3,499 research outputs found
Bridging the Semantic Gap in Multimedia Information Retrieval: Top-down and Bottom-up approaches
Semantic representation of multimedia information is vital for enabling the kind of multimedia search capabilities that professional searchers require. Manual annotation is often not possible because of the shear scale of the multimedia information that needs indexing. This paper explores the ways in which we are using both top-down, ontologically driven approaches and bottom-up, automatic-annotation approaches to provide retrieval facilities to users. We also discuss many of the current techniques that we are investigating to combine these top-down and bottom-up approaches
Metformin as a Therapeutic Target in Endometrial Cancers.
Endometrial cancer is the most common gynecologic malignancy in developed countries. Its increasing incidence is thought to be related in part to the rise of metabolic syndrome, which has been shown to be a risk factor for the development of hyperestrogenic and hyperinsulinemic states. This has consequently lead to an increase in other hormone-responsive cancers as well e.g., breast and ovarian cancer. The correlation between obesity, hyperglycemia, and endometrial cancer has highlighted the important role of metabolism in cancer establishment and persistence. Tumor-mediated reprogramming of the microenvironment and macroenvironment can range from induction of cytokines and growth factors to stimulation of surrounding stromal cells to produce energy-rich catabolites, fueling the growth, and survival of cancer cells. Such mechanisms raise the prospect of the metabolic microenvironment itself as a viable target for treatment of malignancies. Metformin is a biguanide drug that is a first-line treatment for type 2 diabetes that has beneficial effects on various markers of the metabolic syndrome. Many studies suggest that metformin shows potential as an adjuvant treatment for uterine and other cancers. Here, we review the evidence for metformin as a treatment for cancers of the endometrium. We discuss the available clinical data and the molecular mechanisms by which it may exert its effects, with a focus on how it may alter the tumor microenvironment. The pleiotropic effects of metformin on cellular energy production and usage as well as intercellular and hormone-based interactions make it a promising candidate for reprogramming of the cancer ecosystem. This, along with other treatments aimed at targeting tumor metabolic pathways, may lead to novel treatment strategies for endometrial cancer
Acute exacerbations of chronic obstructive pulmonary disease are associated with decreased CD4+ & CD8+ T cells and increased growth & differentiation factor-15 (GDF-15) in peripheral blood
Abstract
Background
Although T cells, especially CD8+, have been implicated in chronic obstructive pulmonary disease (COPD) pathogenesis, their role during acute exacerbations (AE-COPD) is uncertain.
Methods
We recruited subjects with COPD and a history of previous AE-COPD and studied them quarterly to collect blood and spontaneously expectorated sputum while stable. During exacerbations (defined by a change in symptoms plus physician diagnosis and altered medications), we collected blood and sputum before administering antibiotics or steroids. We used flow cytometry to identify leukocytes in peripheral blood, plus Luminex® analysis or ELISA to determine levels of inflammatory biomarkers in serum and sputum supernatants.
Results
Of 33 enrolled subjects, 13 participated in multiple stable visits and had ≥1 AE-COPD visit, yielding 18 events with paired data. Flow cytometric analyses of peripheral blood demonstrated decreased CD4+ and CD8+ T cells during AE-COPD (both absolute and as a percentage of all leukocytes) and significantly increased granulocytes, all of which correlated significantly with serum C-reactive protein (CRP) concentrations. No change was observed in other leukocyte populations during AE-COPD, although the percentage of BDCA-1+ dendritic cells expressing the activation markers CD40 and CD86 increased. During AE-COPD, sICAM-1, sVCAM-1, IL-10, IL-15 and GDF-15 increased in serum, while in sputum supernatants, CRP and TIMP-2 increased and TIMP-1 decreased.
Conclusions
The decrease in CD4+ and CD8+ T cells (but not other lymphocyte subsets) in peripheral blood during AE-COPD may indicate T cell extravasation into inflammatory sites or organized lymphoid tissues. GDF-15, a sensitive marker of cardiopulmonary stress that in other settings independently predicts reduced long-term survival, is acutely increased in AE-COPD. These results extend the concept that AE-COPD are systemic inflammatory events to which adaptive immune mechanisms contribute.
