In vivo and in vitro comparison of the effects of FGF-2 null and haplo-insufficiency on bone formation in mice

We previously reported that deletion of the Fgf2 gene (Fgf2-/-) resulted in decreased bone mass in adult mice. This study examines the effect of haplo-insuffiency (Fgf2+/-) on bone loss in vertebrae from these mutant mice. Fgf2+/+ mice attained peak bone mass at 8-9 months of age. In contrast BMD was significantly reduced in vertebrae from adult (8-9) Fgf2+/- mice. Exogenous FGF-2 rescued reduced bone nodule formation in Fgf2+/- and Fgf2-/- cultures. Runx2 mRNA was reduced in cultures from Fgf2+/- and Fgf2-/- mice. FGF receptor2 mRNA and protein were markedly reduced in Fgf2+/- and Fgf2-/- mice. Decreased bone formation in Fgf2 mutant mice may correlate with impaired FGFR signaling, decreased Runx2 gene expression.     

Evaluating the utility of stable isotope analyses of archived freshwater sample materials

We evaluated the potential utility of stable isotope analysis of tissues commonly archived by aquatic biologists. Previous studies with chemically preserved samples have shown contradictory results, which present an obstacle for the use of archived sample materials. We tested the effects of ethanol and formalin preservation on zooplankton and of ethanol on benthic macroinvertebrate δ¹³C and δ¹⁵N values. We found that neither formalin nor ethanol had a significant effect on δ¹³C and δ¹⁵N values of preserved zooplankton. Nor did ethanol significantly affect δ¹³C or δ¹⁵N values of macroinvertebrates. However, ethanol preservation slightly, but significantly decreased C:N ratios of both zooplankton and macroinvertebrates, probably reflecting some extraction of lipids. Overall, the effects of preservatives on δ¹³C and δ¹⁵N values that we observed were minor. We also compared δ¹³C and δ¹⁵N values analysed from roach scales and perch operculum bones with those analysed from muscle tissue. Decalcification of scales and operculum bones only slightly improved our comparison to muscle tissue δ¹³C and δ¹⁵N values. Decalcified scales had slightly higher δ¹³C and lower δ¹⁵N values. Similarly, decalcified operculum bones showed slightly increased δ¹³C and decreased δ¹⁵N values to those for fish muscle. Our results confirm that scales and operculum bones can provide a suitable proxy for fish muscle in isotope studies with minor correction. We conclude that various archived sample materials can indeed be used with confidence for historical reconstructions of freshwater food webs by stable isotope analysis. Handling editor: K. Martens     

北京凤凰山化石地点发掘简报

北京凤凰山地点位于周口店北京猿人遗址以北8km处, 是一处含哺乳动物化石与灰烬的洞穴-裂隙堆积。该地点包括两个化石层,上层为洞外的冲积物, 由棕红色黏土组成, 靠下部发现有零星的、破碎的化石, 可鉴定出似鸡骨山狐(Vulpes cf.chikushanensis)和羚羊(Antelopinae)两种类型; 下层含有灰烬层, 出土了较为丰富的哺乳动物化石, 可鉴定的哺乳动物化石包括鬣狗(Hyaenidae)、三门马(Equus sameniensis)、犀(Rhinocerotidae)、李氏野猪(Sus lydekkeri)、肿骨大角鹿(Megaloceros pachyosteus)、葛氏斑鹿(Cervus(Sika)grayi)、水牛(Bubalus sp.), 共7种。动物群与周口店第一地点和南京人化石地点的动物群相似, 指示该地点化石层的时代可能为中更新世。部分骨骼表面痕迹与灰烬层的发现显示该地点可能不排除有古人类活动痕迹的存在。     

