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 15 毫秒
1.
ABSTRACT

Introduction: Extracellular vesicles (EVs) represent an important mode of intercellular communication. There is now a growing awareness that predominant EV subtypes; exosomes from endosomal origin, and shed microvesicles from plasma membrane budding, can be further stratified into distinct subtypes, however specific approaches in their isolation and markers that allow them to be discriminated are lacking.

Areas covered: Knowledge about these distinct EV subpopulations is important including the regulation of composition, release, targeting/localization, uptake, and function. This review discusses the mechanisms of distinct EV biogenesis and release, defining select EV classes (and subpopulations), which will be crucial for development of EV-based functions and clinical applications. We review the dynamics of cargo sorting leading to the mechanisms of EV heterogeneity, their mechanisms of formation, intracellular trafficking pathways, and provide an uptake about biochemical/functional differences. With advances in purification strategies and proteomic-based quantitation, allows significant benefit in accurately describing differences in EV protein cargo composition and modification.

Expert commentary: The advent of quantitative mass spectrometry-based proteomics, in conjunction with advances in molecular cell biology, and EV purification strategies, has contributed significantly to our improved characterization and understanding of the molecular composition and functionality of these distinct EV subpopulations.  相似文献   

2.
Adjuvant radiotherapy after breast cancer surgery is an important part of breast cancer treatment improving local control and overall survival. However, a higher risk of cardiac mortality was observed when conventional radiotherapy techniques were used. Cardiac morbidity and mortality after radiation therapy have been studied in many meta-analyses. In those focused on modern radiotherapy techniques, cardiac morbidity and mortality were no longer presented. However, an extremely long follow-up period is required. Importantly, the cardiac morbidity rates vary depending not only on the dose delivered to the heart, but also on the systemic therapies administrated and the pre-existing cardiac disease. Systematic heart dose monitoring is of great importance, as are efforts to constantly decrease doses, using advanced radiotherapy techniques. Nowadays, it is essential to individualize treatment according to tumor characteristics and anatomical predispositions, and to consider the cost and benefits.  相似文献   

3.
Information on the present distribution and status of the threatened freshwater pearl mussel Margaritifera margaritifera populations in Finland was updated. The status of the populations was classified into seven categories which are viable, maybe viable, non-viable/partly viable, dying-out, almost extinct, probably extinct, and extinct. The main criteria for judging the viability class were the population size and proportion of juvenile mussels. According to calculated estimate 1.7% populations were viable, 8.5% maybe viable, 40.2% non-viable/partly viable, 14.5% dying-out, 30.8% almost extinct, and 4.3% probably extinct. The present number of rivers with M. margaritifera in Finland is 117.  相似文献   

4.
Brain tumors are the most common form of solid tumors in children and is presently a serious therapeutic challenge worldwide. Traditional treatment with chemotherapy and radiotherapy was shown to be unsuccessful in targeting brain tumor cancer stem cells (CSCs), leading to recurrent, treatment-resistant secondary malignancies. Oncolytic virotherapy (OV) is an effective antitumor therapeutic strategy which offers a novel, targeted approach for eradicating pediatric brain tumor CSCs by utilizing mechanisms of cell killing that differ from conventional therapies. A number of studies and some clinical trials have therefore investigated the effects of combined therapy of radiations or chemotherapies with oncolytic viruses which provide new insights regarding the effectiveness and improvement of treatment responses for brain cancer patients. This review summarizes the current knowledge of the therapeutic potency of OVs-induced CSCs targeting in the treatment of brain tumors for a better understanding and hence a better management of this disease.  相似文献   

5.
6.
Colorectal cancer is the second most common type of cancer both in Europe and Poland. During the last 30 years more than a 3-fold increase has been observed in Poland due to environmental and genetic factors. Almost all colorectal malignancies are related to the formation and malignant transformation of colorectal dysplasia and adenoma. Efforts aiming to decrease the number of colorectal cancer deaths are focused on the disease early detection. Genetic diagnosis for hereditary syndromes predisposing to colorectal cancer has been developed and is a part of the routine treatment. Most cancers are sporadic. They often develop from polyps in the colon. In addition to the genetic events described in the 1990s, showing the adenoma transformation into carcinoma that has been a prime example of malignant transformation for a long time, there are also other possibilities of neoplastic transformation. The recognition of colorectal cancer risk factors make sense as their nature is lifestyle- and diet-related. In this review paper those risk factors are presented and the prevention of colorectal cancer is discussed taking into account genetic factors.  相似文献   

