96 research outputs found
Hypoxia-inducible factor-1α polymorphisms and TSC1/2 mutations are complementary in head and neck cancers
BACKGROUND: Polymorphisms or mutations in hypoxia inducible factor-1 alpha (HIF-1alpha) that increases its activity and stability under normoxia have recently been identified. Likewise, disruption of the TSC1/TSC2 complex through loss of TSC1 or TSC2 has been shown to result in abnormal accumulation of HIF-1α. Here, we investigate the novel polymorphisms in exon 12, that approximate the oxygen-dependent degradation domain of HIF-1alpha in five cell lines and 28 patients with oral squamous carcinomas. Moreover, we assess for the presence of polymorphisms and mutations in TSC1 and TSC2, to ascertain if dysregulation of such might complement HIF-1alpha expression. RESULTS: Denaturing high pressure liquid chromatography (DHPLC) analysis on PCR fragments in exon 12 of HIF-1alpha from 28 patients with OSCC revealed that 6 of 28 patients had mismatched heteroduplex patterns. Genomic DNA was extracted from peripheral blood leukocytes and direct sequencing showed that in 5 of the six cases these changes represented polymorphisms while, one case was a somatic mutation. Analyses of TSC1 and TSC2 revealed heteroduplexes in exons: TSC1 exon 17; TSC2 exons 36,40, and 41. The relative levels of HIF-1alpha were significantly greater for tumors possessing a HIF-1alpha polymorphism or mutation within exon 12, whereas tumors possessing a deletion or polymorphism in TSC1/TSC2 displayed a trend for higher levels of HIF-1alpha. Western blot analyses for HIF-1alpha, TSC1 and TSC2 in five SCC cell lines revealed high levels of HIF-1alpha in SCC cells possessing TSC1 and/or TSC2 mutations. Wild-type TSC2 cells targeted with siRNA to TSC2 exhibited increased levels of HIF-1alpha. Transfection of a HIF-1alpha mutant produced higher levels of HIF-1alpha in TSC1/TSC2 mutant cell lines than in wild type cells. TSC1/TSC2 mutant cell lines administered Rapamycin blocked S6 phorphorylation and diminished the levels of HIF-1alpha to those observed in cell lines with wild type TSC1/TSC2. CONCLUSION: Dysregulation of the TSC1/TSC2 complex by mutation compliments HIF-1α polymorphisms in the expression of HIF-1alpha in SCC of the head and neck, and may provide biomarkers to predict responses to specific therapies and overall disease prognosis
Juvenile trabecular ossifying fibroma : immunohistochemical expression of MDM2, CDK4 and p53 compared to conventional ossifying fibroma
Juvenile ossifying fibroma (JOF) is an uncommon benign fibro-osseous lesion of the craniofacial skele- ton; compared to conventional ossifying fibroma (OF), JOF is characterized by local aggressiveness and propensity for recurrence. The bio
Histological pattern of tumor inflammation and stromal density correlate with patient demographics and immuno-oncologic transcriptional profile in oral squamous cell carcinoma
IntroductionOral squamous cell carcinoma (OSCC) is the most prevalent oral malignancy, with emerging interest in the characterization of its tumor microenvironment. Herein, we present a comprehensive histological analysis of OSCC stromal density and inflammation and their relationship with patient demographics, clinicopathologic features and immuno-oncologic signatures.Materials-methodsEighty-seven completely excised OSCC tissues were prospectively collected and scored for histopathologic inflammatory subtypes [HIS]—inflamed (INF), immune-excluded (IE) and immune-desert (ID), peritumoral stromal inflammation (PTSI), and peritumoral stromal fibrosis (PTSF). Scoring of inflammation was complemented by Semaphorin 4D immunohistochemistry. NanoString differential gene expression (DGE) analysis was conducted for eight OSCC cases representative of the inflammatory and stromal subtypes and the demographic groups.ResultsPTSF correlated with male gender (p = 0.0043), smoking (p = 0.0455), alcohol consumption (p = 0.0044), increased tumor size (p = 0.0054), and advanced stage (p = 0.002). On the contrary, PTSI occurred predominantly in females (p = 0.0105), non-drinkers (p = 0.0329), and small tumors (p = 0.0044). Transcriptionally, decreased cytokine signaling, and oncogenic pathway activation were observed in HIS-IE. Smokers and males displayed decreased global immune-cell levels and myeloid-cell predominance.ConclusionOur work describes OSCC stromal and inflammatory phenotypes in correlation with distinct patient groups and DGE, highlighting the translational potential of characterizing the tumor microenvironment for optimal patient stratification
The predictive and prognostic value of tumour necrosis in muscle invasive bladder cancer patients receiving radiotherapy with or without chemotherapy in the BC2001 trial (CRUK/01/004)
Background:
Severe chronic hypoxia is associated with tumour necrosis. In patients with muscle invasive bladder cancer (MIBC), necrosis is prognostic for survival following surgery or radiotherapy and predicts benefit from hypoxia modification of radiotherapy. Adding mitomycin C (MMC) and 5-fluorouracil (5-FU) chemotherapy to radiotherapy improved locoregional control (LRC) compared to radiotherapy alone in the BC2001 trial. We hypothesised that tumour necrosis would not predict benefit for the addition of MMC and 5-FU to radiotherapy, but would be prognostic.
