UTE imaging in the musculoskeletal system Chang, Eric Y.; Du, Jiang; Chung, Christine B.
Journal of magnetic resonance imaging,
April 2015, Volume:
41, Issue:
4
Journal Article
Sweet Deal, Bitter Landscape brings us to the mid-2000s, when the Tanzanian government struck a deal with a foreign investor to convert more than 20,000 hectares of long-settled coastal land to ...establish a sugarcane plantation. Ten years on, the deal was abruptly abandoned. Popularly deemed a case of hubristic global development, critics classified this project another in a line of failed modern resource grabs. Youjin B. Chung argues such tidy accounts conceal myriad and profound implications: not only how gender, history, and culture shaped the project's trajectory, but also how, even in its stalled state, the deal upended social life on the land by setting in motion incomplete processes of development and dispossession. With rich ethnographic detail and visual storytelling, Sweet Deal, Bitter Landscape traces the lived experiences of diverse rural women and men as they struggled for survival under a seemingly endless condition of liminality. In so doing, she raises critical questions about the directions and stakes of postcolonial development and nation-building in Tanzania, and the shifting meanings of identity and belonging for those on the margins of capitalist agrarian transformation.
Objective
To examine the efficacy of methotrexate monotherapy relative to etanercept monotherapy and the value of combining methotrexate and etanercept for the treatment of patients with psoriatic ...arthritis (PsA).
Methods
In this double‐blind study, 851 patients with PsA were randomized to 1 of 3 treatment arms, as follows: oral methotrexate (20 mg) plus subcutaneous placebo given weekly (n = 284), subcutaneous etanercept (50 mg) plus oral placebo given weekly (n = 284), or subcutaneous etanercept (50 mg) plus oral methotrexate (20 mg) given weekly (combination therapy; n = 283). The American College of Rheumatology 20% improvement (ACR20) response and Minimal Disease Activity (MDA) response at week 24 were the primary end point and key secondary end point, respectively. Other measures of inflammatory arthritis, radiographic progression, and nonarticular disease manifestations were also assessed.
Results
Patients with PsA had a mean ± SD age of 48.4 ± 13.1 years, and the mean ± SD duration of PsA was 3.2 ± 6.3 years (median 0.6 years). ACR20 and MDA response rates at week 24 were significantly greater in patients who received etanercept monotherapy compared with those who received methotrexate monotherapy (ACR20, 60.9% versus 50.7% of patients P = 0.029; MDA, 35.9% versus 22.9% of patients P = 0.005), and both were significantly greater in the combination therapy group compared with the methotrexate monotherapy group at week 24 (ACR20, 65.0% versus 50.7% of patients P = 0.005; MDA, 35.7% versus 22.9% of patients P = 0.005). Other secondary outcomes (ACR50 and ACR70 response rates, proportions of patients achieving a Very Low Disease Activity score, and PsA disease activity scores) showed between‐group differences that were consistent with the primary and key secondary end point results. Furthermore, patients in both etanercept treatment arms showed less radiographic progression at week 48 compared with patients who received methotrexate monotherapy. Outcomes were similar in the combination therapy and etanercept monotherapy groups, except for some skin end points. No new safety signals were seen.
Conclusion
Etanercept monotherapy and combination therapy with etanercept and methotrexate showed greater efficacy than methotrexate monotherapy in patients with PsA, according to the ACR and MDA response rates and extent of radiographic progression at follow‐up. Overall, combining methotrexate and etanercept did not improve the efficacy of etanercept.
Separating structure and electrons in VO2Above 341 kelvin—not far from room temperature—bulk vanadium dioxide (VO2) is a metal. But as soon as the material is cooled below 341 kelvin, VO2 turns into ...an insulator and, at the same time, changes its crystal structure from rutile to monoclinic. Lee et al. studied the peculiar behavior of a heterostructure consisting of a layer of VO2 placed underneath a layer of the same material that has a bit less oxygen. In the VO2 layer, the structural transition occurred at a higher temperature than the metal-insulator transition. In between those two temperatures, VO2 was a metal with a monoclinic structure—a combination that does not occur in the absence of the adjoining oxygen-poor layer.Science, this issue p. 1037The metal-insulator transition in correlated materials is usually coupled to a symmetry-lowering structural phase transition. This coupling not only complicates the understanding of the basic mechanism of this phenomenon but also limits the speed and endurance of prospective electronic devices. We demonstrate an isostructural, purely electronically driven metal-insulator transition in epitaxial heterostructures of an archetypal correlated material, vanadium dioxide. A combination of thin-film synthesis, structural and electrical characterizations, and theoretical modeling reveals that an interface interaction suppresses the electronic correlations without changing the crystal structure in this otherwise correlated insulator. This interaction stabilizes a nonequilibrium metallic phase and leads to an isostructural metal-insulator transition. This discovery will provide insights into phase transitions of correlated materials and may aid the design of device functionalities.
Spin-triplet superfluids can support exotic objects, such as half-quantum vortices characterized by the nontrivial winding of the spin structure. We present cantilever magnetometry measurements ...performed on mesoscopic samples of Sr(2)RuO(4), a spin-triplet superconductor. With micrometer-sized annular-shaped samples, we observed transitions between integer fluxoid states as well as a regime characterized by "half-integer transitions"--steps in the magnetization with half the height of the ones we observed between integer fluxoid states. These half-height steps are consistent with the existence of half-quantum vortices in superconducting Sr(2)RuO(4).