Trial registration
NCT00281216
, ClinicalTrials.gov.http://deepblue.lib.umich.edu/bitstream/2027.42/112169/1/12931_2015_Article_251.pd
Acute exacerbations of chronic obstructive pulmonary disease are associated with decreased CD4+ & CD8+ T cells and increased growth & differentiation factor-15 (GDF-15) in peripheral blood
Abstract
Background
Although T cells, especially CD8+, have been implicated in chronic obstructive pulmonary disease (COPD) pathogenesis, their role during acute exacerbations (AE-COPD) is uncertain.
Methods
We recruited subjects with COPD and a history of previous AE-COPD and studied them quarterly to collect blood and spontaneously expectorated sputum while stable. During exacerbations (defined by a change in symptoms plus physician diagnosis and altered medications), we collected blood and sputum before administering antibiotics or steroids. We used flow cytometry to identify leukocytes in peripheral blood, plus Luminex® analysis or ELISA to determine levels of inflammatory biomarkers in serum and sputum supernatants.
Results
Of 33 enrolled subjects, 13 participated in multiple stable visits and had ≥1 AE-COPD visit, yielding 18 events with paired data. Flow cytometric analyses of peripheral blood demonstrated decreased CD4+ and CD8+ T cells during AE-COPD (both absolute and as a percentage of all leukocytes) and significantly increased granulocytes, all of which correlated significantly with serum C-reactive protein (CRP) concentrations. No change was observed in other leukocyte populations during AE-COPD, although the percentage of BDCA-1+ dendritic cells expressing the activation markers CD40 and CD86 increased. During AE-COPD, sICAM-1, sVCAM-1, IL-10, IL-15 and GDF-15 increased in serum, while in sputum supernatants, CRP and TIMP-2 increased and TIMP-1 decreased.
Conclusions
The decrease in CD4+ and CD8+ T cells (but not other lymphocyte subsets) in peripheral blood during AE-COPD may indicate T cell extravasation into inflammatory sites or organized lymphoid tissues. GDF-15, a sensitive marker of cardiopulmonary stress that in other settings independently predicts reduced long-term survival, is acutely increased in AE-COPD. These results extend the concept that AE-COPD are systemic inflammatory events to which adaptive immune mechanisms contribute.
Trial registration
NCT00281216
, ClinicalTrials.gov.http://deepblue.lib.umich.edu/bitstream/2027.42/134660/1/12931_2015_Article_251.pd
Age-Related Differences in Health-Related Quality of Life in COPD
OBJECTIVE: Younger persons with COPD report worse health-related quality of life (HRQL) than do older individuals. The factors explaining these differences remain unclear. The objective of this article was to explore factors associated with age-related differences in HRQL in COPD.
METHODS: Cross-sectional analysis of participants with COPD, any Global Initiative for Chronic Obstructive Lung Disease grade of airflow limitation, and ≥ 50 years old in two cohorts: the Genetic Epidemiology of COPD (COPDGene) study and the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS). We compared St. George's Respiratory Questionnaire (SGRQ) scores by age group: middle-aged (age, 50-64) vs older (age, 65-80) adults. We used multivariate linear modeling to test associations of age with HRQL, adjusting for demographic and clinical characteristics and comorbidities.
RESULTS: Among 4,097 participants in the COPDGene study (2,170 middle-aged and 1,927 older adults) SGRQ total scores were higher (worse) among middle-aged (mean difference, -4.2 points; 95% CI, -5.7 to -2.6; P < .001) than older adults. Age had a statistically significant interaction with dyspnea (P < .001). Greater dyspnea severity (modified Medical Research Council ≥ 2, compared with 0-1) had a stronger association with SGRQ score among middle-aged (β, 24.6; 95% CI, 23.2-25.9) than older-adult (β, 21.0; 95% CI, 19.6-22.3) participants. In analyses using SGRQ as outcome in 1,522 participants in SPIROMICS (598 middle-aged and 924 older adults), we found similar associations, confirming that for the same severity of dyspnea there is a stronger association with HRQL among younger individuals.
CONCLUSIONS: Age-related differences in HRQL may be explained by a higher impact of dyspnea among younger subjects with COPD.
TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00608764 and No.: NCT01969344; URL: www.clinicaltrials.gov
Prevalence of left ventricular diastolic dysfunction in a general population
BACKGROUND: Because the process of myocardial remodelling starts before the onset of symptoms, recent heart failure (HF) guidelines place special emphasis on the detection of subclinical left ventricular (LV) systolic and diastolic dysfunction and the timely identification of risk factors for HF. Our goal was to describe the prevalence and determinants (risk factors) of LV diastolic dysfunction in a general population and to compare the amino terminal probrain natriuretic peptide level across groups with and without diastolic dysfunction.
METHODS AND RESULTS: In a randomly recruited population sample (n=539; 50.5% women; mean age, 52.5 years), we measured early and late diastolic peak velocities of mitral inflow (E and A), pulmonary vein flow by pulsed-wave Doppler, and the mitral annular velocities (Ea and Aa) at 4 sites by tissue Doppler imaging. A healthy subsample of 239 subjects (mean age, 43.7 years) provided age-specific cutoff limits for normal E/A and E/Ea ratios and the differences in duration between the mitral A and the reverse pulmonary vein flows during atrial systole (DeltaAd-ARd). The number of subjects in diastolic dysfunction groups 1 (impaired relaxation), 2 (elevated LV end-diastolic filling pressure), and 3 (elevated E/Ea and abnormally low E/A) were 53 (9.8%), 76 (14.1%), and 18 (3.4%), respectively. We used Delta(Ad<ARd+10) to confirm possible elevation of LV filling pressures in group 2. Compared with subjects with normal diastolic function (n=392, 72.7%), group 1 (209 versus 251 pmol/L; P=0.015) and group 2 (209 versus 275 pmol/L; P=0.0003) but not group 3 (209 versus 224 pmol/L; P=0.65) had a significantly higher adjusted NT-probrain natriuretic peptide. Higher age, body mass index, heart rate, systolic blood pressure, serum insulin, and creatinine were significantly associated with a higher risk of LV diastolic dysfunction.
CONCLUSIONS: The overall prevalence of LV diastolic dysfunction in a random sample of a general population, as estimated from echocardiographic measurements, was as high as 27.3%
A distributed geospatial approach to describe community characteristics for multisite studies
Understanding place-based contributors to health requires geographically and culturally diverse study populations, but sharing location data is a significant challenge to multisite studies. Here, we describe a standardized and reproducible method to perform geospatial analyses for multisite studies. Using census tract-level information, we created software for geocoding and geospatial data linkage that was distributed to a consortium of birth cohorts located throughout the USA. Individual sites performed geospatial linkages and returned tract-level information for 8810 children to a central site for analyses. Our generalizable approach demonstrates the feasibility of geospatial analyses across study sites to promote collaborative translational research
Carbohydrate Intake in the Etiology of Crohn's Disease and Ulcerative Colitis
Background: Diet may have a role in the etiology of inflammatory bowel disease. In previous studies, the associations between increased intakes of carbohydrates, sugar, starch, and inflammatory bowel disease are inconsistent. However, few prospective studies have investigated the associations between these macronutrients and incident Crohn's disease (CD) or ulcerative colitis (UC). Methods: A total of 401,326 men and women were recruited between 1991 and 1998. At recruitment, dietary intakes of carbohydrate, sugar, and starch were measured using validated food frequency questionnaires. The cohort was monitored identifying participants who developed incident CD or UC. Cases were matched with 4 controls, and odds ratios were calculated for quintiles of total carbohydrate, sugar, and starch intakes adjusted for total energy intake, body mass index, and smoking. Results: One hundred ten participants developed CD, and 244 participants developed UC during follow-up. The adjusted odds ratio for the highest versus the lowest quintiles of total carbohydrate intake for CD was 0.87, 95% CI = 0.24 to 3.12 and for UC 1.46, 95% CI = 0.62 to 3.46, with no significant trends across quintiles for either (CD, Ptrend = 0.70; UC, Ptrend = 0.41). Similarly, no associations were observed with intakes of total sugar (CD, Ptrend = 0.50; UC, Ptrend = 0.71) or starch (CD, Ptrend = 0.69; UC, Ptrend = 0.17). Conclusions: The lack of associations with these nutrients is in agreement with many case–control studies that have not identified associations with CD or UC. As there is biological plausibility for how specific carbohydrates could have an etiological role in inflammatory bowel disease, future epidemiological work should assess individual carbohydrates, although there does not seem to be a macronutrient effect
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