重力打击式小鼠外伤性视神经病变模型的建立及外伤性视神经病变发病机制的探讨

目的 通过建立重力打击式小鼠外伤性视神经病变模型探讨外伤性视神经病变的发病机制.方法 选取SPF级C57BL/6J成熟小鼠48只(96眼),均取小鼠左眼为实验眼进行造模,右眼为对照眼不做处理.采用重力打击建立小鼠外伤性视神经病变模型,造模后第1、3、5、7天对小鼠进行观察,每个时间点取6只小鼠进行闪光视觉诱发电位检查、...     

癌因性疲劳动物模型的研究进展

癌因性疲劳(CRF)是一种与癌症本身或癌症治疗相关的常见症状,它不仅会中断患者的治疗,还会严重影响患者生存质量.目前,CRF具体的机制仍不明确,且缺乏公认的有效治疗.建立规范的相关动物模型并进一步探讨CRF的产生机制是找寻有效治疗途径的前提条件.本文综述国内外CRF的动物模型,以期找寻合适的临床前实验的造模方法,并区分...     

伊里扎诺夫技术修复兔胫骨骨缺损成骨机制的研究

目的探讨截骨推移区骨愈合的组织学特点和新骨形成规律。方法取青紫蓝兔24只,建立胫骨大段骨缺损模型,在近干骺端截骨。分别于截骨后第1、2、4、6、8、10周各处死4只兔,在近干骺端的分离区取材进行组织学观察。结果截骨后第1周出现血肿机化,第4周出现膜内成骨和软骨内成骨,第6周推移区大部分被骨性骨痂取代,第8周开始改建。结论推移区存在膜内成骨和软骨内成骨2种方式,以膜内成骨为主。     

Animal models for neonatal diseases in humans

The development of vaccines for infants and young children requires the use of animal models at various stages of preclinical development. Animal models are being used to assess the quantity and quality of the immune response, onset and duration of the response, induction of systemic versus local immunity, protection against challenge infection for the assessment of vaccine efficacy, as well as safety and toxicity of the vaccine formulation itself. A variety of animal models are available, each with its own specific advantages and disadvantages. Here, we review the most common animal models for preclinical vaccine development for human infants.     

Herd immunity effect of the HPV vaccination program in Australia under different assumptions regarding natural immunity against re-infection

Deterministic dynamic compartmental transmission models (DDCTMs) of human papillomavirus (HPV) transmission have been used in a number of studies to estimate the potential impact of HPV vaccination programs. In most cases, the models were built under the assumption that an individual who cleared HPV infection develops (life-long) natural immunity against re-infection with the same HPV type (this is known as SIR scenario). This assumption was also made by two Australian modelling studies evaluating the impact of the National HPV Vaccination Program to assist in the health-economic assessment of male vaccination. An alternative view denying natural immunity after clearance (SIS scenario) was only presented in one study, although neither scenario has been supported by strong evidence. Some recent findings, however, provide arguments in favour of SIS.     

Money and trust among strangers

What makes money essential for the functioning of modern society? Through an experiment, we present evidence for the existence of a relevant behavioral dimension in addition to the standard theoretical arguments. Subjects faced repeated opportunities to help an anonymous counterpart who changed over time. Cooperation required trusting that help given to a stranger today would be returned by a stranger in the future. Cooperation levels declined when going from small to large groups of strangers, even if monitoring and payoffs from cooperation were invariant to group size. We then introduced intrinsically worthless tokens. Tokens endogenously became money: subjects took to reward help with a token and to demand a token in exchange for help. Subjects trusted that strangers would return help for a token. Cooperation levels remained stable as the groups grew larger. In all conditions, full cooperation was possible through a social norm of decentralized enforcement, without using tokens. This turned out to be especially demanding in large groups. Lack of trust among strangers thus made money behaviorally essential. To explain these results, we developed an evolutionary model. When behavior in society is heterogeneous, cooperation collapses without tokens. In contrast, the use of tokens makes cooperation evolutionarily stable.     

Molecular Link between Vitamin D and Cancer Prevention

The metabolite of vitamin D, 1α,25-dihydroxyvitamin D₃ (also known as calcitriol), is a biologically active molecule required to maintain the physiological functions of several target tissues in the human body from conception to adulthood. Its molecular mode of action ranges from immediate nongenomic responses to longer term mechanisms that exert persistent genomic effects. The genomic mechanisms of vitamin D action rely on cross talk between 1α,25-dihydroxyvitamin D₃ signaling pathways and that of other growth factors or hormones that collectively regulate cell proliferation, differentiation and cell survival. In vitro and in vivo studies demonstrate a role for vitamin D (calcitriol) in modulating cellular growth and development. Vitamin D (calcitriol) acts as an antiproliferative agent in many tissues and significantly slows malignant cellular growth. Moreover, epidemiological studies have suggested that ultraviolet-B exposure can help reduce cancer risk and prevalence, indicating a potential role for vitamin D as a feasible agent to prevent cancer incidence and recurrence. With the preventive potential of this biologically active agent, we suggest that countries where cancer is on the rise—yet where sunlight and, hence, vitamin D may be easily acquired—adopt awareness, education and implementation strategies to increase supplementation with vitamin D in all age groups as a preventive measure to reduce cancer risk and prevalence.     

The Growth of Radiata Pine On Lateritic Soils at Second Valley,South Australia

Factors involved in the growth of P. radiata (D. Don) on soils of a lateritic landscape have been examined by soil and foliar analysis and the measurement of ring width; this has given an appraisal of factors influencing growth in the past and at the present time.

Perched water tables, which often occurred in winter on the plateau where there were lateritic podzolic soils, did not depress growth. The addition of phosphate was essential, with responses lasting for about 8 years with superphosphate. Regression relationships between the annual growth increment (ΔV in cubic feet) and foliar levels of nitrogen (N) and phosphorus (P) were found for three different foliar sampling positions; these relationships had the form:

ΔV = 4.5%P + 0.28%N—0.47.

Considerable variation was found in the foliar levels of nitrogen, phosphorus, copper, zinc, boron, nickel, molybdenum, chromium and ash for different sample positions within the tree. Preliminary responses to nickel, copper and nitrogen were obtained on 15-year-old trees well supplied with phosphorus. Advisory foliar levels for nitrogen and phosphorus are given.     

Interagency safeguarding adults training for protection and prevention

Abstract

There is a significant gap in interprofessional education (IPE) in relation to safeguarding adults. Trainee health and social care professionals do not have the confidence and competency to safeguard adult patients/service users. Furthermore, IPE in safeguarding has wider ramifications regarding community safety and crime and disorder partnerships, both of which operate at a local level within communities. The IPE safeguarding training pathway is therefore based on the outcome of the interviews with safeguarding practitioners in an English local authority, enabling practitioners in both health and social care to become capable, confident and competent when safeguarding vulnerable adults.