首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 797 毫秒
1.
The extracellular domain of the HER-2 (ERBB2) oncoprotein (p105HER-2, ECD HER-2) is shed in the serum and can be detected by immunoassay. The currently approved cutoff for an elevated HER-2 ECD is greater than 15 ng/mL. HER-2 ECD is attractive as a potentially useful serum biomarker. In metastatic breast cancer, serum assay of HER-2 ECD is recommended to assess HER-2 status when unknown in primary tumor or metastatic biopsy is not feasible. In that case, it has been recommended to consider a 50 ng/mL serum HER-2 ECD cutoff as criteria to select patients for HER-2 targeted therapy. It might offer additional prognostic or predictive value compared with HER-2 tumor tissue testing. In addition, it can be measured serially and might be able to monitor treatment response, predict relapse or provide a real-time assessment of HER-2 status at metastatic disease.  相似文献   

2.
3.
Although much research has been carried out on Australopithecus afarensis locomotion, no consensus has yet been reached. Our new critic study on femoral material brings to the fore a strictly bipedal behaviour within this taxon. Our results are based on the pertinence of human anatomical characteristics among A. afarensis and on the absence of characteristics revealing arboreal displacement. These results have emerged from our different observation and interpretation of some preceding authors concerning the anatomy of these fossil hominids. It is important to underline that apomorphic characteristics of this species are difficult to interpret. They must not however be used to support the idea of arboreal displacement simply based on the fact of a no totally human morphe. We believe that present day humans do not necessarily reflect the earliest strict bipedal anatomic model. An the other hand, it appears that the disagreement between the two locomotor hypothesis for A. afarensis that are bipedalism and arboreal displacement, facing the possibility of bipedalism associated with negligible arboreal displacement, results more from an evolutionary fact than from a real scientific conflict.  相似文献   

4.
本书以自动形象的文学手法介绍了遗传工程与下次产业革命的关系,属于高级科普性读物。书中以介绍遗传学基础知识为背景,重点阐述了遗传工程工业的生产与发展,遗传工程已发展成为羽毛丰满的完整的工业体系。这充分说明了生命科学已步入了生命科学领域,进而叙述了遗传工程对整个科学、商业、社会、医药卫生等各个方面的深刻  相似文献   

5.
The locality Valbro (Quercy, France) has yielded a rich fossil vertebrate fauna. Here are presented the geological context, a preliminary faunal list and the systematics of the Rodentia and carnivores, the most abundant taxa of the fauna. The Rodentia are known from 11 taxa: the Theridomyidae Blainvillimys gregarius Schlosser, 1884, Blainvillimys ?gemellus Vianey-Liaud, 1989, Issiodoromys medius (Vianey-Liaud, 1976) and S. cayluxi Schlosser, 1884, the Aplodontidae Plesispermophilus angustidens Filhol, 1882, the Gliridae Butseloglis tenuis (Bahlo, 1975), Butseloglis micio (Misonne, 1957) and Bransatoglis planus (Bahlo, 1975), the Sciuridae Palaeosciurus goti Vianey-Liaud, 1974 and cf. Oligopetes sp., and the Cricetidae Atavocricetodon sp. aff. A. nanus (Pelaez-Campomanes, 1995). Thirteen taxa of carnivores are present at Valbro; among the Hyaenodontida: Hyaenodon leptorhynchus Laizer et Parieu, 1838 and cf. Apterodon sp.; among the Carnivora: a Feliformia gen. et sp. indet., the Nimravidae Nimravus intermedius (Filhol, 1872), Dinailurictis bonali Helbing, 1922 and Nimravidae gen. et sp. indet. (Certainly belonging to one the two already identified species), the Ursida Pachycynodon crassirostris Schlosser, 1888, Pachycynodon sp., Amphicynodon sp. 1 cf. A. typicus (Schlosser, 1888), Amphicynodon ? sp. 2 and Ursida gen. et sp. indet. cf. Pachycynodon boriei (Filhol, 1876), the Mustelida M. olivieri Bonis, 1997, the Carnivora incertae sedis Palaeogale sectoria (Gervais, 1848–1852), the Arctoidea gen. et sp. indet. and Carnivora gen. et sp. indet. (probably representing taxa already identified at lower taxonomic levels). The evolutionary grade of B. gregarius of Valbro compares to that of the species from Mas de Got, La Plante 2 and Cavalé, which supports an MP22 age for Valbro. This datation is further supported by the association of Theridomyinae yielded by the locality (B. gregarius, B. gemellus, I. medius and S. cayluxi), and by the presence of a N. intermedius that well compares the material of the species from Villebramar, La Plante et Mas de Got, of D. bonali, P. sectoria, M. olivieri (species known only from Mas de Got), and by additional evidence from the remaining vertebrates from Valbro, especially the squamates. Despite a limited amount of specimens (341 specimens have been studied), the faunas of rodents and carnivores from Valbro are the most speciose and diverse known for the MP22 level and, for the Carnivora fauna in particular, for the Oligocene of the Old World.  相似文献   