7.
In 1993, about 52% of the 433 698 tons of thetotal US aquaculture production came from theproduction of freshwater catfish. Excludingsalmonid culture, the percentage of marine finfishculture in total aquaculture production in the UShas been negligible. Commercial scale production ofmarine finfish in hatcheries is very limited in theUS.Studies on eggs and larvae of marine finfishspecies in the US have stemmed from theconsideration of fisheries management rather thanaquaculture. Most of the marine finfish larvaeproduced in the laboratory has been for the purposeof providing materials for other academic relatedstudies. Results of these studies can be applied inthe development of marine finfish hatcherytechnology. Hatchery technology for several marinefinfish species has been developed for stockenhancement, technology transfer and aquaculture. This paper reviews the current hatchery technologyof striped mullet (Mugil cephalus), dolphinfish (Coryphaena hippurus), red drum (Sciaenops ocellatus), and other potentialaquaculture species.  相似文献   

8.
As regards their morphology and biology, tumours consist of heterogeneous cell populations. The cancer stem cell (CSC) hypothesis assumes that a tumour is hierarchically organized and not all of the cells are equally capable of generating descendants, similarly to normal tissue. The only cells being able to self-renew and produce a heterogeneous tumour cell population are cancer stem cells. CSCs probably derive from normal stem cells, although progenitor cells may be taken into consideration as the source of cancer stem cells. CSCs reside in the niche defined as the microenvironment formed by stromal cells, vasculature and extracellular matrix. The CSC assays include FACS sorting, xenotransplantation to immunodeficient mice (SCID), incubation with Hoechst 33342 dye, cell culture in non-adherent conditions, cell culture with bromodeoxyuridine. CSCs have certain properties that make them resistant to anticancer therapy, which suggests they may be the target for potential therapeutic strategies.  相似文献   

9.
Recent scholarship contends that collective action emerges when human rights are violated. This article investigates why Haitians without status in the Bahamas have yet to mobilize collectively for basic rights and protections, despite discrimination and exploitation. The article examines two analogies to explain their immobilization. The analogy of dry land drowning utilizes Goffman's Stigma (1963) framework to describe how social prejudice hinders the ability of Haitians without status to act, while the analogy of rip current survival explains how institutional drawbacks pull Haitians without status away from movement activity through a political process analysis. The article contends that both interpretations are inadequate when taken alone and provides suggestions for future research into Bahamian-Haitian relations.  相似文献   

10.

Background

Studying root biomass, root system distribution and belowground interactions is essential for understanding the composition of plant communities, the impact of global change, and terrestrial biogeochemistry. Most soil samples and minirhizotron pictures hold roots of more than one species or plant individual. The identification of taxa by their roots would allow species-specific questions to be posed; information about root affiliation to plant individuals could be used to determine intra-specific competition.

Scope

Researchers need to be able to discern plant taxa by roots as well as to quantify abundances in mixed root samples. However, roots show less distinctive features that permit identification than aboveground organs. This review discusses the primary use of available methods, outlining applications, shortcomings and future developments.

Conclusion

Methods are either non-destructive, e.g. visual examination of root morphological criteria in situ, or require excavated and excised root samples. Among the destructive methods are anatomical keys, chemotaxonomic approaches and molecular markers. While some methods allow for discerning the root systems of individual plants, others can distinguish roots on the functional group or plant taxa level; methods such as IR spectroscopy and qPCR allow for quantifying the root biomass proportion of species without manual sorting.  相似文献   

11.
Interaction between cell surface integrin receptors and extracellular matrix (ECM) components plays an important role in cell survival, proliferation, and migration, including tumor development and invasion of tumor cells. Matrix metalloproteinases (MMPs) are a family of metalloproteinases capable of digesting ECM components and are important molecules for cell migration. Binding of ECM to integrins initiates cascades of cell signaling events modulating expression and activity of different MMPs. The aim of this study is to investigate fibronectin–integrin-mediated signaling and modulation of MMPs. Our findings indicated that culture of human cervical cancer cell (SiHa) on fibronectin-coated surface perhaps sends signals via fibronectin–integrin-mediated signaling pathways recruiting focal adhesion kinase (FAK) extracellular signal regulated kinase (ERK), phosphatidyl inositol 3 kinase (PI-3K), integrin-linked kinase (ILK), nuclear factor-kappa B (NF-κB), and modulates expression and activation of mainly pro-MMP-9, and moderately pro-MMP-2 in serum-free culture medium.  相似文献   

12.
《Biomarkers》2013,18(6):437-443
Abstract

Context: Bile duct cancer (BDC) is a disease with a very grave prognosis, often diagnosed too late.

