatum. ConclusionCMR is an useful method for evaluating right ventricular structure and functions in patients with cardiac compression and distortion by pectus excavatum before operation, which can bring strong indications for pectus excavatum repair surgery.
ObjectiveTo investigate the three-dimensional (3D) culture and morphology of human eccrine sweat gland cells. MethodsThe human eccrine sweat gland cells were isolated from normal abdominal full thickness skin by digestion of type II collagenase, and cultured in defined-keratinocyte serum free medium supplemented with 5 ng/mL recombinant human epidermal growth factor, 25 mg/mL bovine pituitary extract, 100 U/mL penicillin, and 100 μg/mL streptomycin at 37℃ in a humidified atmosphere of 5%CO2/95% air incubator. When the cell fusion reached above 80%, the cells were harvested and the concentration was adjusted to 1×105 cells/mL. The mixture of 0.3 mL cell suspension and 0.3 mL Matrigel basement-membrane matrix was cultured in 12-well plate. The cell growth was observed under an inverted phase contrast microscope. At 14 days after culture, frozen sections were prepared and were stained with HE to observe the cells morphology, and immunohistochemical analysis was used to detect the antigen expressions of cytokeratin 7 (CK7) and CK19. ResultsInverted phase contrast microscope observation showed that many free eccrine sweat gland tissues were seen after digestion of type II collagenase; eccrine sweat gland cells grew adhering to the wall at 3-5 days and continued division for 2-3 weeks to form single ring around the block sweat glands; cellular senescence were observed after 3-4 weeks. During the process of 3D culture, the single eccrine sweat gland cell divided into 2-4 cells after 2-3 days, and these cells subsequently formed small cell clusters, tubular-like structures and finally spheric-like shapes. After cultured for about 2 weeks, there was crack in part of the gelled mixture or liquefaction occurred. HE staining of frozen sections of the 3D cultures showed some of the tubular-like structures composed of 1-2 layers of epithelial cells, which were similar to the secretion part and the duct part of the eccrine sweat gland. Immunohistochemical analysis showed that CK7 and CK19 antigens expressed positively in the cells. ConclusionHuman eccrine sweat gland cells cultured in Matrigel can form the 3D structures which simulate the morphology of eccrine sweat glands in vivo.