246 research outputs found
The chemopreventive polyphenol Curcumin prevents hematogenous breast cancer metastases in immunodeficient mice
Dissemination of metastatic cells probably occurs long before diagnosis of the primary tumor. Metastasis during early phases of carcinogenesis in high risk patients is therefore a potential prevention target. The plant polyphenol Curcumin has been proposed for dietary prevention of cancer. We therefore examined its effects on the human breast cancer cell line MDA-MB-231 in vitro and in a mouse metastasis model. Curcumin strongly induces apoptosis in MDA- MB- 231 cells in correlation with reduced activation of the survival pathway NF kappa B, as a consequence of diminished I kappa B and p65 phosphorylation. Curcumin also reduces the expression of major matrix metalloproteinases (MMPs) due to reduced NF kappa B activity and transcriptional downregulation of AP-1. NF kappa B/p65 silencing is sufficient to downregulate c-jun and MMP expression. Reduced NF kappa B/AP-1 activity and MMP expression lead to diminished invasion through a reconstituted basement membrane and to a significantly lower number of lung metastases in immunodeficient mice after intercardiac injection of 231 cells (p=0.0035). 68% of Curcumin treated but only 17% of untreated animals showed no or very few lung metastases, most likely as a consequence of down-regulation of NF kappa B/AP-1 dependent MMP expression and direct apoptotic effects on circulating tumor cells but not on established metastases. Dietary chemoprevention of metastases appears therefore feasible. Copyright (c) 2007 S. Karger AG, Basel
Heterologous production of curcuminoids
Curcuminoids, components of the rhizome of turmeric, show several beneficial biological activities, including anticarcinogenic, antioxidant, anti-inflammatory, and antitumor activities. Despite their numerous pharmaceutically important properties, the low natural abundance of curcuminoids represents a major drawback for their use as therapeutic agents. Therefore, they represent attractive targets for heterologous production and metabolic engineering. The understanding of biosynthesis of curcuminoids in turmeric made remarkable advances in the last decade, and as a result, several efforts to produce them in heterologous organisms have been reported. The artificial biosynthetic pathway (e.g., in Escherichia coli) can start with the supplementation of the amino acid tyrosine or phenylalanine or of carboxylic acids and lead to the production of several natural curcuminoids. Unnatural carboxylic acids can also be supplemented as precursors and lead to the production of unnatural compounds with possibly novel therapeutic properties. In this paper, we review the natural conversion of curcuminoids in turmeric and their production by E. coli using an artificial biosynthetic pathway. We also explore the potential of other enzymes discovered recently or already used in other similar biosynthetic pathways, such as flavonoids and stilbenoids, to increase curcuminoid yield and activity.We acknowledge financial support from the Strategic Project PEst-OE/EQB/LA0023/2013, project reference RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462), project SYNBIOBACTHER (PTDC/EBB-BIO/102863/2008), and a doctoral grant (SFRH/BD/51187/ 2010) to J. L. Rodrigues, funded by Fundacao para a Ciencia e a Tecnologia. We thank the MIT-Portugal Program for support given to J. L. Rodrigues
Risk Reducing Salpingectomy and Delayed Oophorectomy in high risk women: views of cancer geneticists, genetic counsellors and gynaecological oncologists in the UK
Risk-reducing-salpingectomy and Delayed-Oophorectomy (RRSDO) is being proposed as a two-staged approach in place of RRSO to reduce the risks associated with premature menopause in high-risk women. We report on the acceptability/attitude of UK health professionals towards RRSDO. An anonymised web-based survey was sent to UK Cancer Genetics Group (CGG) and British Gynaecological Cancer Society (BGCS) members to assess attitudes towards RRSDO. Baseline characteristics were described using descriptive statistics. A Chi square test was used to compare categorical, Kendal-tau-b test for ordinal and Mann–Whitney test for continuous variables between two groups. 173/708 (24.4 %) of invitees responded. 71 % respondents (CGG = 57 %/BGCS = 83 %, p = 0.005) agreed with the tubal hypothesis for OC, 55 % (CGG = 42 %/BGCS = 66 %, p = 0.003) had heard of RRSDO and 48 % (CGG = 46 %/BGCS = 50 %) felt evidence was not currently strong enough for introduction into clinical practice. However, 60 % respondents’ (CGG = 48 %/BGCS = 71 %, p = 0.009) favoured offering RRSDO to high-risk women declining RRSO, 77 % only supported RRSDO within a clinical trial (CGG = 78 %/BGCS = 76 %) and 81 % (CGG = 76 %/BGCS = 86 %) advocated a UK-wide registry. Vasomotor symptoms (72 %), impact on sexual function (63 %), osteoporosis (59 %), hormonal-therapy (55 %) and subfertility (48 %) related to premature menopause influenced their choice of RRSDO. Potential barriers to offering the two-stage procedure included lack of data on precise level of benefit (83 %), increased surgical morbidity (79 %), loss of breast cancer risk reduction associated with oophorectomy (68 %), need for long-term follow-up (61 %) and a proportion not undergoing DO (66 %). There were variations in perception between BGCS/CGG members which are probably attributable to differences in clinical focus/expertise between these two groups. Despite concerns, there is reasonable support amongst UK clinicians to offering RRSDO to premenopausal high-risk women wishing to avoid RRSO, within a prospective clinical trial.This work has not been directly funded by any commercial organisation, or charity
