1,625 research outputs found

    How the Cervical Microbiota Contributes to Cervical Cancer Risk in Sub-Saharan Africa

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    Despite ongoing efforts, sub-Saharan Africa faces a higher cervical cancer burden than anywhere else in the world. Besides HPV infection, definitive factors of cervical cancer are still unclear. Particular states of the cervicovaginal microbiota and viral infections are associated with increased cervical cancer risk. Notably, HIV infection, which is prevalent in sub-Saharan Africa, greatly increases risk of cervicovaginal dysbiosis and cervical cancer. To better understand and address cervical cancer in sub-Saharan Africa, a better knowledge of the regional cervicovaginal microbiome is required This review establishes current knowledge of HPV, HIV, cervicovaginal infections, and the cervicovaginal microbiota in sub-Saharan Africa. Because population statistics are not available for the region, estimates are derived from smaller cohort studies. Microbiota associated with cervical inflammation have been found to be especially prevalent in sub-Saharan Africa, and to associate with increased cervical cancer risk. In addition to high prevalence and diversity of HIV and HPV, intracellular bacterial infections such as Chlamydia, Gonorrhea, and Mycoplasma hominis are much more common than in regions with a low burden of cervical cancer. This suggests the prevalence of cervical cancer in sub-Saharan Africa may be partially attributed to increased cervical inflammation resulting from higher likelihood of cervical infection and/or microbial dysbiosis

    The structure of epitaxial V2O3 films and their surfaces : a medium energy ion scattering study

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    Medium energy ion scattering, using 100 keV H+ incident ions, has been used to investigate the growth of epitaxial films, up to thicknesses of ~200 Å, of V2O3 on both Pd(111) and Au(111). Scattered-ion energy spectra provide a measure of the average film thickness and the variations in this thickness, and show that, with suitable annealing, the crystalline quality is good. Plots of the scattering yield as a function of scattering angle, so-called blocking curves, have been measured for two different incidence directions and have been used to determine the surface structure. Specifically, scattering simulations for a range of different model structures show poor agreement with experiment for half-metal (….V’O3V) and vanadyl (….V’O3V=O) terminations, with and without surface interlayer relaxations. However, good agreement with experiment is found for the modified oxygen-termination structure, first proposed by Kresse et al., in which a subsurface V half-metal layer is moved up into the outermost V buckled metal layer to produce a VO2 overlayer on the underlying V2O3, with an associated layer structure of ….O3VV’’V’O3

    How the Cervical Microbiota Contributes to Cervical Cancer Risk in Sub-Saharan Africa

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    Despite ongoing efforts, sub-Saharan Africa faces a higher cervical cancer burden than anywhere else in the world. Besides HPV infection, definitive factors of cervical cancer are still unclear. Particular states of the cervicovaginal microbiota and viral infections are associated with increased cervical cancer risk. Notably, HIV infection, which is prevalent in sub-Saharan Africa, greatly increases risk of cervicovaginal dysbiosis and cervical cancer. To better understand and address cervical cancer in sub-Saharan Africa, a better knowledge of the regional cervicovaginal microbiome is required This review establishes current knowledge of HPV, HIV, cervicovaginal infections, and the cervicovaginal microbiota in sub-Saharan Africa. Because population statistics are not available for the region, estimates are derived from smaller cohort studies. Microbiota associated with cervical inflammation have been found to be especially prevalent in sub-Saharan Africa, and to associate with increased cervical cancer risk. In addition to high prevalence and diversity of HIV and HPV, intracellular bacterial infections such as Chlamydia, Gonorrhea, and Mycoplasma hominis are much more common than in regions with a low burden of cervical cancer. This suggests the prevalence of cervical cancer in sub-Saharan Africa may be partially attributed to increased cervical inflammation resulting from higher likelihood of cervical infection and/or microbial dysbiosis

    Site-selective adsorption of naphthalene-tetracarboxylic-dianhydride on Ag(110): First-principles calculations

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    The mechanism of adsorption of the 1,4,5,8-naphthalene-tetracarboxylic-dianhydride (NTCDA) molecule on the Ag(110) surface is elucidated on the basis of extensive density functional theory calculations. This molecule, together with its perylene counterpart, PTCDA, are archetype organic semiconductors investigated experimentally over the past 20 years. We find that the bonding of the molecule to the substrate is highly site-selective, being determined by electron transfer to the LUMO of the molecule and local electrostatic attraction between negatively charged carboxyl oxygens and positively charged silver atoms in [1-10] atomic rows. The adsorption energy in the most stable site is 0.9eV. A similar mechanism is expected to govern the adsorption of PTCDA on Ag(110) as well.Comment: 8 pages, 4 figures, high-quality figures available upon reques

