Divergent effects of peripheral and global neuropeptide Y deletion

Objectives:Neuropeptide Y (NPY) is involved in the coordination of bone mass and adiposity. However, multiple NPY sources exist and their individual contribution to the skeleton and adiposity not known. The objectives of our study were to evaluate the effects of peripheral mesenchymal derived NPY to the skeleton and adiposity and to compare them to the global NPY^KO model.Methods:To study the role of mesenchymal-derived NPY, we crossed conditional NPY (NPY^fl/fl) mice with Prx1cre to generate PrxNPY^KO mice. The bone phenotype was assessed using micro-CT. The skeletal phenotype of PrxNPY^KO mice was subsequently compared to global NPY^KO model. We evaluated body weight, adiposity and functionally assessed the feeding response of NPY neurons to determine whether central NPY signaling was altered by Prx1cre.Results:We identified the increase in cortical parameters in PrxNPY^KO mice with no changes to cancellous bone. This was the opposite phenotype to global NPY^KO mice generated from the same conditional allele. Male NPY^KO mice have increased adiposity, while PrxNPY^KO mice showed no difference, demonstrating that local mesenchymal-derived NPY does not influence adiposity.Conclusion:NPY mediates both positive and negative effects on bone mass via separate regulatory pathways. Deletion of mesenchymal-derived NPY had a positive effect on bone mass.     

Effects of manganese-supplemented diets on growth performance,blood biochemistry,nitrogen metabolism and skeletal development of rex rabbits

(Background) Manganese (Mn) is an essential mineral, although its effects on rabbits is not clear. (Research Purpose) This study was conducted to investigate the effects of the level of supplementation of dietary manganese on growth performance, blood biochemistry, nitrogen metabolism and skeletal development of growing Rex rabbits. (Methods) Two hundred 3-month-old healthy Rex rabbits with similar body weights were randomly divided into 5 groups (A, B, C, D, E), with 40 replicates in each group. The rabbits in the 5 groups were fed a basal diet containing 0, 5, 10, 20 and 40 mg/kg manganese (in the form of manganese sulfate), respectively. The trial included 7 days for adaptation and 29 days of testing. Seven days before the end of feeding, eight rabbits from each group were transferred into a metabolic cage for metabolic testing. (Results) The results showed that supplemental dietary manganese levels did not significantly influence final body weight (FBW) or average daily feed intake (ADFI) (P＞0.05). Average daily gains (ADG) were significantly higher in the 20 mg/kg manganese group than in the other groups, and the ratio of feed to body weight gain (F/G) was significantly affected by manganese level (P < 0.05). No significant differences were found in the digestion coefficients among the groups (P > 0.05). Regarding carcass traits, the thymus index and total fat were significantly different (P < 0.05) among the groups, but there were no other significant differences (P > 0.05). The addition of manganese had no significant effect on the intake of nitrogen (IN), fecal nitrogen (FN), digestible nitrogen (DN) or the apparent digestibility of nitrogen (NAD). Compared to the other groups, urinary nitrogen (UN) was lower in the 20 mg/kg group, although nitrogen deposition (RN), nitrogen utilization (NUR) and the biological potency of nitrogen (NBV) were higher in this group (P < 0.05). As the amount of manganese added to the diet increased, serum triglycerides decreased (P < 0.05). Serum Mn-SOD was significantly lower in the 5 mg/kg manganese group than in the other groups (P < 0.05). The results of this study demonstrate that a diet with supplemented manganese can improve Rex rabbit growth performance and increase RN, NUR and NBV. There were no significant effects of different dietary levels of Mn on the ratio of bone to meat (P > 0.05) or bone strength (P < 0.05). (Conclusion) In conclusion, we determined that the optimal level of manganese supplementation in the diet of growing Rex rabbits was 20 mg/kg, which was also found to reduce nitrogen emissions into the environment.     

北京军都山古代居民的颅骨创伤

北京延庆军都山墓地是东周时期玉皇庙文化的代表性墓地。对墓地出土125例个体颅骨创伤的观察表明,军都山男性颅骨创伤的发生率为13.3%,均为生前钝器伤;女性和未成年个体则未发现有颅骨创伤病例。颅骨创伤的发生没有时代变化或墓葬等级间的差异。军都山古代男性居民较高的颅骨创伤率与暴力冲突关系最为密切,是军都山社会关系不稳定性的一种体现,与农牧交错区生态的脆弱性、外来人群流入以及与周边定居农业人群互动等因素所导致的竞争增强有关。     

Current and future uses of skeletal stem cells for bone regeneration

The postnatal skeleton undergoes growth, modeling, and remodeling. The human skeleton is a composite of diverse tissue types, including bone, cartilage, fat, fibroblasts, nerves, blood vessels, and hematopoietic cells. Fracture nonunion and bone defects are among the most challenging clinical problems in orthopedic trauma. The incidence of nonunion or bone defects following fractures is increasing. Stem and progenitor cells mediate homeostasis and regeneration in postnatal tissue, including bone tissue. As multipotent stem cells, skeletal stem cells (SSCs) have a strong effect on the growth, differentiation, and repair of bone regeneration. In recent years, a number of important studies have characterized the hierarchy, differential potential, and bone formation of SSCs. Here, we describe studies on and applications of SSCs and/or mesenchymal stem cells for bone regeneration.     

Approaches to promoting bone marrow mesenchymal stem cell osteogenesis on orthopedic implant surface

Bone marrow-derived mesenchymal stem cells(BMSCs) play a critical role in the osseointegration of bone and orthopedic implant. However, osseointegration between the Ti-based implants and the surrounding bone tissue must be improved due to titanium's inherent defects. Surface modification stands out as a versatile technique to create instructive biomaterials that can actively direct stem cell fate. Here, we summarize the current approaches to promoting BMSC osteogenesis on the surface of titanium and its alloys. We will highlight the utilization of the unique properties of titanium and its alloys in promoting tissue regeneration, and discuss recent advances in understanding their role in regenerative medicine. We aim to provide a systematic and comprehensive review of approaches to promoting BMSC osteogenesis on the orthopedic implant surface.     

史前人类对动物骨骼油脂的开发和利用

动物骨骼油脂的开发和利用是史前人类生存活动的重要组成部分。西方学者的研究表明,这一过程可能包含了敲骨取髓和骨脂提取两种不同的人类行为。相较于敲骨取髓,骨脂提取更为复杂,不仅要将骨骼砸碎成较小尺寸,还要加水煮沸骨骼碎片,过程中不断添冷水使水保持温和沸腾的状态,才能获得浮于水面的骨脂。目前,国内学者在此领域的研究多关注于前一行为而对后者鲜有论述。本文通过对相关科学文献的全面梳理,系统介绍了史前人类骨脂提取行为的鉴定分析手段和方法,进而探讨了这一行为在古人类资源利用程度、流动性、用火方式和烹饪技术等方面的指示意义与价值。