Methods:
Diagnostic tumour samples were available from 230 BC2001 patients. Tumour necrosis was scored on whole-tissue sections as absent or present, and its predictive and prognostic significance explored using Cox proportional hazards models. Survival estimates were obtained by Kaplan–Meier methods.
Results:
Tumour necrosis was present in 88/230 (38%) samples. Two-year LRC estimates were 71% (95% CI 61–79%) for the MMC/5-FU chemoradiotherapy group and 49% (95% CI 38–59%) for the radiotherapy alone group. When analysed by tumour necrosis status, the adjusted hazard ratios (HR) for MMC/5-FU vs. no chemotherapy were 0.46 (95% CI: 0.12–0.99; P=0.05, necrosis present) and 0.55 (95% CI: 0.31–0.98; P=0.04, necrosis absent). Multivariable analysis of prognosis for LRC by the presence vs. absence of necrosis yielded a HR=0.89 (95% CI 0.55–1.44, P=0.65). There was no significant association for necrosis as a predictive or prognostic factor with respect to overall survival.
Conclusions:
Tumour necrosis was neither predictive nor prognostic, and therefore MMC/5-FU is an appropriate radiotherapy-sensitising treatment in MIBC independent of necrosis status
The Murchison Widefield Array: Design Overview
The Murchison Widefield Array (MWA) is a dipole-based aperture array
synthesis telescope designed to operate in the 80-300 MHz frequency range. It
is capable of a wide range of science investigations, but is initially focused
on three key science projects. These are detection and characterization of
3-dimensional brightness temperature fluctuations in the 21cm line of neutral
hydrogen during the Epoch of Reionization (EoR) at redshifts from 6 to 10,
solar imaging and remote sensing of the inner heliosphere via propagation
effects on signals from distant background sources,and high-sensitivity
exploration of the variable radio sky. The array design features 8192
dual-polarization broad-band active dipoles, arranged into 512 tiles comprising
16 dipoles each. The tiles are quasi-randomly distributed over an aperture
1.5km in diameter, with a small number of outliers extending to 3km. All
tile-tile baselines are correlated in custom FPGA-based hardware, yielding a
Nyquist-sampled instantaneous monochromatic uv coverage and unprecedented point
spread function (PSF) quality. The correlated data are calibrated in real time
using novel position-dependent self-calibration algorithms. The array is
located in the Murchison region of outback Western Australia. This region is
characterized by extremely low population density and a superbly radio-quiet
environment,allowing full exploitation of the instrumental capabilities.Comment: 9 pages, 5 figures, 1 table. Accepted for publication in Proceedings
of the IEE
Developing cartoons for long-term condition self-management information
Background: Advocating the need to adopt more self-management policies has brought with it an increasing demand for information about living with and making decisions about long-term conditions, with a significant potential for using cartoons. However, the purposeful use of cartoons is notably absent in many areas of health care as is evidence of their acceptability to patients and lay others. This paper outlines the process used to develop and evaluate cartoons and their acceptability for a series of self-management guidebooks for people with inflammatory bowel disease, irritable bowel syndrome, diabetes, chronic obstructive pulmonary disease and chronic kidney disease (CKD).
Methods: Principles for a process to develop information and cartoons were developed. Cartoon topics were created using qualitative research methods to obtain lay views and experiences. The CKD guidebook was used to provide a detailed exemplar of the process. Focus group and trial participants were recruited from primary care CKD registers. The book was part of a trial intervention; selected participants evaluated the cartoons during in-depth interviews which incorporated think-aloud methods.
Results: In general, the cartoons developed by this process depict patient experiences, common situations, daily management dilemmas, making decisions and choices and the uncertainties associated with conditions. CKD cartoons were developed following two focus groups around the themes of getting a diagnosis; understanding the problem; feeling that facts were being withheld; and setting priorities. Think-aloud interviews with 27 trial participants found the CKD cartoons invoked amusement, recognition and reflection but were sometimes difficult to interpret.
