441 research outputs found
Tantalum versus Titanium Acetabular Shells in Young Active THR Patients: A Radiostereometric Analysis (RSA) Study
Introduction: In the active THR (total hip replacement) population, acetabular component stability is crucial for preventing implant failure. Titanium fiber metal coating is the most common material used in cementless THR. Trabecular metal, composed of porous tantalum, is designed to improve tissue infiltration and limit migration. It is unknown if tantalum offers an advantage over titanium in the biologic fixation of porous-coated acetabular shells. Radiostereometric analysis (RSA) provides highly precise measurements of micromotion that are otherwise not detectable by routine radiographs.
Methods: In this IRB approved, prospective, randomized, blinded study, 46 patients received a primary THR by a single surgeon. Each patient was randomized to receive a titanium (23) or tantalum (23) uncemented cup. Tantalum RSA markers were implanted around the polyethylene liner and into the patient’s femur and periacetabular bone. Also, patients received either a highly cross-linked (n=25) or a conventional liner (n=21). RSA examinations, Harris Hip, UCLA, WOMAC, SF-12 scores were obtained at 10 days, 6 months, and annually through 5 years.
Results: The randomized groups had comparable mean age, preoperative activity, and average BMI. The tantalum shells demonstrated less median translation than the titanium shells at each time-point, but there was no statistical difference between the two shells. At 6 months median translation of tantalum and titanium was -0.01mm and 0.04mm and remained stable with median translation of -0.02mm and 0.04mm at four years. Mean UCLA, WOMAC, Harris Hip, and SF-12 PCS and MCS scores improved similarly in both groups.
Conclusions: After THR, both patient cohorts had excellent clinical outcomes with statistically significant improvements in function and pain relief. Although tantalum porous-coated acetabular shells demonstrated less y-translation and y-rotation at all time points, there was no statistically significant difference in shell migration and both shells demonstrated excellent stability with minimal micromotion at four years
Podocalyxin in the Diagnosis and Treatment of Cancer
Kelly M. McNagny, Michael R. Hughes, Marcia L. Graves, Erin J. DeBruin, Kimberly Snyder, Jane Cipollone, Michelle Turvey, Poh C. Tan, Shaun McColl and Calvin D. Roskelle
Short-term repeatability of electrocardiographic P wave indices and PR interval
P wave indices and PR interval from 12-lead electrocardiograms (ECGs) are predictors of cardiovascular morbidity and mortality, but their repeatability has not been examined
Complement protein C3 and coronary artery calcium in middle-aged women with polycystic ovary syndrome and controls
Circulating complement protein C3 (C3) levels have been associated with coronary artery calcification (CAC) in women with systemic lupus erythematosus, but have yet to be evaluated in women with polycystic ovary syndrome (PCOS). We aimed to determine whether C3 levels were elevated in women with PCOS compared to controls, and to quantify the association of C3 with cardiovascular disease (CVD) risk factors and CAC, and if PCOS modified this association. This cross-sectional analysis included 132 women with PCOS and 155 controls 35-62 years old from the third visit of a case-control study. CAC was measured during the study visit and circulating C3 was measured in stored sera. The presence of CAC and CAC categories (Agatston score 0, 1-9.9, and ≥10) were used for logistic and ordinal regression analysis, respectively. C3 levels were not significantly different between women with PCOS and controls. Among all women, C3 was associated with the presence of CAC and increasing CAC groups after adjusting for age, PCOS status, and insulin or BMI, all p<0.05. In addition, C3 was associated with the presence of CAC after adjusting for age, PCOS status, BMI, insulin and African American race, p=0.049. PCOS status did not modify these associations. In conclusion, circulating C3 levels may prove beneficial in identifying women at risk of CVD in women with PCOS and the general population
Giant Thermoelectric Effect from Transmission Supernodes
We predict an enormous order-dependent quantum enhancement of thermoelectric
effects in the vicinity of a higher-order `supernode' in the transmission
spectrum of a nanoscale junction. Single-molecule junctions based on
3,3'-biphenyl and polyphenyl ether (PPE) are investigated in detail. The
nonequilibrium thermodynamic efficiency and power output of a thermoelectric
heat engine based on a 1,3-benzene junction are calculated using many-body
theory, and compared to the predictions of the figure-of-merit ZT.Comment: 5 pages, 6 figure
Short-term repeatability of electrocardiographic Tpeak–Tend and QT intervals
The electrocardiographic (ECG) Tpeak-Tend interval (TpTe) is associated with arrhythmias and sudden cardiac death. TpTe offers a supplementary measure for the QT interval (QT), yet its repeatability has not been established
RIPK3 activation leads to cytokine synthesis that continues after loss of cell membrane integrity
