Endogenous tissue engineering: PTH therapy for skeletal repair

Based on its proven anabolic effects on bone in osteoporosis patients, recombinant parathyroid hormone (PTH_1-34) has been evaluated as a potential therapy for skeletal repair. In animals, the effect of PTH_1-34 has been investigated in various skeletal repair models such as fractures, allografting, spinal arthrodesis and distraction osteogenesis. These studies have demonstrated that intermittent PTH_1-34 treatment enhances and accelerates the skeletal repair process via a number of mechanisms, which include effects on mesenchymal stem cells, angiogenesis, chondrogenesis, bone formation and resorption. Furthermore, PTH_1-34 has been shown to enhance bone repair in challenged animal models of aging, inflammatory arthritis and glucocorticoid-induced bone loss. This pre-clinical success has led to off-label clinical use and a number of case reports documenting PTH_1-34 treatment of delayed-unions and non-unions have been published. Although a recently completed phase 2 clinical trial of PTH_1-34 treatment of patients with radius fracture has failed to achieve its primary outcome, largely because of effective healing in the placebo group, several secondary outcomes are statistically significant, highlighting important issues concerning the appropriate patient population for PTH_1-34 therapy in skeletal repair. Here, we review our current knowledge of the effects of PTH_1-34 therapy for bone healing, enumerate several critical unresolved issues (e.g., appropriate dosing regimen and indications) and discuss the long-term potential of this drug as an adjuvant for endogenous tissue engineering.     

一种分离人血清白蛋白的简单方法

<正> 自Cohn等和Oncley等发展了低温乙醇方法分离血浆成五种主要成分以来,从Cohn分段V制备临床白蛋白的方法在全世界已沿用了30多年。1962年Kistler和Nitschmann简化了Cohn的方法,但即使专为生产白蛋白,在回收白蛋白之前,为了去除其它蛋白质,最少还需要三个沉淀步骤。为了满足临床上不断地对此重要血浆蛋白的需求,曾报导了几种改进的方法。这些方法包括采用聚乙二醇进行血浆的初步分离,继后用电渗析或反复离子交换层析和Schneider等的方法,其方法涉及在乙醇和稳定剂的参与下对血浆加热,再用聚乙二醇进行白蛋白的沉淀分离。可是,在美国这些方法未得到生产上的广泛应用。     

印度瘿蚊六新种(双翅目:瘿蚊科)

本种近似菲律宾一种稷(Panicum carinatum)上的Lasioptera paniculi Felt,但触角的节数不同,雌18节,雄16节;雌触角各节的比例不同而较短;抱器基节中等粗,端节较细。其雌触角18节也相似于印度一种稷Panicum fluitans上的L.flui-tans Felt,但触角第五节远比端节长,产卵器短得多。