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1.
Over the last decade, evidence has mounted demonstrating thathuman-made compounds released into the environment are disruptingendocrine systems of animals. Research has centered largelyon direct steroidogenic or antisteroidogenic effects of thesecompounds with a recent focus on development of rapid in vitroassays employing estrogen receptors. A literature search andanalysis confirms attention placed on estrogen and anti-estrogen-likeaspects of endocrine disruption at the receptor level. Non-steroidalcomponents of the hypothalamic-pituitary-end gland axes havereceived much less attention in the published endocrine disruptionliterature. Furthermore, aspects of endocrine physiology, suchas the ability of animals to cope with stress or communicatechemically, have also received relatively less literature attentionwhen compared to disruption of development and reproduction.As researchers continue to investigate complex mixes of human-synthesizedcompounds in the environment, it is critical to broaden thespectrum of hormonal disruption investigated beyond estrogenicand androgenic actions and to determine how exposure to mixesaffects physiological function beyond reproduction. Last, inthe field of endocrine disruption, it also important to beginto use data on individuals for development of hypotheses regardingfitness risks, changes in population dynamics, and the potentialfor ecosystem level disruption.  相似文献   

2.
The history of life on this planet is gleaned from analysing how fossils are distributed through time and space. While these patterns are now rather securely known, at least for well-studied parts of the world, their interpretation remains far from simple. Fossils preserve only partial data from which to reconstruct their biology and the geological record is incomplete and biased, so that taxonomic ranges and palaeocommunity structure are imperfectly known. To better understand the often highly complex deep-time processes that gave rise to the empirical fossil record, palaeontologists have turned to modelling the past. Here, we summarize a series of 11 papers that showcase where modelling the past is being applied to advance our understanding across a wide spectrum of current palaeontological endeavours.  相似文献   

3.
We studied the mode of reproduction and its evolution in the fungal subgenus Penicillium Biverticillium using phylogenetic and experimental approaches. We sequenced mating type (MAT) genes and nuclear DNA fragments in sexual and putatively asexual species. Examination of the concordance between individual trees supported the recognition of the morphological species. MAT genes were detected in two putatively asexual species and were found to evolve mostly under purifying selection, although high substitution rates were detected at some sites in some clades. The first steps of sexual reproduction could be induced under controlled conditions in one of the two species, although no mature cleistothecia were produced. Altogether, these findings suggest that the asexual Penicillium species may have lost sex only very recently and/or that the MAT genes are involved in other functions. An ancestral state reconstruction analysis indicated several events of putative sex loss in the genus. Alternatively, it is possible that the supposedly asexual Penicillium species may have retained a cryptic sexual stage.  相似文献   

4.
Amino acids in the central nervous system can be divided into non-neurotransmitter or neurotransmitter depending on their function. The measurement of these small molecules in brain tissue and extracellular fluid has been used to develop effective treatment strategies for neuropsychiatric and neurodegenerative diseases and for the diagnosis of such pathologies. Here we describe the separation and detection techniques that have been used for the measurement of amino acids at trace levels in brain tissue and dialysates. An overview of the function of amino acid transmitters in the brain is given. In addition, the type of sampling techniques that are used for the determination of amino acid levels in the brain is described.  相似文献   

5.
The present study outlines a strategy for studying application of balneotreatment in preventive medicine (balneoprevention). Prophylactic use of spa treatment and mineral water consumption can be studied using epidemiological methods in the involved population. Calculated toxicological risk of balneological treatment can be decreased by performing a complete chemical analysis (including high performance organic analyses) and specific toxicity tests of medicinal water and mud (peloid) samples.  相似文献   

6.
The infusion of plasma-derived or recombinant factors to treat bleeding disorders such as hemophilia A and B is a success story in the management of a chronic disease. The effectiveness of this approach is however limited by challenges with adverse effects of treatment. The most notable of these are the development of inhibitory antibodies that target the protein therapeutic. The current standard of care for management of hemophiliacs is prophylactic treatment that includes frequent infusions of a Factor VIII product. Failure to comply with the prophylactic regimen is a major hurdle in the management of these patients. We discuss here more recent findings that argue for a pharmacogenetic approach to understanding (and eventually circumventing) immunogenicity. We also review strategies used to bioengineer coagulation factors to extend the half-lives of coagulation proteins. The rapid progress in the last few years to bioengineer coagulation factors in different ways to attain this goal is described. Finally, novel technologies and potential products are emerging that utilize synthetic molecules in lieu of replacement proteins obviating the limitations associated with replacement therapies.  相似文献   

