全球变化背景下的几个科技名词

随着人们对全球变化（global change）的关注和研究,这一领域出现了很多科技名词,对这些名词进行统一定名、合理释义非常必要。文章结合国际上全球变化问题的研究进展分析了几个典型名词。     

为自然抑或为人?——对人类中心主义与非人类中心主义争论的分析

生存悖论和人类之死讨论的都是人类最终走向消亡的问题。从人类终结的前提出发,非人类中心主义存在许多误区,人类中心主义是正确的。每一种生命最终的归宿是消亡,人能够做的,只能是延缓人类的终结,这就是最广义的“以人为本”。构建和谐社会和建立节约型社会是延缓人类终结的重大举措。实现生存方式的改变,人能够走出自己的生存危机。     

关于消费的哲学考察

关于消费的哲学考察，就是将消费的本质和功能等问题，放进马克思主义人学视野中加以考察，研究有利于人的生存发展、科学、合理的消费观及其价值评价标准等问题，研究消费作为一种社会和人的观念行为所具有的哲学和人学意义。这些问题构成了消费哲学考察的主要内容。所以，我们消费的哲学研究不能脱离马克思主义人学思想，必须以马克思主义人学思想为根本的理论指导。     

Rapid reversion of aging phenotypes by nicotinamide through possible modulation of histone acetylation

Aging appears to be an irreversible process. Here we report that nicotinamide (NAA) can induce rapid and reversible reversion of aging phenotypes in human diploid fibroblasts in terms of cell morphology and senescence-associated β-galactosidase activity. Although NAA seems to enhance the replicative potential of the cells, it has little effect on their growth rate and life span, suggesting that NAA action is rather separated from the cellular replicative system. The effects are unique to NAA: none of the NAA-related compounds examined (an NAD precursor/niacin, NAD analogs, and poly(ADP-ribose) polymerase inhibitors) exerted similar effects. Thus, NAD-related metabolism and poly(ADP-ribosyl)ation are unlikely related to the NAA action. On the other hand, histone acetyltransferase (HAT) activity was elevated in NAA-exposed cells, while in aged cells, HAT activity and histone H4 acetylation were lowered. Taken together, the results suggest that NAA may cause rejuvenation by restoring, at least in part, altered gene expression in aged cells through its activation of HAT. Received 27 August 2001; received after revision 15 October 2001; accepted 15 October 2001     

Human stem cells as a model for cardiac differentiation and disease

Studies on identification, derivation and characterization of human stem cells in the last decade have led to high expectations in the field of regenerative medicine. Although it is clear that for successful stem cell-based therapy several obstacles have to be overcome, other opportunities lay ahead for the use of human stem cells. A more immediate application would be the development of human models for cell-type specific differentiation and disease in vitro. Cardiomyocytes can be generated from stem cells, which have been shown to follow similar molecular events of cardiac development in vivo. Furthermore, several monogenic cardiovascular diseases have been described, for which in vitro models in stem cells could be generated. Here, we will discuss the potential of human embryonic stem cells, cardiac stem cells and the recently described induced pluripotent stem cells as models for cardiac differentiation and disease. Received 07 August 2008; received after revision 26 September 2008; accepted 03 October 2008     

Increased mitochondrial palmitoylcarnitine/carnitine countertransport by flavone causes oxidative stress and apoptosis in colon cancer cells

Cancer cell metabolism is characterized by limited oxidative phosphorylation in order to minimize oxidative stress. We have previously shown that the flavonoid flavone in HT-29 colon cancer cells increases the uptake of pyruvate or lactate into mitochondria, which is followed by an increase in O₂^−.. production that finally leads to apoptosis. Similarly, a supply of palmitoylcarnitine in combination with carnitine induces apoptosis in HT-29 cells by increasing the mitochondrial respiration rate. Here we show that flavone-induced apoptosis is increased more than twofold in the presence of palmitoylcarnitine due to increased mitochondrial fatty acid transport and the subsequent metabolic generation of O₂^−. in mitochondria is the initiating factor for the execution of apoptosis. Received 12 August 2005; received after revision 12 October 2005; accepted 14 October 2005     