Conclusion: Humour is frequently utilised by people with long-term conditions to help adjustment and coping. Cartoons can help provide clarity and understanding and could address concerns related to health literacy. Using cartoons to engage and motivate people is a consideration untapped by conventional theories with the potential to improve information to support self-management
Reduction of transmission from malaria patients by artemisinin combination therapies: a pooled analysis of six randomized trials
BACKGROUND: Artemisinin combination therapies (ACT), which are increasingly being introduced for treatment of Plasmodium falciparum malaria, are more effective against sexual stage parasites (gametocytes) than previous first-line antimalarials and therefore have the potential to reduce parasite transmission. The size of this effect is estimated in symptomatic P. falciparum infections. METHODS: Data on 3,174 patients were pooled from six antimalarial trials conducted in The Gambia and Kenya. Multivariable regression was used to investigate the role of ACT versus non-artemisinin antimalarial treatment, treatment failure, presence of pre-treatment gametocytes and submicroscopic gametocytaemia on transmission to mosquitoes and the area under the curve (AUC) of gametocyte density during the 28 days of follow up. RESULTS: ACT treatment was associated with a significant reduction in the probability of being gametocytaemic on the day of transmission experiments (OR 0.20 95% CI 0.16-0.26), transmission to mosquitoes by slide-positive gametocyte carriers (OR mosquito infection 0.49 95% CI 0.33-0.73) and AUC of gametocyte density (ratio of means 0.35 95% CI 0.31-0.41). Parasitological treatment failure did not account for the difference between ACT and non-artemisinin impact. The presence of slide-positive gametocytaemia prior to treatment significantly reduced ACT impact on gametocytaemia (p < 0.001). Taking account of submicroscopic gametocytaemia reduced estimates of ACT impact in a high transmission setting in Kenya, but not in a lower transmission setting in the Gambia. CONCLUSION: Treatment with ACT significantly reduces infectiousness of individual patients with uncomplicated falciparum malaria compared to previous first line treatments. Rapid treatment of cases before gametocytaemia is well developed may enhance the impact of ACT on transmission
INTERVAL (investigation of NICE technologies for enabling risk-variable-adjusted-length) dental recalls trial: a multicentre randomised controlled trial investigating the best dental recall interval for optimum, cost-effective maintenance of oral health in dentate adults attending dental primary care
Background
Traditionally, patients at low risk and high risk of developing dental disease have been encouraged to attend dental recall appointments at regular intervals of six months between appointments. The lack of evidence for the effect that different recall intervals between dental check-ups have on patient outcomes, provider workload and healthcare costs is causing considerable uncertainty for the profession and patients, despite the publication of the NICE Guideline on dental recall. The need for primary research has been highlighted in the Health Technology Assessment Group’s systematic review of routine dental check-ups, which found little evidence to support or refute the practice of encouraging 6-monthly dental check-ups in adults. The more recent Cochrane review on recall interval concluded there was insufficient evidence to draw any conclusions regarding the potential beneficial or harmful effects of altering the recall interval between dental check-ups. There is therefore an urgent need to assess the relative effectiveness and cost-benefit of different dental recall intervals in a robust, sufficiently powered randomised control trial (RCT) in primary dental care.
Methods
This is a four year multi-centre, parallel-group, randomised controlled trial with blinded outcome assessment based in dental primary care in the UK. Practitioners will recruit 2372 dentate adult patients. Patient participants will be randomised to one of three groups: fixed-period six month recall, risk-based recall, or fixed-period twenty-four month recall. Outcome data will be assessed through clinical examination, patient questionnaires and NHS databases. The primary outcomes measure gingival inflammation/bleeding on probing and oral health-related quality of life.
Discussion
INTERVAL will provide evidence for the most clinically-effective and cost-beneficial recall interval for maintaining optimum oral health in dentate adults attending general dental practice
Low-Frequency Observations of the Moon with the Murchison Widefield Array
A new generation of low-frequency radio telescopes is seeking to observe the redshifted 21 cm signal from the epoch of reionization (EoR), requiring innovative methods of calibration and imaging to overcome the difficulties of wide-field low-frequency radio interferometry. Precise calibration will be required to separate the expected small EoR signal from the strong foreground emission at the frequencies of interest between 80 and 300 MHz. The Moon may be useful as a calibration source for detection of the EoR signature, as it should have a smooth and predictable thermal spectrum across the frequency band of interest. Initial observations of the Moon with the Murchison Widefield Array 32 tile prototype show that the Moon does exhibit a similar trend to that expected for a cool thermally emitting body in the observed frequency range, but that the spectrum is corrupted by reflected radio emission from Earth. In particular, there is an abrupt increase in the observed flux density of the Moon within the internationally recognized frequency modulated (FM) radio band. The observations have implications for future low-frequency surveys and EoR detection experiments that will need to take this reflected emission from the Moon into account. The results also allow us to estimate the equivalent isotropic power emitted by the Earth in the FM band and to determine how bright the Earth might appear at meter wavelengths to an observer beyond our own solar system
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