7.
This review describes two chromatographic techniques for the separation of three main classes of lipoproteins (HDLs, LDLs and VLDLs) from human serum: hydroxyapatite chromatography and counter-current chromatography. The HDLs, LDLs and VLDLs were purified by the combined use of the two chromatographic techniques without prior ultracentrifugation.  相似文献   

8.
Pagel JM 《Cytotherapy》2008,10(1):13-20
For more than a decade, Ab conjugated to a radionuclide emitting particulate radiation has been used in the management of leukemia in an effort to deliver targeted doses of radiation to BM, spleen and other sites of disease, while sparing normal organs. This radioimmunotherapy (RIT) approach has been employed to achieve significant remissions in patients with AML, particularly when used at high doses of radioactivity in conjunction with myeloablation. This report focuses on the therapeutic aspects of radiolabeled Ab for leukemia. Clinical results from recent leukemia RIT studies are reviewed, with emphasis on approaches being evaluated to improve rates of response and survival. Discussion of pre-clinical studies are limited to those that offer insights into future directions for clinical RIT studies of leukemia.  相似文献   

9.
Historically, many different therapies have been assessed for their ability to alter disease progression of the Neuronal Ceroid Lipofuscinoses (NCLs). While some treatments have lead to minor improvements, none have been able to arrest disease progression or improve the quality or duration of life. Presently, many new therapeutic strategies, such as chaperone therapy, enzyme replacement therapy, gene therapy, and stem cell therapy, are being investigated for their ability to alter the disease course of the NCLs. This review summarizes previous studied therapies, discusses those currently being evaluated and examines possibilities for future therapies for the treatment of patients with NCL.  相似文献   

10.
The molecular mechanism of circadian clocks has been unraveled primarily by the use of phenotype-driven (forward) genetic analysis in a number of model systems. We are now in a position to consider what constitutes a clock component, whether we can establish criteria for clock components, and whether we have found most of the primary clock components. This perspective discusses clock genes and how genetics, molecular biology, and biochemistry have been used to find clock genes in the past and how they will be used in the future.  相似文献   

11.
Genetic, cellular and immune approaches to disease therapy: past and future   总被引:11,自引:0,他引:11  
Nabel GJ 《Nature medicine》2004,10(2):135-141
Advances in immunology and molecular genetics have accelerated our understanding of the genetic and cellular basis of many diseases. At the same time, remarkable progress in recombinant DNA technology has enabled the development of molecular and cellular treatments for infectious diseases, inherited disorders and cancer. This Perspective is intended to give a sample of the progress over the past ten years in cellular, genetic and immune therapy of disease. During this time, monoclonal antibody technology and cellular transplantation have begun to come of age in biomedicine. Innovations in gene delivery have not only catalyzed the nascent field of human gene therapy, but may also ultimately impact human health by advancing recombinant vaccine technology.  相似文献   

12.
Fertility estimation: a review of past experience and future prospects   总被引:1,自引:0,他引:1  
Fertility has many components and stages which require that males and females be functionally capable of carrying out all critical stages if each generational reproductive cycle is to be completed. To accomplish this, the male must produce and ejaculate normal fertile sperm. The female must produce, store and ovulate normal fertilizable oocytes. Furthermore, the female must provide a reproductive system compatible with sperm transport, capacitation, and fertilization of the oocytes, embryo and fetal development, and finally birth of healthy young. Reproductive success or failure at several of these points can be estimated quantitatively on a population basis, and in a few situations on an individual basis. It is important that fertility estimates be determined accurately and with precision to be most useful to researchers and managers of animal enterprises. Many studies have underestimated the biological relationship of fertility to other traits because the estimates lacked precision. Many in vitro manipulations of sperm in artificial insemination, of gametes in various assisted reproductive technologies, and of embryos in embryo transfer are utilized in animal breeding programs. Accurate estimation of reproductive efficiency of these in vitro procedures also is important. Conditions surrounding different sets of fertility estimates almost certainly will be different. These conditions should be described as precisely as possible, and appropriate controls included in all experiments. When possible, experiments should be replicated over time and place to determine the repeatability of the various criteria used to estimate fertility and reproductive efficiency. Advances in genomic information and molecular biology should facilitate characterizing more fully inherent potential fertility of animals at birth. In vitro tests will improve, and automated techniques will facilitate making multiple determinations possible on a large scale. Reliability of fertility estimates will increase, with the potential for enhanced animal reproductive performance through more accurate selection, genetic engineering, and enlightened animal care. Simultaneously, it is important to recognize that prediction of future fertility is more hazardous than estimating fertility, as a completely new set of circumstances may occur which are not predictable. Because fertility estimation may be applied under a myriad of conditions, principles and factors affecting fertility will be emphasized in this review as being more useful than a compilation of numerical examples.  相似文献   