Necroptosis is a form of programmed cell death that is defined by activation of the kinase RIPK3 and subsequent cell membrane permeabilization by the effector MLKL. RIPK3 activation can also promote immune responses via production of cytokines and chemokines. How active cytokine production is coordinated with the terminal process of necroptosis is unclear. Here, we report that cytokine production continues within necroptotic cells even after they have lost cell membrane integrity and irreversibly committed to death. This continued cytokine production is dependent on mRNA translation and requires maintenance of endoplasmic reticulum integrity that remains after plasma membrane integrity is lost. The continued translation of cytokines by cellular corpses contributes to necroptotic cell uptake by innate immune cells and priming of adaptive immune responses to antigens associated with necroptotic corpses. These findings imply that cell death and production of inflammatory mediators are coordinated to optimize the immunogenicity of necroptotic cells
Mapping language function with task-based vs. resting-state functional MRI
BACKGROUND: Use of functional MRI (fMRI) in pre-surgical planning is a non-invasive method for pre-operative functional mapping for patients with brain tumors, especially tumors located near eloquent cortex. Currently, this practice predominantly involves task-based fMRI (T-fMRI). Resting state fMRI (RS-fMRI) offers an alternative with several methodological advantages. Here, we compare group-level analyses of RS-fMRI vs. T-fMRI as methods for language localization.
PURPOSE: To contrast RS-fMRI vs. T-fMRI as techniques for localization of language function.
METHODS: We analyzed data obtained in 35 patients who had both T-fMRI and RS-fMRI scans during the course of pre-surgical evaluation. The RS-fMRI data were analyzed using a previously trained resting-state network classifier. The T-fMRI data were analyzed using conventional techniques. Group-level results obtained by both methods were evaluated in terms of two outcome measures: (1) inter-subject variability of response magnitude and (2) sensitivity/specificity analysis of response topography, taking as ground truth previously reported maps of the language system based on intraoperative cortical mapping as well as meta-analytic maps of language task fMRI responses.
RESULTS: Both fMRI methods localized major components of the language system (areas of Broca and Wernicke) although not with equal inter-subject consistency. Word-stem completion T-fMRI strongly activated Broca\u27s area but also several task-general areas not specific to language. RS-fMRI provided a more specific representation of the language system.
CONCLUSION: We demonstrate several advantages of classifier-based mapping of language representation in the brain. Language T-fMRI activated task-general (i.e., not language-specific) functional systems in addition to areas of Broca and Wernicke. In contrast, classifier-based analysis of RS-fMRI data generated maps confined to language-specific regions of the brain
Redistribution of heart failure as the cause of death: the Atherosclerosis Risk in Communities Study
Background Heart failure is sometimes incorrectly listed as the underlying cause of death (UCD) on death certificates, thus compromising the accuracy and comparability of mortality statistics. Statistical redistribution of the UCD has been used to examine the effect of misclassification of the UCD attributed to heart failure, but sex- and race-specific redistribution of deaths on coronary heart disease (CHD) mortality in the United States has not been examined. Methods We used coarsened exact matching to infer the UCD of vital records with heart failure as the UCD from 1999 to 2010 for decedents 55 years old and older from states encompassing regions under surveillance by the Atherosclerosis Risk in Communities (ARIC) Study (Maryland, Minnesota, Mississippi, and North Carolina). Records with heart failure as the UCD were matched on decedent characteristics (five-year age groups, sex, race, education, year of death, and state) to records with heart failure listed among the multiple causes of death. Each heart failure death was then redistributed to plausible UCDs proportional to the frequency among matched records. Results After redistribution the proportion of deaths increased for CHD, chronic obstructive pulmonary disease, diabetes, hypertensive heart disease, and cardiomyopathy, P < 0.001. The percent increase in CHD mortality after redistribution was the highest in Mississippi (12%) and lowest in Maryland (1.6%), with variations by year, race, and sex. Redistribution proportions for CHD were similar to CHD death classification by a panel of expert reviewers in the ARIC study. Conclusions Redistribution of ill-defined UCD would improve the accuracy and comparability of mortality statistics used to allocate public health resources and monitor mortality trends
Prevalence of Metabolic Syndrome Among Hispanics/Latinos of Diverse Background: The Hispanic Community Health Study/Study of Latinos
Approximately one-third of the adult U.S. population has the metabolic syndrome. Its prevalence is the highest among Hispanic adults, but variation by Hispanic/Latino background is unknown. Our objective was to quantify the prevalence of the metabolic syndrome among men and women 18–74 years of age of diverse Hispanic/Latino background
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