Supplemental educational program to heighten the impact of research - an opportunity for OA imaging.

Objective: To develop and evaluate a supplementary educational program ("IMPACT") centered on enabling participants to consider specifically and articulate explicitly the best path for and potential impact of their research.

Design: Participants (trainees) and faculty mentors were from all areas of biomedical research. The group worked longitudinally in small, rotating groups, through a process of developing a written statement ("Impact Statement"), an overview ("Impact Storyline") and an oral presentation ("Impact Case") of their work.

Noninvasive Monitoring to Detect Dehydration: Are We There Yet?

The need for hydration monitoring is significant, especially for the very young and elderly populations who are more vulnerable to becoming dehydrated and suffering from the effects that dehydration brings. This need has been among the drivers of considerable effort in the academic and commercial sectors to provide a means for monitoring hydration status, with a special interest in doing so outside the hospital or clinical setting. This review of emerging technologies provides an overview of many technology approaches that, on a theoretical basis, have sensitivity to water and are feasible as a routine measurement.

Using deep learning for dermatologist-level detection of suspicious pigmented skin lesions from wide-field images.

A reported 96,480 people were diagnosed with melanoma in the United States in 2019, leading to 7230 reported deaths. Early-stage identification of suspicious pigmented lesions (SPLs) in primary care settings can lead to improved melanoma prognosis and a possible 20-fold reduction in treatment cost. Despite this clinical and economic value, efficient tools for SPL detection are mostly absent.

Remote Monitoring of Treatment Response in Parkinson's Disease: The Habit of Typing on a Computer.

Objective: The recent advances in technology are opening a new opportunity to remotely evaluate motor features in people with Parkinson's disease (PD). We hypothesized that typing on an electronic device, a habitual behavior facilitated by the nigrostriatal dopaminergic pathway, could allow for objectively and nonobtrusively monitoring parkinsonian features and response to medication in an at-home setting.

Methods: We enrolled 31 participants recently diagnosed with PD who were due to start dopaminergic treatment and 30 age-matched controls.

Non-invasive detection of severe neutropenia in chemotherapy patients by optical imaging of nailfold microcirculation.

White-blood-cell (WBC) assessment is employed for innumerable clinical procedures as one indicator of immune status. Currently, WBC determinations are obtained by clinical laboratory analysis of whole blood samples. Both the extraction of blood and its analysis limit the accessibility and frequency of the measurement.

Detecting Motor Impairment in Early Parkinson's Disease via Natural Typing Interaction With Keyboards: Validation of the neuroQWERTY Approach in an Uncontrolled At-Home Setting.

Background: Parkinson's disease (PD) is the second most prevalent neurodegenerative disease and one of the most common forms of movement disorder. Although there is no known cure for PD, existing therapies can provide effective symptomatic relief. However, optimal titration is crucial to avoid adverse effects.

Measures of molecular composition and structure in osteoarthritis.

Osteoarthritis involves ongoing degradative and healing processes that occur at the molecular level in multiple tissues in the joint in response to a number of biochemical and mechanical factors. Understanding these dynamic processes before they affect the structural aspects of the joint motivates the need for metrics to better visualize the compositional and structural molecular aspects of the tissues in vivo. As reviewed here, most of the work to date in this regard has been focused on magnetic resonance imaging approaches for interrogating molecular features of cartilage, including T2 mapping, T1rho mapping, delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), and sodium imaging.

Radiographic and patient factors associated with pre-radiographic osteoarthritis in hip dysplasia.

Background: Hip dysplasia leads to abnormal loading of articular cartilage, which results in osteoarthritis. The purpose of this study was to investigate the anatomic and demographic factors associated with the early onset of osteoarthritis in dysplastic hips by utilizing the delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) index as a marker of the disease.

Methods: Ninety-six symptomatic dysplastic hips in seventy-four patients were assessed with standard radiographs and a dGEMRIC scan.

Toward imaging biomarkers for glycosaminoglycans.

Advances in the diagnosis and treatment of cartilage degeneration will be accelerated with the availability of validated biomarkers that reveal the features relevant to the health of cartilage. Using the delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) technique for evaluating tissue glycosaminoglycan as a case study, I review the types of evidence needed to validate imaging (or other) biomarkers. In addition, I present discussions about face validity and technical validity and offer a review of emerging data that provide pathophysiologic validity.

The effect of paraformaldehyde fixation on the delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) measurement.

The delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) method allows for both qualitative and quantitative measurement of the spatial distribution of glycosaminoglycan [GAG] in excised cartilage. The objective of this study was to determine the effect of paraformaldehyde fixation on dGEMRIC measurements. Five bovine and seven human cartilage pieces were punched into 5-mm plugs, fixed for 18 h in 4% paraformaldehyde solution, and washed.

Effects of chondrogenic and osteogenic regulatory factors on composite constructs grown using human mesenchymal stem cells, silk scaffolds and bioreactors.