Sotos syndrome (SS) represents an important human model system for the study of epigenetic regulation; it is an overgrowth/intellectual disability syndrome caused by mutations in a histone ...methyltransferase, NSD1. As layered epigenetic modifications are often interdependent, we propose that pathogenic NSD1 mutations have a genome-wide impact on the most stable epigenetic mark, DNA methylation (DNAm). By interrogating DNAm in SS patients, we identify a genome-wide, highly significant NSD1(+/-)-specific signature that differentiates pathogenic NSD1 mutations from controls, benign NSD1 variants and the clinically overlapping Weaver syndrome. Validation studies of independent cohorts of SS and controls assigned 100% of these samples correctly. This highly specific and sensitive NSD1(+/-) signature encompasses genes that function in cellular morphogenesis and neuronal differentiation, reflecting cardinal features of the SS phenotype. The identification of SS-specific genome-wide DNAm alterations will facilitate both the elucidation of the molecular pathophysiology of SS and the development of improved diagnostic testing.
Abstract
Background
Moving into a long-term care facility (LTCF) can reduce the ability for older adults to engage in meaningful roles and activities and the size of their social network. These ...changes and losses can lead them to experience existential loneliness (EL)—the intolerable emptiness and lack of meaningful existence resulted from the losses they have experienced. While EL has often been understood as a universal human experience, it has primarily been studied in people from Western cultures; little is known about how EL may be experienced by and manifested in people from Eastern cultures. Hence, this qualitative study aimed to describe the experience and coping of EL in Hong Kong Chinese and Swedish older adults living in LTCFs.
Methods
A qualitative study using Thorne’s (2004) interpretive description was conducted. Thirteen Chinese and 9 Swedes living in LTCFs in Hong Kong, China and Malmo, Sweden, respectively were interviewed about their experience of EL in two series of semi-structured interviews. Data were analyzed using thematic analysis.
Results
The core theme of “overcoming EL” described the participants’ experience of EL, which came about through the combined process of “Feeling EL” and “Self-Regulating”. Both Chinese and Swedish participants had similar experience with EL. Realizing that they did not want to living with EL anymore, they coped by reframing their experience and identifying new meaning in their life.
Conclusions
The study findings suggested that early and clear counselling support that help older adults to define new meaning in life may help them cope. In addition, more opportunities should be available at the LTCFs to promote quality relationships, enable older adults to reflect on their lives with pride, and support their ability to do the things they enjoy.
Novel compositional magnetic resonance (MR) imaging techniques have allowed for both the qualitative and quantitative assessments of tissue changes in osteoarthritis, many of which are difficult to ...characterize on conventional MR imaging. Ultrashort echo time (UTE) and zero echo time (ZTE) MR imaging have not been broadly implemented clinically but have several applications that leverage contrast mechanisms for morphologic evaluation of bone and soft tissue, as well as biochemical assessment in various stages of osteoarthritis progression. Many of the musculoskeletal tissues implicated in the initiation and progression of osteoarthritis are short T2 in nature, appearing dark as signal has already decayed to its minimum when image sampling starts. UTE and ZTE MR imaging allow for the qualitative and quantitative assessments of these short T2 tissues (bone, tendon, calcified cartilage, meniscus, and ligament) with both structural and functional reference standards described in the literature 1–3. This review will describe applications of UTE and ZTE MR imaging in musculoskeletal tissues focusing on its role in knee osteoarthritis. While the review will address tissue-specific applications of these sequences, it is understood that osteoarthritis is a whole joint process with involvement and interdependence of all tissues.
Key points
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UTE MR imaging allows for the qualitative and quantitative evaluation of short T2 tissues (bone, calcified cartilage, and meniscus), enabling identification of both early degenerative changes and subclinical injuries that may predispose to osteoarthritis
.
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ZTE MR imaging allows for the detection of signal from bone, which has some of the shortest T2 values, and generates tissue contrast similar to CT, potentially obviating the need for CT in the assessment of osseous features of osteoarthritis
.
Saccular intracranial aneurysm is a common disease that may cause devastating intracranial hemorrhage. Hemodynamics, wall remodeling, and wall inflammation have been associated with saccular ...intracranial aneurysm rupture. We investigated how saccular intracranial aneurysm hemodynamics is associated with wall remodeling and inflammation of the saccular intracranial aneurysm wall.
Tissue samples resected during a saccular intracranial aneurysm operation (11 unruptured, 9 ruptured) were studied with histology and immunohistochemistry. Patient-specific computational models of hemodynamics were created from preoperative CT angiographies.
More stable and less complex flows were associated with thick, hyperplastic saccular intracranial aneurysm walls, while slower flows with more diffuse inflow were associated with degenerated and decellularized saccular intracranial aneurysm walls. Wall degeneration (P = .041) and rupture were associated with increased inflammation (CD45+, P = .031). High wall shear stress (P = .018), higher vorticity (P = .046), higher viscous dissipation (P = .046), and high shear rate (P = .046) were associated with increased inflammation. Inflammation was also associated with lack of an intact endothelium (P = .034) and the presence of organized luminal thrombosis (P = .018), though overall organized thrombosis was associated with low minimum wall shear stress (P = .034) and not with the flow conditions associated with inflammation.
Flow conditions in the saccular intracranial aneurysm are associated with wall remodeling. Inflammation, which is associated with degenerative wall remodeling and rupture, is related to high flow activity, including elevated wall shear stress. Endothelial injury may be a mechanism by which flow induces inflammation in the saccular intracranial aneurysm wall. Hemodynamic simulations might prove useful in identifying saccular intracranial aneurysms at risk of developing inflammation, a potential biomarker for rupture.
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