479 research outputs found

    Methods for modelling the cost-effectiveness of interventions for prostate cancer: a systematic review - Protocol

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    This is a protocol for a systematic review of methods for modelling the cost-effectiveness of interventions for prostate cancer. It will aim to identify and bring together all health economic modelling studies in prostate cancer, to inform the subsequent development of a whole disease model for prostate cancer. This protocol is being deposited prospectively. The following review activities have been completed at the time of depositing: Bibliographic database search strategies designed (MEDLINE, Embase, NHSEED, HTA) Bibliographic database searches conducted and results combined into an EndNote library prepared for screening Random sample of 100 citations selected for pilot screening No further review activities have been initiated or completed at time of depositing

    Footprint of Positive Selection in Treponema pallidum subsp. pallidum Genome Sequences Suggests Adaptive Microevolution of the Syphilis Pathogen

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    In the rabbit model of syphilis, infection phenotypes associated with the Nichols and Chicago strains of Treponema pallidum (T. pallidum), though similar, are not identical. Between these strains, significant differences are found in expression of, and antibody responses to some candidate virulence factors, suggesting the existence of functional genetic differences between isolates. The Chicago strain genome was therefore sequenced and compared to the Nichols genome, available since 1998. Initial comparative analysis suggested the presence of 44 single nucleotide polymorphisms (SNPs), 103 small (≤3 nucleotides) indels, and 1 large (1204 bp) insertion in the Chicago genome with respect to the Nichols genome. To confirm the above findings, Sanger sequencing was performed on most loci carrying differences using DNA from Chicago and the Nichols strain used in the original T. pallidum genome project. A majority of the previously identified differences were found to be due to errors in the published Nichols genome, while the accuracy of the Chicago genome was confirmed. However, 20 SNPs were confirmed between the two genomes, and 16 (80.0%) were found in coding regions, with all being of non-synonymous nature, strongly indicating action of positive selection. Sequencing of 16 genomic loci harboring SNPs in 12 additional T. pallidum strains, (SS14, Bal 3, Bal 7, Bal 9, Sea 81-3, Sea 81-8, Sea 86-1, Sea 87-1, Mexico A, UW231B, UW236B, and UW249C), was used to identify “Chicago-“ or “Nichols -specific” differences. All but one of the 16 SNPs were “Nichols-specific”, with Chicago having identical sequences at these positions to almost all of the additional strains examined. These mutations could reflect differential adaptation of the Nichols strain to the rabbit host or pathoadaptive mutations acquired during human infection. Our findings indicate that SNPs among T. pallidum strains emerge under positive selection and, therefore, are likely to be functional in nature

    Whole Genome Sequences of Three Treponema pallidum ssp. pertenue Strains: Yaws and Syphilis Treponemes Differ in Less than 0.2% of the Genome Sequence

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    Spirochete Treponema pallidum ssp. pertenue (TPE) is the causative agent of yaws while strains of Treponema pallidum ssp. pallidum (TPA) cause syphilis. Both yaws and syphilis are distinguished on the basis of epidemiological characteristics and clinical symptoms. Neither treponeme can reproduce outside the host organism, which precludes the use of standard molecular biology techniques used to study cultivable pathogens. In this study, we determined high quality whole genome sequences of TPE strains and compared them to known genetic information for T. pallidum ssp. pallidum strains. The genome structure was identical in all three TPE strains and also between TPA and TPE strains. The TPE genome length ranged between 1,139,330 bp and 1,139,744 bp. The overall sequence identity between TPA and TPE genomes was 99.8%, indicating that the two pathogens are extremely closely related. A set of 34 TPE genes (3.5%) encoded proteins containing six or more amino acid replacements or other major sequence changes. These genes more often belonged to the group of genes with predicted virulence and unknown functions suggesting their involvement in infection differences between yaws and syphilis

    Hepatitis B Virus X Protein Drives Multiple Cross-Talk Cascade Loops Involving NF-κB, 5-LOX, OPN and Capn4 to Promote Cell Migration

