Sonographically Guided Knee Meniscus Injections: Feasibility, Techniques, and Validation

BackgroundThere is a growing interest in the use of biologic agents such as platelet‐rich plasma and mesenchymal stem/stromal cells to treat musculoskeletal injuries, including meniscal tears. Although previous research has documented the role of diagnostic ultrasound to evaluate meniscal tears, sonographically guided (SG) techniques to specifically deliver therapeutic agents into the meniscus have not been described.ObjectiveTo describe and validate SG injection techniques for the body and posterior horn of the medial and lateral meniscus.DesignProspective, cadaveric laboratory investigation.SettingAcademic institution procedural skills laboratory.SubjectsFive unenbalmed cadaveric knee‐ankle‐foot specimens from 5 donors (3 female and 2 male) ages 33‐92 years (mean age 74 years) with body mass indices of 21.1‐32.4 kg/m2 (mean 24.1 kg/m2).MethodsA single, experienced operator completed SG injections into the bodies and posterior horns of the medial and lateral menisci of 5 unenbalmed cadaveric knees using colored latex and a 22‐gauge, 38‐mm needle. After injection, coinvestigators dissected each specimen to assess latex distribution within the menisci and identify injury to intra‐articular and periarticular structures.Main Outcome MeasuresLatex location within the target region of meniscus (accurate/inaccurate), and iatrogenic injury to “at risk” intra‐ and periarticular structures (present/absent).ResultsSeventeen of 20 injections were accurate. Two of 3 inaccurate injections infiltrated the posterior horn of the medial meniscus instead of the targeted meniscal body. One inaccurate lateral meniscus injection did not contain latex despite sonographically accurate needle placement. No specimen exhibited injury to regional neurovascular structures or intra‐articular hyaline cartilage.ConclusionsSG meniscus injections are feasible and can accurately and safely deliver injectates such as regenerative agents into bodies and posterior horns of the medial and lateral menisci. The role of SG intrameniscal injections in the treatment of patients with degenerative and traumatic meniscal disorders warrants further exploration.Level of EvidenceNot applicable.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147070/1/pmr2998.pd

Individual Differences in Dopamine Are Associated with Reward Discounting in Clinical Groups But Not in Healthy Adults.

Some people are more willing to make immediate, risky, or costly reward-focused choices than others, which has been hypothesized to be associated with individual differences in dopamine (DA) function. In two studies using PET imaging, one empirical (Study 1: N = 144 males and females across 3 samples) and one meta-analytic (Study 2: N = 307 across 12 samples), we sought to characterize associations between individual differences in DA and time, probability, and physical effort discounting in human adults. Study 1 demonstrated that individual differences in DA D2-like receptors were not associated with time or probability discounting of monetary rewards in healthy humans, and associations with physical effort discounting were inconsistent across adults of different ages. Meta-analytic results for temporal discounting corroborated our empirical finding for minimal effect of DA measures on discounting in healthy individuals but suggested that associations between individual differences in DA and reward discounting depend on clinical features. Addictions were characterized by negative correlations between DA and discounting, but other clinical conditions, such as Parkinson's disease, obesity, and attention-deficit/hyperactivity disorder, were characterized by positive correlations between DA and discounting. Together, the results suggest that trait differences in discounting in healthy adults do not appear to be strongly associated with individual differences in D2-like receptors. The difference in meta-analytic correlation effects between healthy controls and individuals with psychopathology suggests that individual difference findings related to DA and reward discounting in clinical samples may not be reliably generalized to healthy controls, and vice versa.SIGNIFICANCE STATEMENT Decisions to forgo large rewards for smaller ones due to increasing time delays, uncertainty, or physical effort have been linked to differences in dopamine (DA) function, which is disrupted in some forms of psychopathology. It remains unclear whether alterations in DA function associated with psychopathology also extend to explaining associations between DA function and decision making in healthy individuals. We show that individual differences in DA D2 receptor availability are not consistently related to monetary discounting of time, probability, or physical effort in healthy individuals across a broad age range. By contrast, we suggest that psychopathology accounts for observed inconsistencies in the relationship between measures of DA function and reward discounting behavior

Lipid Order in Red Blood Cell Membranes Exposed to Hypo-Osmotic Stress and Self-Inserting Pore-Forming Proteins

