Skin eruption and gastrointestinal symptoms as presentation of COVID-19.

Recently, several cutaneous manifestations of coronavirus disease 2019 (COVID-19) have been reported. However, there is a paucity of published images. Those that have been published so far tend to fall under distinct morphologic categories.

Extinction dynamics of spiral defect chaos.

Spatially extended excitable systems can exhibit spiral defect chaos (SDC) during which spiral waves continuously form and disappear. To address how this dynamical state terminates using simulations can be computationally challenging, especially for large systems. To circumvent this limitation, we treat the number of spiral waves as a stochastic population with a corresponding birth-death equation and use techniques from statistical physics to determine the mean episode duration of SDC.

Characterizing Electrogram Signal Fidelity and the Effects of Signal Contamination on Mapping Human Persistent Atrial Fibrillation.

Determining accurate intracardiac maps of atrial fibrillation (AF) in humans can be difficult, owing primarily to various sources of contamination in electrogram signals. The goal of this study is to develop a measure for signal fidelity and to develop methods to quantify robustness of observed rotational activity in phase maps subject to signal contamination. We identified rotational activity in phase maps of human persistent AF using the Hilbert transform of sinusoidally recomposed signals, where localized ablation at rotational sites terminated fibrillation.

Spatiotemporal Progression of Early Human Ventricular Fibrillation.

Objectives: The objective of this study was to evaluate the spatio-temporal organization and progression of human ventricular fibrillation (VF) in the left (LV) and right (RV) ventricles.

Background: Studies suggest that localized sources contribute to VF maintenance, but the evolution of VF episodes has not been quantified.

Methods: Synchrony between electrograms recorded from 25 patients with induced VF is computed and used to define the Asynchronous Index (ASI), indicating regions which are out-of-step with surrounding tissue.

Two Independent Mapping Techniques Identify Rotational Activity Patterns at Sites of Local Termination During Persistent Atrial Fibrillation.

Introduction: The mechanisms for atrial fibrillation (AF) are unclear in part because diverse mapping techniques yield diverse maps, ranging from stable organized sources to highly disordered waves. We hypothesized that AF mechanisms may be clarified if mapping techniques were compared in the same patients, and referenced to a clinical endpoint. We compared two independent AF mapping techniques in patients in whom ablation terminated persistent AF before pulmonary vein isolation (PVI).

Determining conduction patterns on a sparse electrode grid: Implications for the analysis of clinical arrhythmias.

We present a general method of utilizing bioelectric recordings from a spatially sparse electrode grid to compute a dynamic vector field describing the underlying propagation of electrical activity. This vector field, termed the wave-front flow field, permits quantitative analysis of the magnitude of rotational activity (vorticity) and focal activity (divergence) at each spatial point. We apply this method to signals recorded during arrhythmias in human atria and ventricles using a multipolar contact catheter and show that the flow fields correlate with corresponding activation maps.

Dynamic contrast-enhanced ultrasound of the bowel wall with quantitative assessment of Crohn's disease activity in childhood.

Background: Contrast-enhanced ultrasound (CEUS) has become an established non-invasive, patient-friendly imaging technique which improves the characterization of lesions. In addition, dynamic contrast-enhanced ultrasound (DCE-US) provides valuable information concerning perfusion of examined organs. This review addresses current applications of CEUS in children, focused on DCE-US of the bowel wall in patients with Crohn disease, which enables realtime assessment of the bowel wall vascularity with semi-quantitative and quantitative assessment of disease activity and response to medical treatment.

Phase synchrony reveals organization in human atrial fibrillation.

It remains unclear if human atrial fibrillation (AF) is spatially nonhierarchical or exhibits a hierarchy of organization sustained by sources. We utilize activation times obtained at discrete locations during AF to compute the phase synchrony between tissue regions, to examine underlying spatial dynamics throughout both atria. We construct a binary synchronization network and show that this network can accurately define regions of coherence in coarse-grained in silico data.

Correlation of Culture Positivity, PCR Positivity, and Burden of Borrelia burgdorferi Sensu Lato in Skin Samples of Erythema Migrans Patients with Clinical Findings.

Background: Limited data are available regarding the relationship of Borrelia burden in skin of patients with erythema migrans (EM) and the disease course and post-treatment outcome.

Methods: We studied 121 adult patients with EM in whom skin biopsy specimens were cultured and analyzed by quantitative PCR for the presence of Borreliae. Evaluation of clinical and microbiological findings were conducted at the baseline visit, and 14 days, 2, 6, and 12 months after treatment with either amoxicillin or cefuroxime axetil.

Improvement of pneumococcal pneumonia diagnostics by the use of rt-PCR on plasma and respiratory samples.

Background: The aim of the study was to assess the performance of a real-time polymerase chain reaction (rt-PCR) assay on plasma and respiratory samples for the diagnosis of pneumococcal pneumonia.