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    Hepatitis B virus X protein (HBx) plays an important role in the development of hepatocellular carcinoma (HCC). However, the mechanism remains unclear. Recently, we have reported that HBx promotes hepatoma cell migration through the upregulation of calpain small subunit 1 (Capn4). In addition, several reports have revealed that osteopontin (OPN) plays important roles in tumor cell migration. In this study, we investigated the signaling pathways involving the promotion of cell migration mediated by HBx. We report that HBx stimulates several factors in a network manner to promote hepatoma cell migration. We showed that HBx was able to upregulate the expression of osteopontin (OPN) through 5-lipoxygenase (5-LOX) in HepG2-X/H7402-X (stable HBx-transfected cells) cells. Furthermore, we identified that HBx could increase the expression of 5-LOX through nuclear factor-κB (NF-κB). We also found that OPN could upregulate Capn4 through NF-κB. Interestingly, we showed that Capn4 was able to upregulate OPN through NF-κB in a positive feedback manner, suggesting that the OPN and Capn4 proteins involving cell migration affect each other in a network through NF-κB. Importantly, NF-κB plays a crucial role in the regulation of 5-LOX, OPN and Capn4. Thus, we conclude that HBx drives multiple cross-talk cascade loops involving NF-κB, 5-LOX, OPN and Capn4 to promote cell migration. This finding provides new insight into the mechanism involving the promotion of cell migration by HBx

    Factors That Affect Large Subunit Ribosomal DNA Amplicon Sequencing Studies of Fungal Communities: Classification Method, Primer Choice, and Error

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    Nuclear large subunit ribosomal DNA is widely used in fungal phylogenetics and to an increasing extent also amplicon-based environmental sequencing. The relatively short reads produced by next-generation sequencing, however, makes primer choice and sequence error important variables for obtaining accurate taxonomic classifications. In this simulation study we tested the performance of three classification methods: 1) a similarity-based method (BLAST + Metagenomic Analyzer, MEGAN); 2) a composition-based method (Ribosomal Database Project naïve Bayesian classifier, NBC); and, 3) a phylogeny-based method (Statistical Assignment Package, SAP). We also tested the effects of sequence length, primer choice, and sequence error on classification accuracy and perceived community composition. Using a leave-one-out cross validation approach, results for classifications to the genus rank were as follows: BLAST + MEGAN had the lowest error rate and was particularly robust to sequence error; SAP accuracy was highest when long LSU query sequences were classified; and, NBC runs significantly faster than the other tested methods. All methods performed poorly with the shortest 50–100 bp sequences. Increasing simulated sequence error reduced classification accuracy. Community shifts were detected due to sequence error and primer selection even though there was no change in the underlying community composition. Short read datasets from individual primers, as well as pooled datasets, appear to only approximate the true community composition. We hope this work informs investigators of some of the factors that affect the quality and interpretation of their environmental gene surveys

    Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides

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    Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus

    The Evolution of Compact Binary Star Systems

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    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

    Selecting for BRCA1 testing using a combination of homogeneous selection criteria and immunohistochemical characteristics of breast cancers

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    <p>Abstract</p> <p>Background</p> <p>BRCA1 gene-related tumours are more frequently estrogen receptor (ER) and progesterone receptor (PR) negative with a lower prevalence of human epidermal growth factor receptor 2 (HER2) overexpression or amplification. We evaluated the effectiveness of a combination of homogeneously selected criteria and immunohistochemical (IHC) characteristics of Familial Breast Cancers (FBCs) in detecting BRCA1 mutation carriers.</p> <p>Methods</p> <p>Primary breast tumours from 93 FBC patients defined by specific eligibility criteria, based on personal and familial tumour history, were evaluated by Allred's method. The BRCA1 molecular analysis, including Multiplex Ligation-dependent Probe Amplification (MLPA), was considered as the gold standard assay.</p> <p>Results</p> <p>A total of 10 BRCA1 pathogenetic mutations was found. With the exclusion of the tumours characterized by double positive receptorial status and/or strong HER2 positivity (3+), we identified 22 patients, 10 of whom resulted as BRCA1 mutation carriers. The sensitivity, specificity, positive and negative predictive values were 100%, 83.3%, 45.4% and 100% respectively.</p> <p>Conclusion</p> <p>Our findings suggest that the IHC analysis by Allred's method improves our ability to select patients for BRCA1 testing.</p

    Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides

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    Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus
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