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1.
VEGFC is a crucial player of lymphangiogenesis. Besides VEGFR2 and VEGFR3, it also binds NRP2. NRP2 enhances VEGFC/VEGFR3 effects in developmental lymphangiogenesis, but its role in adult and tumoral lymphangiogenesis is not known. In their study, Bagri and colleagues demonstrate that blocking NRP2 results in a decrease of metastasis formation, a phenomenon relying on tumoral lymphangiogenesis. Thus they identified NRP2 as an attractive new target for modulating metastasis.  相似文献   

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Increasing evidence suggests that superantigens play a role in immune-mediated diseases. Superantigens are potent activators of CD4+ T cells, causing rapid and massive proliferation of cells and cytokine production. This characteristic of superantigens can be exploited in diseases where strong immunologic responses are required, such as in the B16F10 animal model of melanoma. Superantigen administration is able to significantly enhance ineffective anti-tumor immune responses, resulting in potent and long-lived protective anti-tumor immunity. However, superantigens are more well-known for the role they play in diseases. Studies using an animal model for neurologic demyelinating diseases such as multiple sclerosis show that superantigens can induce severe relapses and activate autoreactive T cells not involved in the initial bout of disease. This may also involve epitope spreading of disease. Superantigens have also been implicated in acute diseases such as food poisoning and TSS, and in chronic diseases such as psoriasis and rheumatoid arthritis. Viral superantigens are also involved in the disease process, including superantigens derived from human immunodeficiency virus and mouse mammary tumor virus. Finally, immunotherapies that ameliorate the role played by superantigens in disease are discussed.  相似文献   

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The range of antibodies available commercially grows ever larger. Perhaps as a consequence, quality control is not always what it could and should be. Investigators must be aware of potential pitfalls and take steps to assure themselves that the specificity of each antibody is as advertised. Additionally, companies should provide the necessary information about the antigen and antibody to investigators, including references, so that the appropriate controls can be included.  相似文献   

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Herbal bioactivation: the good, the bad and the ugly   总被引:14,自引:0,他引:14  
Zhou S  Koh HL  Gao Y  Gong ZY  Lee EJ 《Life sciences》2004,74(8):935-968
It has been well established that the formation of reactive metabolites of drugs is associated with drug toxicity. Similarly, there are accumulating data suggesting the role of the formation of reactive metabolites/intermediates through bioactivation in herbal toxicity and carcinogenicity. It has been hypothesized that the resultant reactive metabolites following herbal bioactivation covalently bind to cellular proteins and DNA, leading to toxicity via multiple mechanisms such as direct cytotoxicity, oncogene activation, and hypersensitivity reactions. This is exemplified by aristolochic acids present in Aristolochia spp, undergoing reduction of the nitro group by hepatic cytochrome P450 (CYP1A1/2) or peroxidases in extrahepatic tissues to reactive cyclic nitrenium ion. The latter was capable of reacting with DNA and proteins, resulting in activation of H-ras oncogene, gene mutation and finally carcinogenesis. Other examples are pulegone present in essential oils from many mint species; and teucrin A, a diterpenoid found in germander (Teuchrium chamaedrys) used as an adjuvant to slimming diets. Extensive pulegone metabolism generated p-cresol that was a glutathione depletory, and the furan ring of the diterpenoids in germander was oxidized by CYP3A4 to reactive epoxide which reacts with proteins such as CYP3A and epoxide hydrolase. On the other hand, some herbal/dietary constituents were shown to form reactive intermediates capable of irreversibly inhibiting various CYPs. The resultant metabolites lead to CYP inactivation by chemical modification of the heme, the apoprotein, or both as a result of covalent binding of modified heme to the apoprotein. Some examples include bergamottin, a furanocoumarin of grapefruit juice; capsaicin from chili peppers; glabridin, an isoflavan from licorice root; isothiocyanates found in all cruciferous vegetables; oleuropein rich in olive oil; dially sulfone found in garlic; and resveratrol, a constituent of red wine. CYPs have been known to metabolize more than 95% therapeutic drugs and activate a number of procarcinogens as well. Therefore, mechanism-based inhibition of CYPs may provide an explanation for some reported herb-drug interactions and chemopreventive activity of herbs. Due to the wide use and easy availability of herbal medicines, there is increasing concern about herbal toxicity. The safety and quality of herbal medicine should be ensured through greater research, pharmacovigilance, greater regulatory control and better communication between patients and health professionals.  相似文献   