巫山蓝家寨遗址家畜的动物骨骼

2012年巫山蓝家寨遗址考古发掘中,出土了春秋时期的马(Equus caballus)、黄牛(Bos taurus)、山羊(Capra hircus)、鸡(Gallus gallus domesticus)、狗(Canis familiaris)、猪(Sus domestica)6种家畜的骨骼。这是三峡地区唯一一个在先秦时期六畜兼备的古文化遗址。遗址中的马、牛,是三峡地区同类家畜中时代最早的发现资料。三峡地区早期历史时期,人类肉食资源以野生动物为主,家畜动物骨骼发现材料较少。蓝家寨遗址出现种类较多的家畜动物种类,为全面分析和认识三峡地区经济形态发展过程、古居民行为模式和区域文化等,提供了重要资料。遗址中在春秋时期出现的家畜马和黄牛,与该时期各种区域文化在三峡地区的碰撞、交流、融合有关。     

Multifactorial effects of hyperglycaemia,hyperinsulinemia and inflammation on bone remodelling in type 2 diabetes mellitus

Bones undergo continuous cycles of bone remodelling that rely on the balance between bone formation and resorption. This balance allows the bone to adapt to changes in mechanical loads and repair microdamages. However, this balance is susceptible to upset in various conditions, leading to impaired bone remodelling and abnormal bones. This is usually indicated by abnormal bone mineral density (BMD), an indicator of bone strength. Despite this, patients with type 2 diabetes mellitus (T2DM) exhibit normal to high BMD, yet still suffer from an increased risk of fractures. The activity of the bone cells is also altered as indicated by the reduced levels of bone turnover markers in T2DM observed in the circulation. The underlying mechanisms behind these skeletal outcomes in patients with T2DM remain unclear. This review summarises recent findings regarding inflammatory cytokine factors associated with T2DM to understand the mechanisms involved and considers potential therapeutic interventions.     

金丝猴某些骨骼的功能形态学研究

根据形态学测量方法,本文对三种金丝猴与运动有关的一些骨骼进行了研究。从形态与功能统一的观点讨论了金丝猴的运动类型。     

Revisiting the localisation of Zn cations sorbed on pathological apatite calcifications made through X-ray absorption spectroscopy

The role of oligo-elements such as Zn in the genesis of pathological calcifications is widely debated in the literature. An essential element of discussion is given by their localisation either at the surface or within the Ca apatite crystalline network. To determine the localisation, X-ray absorption experiments have been performed at SOLEIL. The Exafs results suggest that Zn atoms, present in the Zn²⁺ form, are bound to about 4 O atoms at a distance of 2.00 Å, while the interatomic distance R_CaO ranges between 2.35 Å and 2.71 Å. Taking into account the content of Zn (around 1000 ppm) and the difference in ionic radius between Zn²⁺ (0.074 nm) and Ca²⁺ (0.099 nm), a significant longer interatomic distance would be expected in the case of Zn replacing Ca within the apatite crystalline network. We thus conclude that Zn atoms are localised at the surface and not in the apatite nanocrystal structure. Such structural result has essential biological implications for at least two reasons. Some oligoelements have a marked effect on the transformation of chemical phases, and may modify the morphology of crystals. These are both major issues because, in the case of kidney stones, the medical treatment depends strongly on the precise chemical phase and on the morphology of the biological entities at both macroscopic and mesoscopic scales.     

Evidence of Electrical Hysteresis in Bones

The aim of this paper is to investigate: (1) the electrical behavior of bone samples when low (<100 mV) stationary voltages are applied; (2) the reproducibility of successive high impedance (200 TΩ) voltage measurements; and (3) the existence of a spontaneous potential, suggested by previous work. We studied 16 cow bone samples, eight fresh and eight old. We applied analysis of variance to verify the constancy of the bone resistance and the behavior of the time constants. We found that: (1) the existence of a spontaneous potential, on the order of magnitude 10 m V, is confirmed; (2) one constant of time, out of two in a double exponential model, strongly depends on the current direction (p < 0.001); (3) the characteristic voltage-current curve shows a hysteresis loop, maximum amplitude 15% of the full current range; and (4) voltage measurements should be considered perturbative with respect to the electrical response of the samples.