与转基因争论有关的一些文献

屠狗英雄 发表于 2013-11-3 03:26
兄弟敢说敢当，是条汉子。论坛里有的情绪化的斗嘴我们就忽略不计了。
这个文章是发在cell research 上.影 ...

屠狗英雄 发表于 2013-11-3 03:43
转基因技术掌握在外国公司手里。这些货能有什么节操。
黄金大米非法儿童实验。国内搞转基因水稻的可以把实 ...

杂交大米食用功效及安全性的评价研究
《食品科技》2012年 第11期 | 王晓光 王德芝 周则卫 沈秀 李济洋 龙伟   中国医学科学院北京协和医学院放射医学研究所 天津300192

摘　要：通过小鼠实验研究杂交大米功效及安全，建立一种综合评价人工修饰食物营养、健康效应及安全性的评价新方法。实验用生长期健康雄性ICR小鼠，通过低营养玉米空白饲料、“两优363”杂交大米及普通大米与玉米掺和饲料喂养，统计考察小鼠体重、脏器质量、系数及其效应的损益指数（BDI）等指标，综合评价杂交大米食用功效及安全性差异。研究表明“两优363”杂交大米的营养功效较全面，但总体效价较低，对胸腺、脾、性腺的营养、健康效应均不如普通大米。与普通大米相比，长期食用该杂交大米对机体免疫、脾胃及生育功能存在一定不利影响，但可望降低患Ⅱ型糖尿病风险。评价方法具有直观、具体、综合的特点，可用于各类人工修饰食品功效及安全的评价。

Nature 401, 640-641 (14 October 1999) | doi:10.1038/44262

No GM conspiracy
Editor -- Nature

Sir

Last week's Commentary by Millstone et al.1 is misleading and inaccurate. The authors do not seem to be aware of a meeting organized by the Organization for Economic Co-operation and Development, held in Aussois, France, in March 1997, which is about to be published. Hence they present an outdated view of the use of substantial equivalence, while their characterization of this tool as the outcome of an international conspiracy to foist genetically modified (GM) foods on a gullible public is beyond belief. Do Millstone et al. really believe in a worldwide conspiracy? They have no evidence for this assertion.

Second, by such accusations, Millstone et al. denigrate the whole regulatory process and all the hard-working academics who make up the British regulatory committees. Throughout their article, they reveal their ignorance of the way the regulatory process works. Substantial equivalence is a tool only: the 'first cut' at the decision-making rather than a quick solution, as the authors infer. I was chairman of the Advisory Committee on Novel Foods and Processes (ACNFP) from 1989 to 1997, and we never received any political or commercial pressure when making decisions. I totally reject the slur on our integrity.

Finally, Millstone et al. are wrong in what they say about GM soya. They imply that a herbicide that has no effect on the target enzyme, and that does not persist in the plant, has far-reaching effects on intermediary metabolism. If the herbicide does not affect its target, how can it affect the plant? Not only is this idea bizarre, it is wrong: GM beans have been analysed after treatment with herbicide and their composition is unaffected2, 3, 4. Millstone et al. are also wrong to say that treatment with herbicide alters the isoflavone content; they do quote one paper reporting some variation but ignore others showing that this difference is well within the normal range of isoflavone content4. More than 1,400 compositional analyses of Roundup Ready soya beans have been conducted, showing that there are no significant differences in the key soya bean nutrients and anti-nutrients; these data have been reviewed by the ACNFP. The authors use the literature selectively to make their point, which is not good enough for any scientific journal.

I contend that these data establish that GM soya beans are as safe as conventional soya beans. This conclusion was reached by the ACNFP after a thorough safety assessment, using substantial equivalence as a key safety assessment approach. This conclusion has been confirmed by regulatory agencies in the 13 countries that have approved these GM soya beans. This food has been used commercially for four years, and 300 million Americans are currently eating it with no sign of a problem.

How did such a mish-mash of old hat sociology and poor science get published? I would like an assurance from the editor that all such contributions — especially from activists — are rigorously refereed. Nature, in my view, damages its reputation by publishing such propaganda.

Derek Burke1

    13 Pretoria Road, Cambridge CB4 1HD, UK

The publication policy of Commentaries is long established. The Commentary section, like the Book Reviews and Correspondence sections, is intended to convey original and stimulating opinions, both solicited and unsolicited, from outside contributors. Publication does not imply endorsement by Nature of the authors' views. In contrast to Articles, Letters and Brief Communications, not all Commentaries are refereed, but it is Nature's policy to seek advice especially where we believe there is a risk of readers being misled. On the few occasions when, despite that policy, falsehoods or significant misrepresentations have been published, rebuttals or corrections have been published as soon as possible.