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14.
Sex and polymorphism as strategies in host-pathogen interactions   总被引:2,自引:0,他引:2  
Sexual reproduction in a polymorphic population generates ever novel recombinations. It is shown that this variety is essential in preventing pathogens from adaptively breaking through immunological host resistance. The theory explains the extensive polymorphism of wild-type populations and catastrophic diseases in genetically homogeneous cultivars. It offers a new model of the selective forces that maintain sex. It interprets self-incompatibility in angiosperms as a mechanism that maintains polymorphism. An analogous mechanism involving sperm selection based on histocompatibility haplotype is postulated for mammalian fertilization. Mate selection involving odor clues is conjectured for eusocial insects. Population regulation of asexual species through pathogens also involves polymorphism. The proposed theory of polymorphism overcomes difficulties present in the balanced and neutral selection theory of mathematical genetics.  相似文献   

15.
China has the world's longest history of soil bioengineering, with the first mention of giant fascines to control torrential floodwaters dating from over 2000 BC. However, soil degradation on steep slopes has accelerated hugely over the last 50 years, due to poor farming practice, deforestation, road and dam construction. The central government has therefore devised a series of major programs to reduce the exploitation of forest resources (Natural Forest Protection Program – NFPP) and to rehabilitate steep slopes by encouraging the conversion of cropland to forest and orchards (Sloping Land Conversion Program – SLCP). In this review, we define soil bio- and eco-engineering and examine China's past experience in both domains. We focus on case studies whereby vegetation has been used in conjunction with civil engineering to prevent landslides in Hong Kong and the social and practical aspects of planting on steep slopes to conserve soil on a large-scale in mainland China. The successes and failures of tree planting and forest management in the NFPP and SLCP are discussed along with the priorities for future research and practical applications. This review introduces a special edition of the journal Ecological Engineering, whereby a selection of papers presented at the Second International Conference ‘Ground Bio- and Eco-engineering: The Use of Vegetation to Improve Slope Stability – ICGBE2’ held in Beijing, China, 14–18 July 2008, are published. This congress joined together scientists and practitioners with the aim of discussing new theory, methods and applications for using vegetation to fix soil on steep slopes prone to landslides and erosion. In this review, we consider the key points from the conference and place them in the context of managing and restoring degraded slopes in China, one of the world's most pertinent study sites.  相似文献   

16.
A brief report is given on the possible role of oxygen-derived free radicals and cholecystokinin in the pathogenesis of experimentally induced acute pancreatitis. Furthermore, use of scavengers (superoxide dismutase, catalase), CCK-receptor antagonists and somatostatin are discussed in the therapy of acute pancreatitis induced in animal models. It is suggested that both the term of direct pancreatic cytoprotection of the above-mentioned agents and the validity of the animal models used for induction of acute pancreatitis have to be reconsidered.  相似文献   

17.
Sex change in plants: Old and new observations and new hypotheses   总被引:8,自引:1,他引:8  
Summary Evidence is presented that individuals of a large number of dioecious and subdioecious plant species are able to alter their sexual state in response to changes in the ambient environment and/or changes in size or age. We suggest that lability of sexual expression probably has survival value where a significant portion of the females must otherwise bear the cost of fruit production in unfavorable environments. We demonstrate that in patchy environments of the proper scale and variability in quality, labile sexual expression will enhance an individual's genetic contribution to the next generation.  相似文献   

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