Involvement in surface antigen expression by a moonlighting FG-repeat nucleoporin in trypanosomes
Components of the nuclear periphery coordinate a multitude of activities, including macromolecular transport, cell-cycle progression, and chromatin organization. Nuclear pore complexes (NPCs) mediate nucleocytoplasmic transport, mRNA processing, and transcriptional regulation, and NPC components can define regions of high transcriptional activity in some organisms at the nuclear periphery and nucleoplasm. Lineage-specific features underpin several core nuclear functions and in trypanosomatids, which branched very early from other eukaryotes, unique protein components constitute the lamina, kinetochores, and parts of the NPCs. Here we describe a phenylalanine-glycine (FG)-repeat nucleoporin, TbNup53b, that has dual localizations within the nucleoplasm and NPC. In addition to association with nucleoporins, TbNup53b interacts with a known trans-splicing component, TSR1, and has a role in controlling expression of surface proteins including the nucleolar periphery-located, procyclin genes. Significantly, while several nucleoporins are implicated in intranuclear transcriptional regulation in metazoa, TbNup53b appears orthologous to components of the yeast/human Nup49/Nup58 complex, for which no transcriptional functions are known. These data suggest that FG-Nups are frequently co-opted to transcriptional functions during evolution and extend the presence of FG-repeat nucleoporin control of gene expression to trypanosomes, suggesting that this is a widespread and ancient eukaryotic feature, as well as underscoring once more flexibility within nucleoporin function
International criteria for acute kidney injury: advantages and remaining challenges
• Acute Kidney Injury (AKI) is defined using widely accepted international criteria that are based on changes in serum creatinine concentration and degree of oliguria.
• AKI, when defined in this way, has a strong association with poor patient outcomes, including high mortality rates and longer hospital admissions with increased resource utilisation and subsequent chronic kidney disease.
• The detection of AKI using current criteria can assist with AKI diagnosis and stratification of individual patient risk.
• The diagnosis of AKI requires clinical judgement to integrate the definition of AKI with the clinical situation, to determine underlying cause of AKI, and to take account of factors that may affect performance of current definitions
The global pendulum swing towards community health workers in low- and middle-income countries: A scoping review of trends, geographical distribution and programmatic orientations, 2005 to 2014
BACKGROUND: There has been a substantial increase in publications and interest in community health workers (CHWs) in low- and middle-income countries (LMIC) over the last years. This paper examines the growth, geographical distribution and programmatic orientations of the indexed literature on CHWs in LMIC over a 10-year period. METHODS: A scoping review of publications on CHWs from 2005 to 2014 was conducted. Using an inclusive list of terms, we searched seven databases (including MEDLINE, CINAHL, Cochrane) for all English-language publications on CHWs in LMIC. Two authors independently screened titles/abstracts, downloading full-text publications meeting inclusion criteria. These were coded in an Excel spreadsheet by year, type of publication (e.g. review, empirical), country, region, programmatic orientation (e.g. maternal-child health, HIV/AIDS, comprehensive) and CHW roles (e.g. prevention, treatment) and further analysed in Stata14. Drawing principally on the subset of review articles, specific roles within programme areas were identified and grouped. FINDINGS: Six hundred seventy-eight publications from 46 countries on CHWs were inventoried over the 10-year period. There was a sevenfold increase in annual number of publications from 23 in 2005 to 156 in 2014. Half the publications were reporting on initiatives in Africa, a third from Asia and 11 % from the Americas (mostly Brazil). The largest single focus and driver of the growth in publications was on CHW roles in meeting the Millennium Development Goals of maternal, child and neonatal survival (35 % of total), followed by HIV/AIDS (16 %), reproductive health (6 %), non-communicable diseases (4 %) and mental health (4 %). Only 17 % of the publications approached CHW roles in an integrated fashion. There were also distinct regional (and sometimes country) profiles, reflecting different histories and programme traditions. CONCLUSIONS: The growth in literature on CHWs provides empirical evidence of ever-increasing expectations for addressing health burdens through community-based action. This literature has a strong disease- or programme-specific orientation, raising important questions for the design and sustainable delivery of integrated national programmes.Scopu