6.
7.
Study aimTo find a correlation between epidemiological factors, risk factors and history and the results of myocardial scintigraphy according to the type of pain and discuss the role of scintigraphy in the diagnosis and therapeutic care.Patients and methodsOur study is retrospective, on 171 patients with typical chest pain (TCP) or atypical (ACP), addressed for myocardial scintigraphy.ResultsFemale predominance was clear. Average age was 59 years. Frequency of risk factors: smoking, diabetes, hypertension, hyperlipidemia, history of heart disease and hypothyroidism was respectively 21.6%, 39.8%, 73.7%, 25.1%, 11.1% and 6.4%. ACP was found in 57.9% of patients, it was more common among women (59.8%). Scintigraphy was abnormal in 36.8% of patients. Scintigraphy was normal in 59.7% of patients with TCP. In the case of ACP, scintigraphy was normal in 65.7%. This difference is not significant. All patients having abnormal scintigraphy had abnormal coronary angiography with a statistically significant correlation. Normal scintigraphy was more frequent (83.3%) in young patients ( < 40 years) and more common in women (67%) than men (55.9%). The sensitivity of scintigraphy is 100%. Its specificity is 66.6%. Its PPV of 57.1%. Its VPN is 100%.ConclusionMyocardial scintigraphy can help clinicians to identify the etiologic diagnosis and assess the prognosis of chest pain.  相似文献   

8.
Rebuttal to Miller: ‘Accelerated aging’: a primrose path to insight?’   总被引:1,自引:0,他引:1  
Hasty P  Vijg J 《Aging cell》2004,3(2):67-69
  相似文献   

9.
10.
11.
12.
During the last years, an international debate about the concept of “Palaeolithic art” has taken place. On one hand, several specialists have critiqued the use of the concept of “art” in naming the images created by Homo sapiens during the Palaeolithic era. They claim that the use of this term implies the projection of a modern category to a world - that of prehistoric humans - which is completely different from our own. On the other hand, some archaeologists consider that the term “Palaeolithic art” does not imply an anachronistic interpretation of prehistoric representations. In presenting the historical context, which has made such a discussion possible, we consider the causes and effects of this controversy. Firstly, we analyze the traditional interpretation, which considered Palaeolithic images as “works of art”. Secondly, we examine the connections, which can be found between the debate about “Palaeolithic art” and certain polemics, which have arisen from the history of art and anthropological frameworks. Thirdly, we consider the arguments utilized by those who are for and those who are against the term “Palaeolithic art”. Finally, we emphasize the importance of this debate to better understand the categories and the concepts, which determine the scientific practice.  相似文献   