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Baculoviruses and apoptosis: the good, the bad, and the ugly   总被引:8,自引:0,他引:8  
Since 1991, when a baculovirus was first shown to inhibit apoptosis of its host insect cells, considerable contributions to our knowledge of apoptosis have arisen from the study of these viruses and the anti-apoptotic genes they encode. Baculovirus anti-apoptotic genes include p35, which encodes the most broadly acting caspase inhibitor protein known, and iap (inhibitor of apoptosis) genes, which were the first members of an evolutionarily conserved gene family involved in regulation of apoptosis and cytokinesis in organisms ranging from yeast to humans. Baculoviruses also provide an ideal system to study the effects of an apoptotic response on viral pathogenesis in an animal host. In this review, I discuss a number of interesting recent developments in the areas of apoptotic regulation by baculoviruses and the effects of apoptosis on baculovirus replication and pathogenesis.  相似文献   

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Fluorescent protein FRET: the good, the bad and the ugly   总被引:13,自引:0,他引:13  
Dynamic protein interactions play a significant part in many cellular processes. A technique that shows considerable promise in elucidating such interactions is F?rster resonance energy transfer (FRET). When combined with multiple, colored fluorescent proteins, FRET permits high spatial resolution assays of protein-protein interactions in living cells. Because FRET signals are usually small, however, their measurement requires careful interpretation and several control experiments. Nevertheless, the use of FRET in cell biological experiments has exploded over the past few years. Here we describe the physical basis of FRET and the fluorescent proteins appropriate for these experiments. We also review the approaches that can be used to measure FRET, with particular emphasis on the potential artifacts associated with each approach.  相似文献   

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MicroRNAs (miRNAs) have quite recently emerged as a novel class of gene regulators. Many miRNAs exhibit altered expression levels in cancer, and we are only starting to understand the functional consequences of the loss or gain of particular miRNAs to the cancerous phenotype. miRNAs can be classified with regard to their role in cancer as the Good, the Bad and the Ugly. The "Good", those miRNAs that are innocent bystanders in the oncogenic transformation process, whose expression profile might even be used for cancer diagnosis or prognosis. The "Bad", those miRNAs that are causally linked to tumorigenesis and directly modify tumor suppressor- or oncogenic- pathways. And the "Ugly", those miRNAs whose inappropriate loss or gain destabilizes the cellular identity of a tumor, which indirectly results in enhanced phenotypic variability and progression of the tumor. Hereunder we will discuss the possible ways in which miRNAs can be relevant to cancer biology, and possible experimental strategies for elucidating the mechanisms involved.  相似文献   

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Improvements in upstream production have boosted productivity in the biomanufacturing industry, but this is leading to bottlenecks in downstream processing as current technology platforms reach their limits of throughput and scalability. Although chromatography remains an indispensible component of downstream processing due to its simplicity and high resolving power (The Good), there is virtually no economy of scale effect so more product translates almost linearly into greater production costs. Bind-and-elute processes (such as the initial capture step in antibody manufacturing) are volume-driven and therefore have knock-on effects that impact on the entire production facility since the space required for preparation, storage, and cleaning steps has to be similarly adapted (The Bad). During long-term operations with multiple cycles, thorough cleaning is necessary to prevent progressive fouling and microbial contamination (The Ugly). Innovative solutions are required, which may include revisiting simpler and less expensive separation technologies, the use of disposable modules, and the integration of improved processes that are scalable to cope with increased demands. Among the alternatives that have been put forward, membrane adsorbers are beginning to make a real impact on the industry, particularly for flow-through applications such as polishing and viral clearance.  相似文献   

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Making sense of microarray data is a complex process, in which the interpretation of findings will depend on the overall experimental design and judgement of the investigator performing the analysis. As a result, differences in tissue harvesting, microarray types, sample labelling and data analysis procedures make post hoc sharing of microarray data a great challenge. To ensure rapid and meaningful data exchange, we need to create some order out of the existing chaos. In these ground-breaking microarray standardization and data sharing efforts, NIH agencies should take a leading role  相似文献   