    Mycoplasma Co-Infection Is Associated with Cervical Cancer Risk

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    Tanzania faces one of the highest cervical cancer burdens in the world. Recent work has suggested that the bacterial family Mycoplasmataceae is associated with higher levels of human papillomavirus (HPV), human immunodeficiency virus (HIV), and pre-cancerous cervical lesions. Mycoplasmataceae infection in Tanzania is not well understood, especially when considering the differences between sexually transmitted species of Mycoplasmataceae. To establish the prevalence of common Mycoplasmataceae cervical infections and evaluate their relationship with risk factors for cervical cancer, 1160 Tanzanian women responded to an epidemiological questionnaire and were tested for HIV, HPV, cervical lesions, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma spp., and Lactobacillus iners. A subset of 134 women were used for 16s metagenomic sequencing of cervical DNA to establish the relative abundance of Mycoplasmataceae and Lactobacillus present. PCR detection of bacteria at the cervix found Ureaplasma spp. in 51.4% of women, M. hominis in 34%, M. genitalium in 2.3%, and L. iners in 75.6%. M. hominis and M. genitalium infection were significantly more prevalent among women with HPV and HIV. M. hominis prevalence was similar despite severity of cervical lesions; however, abundance of M. hominis increased significantly in women with cervical lesions. These results emphasize the importance of understanding the relationship between M. hominis and HPV-related cervical pathogenesis

    Most women diagnosed with cervical cancer by a visual screening program in Tanzania completed treatment: evidence from a retrospective cohort study

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    Abstract Background Visual inspection with acetic acid (VIA) to identify and treat pre-cancerous lesions is effective for cervical cancer prevention. Screening programs also facilitate screening and diagnosis of invasive cancers that must be referred for radiation therapy or chemotherapy. This study compared characteristics of women diagnosed with invasive cervical cancer by a VIA screening program who did and did not follow up for treatment and who did and did not complete treatment at the Ocean Road Cancer Institute (ORCI), Dar es Salaam, Tanzania. Methods We conducted a retrospective cohort study of ORCI screening referrals from the period November 2002 to June 2011. Women referred for treatment of invasive disease (n = 980) were identified from an existing database of all women attending the screening clinic during this period (n = 20,131) and matched to a dataset of all cervical cancer patients attending ORCI in this period (n = 8,240). Treatment information was abstracted from patient records of women who followed up. Records of a random sample (n = 333) of unscreened patients were reviewed for disease stage. Results Of the 980 women referred women, 829 (84.6%) sought treatment. Most of those women (82.8%) completed their prescribed radiation. Lower disease stage, having a skilled occupation, residence in Dar es Salaam, and younger age were independently associated with loss to follow-up. Higher disease stage, residence in Dar es Salaam, older age, and later year of first treatment appointment were independently associated with incomplete treatment among those who followed up. Significantly more screened women had stage 1 disease (14.0%) than unscreened women (7.8%). Conclusions Most women referred from the screening clinic completed treatment for their cancer at ORCI. Some of those lost to follow-up may have sought treatment elsewhere. In most cases, the screening clinic appears to facilitate diagnosis and treatment, rather than screening, for women with invasive cervical cancer.http://deepblue.lib.umich.edu/bitstream/2027.42/109468/1/12889_2013_Article_7027.pd

    The Molecular Pathogenesis of Osteosarcoma: A Review

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    Osteosarcoma is the most common primary malignancy of bone. It arises in bone during periods of rapid growth and primarily affects adolescents and young adults. The 5-year survival rate for osteosarcoma is 60%–70%, with no significant improvements in prognosis since the advent of multiagent chemotherapy. Diagnosis, staging, and surgical management of osteosarcoma remain focused on our anatomical understanding of the disease. As our knowledge of the molecular pathogenesis of osteosarcoma expands, potential therapeutic targets are being identified. A comprehensive understanding of these mechanisms is essential if we are to improve the prognosis of patients with osteosarcoma through tumour-targeted therapies. This paper will outline the pathogenic mechanisms of osteosarcoma oncogenesis and progression and will discuss some of the more frontline translational studies performed to date in search of novel, safer, and more targeted drugs for disease management
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