274 research outputs found
Thyroid cancers amongst goiter population in a Nigerian tertiary hospital: surgical and radiographic perspective
Background: Goiters are commonly benign, but cases of malignancy can develop. Thyroid cancer is known to be commoner in whites than in blacks and in females than in males. Bone metastasis is a common occurrence and may be the initial manifestation in a small subset. We hope to determine the incidence and the cervical radiographic patterns of thyroid cancer amongst goiter population in Nigeria. Method: Surgical, histological and radiographic findings in patients with goiter who had thyroidectomy in our hospital from 1999 to 2006 were reviewed. Those with proven cancer were analyzed for sex, age and radiographic changes using SPSS 11.0 for windows. Results Thirteen (8.2%) cases out of the 160 goiters were malignant and distant metastases were present in 1.3% at presentation. The histological sub-types of malignant goiters were follicular (5.0%), papillary (1.9%) and poorly differentiated or anaplastic thyroid carcinoma (1.3%). As much as 30% of thyroid cancers demonstrated calcification on plain neck radiograph, which were commonly scattered or diffused.Conclusions: Carcinomatous goiters occurred in 9.3% of the goiter population studied with predominance of follicular variant. Surgery remains the main stay but was inappropriate in about 1.2 % of population with goitre. Aside evidence of bony destruction, TC should be suspected in goiters with mixed (diffused or scattered) calcifications
Experimental study of masonry wall exposed to blast loading
The challenge of protecting the nation against the attack of terrorism has raised the importance to explore the understanding of building materials against the explosion. Unlike most of the building materials, brick masonry materials offer relatively small resistance against blast loading. In this research, a brick masonry wall was exposed to varying blast load at different scaled distances. Six tests with different amounts of explosives at various distances were carried out. Pressure time history, acceleration time history and strain at specific location were measured. The parameters measured from experimental pressure time history and acceleration time history is compared with those determined by ConWep to establish the correlations between experimental determined records and ConWep values. The experimental results were also compared with some researchers. These correlations may assist in understanding the behaviour of masonry structures subjected to explosive loading
Survivorship patterns of histopathological variants and molecular subtypes of breast cancer in a teaching hospital in Nigeria
Objective: To study the relationship of histopathological characteristics, molecular subtypes of breast cancer and survival in a low resource setting.Design: Tumours from prospectively ascertained patients newly diagnosed with breast cancer were analyzed. Formalin-fixed and paraffin-embedded sections were constructed into tissue micro-arrays and immunostained with five anti-bodies. Five molecular subtypes were determined.Settings: The study was conducted jointly in the Department of Pathology of University of Ilorin Teaching Hospital, Ilorin in Nigeria and at the University of Chicago in the United States.Subjects: The study included a total of 203 histologically confirmed breast cancer patients whose pathological specimens were processed in the Department of Pathology of University of Ilorin Teaching Hospital, Ilorin, Nigeria between January 2003 and December 2007.Results: Mean age at diagnosis was 49.2 (SO ±11.9) years. Median time from symptom onset to cancer diagnosis was six months. Median follow-up time was 8.3 months. Median tumour size at diagnosis was 6cm. The proportion of ER+, PR+, HER2+ tumours were 27%, 16% and 30%, respectively. The most common molecular subtype was basal-like (25.1%) followed by unclassified (24.0%), luminal A (20.5%), HER2+/ER( 19.3%) and luminal B (11.1 %). Luminal A and B had best prognosis while basal-like and unclassified had worst prognosis. ER+ patients had longer duration of symptoms to diagnosis (median 8 months) than ER- patients (5 months) but ER+ patients had smaller tumours (median 5cm) than ER-patients (6cm, p=0.02). Recurrence-free survival was best for stage 1 and worst for stage 4 tumours. About 32.6% of patients had locoregional and/or metastatic recurrence.Conclusions: In consecutive breast cancer cases in Nigeria, almost half of patients were triple negative. Luminal A and B subtypes had best prognosis while triple negative had worst prognosis. The delay in breast cancer diagnosis and higher proportion of late stage of breast cancer underscores need for prompt diagnosis and initiation of treatment, especially hormonal therapy for ER positive patients
Amine Containing Analogs of Sulindac for Cancer Prevention
Background:
Sulindac belongs to the chemically diverse family of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) that effectively prevent adenomatous colorectal polyps and colon cancer, especially in patients with familial adenomatous polyposis. Sulindac sulfide amide (SSA), an amide analog of sulindac sulfide, shows insignificant COX-related activity and toxicity while enhancing anticancer activity in vitro and demonstrating in vivo xenograft activity.
Objective:
Develop structure-activity relationships in the sulindac amine series and identify analogs with promising anticancer activities.
Method:
A series of sulindac amine analogs were designed and synthesized and then further modified in a “libraries from libraries” approach to produce amide, sulfonamide and N,N-disubstituted sulindac amine sub-libraries. All analogs were screened against three cancer cell lines (prostate, colon and breast).
Results:
Several active compounds were identified viain vitro cancer cell line screening with the most potent compound (26) in the nanomolar range.