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CD1d ligands: the good, the bad, and the ugly   总被引:1,自引:0,他引:1  
The MHC class I-like CD1d glycoprotein is a member of the CD1 family of Ag-presenting molecules and is responsible for the selection of NKT cells. A number of ligands that can be presented by CD1d to NKT or other CD1d-restricted T cells have been identified. These include glycolipids from a marine sponge, bacterial glycolipids, normal endogenous glycolipids, tumor-derived phospholipids and glycolipids, and nonlipidic molecules. The presentation of many of these molecules can have immunopotentiating effects, such as serving as an adjuvant against malaria or resulting in a more rapid clearance of certain virus infections. They can also be protective in autoimmune diseases or cancer or can be deleterious. This review will highlight these ligands in a discussion of their potential use against (and role in the pathogenesis of) these diseases.  相似文献   

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Damage to any tissue triggers a cascade of events that leads to rapid repair of the wound - if the tissue is skin, then repair involves re-epithelialization, formation of granulation tissue and contraction of underlying wound connective tissues. This concerted effort by the wounded cell layers is accompanied by, and might also be partially regulated by, a robust inflammatory response, in which first neutrophils and then macrophages and mast cells emigrate from nearby tissues and from the circulation. Clearly, this inflammatory response is crucial for fighting infection and must have been selected for during the course of evolution so that tissue damage did not inevitably lead to death through septicemia. But, aside from this role, exactly what are the functions of the various leukocyte lineages that are recruited with overlapping time courses to the wound site, and might they do more harm than good? Recent knockout and knockdown studies suggest that depletion of one or more of the inflammatory cell lineages can even enhance healing, and we discuss new views on how regulation of the migration of inflammatory cells to sites of tissue damage might guide therapeutic strategies for modulating the inflammatory response.  相似文献   

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The question is raised, whether there are peculiarly scientific values which can be applied in environmental assessment. The use of the expression scientific interest is traced from its 19th century origins to modern British statutes. It is argued that attempts to replace expert judgements by objective scientific criteria (e.g., indices of biodiversity) can never be completely successful. In particular, interest is an aesthetic atribute particularly valued by scientists but incapable of precise measurement. While science provides the best framework for informed judgements on conservation issues, the judgements of scientists are inevitably distinct from their experimental results. Judgements rest on ethical and aesthetic values such as importance and interest, which are essential constituents of the scientific sub-culture, but which are not uniquely scientific.  相似文献   

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Genomic medicine seeks to exploit an individual’s genomic information in the context of guiding the clinical decision-making process. In the post-genomic era, a range of novel molecular genetic testing methodologies have emerged, allowing the genetic testing industry to grow at a very rapid pace. As a consequence, a considerable number of different private diagnostic testing laboratories now provide a wide variety of genetic testing services, often employing a direct-to-consumer (DTC) business model to identify mutations underlying (or associated with) common Mendelian disorders, to individualize drug response, to attempt to determine an individual’s risk of a multitude of complex (multifactorial) diseases, or even to determine a person’s identity. Recently, we have noted a novel trend in the provision of private molecular genetic testing services, namely saliva and buccal swab collection kits (for deoxyribonucleic acid (DNA) isolation) being offered for sale over the counter by pharmacies. This situation is somewhat different from the standard DTC genetic testing model, since pharmacists are healthcare professionals who are supposedly qualified to give appropriate advice to their clients. There are, however, a number of issues to be addressed in relation to the marketing of DNA collection kits for genetic testing through pharmacies, namely a requirement for regulatory clearance, the comparative lack of appropriate genetics education of the healthcare professionals involved, and most importantly, the lack of awareness on the part of both the patients and the general public with respect to the potential benefits or otherwise of the various types of genetic test offered, which may result in confusion as to which test could be beneficial in their own particular case. We believe that some form of genetic counseling should ideally be integrated into, and made inseparable from, the genetic testing process, while pharmacists should be obliged to receive some basic training about the genetic tests that they offer for sale.  相似文献   

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