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References

    Millstone, E. , Brunner, E. & Mayer, S. Nature 401, 525–526 (1999). | Article | PubMed | ISI | ChemPort |
    ACNFP Annual Report Appendix XII, par. 8 (1998).
    Padgette et al. J. Nutr. 126, 702–716 (1996). | PubMed | ISI | ChemPort |
    Taylor et al. J. Agric. Food Chem. (in the press).

Nature 401, 640 (14 October 1999) | doi:10.1038/44258

Conventional crops are the test of GM prejudice

Anthony Trewavas1 & C. J. Leaver2

    Institute of Cell and Molecular Biology, University of Edinburgh, Edinburgh EH9 3JH, UK
    Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK

Sir

Millstone et al., in their Commentary in last week's issue1, claim that 'substantial equivalence', a rule governing toxicity testing of genetically modified (GM) crops, is a pseudo-scientific concept.

One of their arguments is that it is insufficient to test glyphosate-tolerant soybeans (GTSBs) for toxicity and health problems; beans must be tested specifically after glyphosate treatment when isoflavone levels are modified. Millstone et al. suppose that toxicity could result from unspecified interactions with the single gene incorporated in the GTSB. The GTSB (Roundup) technology actually requires glyphosate spraying only early in the season when soybean plants are small and weeds a strong competitor for soil and light resources. The beans themselves form months later when the effects of the biodegradable glyphosate sprays have disappeared.

As in all discussion about GM plants, it is important to ascertain the applicability of these arguments to conventionally bred crops, either to avoid, or to expose, simple prejudice against the technology itself. We are unable to think of any environmental stress condition in the quality or supply of light, in the supply of water, minerals or a host of pests and diseases which does not modify isoflavone levels and indeed the content of a host of potential carcinogens that are found in most plants2.

Using the logic of Millstone et al., every new crop seed variety would have to be separately tested for toxicity when it has been treated with every herbicide, every pesticide, fertilizer variations, attack by every individual predator, infection with every individual disease and grown in an astronomically large number of different environmental combinations. We would be drowning in toxicity tests. And all these tests would be simply to eliminate the remote possibility that a particular balance of carcinogenic chemicals inside the plant induced by a unique set of conditions might interact in some unexpected way with the many new genes that are combined by conventional plant breeding in the new seed variety.

If this phenomenon ever happens it is more likely to occur in conventional new-variety crops, because many new genes are present rather than the single well characterized trans gene and its protein product in a GM plant. Only two examples, to our knowledge, of the environmental induction of a toxic compound that was not detected during routine testing have ever emerged out of the many millions of conventional crop lines produced. Psoralen was found to accumulate in one line of insect-resistant non-GM celery in response to light, and to cause skin burns3. Cool weather-induced toxic accumulations of solanine caused the withdrawal of the non-GM Magnum Bonum potato line in Sweden4.

The UK Health and Safety Executive concluded, after 25 years of intensive scrutiny, that GM food technology is one of the safest yet developed5. GM soya has been eaten for 3–4 years by hundreds of millions of people in the United States and Europe with no untoward effects. The type of ill-informed logic expressed by Millstone et al. obstructs the acceptance of a new and far safer technology, simply because the authors don't like it. Their arguments are a distraction from the task of developing a sustainable and environmentally friendly agriculture, which combines the best of conventional plant breeding approaches with the new technologies.

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References

    Millstone, E. , Brunner, E. & Mayer, S. Nature 401, 525–526 (1999). | Article | PubMed | ISI | ChemPort |
    Ames, B. N. , Profet, M. & Gold, L. S. Proc. Natl Acad. Sci. USA 87, 7772–7776 (1990). | PubMed | ChemPort |
    Ames, B. N. & Gold, L. S. in Fearing Food (eds Morris, J. & Bate, R.) 18–38 (Butterworth Heinemann, Oxford, 1999).
    Van Gelder, W. M. J. , Vinke, J, H. & Scheffer, J. J. C. Euphytica 88, 147–158 (1988).
    Wilson, M. A. , Hillman, J. R. & Robinson, D. J. in Fearing Food (eds Morris, J. & Bate, R.) 58–78 (Butterworth Heinemann, Oxford, 1999).