Objective: The aim of this review is to evaluate available literature on tumor markers in serum from patients with BDC.

Methods: Using the search words “serum markers”, “bile duct cancer”, “cholangiocarcinoma”, “biomarker” and “tumor marker”, a search was carried out.

Results: Seventy-five studies were included in the review.

Conclusion: CA19-9 is by far the most studied and most promising diagnostic and/or prognostic marker in BDC. But also the different mucins are interesting as new markers of BDC in serum.  相似文献   

13.
Summary Progress in rye karyology is reviewed with respect to chromosome structure, recognition and chromosome nomenclature. Considerable contributions have been brought about by molecular techniques which have even revealed nucleotide sequences of some of the ribosomal DNA. DNA sequence organization correlates with the distribution of major Giemsa C-band regions as well as with N-bands and the binding sites of fluorescent dyes. The several banding patterns permit the classification of rye chromosomes. The increased data and widespread application of banding analysis require a consistent system of chromosome and/or band designation. Therefore, a standard band nomenclature is proposed with reference to the recommendations of the Paris Conference on Standardization in Human Cytogenetics. In addition, advances in genetics are summarized and discussed. Based on the original accepted standard karyogram and banding patterns of the rye chromosomes, meanwhile, 120 genes determining several characters have been associated with individual chromosomes and/or chromosome arms, including linkage studies for about 19 arrangements. Most results were obtained using wheat-rye addition lines as well as test crosses with defined translocations. Moreover, genetical studies based on appropriate trisomic and telotrisomic material resulted in the localization of 19 genes, including their linkage relationships.  相似文献   

14.
Aim To estimate relative contribution and time trends of HPV types in cervical cancer in Cali, Colombia over a 50 years’ period.MethodsParaffin blocks of 736 cervical cancer histological confirmed cases were retrieved from the pathology laboratory at Hospital Universitario del Valle (Cali, Colombia) and HPV genotyped using SPF10-PCR/DEIA/LiPA25 (version 1) assay. Marginal effect of age and year of diagnosis in secular trends of HPV type prevalence among HPV+ cases were assessed by robust Poisson regression analysis.Results64.7% (95%CI: 59.9–69.2) of squamous cell carcinomas (SCCs) were attributed to HPV 16 and 18, 78.2% (95%CI: 74–82) to HPV 16, 18, 31, 33 and 45 and 84.8% (95%CI: 81–88.1) to HPV 16, 18, 31, 33, 45, 52 and 58 while ninety-three percent of adenocarcinomas (ADCs) were attributed to HPV 16, 18 and 45 only. The prevalence of specific HPV types did not change over the 50-year period. A significant downward trend of prevalence ratios of HPV16 (​P = 0.017) and α7 but HPV 18 (i.e., HPV 39, 45, 68, 70, ​P = 0.024) with increasing age at diagnosis was observed. In contrast, the prevalence ratio to other HPV genotypes of α9 but HPV 16 genotypes (i.e., HPV 31, 33, 35, 52, 58, 67, ​P = 0.002) increased with increasing age at diagnosis.ConclusionNo changes were observed in the relative contribution of HPV types in cervical cancer in Cali, Colombia during the 50 years. In this population, an HPV vaccine including the HPV 16, 18, 31, 33, 45, 52 and 58 genotypes may have the potential to prevent ∼85% and 93% of SCC and ADC cases respectively.  相似文献   

15.
One of the paradigms in cancer pathogenesis is the requirement of a cell to undergo transformation from respiration to aerobic glycolysis – the Warburg effect – to become malignant. The demands of a rapidly proliferating cell for carbon metabolites for the synthesis of biomass, energy and redox equivalents, are fundamentally different from the requirements of a differentiated, quiescent cell, but it remains open whether this metabolic switch is a cause or a consequence of malignant transformation. One of the major requirements is the synthesis of lipids for membrane formation to allow for cell proliferation, cell cycle progression and cytokinesis. Enzymes involved in lipid metabolism were indeed found to play a major role in cancer cell proliferation, and most of these enzymes are conserved in the yeast, Saccharomyces cerevisiae. Most notably, cancer cell physiology and metabolic fluxes are very similar to those in the fermenting and rapidly proliferating yeast. Both types of cells display highly active pathways for the synthesis of fatty acids and their incorporation into complex lipids, and imbalances in synthesis or turnover of lipids affect growth and viability of both yeast and cancer cells. Thus, understanding lipid metabolism in S. cerevisiae during cell cycle progression and cell proliferation may complement recent efforts to understand the importance and fundamental regulatory mechanisms of these pathways in cancer.  相似文献   

