T1ρ and T2 relaxation times predict progression of knee osteoarthritis

SummaryObjectiveTo evaluate whether T2 and T1ρ relaxation times of knee cartilage determined with 3T magnetic resonance imaging (MRI) at baseline predict longitudinal progression of cartilage degenerative changes.MethodsQuantitative analysis of cartilage was performed using 3T MRI with both T2 and T1ρ mapping techniques in 55 subjects without evidence of severe osteoarthritis (OA) [Kellgren–Lawrence (KL) score of 0–3] at baseline. Morphological abnormalities of cartilage, menisci, ligaments and bone marrow were analyzed on sagittal fat-saturated intermediate-weighted fast spin echo (FSE) sequences. Progression of degenerative changes was analyzed over a period of 2 years. Progression was detected in 27 subjects while in 28 subjects no changes were found. Differences between T2 and T1ρ relaxation times in these two cohorts were compared using one-way analysis of variance (ANOVA) and t tests.ResultsBaseline T2 and T1ρ values were significantly higher in the progression cohort in all compartments (P < 0.05) except the lateral tibia (LT) for T2 and the medial tibia (MT) for T1ρ. Progression of cartilage degenerative disease was most pronounced at the medial femoral condyles and at the femoro-patellar joint; differences between the two cohorts for T2 and T1ρ were also most significant in these compartments.ConclusionsT2 and T1ρ measurements were significantly higher at baseline in individuals that showed progression of cartilage abnormalities over a period of 2 years and may therefore serve as potential predictors for progression of degenerative cartilage abnormalities in knee OA

Bodyweight Perceptions among Texas Women: The Effects of Religion, Race/Ethnicity, and Citizenship Status

Despite previous work exploring linkages between religious participation and health, little research has looked at the role of religion in affecting bodyweight perceptions. Using the theoretical model developed by Levin et al. (Sociol Q 36(1):157–173, 1995) on the multidimensionality of religious participation, we develop several hypotheses and test them by using data from the 2004 Survey of Texas Adults. We estimate multinomial logistic regression models to determine the relative risk of women perceiving themselves as overweight. Results indicate that religious attendance lowers risk of women perceiving themselves as very overweight. Citizenship status was an important factor for Latinas, with noncitizens being less likely to see themselves as overweight. We also test interaction effects between religion and race. Religious attendance and prayer have a moderating effect among Latina non-citizens so that among these women, attendance and prayer intensify perceptions of feeling less overweight when compared to their white counterparts. Among African American women, the effect of increased church attendance leads to perceptions of being overweight. Prayer is also a correlate of overweight perceptions but only among African American women. We close with a discussion that highlights key implications from our findings, note study limitations, and several promising avenues for future research

Characterization of Human Osteoarthritic Cartilage Using Optical and Magnetic Resonance Imaging

Purpose: Osteoarthritis (OA) is a degenerative disease starting with key molecular events that ultimately lead to the breakdown of the cartilage. The purpose of this study is to use two imaging methods that are sensitive to molecular and macromolecular changes in OA to better characterize the disease process in human osteoarthritic cartilage. Procedures: Human femoral condyles were collected from patients diagnosed with severe OA during total knee replacement surgeries. T1ρ and T2 magnetic resonance measurements were obtained using a 3-Tesla whole body scanner to assess macromolecular changes in the damaged cartilage matrix. Optical imaging was performed on specimens treated with MMPSense 680 to assess the matrix metalloproteinase (MMP) activity. A linear regression model was used to assess the correlation of MMP optical data with T 1ρ magnetic resonance (MR) measurements. Slices from a representative specimen were removed from regions with high and low optical signals for subsequent histological analysis. Results: All specimens exhibit high T1ρ and T2 measurements in the range of 48–75 ms and 36– 69 ms, respectively. They also show intense photon signals (0.376 to 7.89×10 −4 cm 2) from th

Physiological Correlates of Volunteering

We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

Longitudinal Evaluation of Osteoarthritic and Control Human Knee Articular Cartilage Morphology and MR Relaxation