“罪”与“赎”——关于人类工程之“非”的反省与超越

工程作为人的存在方式,具有历史生成性。尽管工程的发生与发展不仅创造、呈现和积淀着人类古往今来的物质和精神文明,而且确证、提升着人之为人的类本性,但由于人的理性、能力和人自身的有限性以及工程活动的复杂性,就使得人为的、人工开物的工程具有非完善性,无论对自然还是对人类自身都具有潜在的风险性或现实的威胁性,甚至以异化的形式奴役人。所以,工程既有功也有过,人类因工程之罪而遭到自然的报复和惩罚,以至于引发了前所未有的生态和生存危机。这就警醒我们必须反思征服、宰制自然的工程实践,在肯定工程之是的同时,正视、检讨工程之非,进而优化工程观,并在现实中以赎罪之感合理地规范工程行动,自觉地建构无为、善为的工程,寻求人与自然的和解。     

Differential basal synthesis of Hsp70/Hsc70 contributes to interindividual variation in Hsp70/Hsc70 inducibility

The source of intraspecies variation in the expression of heat shock proteins (HSPs) remains unresolved but could shed light on differential stress tolerance and disease susceptibility. This study investigated the influence of variable basal HSP synthesis on differential inducibility of HSP synthesis. Basal and heat-induced synthesis of the major HSP families in peripheral blood monocytes from healthy donors (n=42) were analysed using biometabolic labelling and densitometry. Basal Hsp70/Hsc70 synthesis and percentage induction of Hsp70/Hsc70 synthesis were significantly correlated (r=−0.57, p<0.0001), and described most accurately by an exponential decay equation (R=0.68, R²=0.46). This regression equation suggests that increasing levels of basal Hsp70/Hsc70 synthesis are accompanied byan exponential decrease in the percentage induction of Hsp70/Hsc70 synthesis. The model fits data from European and non-European population groups independently, although both coefficients in the regression equation were larger for non-Europeans. This implies population group as an additional factor influencing differential HSP expression. The differential inducibility of Hsp70/Hsc70 due to variable basal synthesis of Hsp70/Hsc70 and based upon population group may contribute to differential stress tolerance or disease susceptibility. Received 27 March 2000; received after revision 19 June 2000; accepted 20 June 2000     

The neurotrophic receptor TrkB: a drug target in anti-cancer therapy?

Increasing evidence implies altered signaling through the neurotrophic receptor tyrosine kinase TrkB in promoting tumor formation and metastasis. TrkB, sometimes in conjunction with its primary ligand BDNF, is often overexpressed in a variety of human cancers, ranging from neuroblastomas to pancreatic ductal adenocarcinomas, in which it may allow tumor expansion and contribute to resistance to anti-tumor agents. In vitro, TrkB acts as a potent suppressor of anoikis (detachment-induced apoptosis), which is associated with the acquisition of an aggressive tumorigenic and metastatic phenotype in vivo. In view of its predicted contribution to tumorigenicity and metastasis in humans, TrkB corresponds to a potential drug target, and preclinical models have already been established. The encouraging results of pharmacological Trk inhibitors in tumor xenograft models suggest that TrkB inhibition may represent a promising novel anti-tumor therapeutic strategy. This hypothesis is currently being evaluated in clinical trials. Here, we will discuss the latest developments on TrkB in these contexts as well as highlight some critical questions that remain to be addressed for evaluating TrkB as a therapeutic target in cancer. Received 12 October 2005; received after revision 19 December 2005; accepted 11 January 2006     

An immunohistochemical study of the clearance of apoptotic cellular fragments

We investigated the distribution and fate of apoptotic bodies during human development and in the adult, using an antibody (M30) that recognizes a neo-epitope formed early in the apoptotic cascade by caspase cleavage of cytokeratin 18. In the fetus, we found extensive accumulation of M30-positive, non-phagocytosed fragments in the red pulp of the spleen, subcutaneous and submucosal vessels, the interstitium of the lung, and the glomerular mesangium of the kidneys. In the liver, M30-immunoreactive fragments were found inside macrophages in the sinusoids. The number of these fragments and the intensity of the immunostaining increased with the gestational age of the fetus. In the adult, M30-positive fragments were barely detectable in normal tissues. However, many pathological situations, including both chronic degenerative processes and metastatic cancer, were associated with accumulation of M30-positive fragments in the red pulp of the spleen. In the liver and kidney, no fragments could be detected. Remarkably, 13 of the 16 patients with metastasized cancer showed pronounced accumulation of M30-positive fragments containing hematoxylin-reactive material in the red pulp of the spleen. In the non-cancerous cases, such DNA-containing fragments were only seen in 9 of 94 cases. The results show that when apoptotic activity is high, as during development in the fetus or during metastasis and other pathological processes in the adult, the phagocytic clearance of apoptotic bodies can be overloaded. These apoptotic fragments then accumulate in the spleen. The visual detection of apoptotic fragments is concluded to reflect increased cell turnover. Received 1 July 2002; accepted 1 July 2002