Panel 4 : Report of the Microbiology Panel
Objective. To perform a comprehensive review of the literature from July 2011 until June 2015 on the virology and bacteriology of otitis media in children. Data Sources. PubMed database of the National Library of Medicine. Review Methods. Two subpanels comprising experts in the virology and bacteriology of otitis media were created. Each panel reviewed the relevant literature in the fields of virology and bacteriology and generated draft reviews. These initial reviews were distributed to all panel members prior to meeting together at the Post-symposium Research Conference of the 18th International Symposium on Recent Advances in Otitis Media, National Harbor, Maryland, in June 2015. A final draft was created, circulated, and approved by all panel members. Conclusions. Excellent progress has been made in the past 4 years in advancing our understanding of the microbiology of otitis media. Numerous advances were made in basic laboratory studies, in animal models of otitis media, in better understanding the epidemiology of disease, and in clinical practice. Implications for Practice. (1) Many viruses cause acute otitis media without bacterial coinfection, and such cases do not require antibiotic treatment. (2) When respiratory syncytial virus, metapneumovirus, and influenza virus peak in the community, practitioners can expect to see an increase in clinical otitis media cases. (3) Biomarkers that predict which children with upper respiratory tract infections will develop otitis media may be available in the future. (4) Compounds that target newly identified bacterial virulence determinants may be available as future treatment options for children with otitis media.Peer reviewe
QCD and strongly coupled gauge theories : challenges and perspectives
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe
The Pentameric Vertex Proteins Are Necessary for the Icosahedral Carboxysome Shell to Function as a CO2 Leakage Barrier
BACKGROUND: Carboxysomes are polyhedral protein microcompartments found in many autotrophic bacteria; they encapsulate the CO(2) fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) within a thin protein shell and provide an environment that enhances the catalytic capabilities of the enzyme. Two types of shell protein constituents are common to carboxysomes and related microcompartments of heterotrophic bacteria, and the genes for these proteins are found in a large variety of bacteria. METHODOLOGY/PRINCIPAL FINDINGS: We have created a Halothiobacillus neapolitanus knockout mutant that does not produce the two paralogous CsoS4 proteins thought to occupy the vertices of the icosahedral carboxysomes and related microcompartments. Biochemical and ultrastructural analyses indicated that the mutant predominantly forms carboxysomes of normal appearance, in addition to some elongated microcompartments. Despite their normal shape, purified mutant carboxysomes are functionally impaired, although the activities of the encapsulated enzymes are not negatively affected. CONCLUSIONS/SIGNIFICANCE: In the absence of the CsoS4 proteins the carboxysome shell loses its limited permeability to CO(2) and is no longer able to provide the catalytic advantage RubisCO derives from microcompartmentalization. This study presents direct evidence that the diffusion barrier property of the carboxysome shell contributes significantly to the biological function of the carboxysome
Engineered Protein Nano-Compartments for Targeted Enzyme Localization
Compartmentalized co-localization of enzymes and their substrates represents an attractive approach for multi-enzymatic synthesis in engineered cells and biocatalysis. Sequestration of enzymes and substrates would greatly increase reaction efficiency while also protecting engineered host cells from potentially toxic reaction intermediates. Several bacteria form protein-based polyhedral microcompartments which sequester functionally related enzymes and regulate their access to substrates and other small metabolites. Such bacterial microcompartments may be engineered into protein-based nano-bioreactors, provided that they can be assembled in a non-native host cell, and that heterologous enzymes and substrates can be targeted into the engineered compartments. Here, we report that recombinant expression of Salmonella enterica ethanolamine utilization (eut) bacterial microcompartment shell proteins in E. coli results in the formation of polyhedral protein shells. Purified recombinant shells are morphologically similar to the native Eut microcompartments purified from S. enterica. Surprisingly, recombinant expression of only one of the shell proteins (EutS) is sufficient and necessary for creating properly delimited compartments. Co-expression with EutS also facilitates the encapsulation of EGFP fused with a putative Eut shell-targeting signal sequence. We also demonstrate the functional localization of a heterologous enzyme (β-galactosidase) targeted to the recombinant shells. Together our results provide proof-of-concept for the engineering of protein nano-compartments for biosynthesis and biocatalysis
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