16.
BackgroundCervical cancer is the fourth leading oncological cause of death in women. Variable trends in cervical cancer mortality have been observed across Europe, despite the widespread adoption of screening programs. This variability has previously been attributed to heterogeneity in the quality of screening programs.MethodsAge-standardized cervical cancer death rates for European countries between 1985 and 2014 were analyzed using Joinpoint regression. Countries were dichotomized based on year of implementation and population invitational coverage of national population-based cervical cancer screening programs. National cervical cancer mortality trends during the study period were compared based on this classification.ResultsDecreasing trends in mortality were observed in all European countries with the specific exceptions of Bulgaria, Greece and Latvia. The highest rates of cervical cancer mortality throughout the study period were in Romania (16.0-14.9/100,000) and the lowest rates in Italy (1.4-1.2/100,000). The greatest percentage decline in mortality was observed in the United Kingdom and the greatest absolute reduction in mortality was seen in Hungary. European countries which implemented a national population-based cervical cancer screening program prior to 2009 demonstrated greater improvements in cervical cancer mortality outcomes compared to those that did not (p = 0.016).ConclusionCervical cancer mortality is improving in most European countries; however, substantial variation remains. Trends in mortality were associated with the time of implementation of national population-based cervical screening programs.  相似文献   

17.
18.
Microbial degradation of tannins – A current perspective   总被引:26,自引:0,他引:26  
Tannins are water-soluble polyphenolic compounds having wide prevalence in plants. Hydrolysable and condensed tannins are the two major classes of tannins. These compounds have a range of effects on various organisms – from toxic effects on animals to growth inhibition of microorganisms. Some microbes are, however, resistant to tannins, and have developed various mechanisms and pathways for tannin degradation in their natural milieu. The microbial degradation of condensed tannins is, however, less than hydrolysable tannins in both aerobic and anaerobic environments. A number of microbes have also been isolated from the gastrointestinal tract of animals, which have the ability to break tannin-protein complexes and degrade tannins, especially hydrolysable tannins. Tannase, a key enzyme in the degradation of hydrolysable tannins, is present in a diverse group of microorganisms, including rumen bacteria. This enzyme is being increasingly used in a number of processes. Presently, there is a need for increased understanding of the biodegradation of condensed tannins, particularly in ruminants.  相似文献   

19.
We have previously documented that naked antisense CK2α ODN can potently induce apoptosis in cancer cells in culture and in mouse xenograft human prostate cancer. The effects of the antisense CK2α are related to downregulation of CK2α message and rapid loss of the CK2 from the nuclear compartment. Here we demonstrate that downregulation of CK2 elicited by diverse methods leads to inhibition of cell growth and induction of apoptosis. The various approaches to downregulation of CK2 employed were transfection with kinase-inactive plasmid, use of CK2α siRNA, use of inhibitors of CK2 activity, and use of antisense CK2α ODN packaged in sub-50 nm nanocapsules made from tenascin. In all cases, the downregulation of CK2 is associated with loss in cell survival. We have also described preliminary observations on an approach to targeting CK2 in cancer cells. For this, sub-50 nm tenascin-based nanocapsules bearing the antisense CK2α ODN were employed to test that the antisense is delivered to the cancer cells in vivo. The results provide the first preliminary evidence that such an approach may be feasible for targeting CK2 in cancer cells. Together, our results suggest that CK2 is potentially a highly plausible target for cancer therapy.  相似文献   

20.
The genus Artemisia has been utilized worldwide due to its immense potential for protection against various diseases, especially malaria. Artemisia absinthium, previously renowned for its utilization in the popular beverage absinthe, is gaining resurgence due to its extensive pharmacological activities. Like A. annua, this species exhibits strong biological activities like antimalarial, anticancer and antioxidant. Although artemisinin was found to be the major metabolite for its antimalarial effects, several flavonoids and terpenoids are considered to possess biological activities when used alone and also to synergistically boost the bioavailability of artemisinin. However, due to the limited quantities of these metabolites in wild plants, in vitro cultures were established and strategies have been adopted to enhance medicinally important secondary metabolites in these cultures. This review elaborates on the traditional medicinal uses of Artemisia species and explains current trends to establish cell cultures of A. annua and A. absinthium for enhanced production of medicinally important secondary metabolites.  相似文献   

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