Percussion hemoglobinuria - a novel term for hand trauma-induced mechanical hemolysis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Extracorpuscular hemolysis caused by mechanical trauma has been well described in relation to lower extremity use, such as in soldiers and runners. Terms such as "march hemoglobinuria", "foot strike hemolysis" and "runners hemoglobinuria" have previously been coined and are easily recalled. Newer cases, however, are being identified in individuals vigorously using their upper extremities, such as drum players who use their hands to strike the instrument. Given the increased recognition of upper extremity-related mechanical hemolysis and hemoglobinuria in drummers, and the use of hand drumming worldwide, we would like introduce a novel term for this condition and call it "percussion hemoglobinuria".</p> <p>Case presentation</p> <p>A 24-year-old Caucasian man presented with reddish brown discoloration of his urine after playing the djembe drum. Urine examination after a rigorous practice session revealed blood on the dipstick, and 0 to 2 red blood cells per high power field microscopically. The urine sample was negative for myoglobulin. Other causes of hemolysis and hematuria were excluded and cessation of drum playing resulted in resolution of his symptoms.</p> <p>Conclusions</p> <p>The association of mechanical trauma-induced hemoglobinuria and playing hand percussion instruments is increasingly being recognized. We, however, feel that the true prevalence is higher than what has been previously recorded in the literature. By coining the term "percussion hemoglobinuria" we hope to raise the awareness of screening for upper extremity trauma-induced mechanical hemolysis in the evaluation of a patient with hemoglobinuria.</p

In vivo Magnetic Resonance Imaging of Tumor Protease Activity

Increased expression of cathepsins has diagnostic as well as prognostic value in several types of cancer. Here, we demonstrate a novel magnetic resonance imaging (MRI) method, which uses poly-L-glutamate (PLG) as an MRI probe to map cathepsin expression in vivo, in a rat brain tumor model. This noninvasive, high-resolution and non-radioactive method exploits the differences in the CEST signals of PLG in the native form and cathepsin mediated cleaved form. The method was validated in phantoms with known physiological concentrations, in tumor cells and in an animal model of brain tumor along with immunohistochemical analysis. Potential applications in tumor diagnosis and evaluation of therapeutic response are outlined

An integrated congestion management architecture for internet hosts

Abstract past decade. This paper presents a novel framework for managing net-work congestion from an end-toend perspective. Our work is motivated by trends in traffic patterns that threaten the long-term stability of the Internet. These trends include the use of multiple independent concurrent flows by Web ap-plications and the increasing use of transport protocols and applications that do not adapt to congestion. We present an end-system architecture centered around a Congestion Man-ager (CM) that ensures proper congestion behavior and al-lows applications to easily adapt to network congestion. Our framework integrates congestion management across all ap plications and transport protocols. The CM maintains con-gestion parameters and exposes an API to enable applica-tions to learn about network characteristics, pass inform

An end-system architecture for unified congestion management

In this position paper we motivate and describe the Congestion Manager (CM), a novel end-system architecture, which enables application adaptation to network congestion. The CM maintains congestion and path related information and allows flows to learn from each other and share information. It also exports an API to enable applications to learn about network status and regulate data transmission. As a result, applications are freed from having to detect network congestion and probe for spare bandwidth. We describe how TCP can be implemented using the CM and conclude that the CM provides an excellent framework for building adaptive Internet applications. 1

High resolution T1ρ mapping of in vivo human knee cartilage at 7T.

Spin lattice relaxation time in rotating frame (T1ρ) mapping of human knee cartilage has shown promise in detecting biochemical changes during osteoarthritis. Due to higher field strength, MRI at 7T has advantages in term of SNR compared to clinical MR scanners and this can be used to increase in image resolution. Objective of current study was to evaluate the feasibility of high resolution T1ρ mapping of in vivo human knee cartilage at 7T MR scanner.In this study we have used a T1ρ prepared GRE pulse sequence for obtaining high resolution (in plan resolution  = 0.2 mm2) T1ρ MRI of human knee cartilage at 7T. The effect of a global and localized reference frequency and reference voltage setting on B0, B1 and T1ρ maps in cartilage was evaluated. Test-retest reliability results of T1ρ values from asymptomatic subjects as well as T1ρ maps from abnormal cartilage of two human subjects are presented. These results are compared with T1ρ MRI data obtained from 3T.Our approach enabled acquisition of 3D-T1ρ data within allowed SAR limits at 7T. SNR of cartilage on T1ρ weighted images was greater than 90. Off-resonance effects present in the cartilage B0, B1 and T1ρ maps obtained using global shim and reference frequency and voltage setting, were reduced by the proposed localized reference frequency and voltage setting. T1ρ values of cartilage obtained with the localized approach were reproducible. Abnormal knee cartilage showed elevated T1ρ values in affected regions. T1ρ values at 7T were significantly lower (p<0.05) compared to those obtained at 3T.In summary, by using proposed localized frequency and voltage setting approach, high-resolution 3D-T1ρ maps of in vivo human knee cartilage can be obtained in clinically acceptable scan times (<30 min) and SAR constraints, which provides the ability to characterize cartilage molecular integrity

High quality three-dimensional gagCEST imaging of in vivo human knee cartilage at 7 Tesla

\u3cp\u3ePurpose: To develop a new faster and higher quality three-dimensional (3D) gagCEST MRI technique for reliable quantification of glycosaminoglycan (GAG) present in the human knee cartilages. Methods: A new magnetization-prepared 3D gradient echo-based MRI pulse sequence has been designed to obtain the B\u3csub\u3e0\u3c/sub\u3e inhomogeneity, B\u3csub\u3e1\u3c/sub\u3e inhomogeneity, and CEST Z-spectra images. Results: The gagCEST values of different compartments of knee cartilage are calculated using a newly developed technique for healthy subjects and a symptomatic knee cartilage degenerated subject. The effect of the acquired CEST saturation frequency offset step-size was investigated to establish the optimal step-size to obtain reproducible gagCEST maps. Our novel 3D gagCEST technique demonstrates markedly higher gagCEST contrast value than the previously reported 3D gagCEST studies. This study demonstrates the need for separate B\u3csub\u3e0\u3c/sub\u3e and B\u3csub\u3e1\u3c/sub\u3e inhomogeneity estimation and correction. Conclusion: The new technique provided high quality gagCEST maps with clearer visualization of different layers of knee cartilage with reproducible results. Magn Reson Med 77:1866–1873, 2017.\u3c/p\u3