Methods: Three hundred and forty patients (160 children and 180 adults) with community-acquired pneumonia were included prospectively from January 2011 to May 2012. Blood samples were obtained simultaneously for culture and rt-PCR targeting the lytA gene.

Collision tumor composed of Merkel cell carcinoma and lentigo maligna melanoma.

We report the case of an immunocompetent 79-year-old white man with a history of melanoma in situ on the back with a collision tumor composed of a Merkel cell carcinoma (MCC) and lentigo maligna melanoma on the left cheek. The cells of the MCC expressed cytokeratin 20 (CK 20) in a diffuse cytoplasmic pattern, AE1 and AE3 in a perinuclear dot-like pattern and diffusely with neuron-specific enolase. The tumor cells of the MCC failed to express thyroid transcription factor-1.

Clinical and laboratory methods in diagnosis of acute appendicitis in children.

Aim: To compare the diagnostic accuracy of clinical examination, white blood cell and differential count, and C-reactive protein as routine tests for acute appendicitis with that of interleukin-6 (IL-6) and ultrasonography.

Methods: Eighty-two children were admitted to the Department of Pediatric Surgery and Intensive Care, Ljubljana, Slovenia because of suspected acute appendicitis. Among them, 49 children underwent surgery for acute appendicitis and 33 had abdominal pain but were not treated surgically and were diagnosed with non-specific abdominal pain or mesenteric lymphadenitis on sonography.

An unusual complication after percutaneous drainage of a pancreatic pseudocyst into the stomach.

In the period between September 1995 and June 1999, we performed percutaneous drainage into the stomach in 12 patients. There were no complications or pseudocyst recurrences on insertion or after endoscopic removal of the catheter, which was left in site for 1 year on average. After endoscopic removal of the drainage catheter, one of the patients presented with a cystic formation in the stomach wall, which caused stomach emptying disorder.

The effect of decreasing digital image resolution on teledermatology diagnosis.

Objective: To determine the effect of degraded digital image resolution (as viewed on a monitor) on the accuracy and confidence of dermatologic interpretation.

Materials And Methods: Eight dermatologists interpreted 180 clinical cases divided into three Logical Competitor Sets (LCS) (pigmented lesions, non-pigmented lesions, and inflammatory dermatoses). Each case was digitized at three different resolutions.

Assessment of the ability of the topical skin protectant (TSP) to protect against contact dermatitis to urushiol (Rhus) antigen.

Background: Military personnel have a need for effective protection against cutaneous exposure to chemical warfare agents (CWA). Topical Skin Protectant (TSP) is being developed to supplement chemical warfare protective garments. TSP protects against CWA exposure in animals, but does it work for humans? Because humans should not be tested with live CWA, urushiol (poison ivy) extract was used as a surrogate substance in place of CWA for human efficacy testing of TSP.

The history of teledermatology in the Department of Defense.

The Department of Defense (DoD) healthcare system supports the medical needs of service members while engaged in a variety of missions frequently in isolated, remote, and austere locations. As a result, the DoD has been a leader in the development of telemedicine, including teledermatology as a way to provide "good medicine in bad places." A brief technical history of teledermatology, representative DoD experiences including military unique concerns, and a novel approach to increase the access of DoD teledermatology consultation are presented in this article.

Percutaneous drainage of pancreatic pseudocyst into the stomach.

Background: We present our experience with percutaneous ultrasonographically guided internal cystogastric drainage of pancreatic pseudocysts using a double pigtail catheter.

Methods: In nine patients, the pancreatic pseudocysts following acute pancreatitis were drained percutaneously into the stomach with the double pigtail catheter under ultrasonographical (US) control. The needle insertion through both gastric walls and the final position of the proximal curve of the catheter were monitored with a gastroscope.

Plea for standardization in teledermatology: a worm's eye view.

Like any clinical interaction, teledermatology requires accurate, timely, and relevant information. The need to provide reliable, representative, diagnostic-quality images to the consultant is obvious. Predetermined patient views for a given clinical presentation and optimal hands on techniques to acquire them are not standardized.

The epidemiology of dermatologic and venereologic disease in a deployed operational setting.

We studied the epidemiology, morbidity, and etiology of dermatologic and non-human immunodeficiency virus venereologic disease (Derm/STD) aboard a deployed aircraft carrier to revise Derm/STD training objectives for shipboard primary care providers. Onboard supplies for treatment of Derm/STD were also evaluated. Over 3 months, 929 Derm/STD patients were treated for 1,320 diagnoses generating 2,011 visits.

An atypical piloleiomyoma presenting as a nonhealing ulcerated nodule.

Piloleiomyomas are benign smooth muscle tumors arising from the arrectores pilorum muscles in the skin. They vary in size and number, and are often spontaneously painful or sensitive to touch and cold. An unusual case of an ulcerated and painless piloleiomyoma is presented.