Conclusion:
Compound 26 and analogs showing the most potent inhibitory activity may be considered for further design and optimization efforts as anticancer hit scaffolds
Development of a population-based microsimulation model of osteoarthritis in Canada
OBJECTIVES: The purpose of the study was to develop a population-based simulation model of osteoarthritis (OA) in Canada that can be used to quantify the future health and economic burden of OA under a range of scenarios for changes in the OA risk factors and treatments. In this article we describe the overall structure of the model, sources of data, derivation of key input parameters for the epidemiological component of the model, and preliminary validation studies. DESIGN: We used the Population Health Model (POHEM) platform to develop a stochastic continuous-time microsimulation model of physician-diagnosed OA. Incidence rates were calibrated to agree with administrative data for the province of British Columbia, Canada. The effect of obesity on OA incidence and the impact of OA on health-related quality of life (HRQL) were modeled using Canadian national surveys. RESULTS: Incidence rates of OA in the model increase approximately linearly with age in both sexes between the ages of 50 and 80 and plateau in the very old. In those aged 50+, the rates are substantially higher in women. At baseline, the prevalence of OA is 11.5%, 13.6% in women and 9.3% in men. The OA hazard ratios for obesity are 2.0 in women and 1.7 in men. The effect of OA diagnosis on HRQL, as measured by the Health Utilities Index Mark 3 (HUI3), is to reduce it by 0.10 in women and 0.14 in men. CONCLUSIONS: We describe the development of the first population-based microsimulation model of OA. Strengths of this model include the use of large population databases to derive the key parameters and the application of modern microsimulation technology. Limitations of the model reflect the limitations of administrative and survey data and gaps in the epidemiological and HRQL literature
Contribution of Color Information in Visual Saliency Model for Videos
International audienceMuch research has been concerned with the contribution of the low level features of a visual scene to the deployment of visual attention. Bottom-up saliency models have been developed to predict the location of gaze according to these features. So far, color besides to brightness, contrast and motion is considered as one of the primary features in computing bottom-up saliency. However, its contribution in guiding eye movements when viewing natural scenes has been debated. We investigated the contribution of color information in a bottom-up visual saliency model. The model efficiency was tested using the experimental data obtained on 45 observers who were eye tracked while freely exploring a large data set of color and grayscale videos. The two datasets of recorded eye positions, for grayscale and color videos, were compared with a luminance-based saliency model. We incorporated chrominance information to the model. Results show that color information improves the performance of the saliency model in predicting eye positions
Location-based mobile phone applications for increasing student engagement with field-based extra-curricular activities
With pressures on university and student finance, and an ever-growing number of internet-enabled portable devices, we investigate the ability for free, ‘self-guided’
field-trips – using Global Positioning Systems (GPS) features present on most modern smartphones, combined with internet access to provide background information and receive responses from participants. We create a field-trip around Cheltenham, to examine rock types commonly used for buildings. Student
motivation to complete the extra-curricular task was reasonable, with 50% of students participating. However, few thought their geological knowledge had
improved. We suggest that, as well as some minor technological issues, the potential use of mobile internet and apps for teaching in Higher Education
may have been overestimated (especially since motivation will decrease with novelty of the use of the technology). However, we acknowledge these
conclusions are based only on a small pilot study. This may be related to how people in general, and students in particular, use mobile technology: instant bite-sized knowledge conflicting with the deep learning required for Higher Education
Longitudinal changes in peri-papillary retinal nerve fiber layer thickness in patients with unilateral branch retinal vein occlusion
Background: Associations between retinal venous occlusion (RVO), elevated intraocular pressure, and glaucoma have been reported. Further investigations into structural alterations in the fellow eyes of individuals with unilateral RVO have revealed that the peripapillary retinal nerve fiber layer is thinner than in healthy eyes, suggesting that there may be systemic risk factors common to both RVO and glaucoma. We aimed to evaluate changes in peripapillary retinal nerve fiber layer thickness (pRNFLT) among individuals with unilateral branch retinal vein occlusion (BRVO).
Methods: This prospective observational study recruited 30 individuals (60 eyes) with newly diagnosed unilateral BRVO and macular edema, and a control group of 30 healthy individuals (30 eyes) with no abnormalities on fundus examination or concurrent systemic comorbidities. After baseline measurements, the participants were reassessed at 6, 12, and 24 months by measuring global and sectoral pRNFLT using spectral-domain optical coherence tomography.
Results: The mean age and sex distributions were comparable between the patient and control groups (both P > 0.05). When compared to fellow eyes, global and sectoral pRNFLT in eyes with BRVO were significantly higher at baseline (all P < 0.05). Over time, pRNFLT decreased dramatically, and by the conclusion of the two-year follow-up, there was a significant reduction from baseline in the affected eyes (all P < 0.05). Likewise, affected eyes experienced a significant improvement in best-corrected distance visual acuity and central macular thickness over the two-year follow-up (both P Less than or equal to 0.001). Comparing the global and all-sector pRNFLT of fellow eyes in the patient group with those of normal eyes in the control group, there were no significant differences at any visit, except in the temporal sector, which revealed a significant reduction in pRNFLT at 24 months in the fellow eyes of patients with unilateral BRVO (P = 0.02).
Conclusions: Patients with unilateral BRVO experienced a significant reduction in pRNFLT in the affected eyes and, to a lesser extent, in the fellow eyes, compared with that of the control arm, suggesting that they are prone to retinal nerve fiber layer damage. The reduction in pRNFLT in the normal fellow eyes of patients with BRVO may be attributed to age or concurrent systemic comorbidities. Further studies with long follow-up periods are required to shed light on the etiology of functional and structural changes in both the retinal nerve fiber layer and ganglion cell complex in the normal and affected eyes of patients with unilateral BRVO
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
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