13.
14.
Waters JM 《Molecular ecology》2011,20(21):4388-4394
Phylogeographic and evolutionary research programmes have successfully elucidated compelling genetic signatures of earth history. Particularly influential achievements include the demonstration of postglacial recolonization patterns for high-latitude taxa and phylogenetic demonstration of the 'progression rule' along oceanic island chains such as Hawaii. While both of these major biogeographic patterns clearly rely on rapid dispersal over long distances, their phylogeographic detection also apparently relies on the competitive exclusion of secondary dispersers. Such exclusion could occur either between or within species and might reflect fitness differences between lineages or, alternatively, neutral demographic processes (e.g. 'high-density blocking'). Regardless, such spatial genetic patterns would be rapidly eroded were it not for the failure of subsequent dispersers to contribute genetically to newly colonized populations. In addition to its role in revealing colonization patterns, competitive exclusion may also explain the maintenance of historic phylogeographic disjunctions long after the original physical barriers to dispersal have ceased to exist. Additionally, some of the most persuasive evidence of competitive exclusion comes from studies of anthropogenic extinction, where surviving lineages have subsequently expanded their ranges, apparently benefitting from the demise of their prehistoric sisters. Broadly, these biogeographic paradigms are united by the 'disconnect' between dispersal and colonization success, the latter being heavily influenced by inter- and intraspecific competition. Despite its apparent importance, such exclusion (especially within species) has received virtually no attention in the phylogeographic literature. Future studies should aim to test directly for the role of competitive exclusion in constraining the biogeography of highly dispersive taxa.  相似文献   

15.
The historical file of Moulin Quignon (Abbeville, France), around the human jaw unearthed in this site, is a form of black hole that swallowed a prehistoric archaeological site and Lower Palaeolithic collection. This article, based on a corpus of unpublished archives, illuminates the matter in a different light. It focuses on archaeological and epistemological issues, the roles of the different actors, interaction games and solidarity in a global scientific community previously welded by the recognition in 1859 of the paradigm of high antiquity of Man.  相似文献   

16.
Functional foods might be helpful in improving the nutritional status and preventing certain diseases. In order to inform the consumer about the benefit of a product it will be necessary to enable scientifically proved health claims. These health claims have to be supported by studies and should make clear how a product can influence health. Only if there are proven facts, functional foods could establish on the market as foods of the future in the longer term beside the naturally healthful products. It will be of no use neither to the consumer nor to the food industry to promote these product group with exaggerated promises as a kind of miracle cure which can help against all diseases. The acceptance of the consumer will depend on credible product concepts. Another important precondition for functional foods is that there are absolutely no health risks associated with the consumption of these products. Recommendations regarding fortification and intake of functional foods must consider this aspect. Side effects by excessive doses or imbalances are to be avoided. The consumer should know that the point is not to take as much as possible of potentially healthful single substances but to show clearly that physiological dosages, which can also be attained by a higher intake of traditional food are associated with the best benefit‐risk relation, i.e. show the greatest benefit and minimal risk. In general functional foods do not resolve any nutritional problem. The effects are limited, especially if the nutrition is imbalanced (e.g. hyperenergetic, high fat). In these cases the addition of functional foods offers no or only small corrective effects. Functional foods represent no substitute for a fully balanced nourishment with a high amount of naturally healthy foods such as vegetables, fruits, whole grain products as well as milk and milk products.  相似文献   

17.
P2X<Subscript>7</Subscript> receptor: Death or life?   总被引:1,自引:1,他引:0  
The P2X(7) plasma membrane receptor is an intriguing molecule that is endowed with the ability to kill cells, as well as to activate many responses and even stimulate proliferation. Here, the authors give an overview on the multiplicity and complexity of P2X(7)-mediated responses, discussing recent information on this receptor. Particular attention has been paid to early and late signs of apoptosis and necrosis linked to activation of the receptor and to the emerging field of P2X(7) function in carcinogenesis.  相似文献   

18.
Male genes: X‐pelled or X‐cluded?   总被引:3,自引:0,他引:3  
Two recent studies by Parisi et al. and Ranz et al., catalogue sex differences in gene expression across the whole genome of the fruit fly Drosophila melanogaster. Both report striking associations of sex-biased gene expression with the X chromosome. Genes with male-biased expression are depauperate on the X chromosome, whereas genes with female-biased expression show weaker evidence of being in excess. A number of evolutionary hypotheses for the expulsion or exclusion of male-biased genes from the X chromosome have been suggested. None is entirely consistent with the available evidence.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号