Nature 402, 229 (18 November 1999) | doi:10.1038/46147

Genetically modified foods face rigorous safety evaluation

M. J. Gasson1

    Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK

Sir

The Commentary by Erik Millstone et al.1 on the role of substantial equivalence in the safety evaluation of genetically modified (GM) food draws attention to important issues, but it gives an inaccurate and misleading account of the work of regulatory committees and the current role of substantial equivalence in safety evaluation.

The authors imply that regulatory committees depend on substantial equivalence as the sole basis for the safety evaluation of GM foods. They suggest that only chemical tests are used, and that biological, toxicological and immunological methods are ignored. This seriously misrepresents the work of independent expert committees that give careful and wide-ranging consideration to the safety of GM foods on a case-by-case basis, and do not rely solely on substantial equivalence.

From the standpoint of safety evaluation, substantial equivalence is a useful tool to address a major limitation in traditional toxicology approaches to whole GM foods. The feeding of excess quantities of individual chemical components to experimental animals can easily be distinguished from overall nutrition. This approach can be used to set acceptable daily intakes for non-nutrient chemical components of the diet. In contrast, whole GM foods are complex, contribute to nutrition and are limited in the quantity that can be consumed. So the interpretation of data from animal feeding experiments is far from simple.

The safety evaluation of GM food is far more rigorous than is applied to its conventional counterpart, and aims to establish that the accepted safety of the conventional counterpart has not been compromised. In Europe, the safety evaluation of GM foods is covered by European Commission (EC) regulation 258/97. The work of the UK Advisory Committee on Novel Foods and Processes (ACNFP) now falls within its framework2. According to the EC, "substantial equivalence is not a safety or nutritional assessment in itself, but an approach to compare a potential new food with its conventional counterpart"3.

In most instances GM technology is applied to a crop plant to introduce a new trait, so the GM plant cannot be substantially equivalent to its conventional parent. An example that illustrates the fact that much more than substantial equivalence is involved is the safety evaluation of GM soya4. Safety evaluation focused on four issues: intentional changes; unintentional changes; stability; and gene transfer. GM soya contains a single introduced bacterial gene that confers tolerance to the herbicide glyphosate. This gene produces a glyphosate-insensitive homologue of the natural plant enzyme, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), that is involved in aromatic amino-acid biosynthesis. Detailed molecular analysis authenticated the genetic modification and demonstrated that it was stable through several generations of conventional plant breeding. An acute toxicity study in mice showed that the introduced EPSPS protein was non-toxic, and it was demonstrated that this protein is rapidly degraded under conditions encountered following consumption. Furthermore, the conventional processing of soya was shown to destroy the protein. So EPSPS, which in any event is inactivated in marketed GM food, is safe.

The possibility that unintended changes had taken place was evaluated by comparing compositional data and nutritional studies for GM and conventional soya. It is known that unprocessed soya beans can cause food allergy, and the levels of known allergenic proteins were unchanged in GM soya. The possibility of gene transfer from GM soya was eliminated by DNA degradation during processing. On the basis of this evaluation, ACNFP concluded that GM soya was as safe as its conventional counterpart.

Substantial equivalence has recently been re-evaluated by the Organization for Economic Cooperation and Development5. A useful aspect of this evaluation is the recommendation of a consensus on appropriate components for compositional analysis so as to standardize safety evaluation. Key nutrients and known toxins, antinutrients and allergens would be included in this consensus.

The expression of previously unknown toxins, antinutrients or allergens in GM foods so as to cause previously unrecognized harm is unlikely, given that conventional foods have been subject to massive changes in genetic make-up by established plant-breeding methods. The use of chemical fingerprinting, messenger RNA analysis, DNA arrays and proteomics to investigate unintended effects are recognized possibilities for the future, but the practical value of these techniques has not been established. Changes to gene expression and to the levels of individual proteins and metabolites are a normal feature of plant development and response to environmental change. Any such detailed holistic analysis needs to be considered in the context of a dynamic situation in which flux in gene expression is the norm.

Top of page
References

    Millstone, E., Brunner, E., & Mayer, S. Nature 401, 525–526 (1999). | Article | PubMed | ISI | ChemPort |
    ACNFP Annual Report 1997 3–6 (1997).
    Official Journal of the European Communities L253, 16/09/1997, 1–36 (1997). (http://europa.eu.int/eur-lex/en/lif/dat/1997/en_397X0618)
    ACNFP Annual Report 1994 59–65 (1994).
    http://www.oecd.org/ehs/food

炎运宏开世界同 发表于 2013-11-3 22:12
你如果真的对概率问题很熟悉，那你这么设定前提隐藏了一个模糊的误导性认识，也许你自己确实没意识到。
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