Elephantiasis nostras verrucosa: an atypical presentation following intrapelvic lymphoma

Elephantiasis nostras verrucosa is a progressively debilitating and disfiguring disease commonly presenting with verrucous, cobblestone-like papules, nodules, or plaques with nonpitting edema in the lower extremities. Histopathology is marked by hyperkeratosis and dermal or subcutaneous fibrosis as a result of chronic lymphedema. Risk factors include obesity, recurrent cellulitis, chronic venous insufficiency, congestive heart failure, scleroderma, radiation, trauma, and tumors. We report a 72-year-old man who presented to the dermatology clinic for an 11-year history of edematous legs, occasionally associated with ulcerations. The findings developed within a year of intrapelvic non-Hodgkin lymphoma and progressed gradually over 10 years after lymphoma remission. Physical examination revealed atypical features including compressible cysts and pitting edema extending from the lower legs to the thighs bilaterally. The patient was noncompliant for the recommended compressive devices and the condition progressively worsened over the course of 7 months of follow-up. Early interdisciplinary management using compressive devices and a lymphatic pump are recommended. Underlying causative factors should be assessed with regular follow-up to optimize treatment outcomes

Elastic response of the electron fluid in intrinsic graphene: The collisionless regime

The elastic response of an electron fluid at finite frequencies is defined by the electron viscosity $\eta(\omega)$. We determine $\eta(\omega)$ for graphene at the charge neutrality point in the collisionless regime, including the leading corrections due to the electron-electron Coulomb interaction. We find interaction corrections to $\eta(\omega)$ that are significantly larger if compared to the corresponding corrections to the optical conductivity. In addition, we find comparable contributions to the dynamic momentum flux due to single-particle and many-particle effects. We also demonstrate that $\eta(\omega)$ is directly related to the nonlocal energy-flow response of graphene at the Dirac point. The viscosity in the collisionless regime is determined with the help of the strain generators in the Kubo formalism. Here, the pseudo-spin of graphene describing its two sublattices plays an important role in obtaining a viscosity tensor that fulfills the symmetry properties of a rotationally symmetric system.Comment: 18 pages, 5 figure

Universal collisionless transport of graphene

The impact of the electron-electron Coulomb interaction on the optical conductivity of graphene has led to a controversy that calls into question the universality of collisionless transport in this and other Dirac materials. Using a lattice calculation that avoids divergences present in previous nodal Dirac approaches, our work settles this controversy and obtains results in quantitative agreement with experiment over a wide frequency range. We also demonstrate that dimensional regularization methods agree, as long as the scaling properties of the conductivity and the regularization of the theory in modified dimension are correctly implemented. Tight-binding lattice and nodal Dirac theory calculations are shown to coincide at low energies even when the non-zero size of the atomic orbital wave function is included, conclusively demonstrating the universality of the optical conductivity of graphene.Comment: 4+ pages,4 figures; includes Supplemental Material (18 pages, 2 figures

Regulation of hematopoietic stem cell activity by inflammation

Hematopoietic stem cells (HSCs) are quiescent cells with self-renewal capacity and the ability to generate all mature blood cells. HSCs normally reside in specialized niches in the bone marrow that help maintain their quiescence and long-term repopulating activity. There is emerging evidence that certain cytokines induced during inflammation have significant effects on HSCs in the bone marrow. Type I and II interferons, tumor necrosis factor, and LPS directly stimulate HSC proliferation and differentiation, thereby increasing the short-term output of mature effector leukocytes. However, chronic inflammatory cytokine signaling can lead to HSC exhaustion and may contribute the development of hematopoietic malignancies. Pro-inflammatory cytokines such as G-CSF can also indirectly affect HSCs by altering the bone marrow microenvironment, disrupting the stem cell niche and leading to HSC mobilization into the blood. Herein, we review our current understanding of the effects of inflammatory mediators on HSCs, and we discuss the potential clinical implications of these findings with respect to bone marrow failure and leukemogenesis

Chronic Iliac Vein Occlusion and Painful Nonhealing Ulcer Induced by High Venous Pressures from an Arteriovenous Malformation

Chronic femoral vein compression (May-Thurner Syndrome) is a known rare cause of deep venous thrombosis. Subsequent angiogenesis and the development of arteriovenous malformation (AVM) in the setting of chronic venous thrombosis is by itself a rare and poorly understood phenomenon. We report a case in which elevated venous pressures resulting from such compression appear to have resulted in the development of a pelvic arteriovenous malformation, which was further complicated by chronic, nonhealing painful lower extremity ulcers, and the development of extensive subcutaneous venous collaterals. Following successful embolization of the pelvic AVM and ablation of veins under the ulcers with laser and sclerotherapy, the patient's ulcers healed and she became pain-free

Dynamic retinal vessel analysis using a spatial light modulator for stimulation

Purpose : Dynamic vessel analysis (DVA) with the Retinal Vessel Analyzer (Imedos Systems UG) is the Gold standard to measure alterations in retinal vessel diameter in health and disease. The DVA guidelines provide flicker stimulation of 12.5 Hz in a 30° field of view [1] (fixed full-field). However, to investigate local effects in the regulation of retinal perfusion, e.g. neuro vascular coupling, spatially varying stimuli are required. We introduce and validate a spatial light modulator (SLM) based setup for DVA providing arbitrary stimuli in location and size. Methods : We studied 15 volunteers (8m, 7f, 24.7±1.1 yr) to investigate the repeatability of the novel setup and to compare the new setup with the Gold standard. The relative vaso-dilatation value was determined for both. We measured four primary vessels: one superior temporal artery and vein (STa/STv), one inferior temporal artery and vein (ITa/ITv). All subjects were free of ocular and systemic diseases. A high-power LED (515 nm) and a transmissive liquid crystal SLM were connected to a mydriatic fundus camera. The field of view was set to 30°. The SLM was controlled via standard graphics card and a customized software (60 Hz refresh rate / 15 Hz flicker frequency). Each volunteer was measured three times. One measurement with the Gold standard and two with the new setup, in a random order (10 min pause time). Repeatability and comparison of the two setups were analyzed using the Bland-Altmann method. To value the differences among the group means we performed the t-test. For groups that did not meet the normality assumption we employed the Mann-Whitney U test. Results : The repeatability analysis showed the following mean differences (MD), Limits of Agreement (LoA), both in %, and p-values. STa: MD=-0.78, LoA=-4.35/+2.79, p=0.134. ITa: MD=-0.67, LoA=-3.82/+2.48, p=0.131. STv: MD=-0.69, LoA=-4.30/+2.92, p=0.186. ITv: MD=-0.03, LoA=-3.00/+2.94, p=0.947. Comparing the two different setups the p-values were 0.545 (STa), 0.405 (ITa), 0.05 (STv), and 0.137 (ITv). Conclusions : We realized a working experimental setup and applied a new approach of Dynamic Vessel Analysis using a spatial light modulator. Validation was realized in comparison to the Gold standard. The agreement between the two different setups was predominantly good. Neither the repeatability analysis nor the comparison of the two setups showed significant differences

Massive Hematochezia: A Complication of Methamphetamine-Induced Vasculitis Treated by Transcatheter Hemostasis

A long-term, heavy methamphetamine user with life-threatening rectal hemorrhage was treated with transcatheter occlusion of the bleeding arteries. The bleeding blood vessels were vulnerable submucosal arteries, part of the collateral supply to the distal colon. Visceral arteriography demonstrates severe arterial stenotic lesions of the celiac axis, superior mesenteric artery and the inferior mesenteric artery. Collateral vessels were seen with corkscrew morphology similar to that seen with thromboangiitis obliterans