Human mesenchymal stem cells (hMSCs) isolated from bone marrow aspirates were cultured on silk scaffolds in rotating bioreactors for three weeks with either chondrogenic or osteogenic medium supplements to engineer cartilage- or bone-like tissue constructs. Osteochondral composites formed from these cartilage and bone constructs were cultured for an additional three weeks in culture medium that was supplemented with chondrogenic factors, supplemented with osteogenic factors or unsupplemented. Progression of cartilage and bone formation and the integration between the two regions were assessed by medical imaging (magnetic resonance imaging and micro-computerized tomography imaging), and by biochemical, histological and mechanical assays.

Suitability of T(1Gd) as the dGEMRIC index at 1.5T and 3.0T.

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is based on the theory that Gd-DTPA(2-) will distribute in inverse relation to cartilage glycosaminoglycan (GAG). T(1Gd) (T(1) after penetration of a 0.2 mmol/kg dose of Gd-DTPA(2-)) has been used as the dGEMRIC index, although (1/T(1Gd)-1/T(1o)) should be more representative of Gd-DTPA(2-) concentration (where T(1o) = T(1) before contrast).

2007 Elizabeth Winston Lanier Award Winner. Magnetic resonance imaging of cartilage glycosaminoglycan: basic principles, imaging technique, and clinical applications.

Many new therapeutic strategies have been and are being developed to prevent, correct, or slow the progression of osteoarthritis. Our ability to evaluate the efficacy of these techniques, or to determine the situations for which they might provide the most benefit, critically depends on diagnostic measures that can serve as proxies for the present or predicted state of the cartilage. We focus here on a body of work surrounding the development of magnetic resonance imaging (MRI) techniques to noninvasively image the glycosaminoglycan (GAG) concentration of articular cartilage.

Advanced tools for tissue engineering: scaffolds, bioreactors, and signaling.

This article contains the collective views expressed at the second session of the workshop "Tissue Engineering--The Next Generation,'' which was devoted to the tools of tissue engineering: scaffolds, bioreactors, and molecular and physical signaling. Lisa E. Freed and Farshid Guilak discussed the integrated use of scaffolds and bioreactors as tools to accelerate and control tissue regeneration, in the context of engineering mechanically functional cartilage and cardiac muscle.

Relationship between cartilage stiffness and dGEMRIC index: correlation and prediction.

We sought to determine if a generalized relationship between the dGEMRIC index (T1Gd relaxation time) and compressive stiffness of articular cartilage could be defined across multiple samples. Osteochondral blocks were cut from 12 human tibial plateaus, six from cadaveric sources and six from total knee replacement surgeries. Each block contained submeniscal ("covered") and extrameniscal ("uncovered") cartilage regions.

Diffusion tensor imaging of native and degenerated human articular cartilage.

Diffusion tensor imaging (DTI) is potentially sensitive to collagen degeneration in cartilage. In this study, DTI was measured on human cartilage samples with interventions of trypsin and collagenase. The measured preferred diffusion direction was consistent with the zonal structure of collagen network.

Bone and cartilage tissue constructs grown using human bone marrow stromal cells, silk scaffolds and rotating bioreactors.

Human bone marrow contains a population of bone marrow stromal cells (hBMSCs) capable of forming several types of mesenchymal tissues, including bone and cartilage. The present study was designed to test whether large cartilaginous and bone-like tissue constructs can be selectively engineered using the same cell population (hBMSCs), the same scaffold type (porous silk) and same hydrodynamic environment (construct settling in rotating bioreactors), by varying the medium composition (chondrogenic vs. osteogenic differentiation factors).

Spatially-localized correlation of dGEMRIC-measured GAG distribution and mechanical stiffness in the human tibial plateau.

The concentration of glycosaminoglycan (GAG) in articular cartilage is known to be an important determinant of tissue mechanical properties based on numerous studies relating bulk GAG and mechanical properties. To date limited information exists regarding the relationship between GAG and mechanical properties on a spatially-localized basis in intact samples of native tissue. This relation can now be explored by using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC--a recently available non-destructive magnetic resonance imaging method for measuring glycosaminoglycan concentration) combined with non-destructive mechanical indentation testing.

Toward imaging biomarkers for osteoarthritis.

Many new therapeutic strategies have been and are being developed to correct, prevent, or slow the progression of osteoarthritis. Our ability to evaluate the efficacy of these techniques, or to determine the situations for which they might provide the most benefit, critically depends on diagnostic measures that can serve as proxies for the present or predicted state of the cartilage. Many of the magnetic resonance imaging techniques that have been emerging over the past decades appear promising in that they have shown technical validity in measuring the morphologic and molecular state of cartilage.

T2 and T1rho MRI in articular cartilage systems.

T2 and T1rho have potential to nondestructively detect cartilage degeneration. However, reports in the literature regarding their diagnostic interpretation are conflicting. In this study, T2 and T1rho were measured at 8.