Knee osteoarthritis (OA) is a multifaceted diseases affecting many older adults. A main physiological characteristic of OA is the progressive loss of articular hyaline cartilage. Recently, there have been many proposed techniques that attempt to quantify early hyaline cartilage breakdown associated with OA. Preliminary stages of OA are marked by a reduction in PG and GAG followed by the degradation of the collagen network. Many techniques utilizing magnetic resonance imaging (MRI) have been proposed to noninvasively probe biochemical changes in human osteoarthritic cartilage. T1ρ and T2 relaxation time mapping may be useful as a noninvasive quantification of cartilage degradation. Moreover, osteoarthritic cartilage has displayed elevated voxel spatial heterogeneity of cartilage T1ρ and T2 relaxation time, as calculated by the grey-level co-occurrence (GLCM). In this study we monitored cross-sectional and longitudinal evaluation of T1ρ and T2 relaxation times, GLCM spatial heterogeneity (texture analysis) of T1ρ and T2 relaxation, and cartilage volume and thickness in OA subjects versus healthy controls. Our results display significant increases over time in GLCM entropy in the medial tibia for both T1ρ and T2 relaxation and in the medial femoral condyle for T1ρ relaxation. A significant decrease in volume and thickness was observed in the medial tibia was also noted. These results indicate medial knee OA cartilage experiences a heightened level of spatial heterogeneity, possibly suggesting a predicative utility of T1ρ and T2 relaxation time texture analysis in the development of medial knee OA

Guest editors' introduction:smart energy systems

The authors suggest that smart energy management will be an important application area for pervasive computing, as the pressing societal need for a solution is clear and there is a close fit with technologies and approaches being developed under the pervasive rubric. They present five full papers, including a comprehensive survey spanning four decades of smart energy research, recent results from a UK study of home-deployed smart energy systems that involved both persuasive media and diverse energy-consumption sensing, nonintrusive load identification and estimation, and minimally intrusive load shedding. A short Spotlight article highlights the need to systematically integrate human management into the complex control schemes that these smart grid schemes will enable

Egg Case Proteins of Latrodectus Hesperus

Spider silk has extraordinary mechanical properties and different silk types display different degrees of stiffness and strength. Dragline silk and capture silk have been the attention of many molecular studies because of their potential to be used as more environmentally friendly replacements for various industrial products while other silks have been ignored. In our studies of the black window spider Latrodectus hesperus we discovered two different proteins present within egg case silk that display different chemical and physical characteristics. To date little information is known about egg case silk and their molecular constituents. Our studies were designed to investigate the expression level of 2 recently isolated genes from the spider. Different glands of the black widow spider were used to isolate mRNAs and proteins for expression analyses using molecular techniques such as western blot analysis and real-time quantitative PCR. Western blot analysis analyzes silk proteins by using antibodies that bind to specific antigens to determine their expression levels. We also analyzed patterns of expression using constructed primers to amplify egg case gene sequence of interest using real-time PCR. The results of these studies will be discussed

Egg Case Proteins of Latrodectus Hesperus

Spider silk has extraordinary mechanical properties and different silk types display different degrees of stiffness and strength. Dragline silk and capture silk have been the attention of many molecular studies because of their potential to be used as more environmentally friendly replacements for various industrial products while other silks have been ignored. In our studies of the black window spider Latrodectus hesperus we discovered two different proteins present within egg case silk that display different chemical and physical characteristics. To date little information is known about egg case silk and their molecular constituents. Our studies were designed to investigate the expression level of 2 recently isolated genes from the spider. Different glands of the black widow spider were used to isolate mRNAs and proteins for expression analyses using molecular techniques such as western blot analysis and real-time quantitative PCR. Western blot analysis analyzes silk proteins by using antibodies that bind to specific antigens to determine their expression levels. We also analyzed patterns of expression using constructed primers to amplify egg case gene sequence of interest using real-time PCR. The results of these studies will be discussed