The packing of lipids comprising a cell membrane, known as lipid order, has been under increasing scrutiny due to continuous findings of its biological significance. There is extensive literature detailing the changes in lipid order, and multiple temperature-induced phase transitions have been clarified. However, these experiments have not considered common external factors, such as hypo-osmotic stress and protein insertion. To fill these gaps in our knowledge, Red Blood Cell (RBC) membranes stained with membrane probes were investigated by general polarization (GP) and anisotropy (p). We evaluated RBC membranes under hypo-osmotic shock, and membranes with pore-forming toxins. Significant changes in lipid order were observed after exposure to hypo-osmotic stress or insertion of pore-forming toxins, echoing temperature-induced phase transitions of lipids in membranes. We hypothesized a short-range interaction model to explain the significant changes in lipid order under hypo-osmotic shock, together with a hydrophobic mismatch to explain the changes observed upon protein insertion. Our findings may provide a better understanding of the modulation of physiological functionals, such as transport and signaling, by physical cues and interactions with drugs or other bioactive molecules

Analysis of Changes in Muscle Architecture and Explosive Ability in NCAA Division I Volleyball Players

Abstract available in the 10th Annual Coaches and Sport Science College

Lubricating Bacteria Model for Branching growth of Bacterial Colonies

Various bacterial strains (e.g. strains belonging to the genera Bacillus, Paenibacillus, Serratia and Salmonella) exhibit colonial branching patterns during growth on poor semi-solid substrates. These patterns reflect the bacterial cooperative self-organization. Central part of the cooperation is the collective formation of lubricant on top of the agar which enables the bacteria to swim. Hence it provides the colony means to advance towards the food. One method of modeling the colonial development is via coupled reaction-diffusion equations which describe the time evolution of the bacterial density and the concentrations of the relevant chemical fields. This idea has been pursued by a number of groups. Here we present an additional model which specifically includes an evolution equation for the lubricant excreted by the bacteria. We show that when the diffusion of the fluid is governed by nonlinear diffusion coefficient branching patterns evolves. We study the effect of the rates of emission and decomposition of the lubricant fluid on the observed patterns. The results are compared with experimental observations. We also include fields of chemotactic agents and food chemotaxis and conclude that these features are needed in order to explain the observations.Comment: 1 latex file, 16 jpeg files, submitted to Phys. Rev.

Multi-axis fields boost SABRE hyperpolarization via new strategies

The inherently low signal-to-noise ratio of NMR and MRI is now being addressed by hyperpolarization methods. For example, iridium-based catalysts that reversibly bind both parahydrogen and ligands in solution can hyperpolarize protons (SABRE) or heteronuclei (X-SABRE) on a wide variety of ligands, using a complex interplay of spin dynamics and chemical exchange processes, with common signal enhancements between $10^3-10^4$. This does not approach obvious theoretical limits, and further enhancement would be valuable in many applications (such as imaging mM concentration species in vivo). Most SABRE/X-SABRE implementations require far lower fields (${\mu}T-mT$) than standard magnetic resonance (>1T), and this gives an additional degree of freedom: the ability to fully modulate fields in three dimensions. However, this has been underexplored because the standard simplifying theoretical assumptions in magnetic resonance need to be revisited. Here we take a different approach, an evolutionary strategy algorithm for numerical optimization, Multi-Axis Computer-aided HEteronuclear Transfer Enhancement for SABRE (MACHETE-SABRE). We find nonintuitive but highly efficient multi-axial pulse sequences which experimentally can produce a 10-fold improvement in polarization over continuous excitation. This approach optimizes polarization differently than traditional methods, thus gaining extra efficiency

Algorithm Selection Framework for Cyber Attack Detection

The number of cyber threats against both wired and wireless computer systems and other components of the Internet of Things continues to increase annually. In this work, an algorithm selection framework is employed on the NSL-KDD data set and a novel paradigm of machine learning taxonomy is presented. The framework uses a combination of user input and meta-features to select the best algorithm to detect cyber attacks on a network. Performance is compared between a rule-of-thumb strategy and a meta-learning strategy. The framework removes the conjecture of the common trial-and-error algorithm selection method. The framework recommends five algorithms from the taxonomy. Both strategies recommend a high-performing algorithm, though not the best performing. The work demonstrates the close connectedness between algorithm selection and the taxonomy for which it is premised.Comment: 6 pages, 7 figures, 1 table, accepted to WiseML '2

When Programs Collide - A Panel Discussion on the Competing Interests of Analytics and Security

The increasing demand for business analytics and cybersecurity professionals provides an exciting job outlook for graduates of information systems programs. However, the rapid proliferation of devices and systems that has spurred this trend has created a challenging ethical dilemma for those responsible for educating future generations of IT professionals. Many firms are collecting and storing as much data as possible in the hopes that technology might uncover useful insights in the future. This results in an ever-increasing challenge for those charged with protecting organizational assets and exerts pressure on executives seeking an analytical edge to remain profitable in a hyper-competitive marketplace. With this dilemma in mind, the panel will search for a delicate balance between unleashing the power of analytics and securing the sensitive data it consumes. Keyword