Influence of biological scaffold regulation on the proliferation of chondrocytes and the repair of articular cartilage.

PURPOSE: To investigate the effects of hard tissue engineering scaffold (the material is ß-TCP) with different micro-structures on the proliferation of chondrocytes, and the influence of its composite erythrocytes on the repair of articular cartilage defects. METHODS: Rabbit cartilage cells were on ß-TCP bioceramic scaffold with different micro-structures in vitro, the proliferation growth trend of chondrocytes within the scaffold was calculated, and a optimal micro-structure suitable for cartilage cell growth was determined. Composite chondrocytes were implanted into rabbit models of articular cartilage defects, and the repair situation was observed. RESULTS: the bioceramic scaffold with an inner diameter of 120 µm and an aperture of 500-630 µm was suitable for the growth of cartilage cells. Scaffold loaded with second generation of cartilage cell suspension got a top histological score of 20.76±2.13, which was closely similar to that of normal cartilage. CONCLUSION: When loaded with the second generation of cartilage cells, the ß-TCP biological ceramic scaffold with a pore size of 500-630 µm, and an inner diameter of 120 µm, shows a best repairing effect on animal articular cartilage defects.

An Alternative Intraoperative Radiographic Method for Optimizing Cup Inclination during Total Hip Arthroplasty.

OBJECTIVE: During total hip arthroplasty (THA), the location of the acetabular prosthesis is very important for guaranteeing successful surgery. However, this remains a challenge for many surgeons. This study aimed to investigate the feasibility of using the intraoperative fluoroscopic iliopubic tangential angle (IPTA) to determine the valgus angles of acetabular prostheses. METHODS: In the first stage, the IPTA and valgus angles of native acetabula were defined and measured in 102 THAs obtained from the picture archiving and communication systems of our hospital. Obturator foramen morphology was also measured and divided into groups according to the axial length ratio. Correlations between obturator foramen morphology and IPTA and valgus angles of native acetabula were then determined. In the second stage, angular differences (angle θ) between the IPTA and valgus angles of native acetabula were measured during unilateral THA in 136 patients to determine whether this is a stable value that could be used as a reference for placement of acetabular prostheses. Postoperative data such as Harris Hip Score (HHS) scores and complications were collected and evaluated. RESULTS: The average IPTA at the apex of the true acetabulum was 58.8° ± 4.1°. The average valgus angle of native acetabula was 43.1° ± 3.9° and angle θ was 15.7° ± 1.3°. Obturator foramen morphology was divided into five groups according to the axial length ratio. IPTA was closely related to obturator foramen morphology (Pearson r = 0.489, P ≈ 0.000). Angle θ was stable and independent of obturator foramen morphology. When the IPTA and angle θ were used as references for placing acetabular prostheses in 136 THAs, the average postoperative valgus angles of acetabular prostheses was 45.13° ± 4.07° and the good-to-excellent rate was 97.05%. There were no short-term complications such as fracture, dislocation or infection. The average HHS score 6 months after surgery was 37.2 higher than the preoperative score, this difference being significant (P < 0.01). Neither infection nor dislocation was found 6 months after surgery. CONCLUSIONS: The IPTA (at the apex of the true acetabulum) and angle θ (obtained by intraoperative fluoroscopy) are consistent in determining the postoperative valgus angle of acetabular prosthesis during THA. Thus, IPTA and angle θ are of value in guiding placement of acetabular prostheses; in particular, this method can facilitate the learning of young surgeons.

HDAC5 promotes osteosarcoma progression by upregulation of Twist 1 expression.

Histone deacetylases (HDACs) form a family of enzymes, which have fundamental roles in the epigenetic regulation of gene expression and contribute to the growth, differentiation, and apoptosis of cancer cells. In this study, we firstly investigated the biological function of HDAC5 in osteosarcoma cells. We found that mRNA and protein levels of HDAC5 were upregulated in osteosarcoma tissues and cell lines. Furthermore, overexpression of HDAC5 could promote cell proliferation in osteosarcoma cell lines. In contrast, HDAC5 knockdown using small interfering RNA inhibited cell proliferation. At the molecular level, we demonstrated that HDAC5 promoted mRNA expression of twist 1, which has been reported as an oncogene. Together, these results highlighted for the first time an unrecognized link between HDAC5 and osteosarcoma progression and demonstrated that its specific inhibition might contribute to the treatment of tumorigenesis.

[Study of the effects of utero-placental ischemia on the body and nervous system development in fetal rats].

OBJECTIVE: To discuss the effects of utero-placental ischemia on the body and nervous system development in fetal rats. METHODS: By clamping the unilateral uterine artery of the rat, we produced a utero-placental ischemia model. The opposite uterus of the rat with normal uterine artery supply served as control. We compared the body weight, weight of brain, and the expression of growth associated protein-43 (GAP-43) mRNA in cerebral tissue by RT-PCR in the 13 day (group 1) and 17 day (group 2) old fetal rats respectively. RESULTS: The body weight and weight of brain in group 1 were 3.2 g and 0.16 g respectively, significantly lower than those of control 1 of 3.6 g and 0.18 g respectively (P < 0.01, P < 0.05). The body weight and weight of brain in group 2 were 3.1 g and 0.16 g respectively, also significantly lower than those of control 2 of 3.72 g and 0.17 g respectively (P < 0.01, P < 0.05). The expression of GAP-43 mRNA in cerebral tissue of the group 1 (1.10) and its control (1.12) showed no obvious difference (P > 0.05). However, GAP-43 mRNA in cerebral tissue of the group 2 (1.06) was significantly decreased compared with that of its control (1.21) (P < 0.01). CONCLUSION: Clamping the uterine artery can mimic intrauterine ischemia and produce FGR model. Intrauterine ischemia in the late stage of pregnancy may decrease the expression of GAP-43 mRNA, which might affect the development of nervous system in rats.