Enhancing Synchronization by Optimal Correlated Noise.

From the flashes of fireflies to Josephson junctions and power infrastructure, networks of coupled phase oscillators provide a powerful framework to describe synchronization phenomena in many natural and engineered systems. Most real-world networks are under the influence of noisy, random inputs, potentially inhibiting synchronization. While noise is unavoidable, here we show that there exist optimal noise patterns which minimize desynchronizing effects and even enhance order. Specifically, using analytical arguments we show that in the case of a two-oscillator model, there exists a sharp transition from a regime where the optimal synchrony-enhancing noise is perfectly anticorrelated, to one where the optimal noise is correlated. More generally, we then use numerical optimization methods to demonstrate that there exist anticorrelated noise patterns that optimally enhance synchronization in large complex oscillator networks. Our results may have implications in networks such as power grids and neuronal networks, which are subject to significant amounts of correlated input noise.

Drug reaction with eosinophilia and systemic symptoms (DRESS) associated with azithromycin in acute Epstein-Barr virus infection.

We report the first pediatric case of drug reaction with eosinophilia and systemic symptoms associated with azithromycin use in the setting of acute Epstein-Barr virus infection in an 8-year-old boy. Our patient presented with fever, cutaneous eruption, eosinophilia, and hypotension requiring intensive care unit admission. He was discharged in good condition without any long-term sequelae. This case underscores the importance of timely and accurate diagnosis of acute viral infections and appropriate use of antibiotics as well as recognition of the clinical signs of drug reaction with eosinophilia and systemic symptoms.

The inadequacy of punch-excised melanocytic lesions: sampling through the block for the determination of "margins".

BACKGROUND: Dermatopathologists often are asked by clinicians to report margins on punch excisions of melanocytic lesions. OBJECTIVE: We sought to determine the adequacy of surgical margins on melanocytic lesions submitted with intention of complete excision using punch removal technique. METHODS: We conducted prospective analysis of surgical margins on 266 consecutive patients who underwent attempted complete removal of 405 melanocytic nevi submitted as punch and fusiform excisions. RESULTS: Of 206 nonbisected punch excisions, 127 (62%) had final positive margins. Of 159 bisected punch excisions, 76 (48%) had final positive margins. Of 40 elliptical excisions, two (5%) had final positive margins. LIMITATIONS: Information on the perilesional rim of nonpigmented skin included in the excision was not available. CONCLUSIONS: Of punch excisions, 56% had positive margins. Importantly, 30% of these punch excised specimens were negative on initial levels but had positive margins after extensive sectioning, affirming that fusiform excisions are the preferred method to evaluate margins in melanocytic lesions.

A male infant with anhidrotic ectodermal dysplasia/immunodeficiency accompanied by incontinentia pigmenti and a mutation in the NEMO pathway.

Patients with anhidrotic ectodermal dysplasia and immunodeficiency (EDA-ID) have mutations in the gene on the X chromosome encoding nuclear factor kappaB (NF-kappaB) essential modulator (NEMO), resulting in conical teeth, sparse hair, anhidrosis or hypohydrosis, and recurrent bacterial infections. The same gene is mutated in incontinentia pigmenti (IP), and mutations that do not completely abolish NF-kappaB activity allow survival of male fetuses. We present a case of a 1-year-old boy with a history of EDA-ID who was evaluated for an eruption that intermittently affected his scalp, upper back, cheeks, legs, and arms. A biopsy specimen taken from the back showed the presence of compact dyskeratotic cells with fragmented nuclei and numerous apoptotic keratinocytes scattered throughout the spinous and granular layer. The diagnosis of EDA-ID with IP was made. This case illustrates the complexity and overlapping features of the genodermatoses involving signaling pathways of the cell.

Esophagitis due to tetracycline and its derivatives in dermatology patients.

Medication induced esophagitis (MIE) has been reported in dermatology patients taking tetracycline antibiotics. The symptoms of esophagitis, preventable with proper instruction, can create morbidity and lead to increased costs for patients. Our study sought to quantify the incidence of MIE in patients taking tetracycline antibiotics and to investigate how these patients develop MIE. A cross-sectional questionnaire survey was given at outpatient dermatology clinics. Ninety-three surveys from patients who had taken tetracycline antibiotics and 48 surveys from a control group were analyzed. Incidence of esophagitis symptoms (difficulty or pain with swallowing) was measured in both survey and control groups. We found that esophagitis is significantly more common in patients taking tetracycline and its derivatives as compared with a control group (p<.03). Patients should be counseled to take tetracycline antibiotics in an upright position with a large amount of fluid and to report esophagitis symptoms to the prescribing physician.

Atopic dermatitis: the role of recombinant interferon-gamma therapy.

Atopic dermatitis is a common, chronic, relapsing cutaneous disease with typical cellular and humoral immunologic abnormalities that can result in significant physical and psychological morbidity to the patient. Atopic dermatitis typically begins in childhood and can often persist through adolescence into adulthood. Although there are a variety of treatments for atopic dermatitis, many patients' symptoms do not improve or they have adverse reactions to medications, requiring the search for other, effective therapeutic agents. A number of inflammatory and immunological abnormalities have long been noted in patients with atopic dermatitis. Although great strides have been made in understanding the causes, the complex pathophysiology of atopic dermatitis is still not completely understood. Most notably, patients with atopic dermatitis often have an elevation of serum immunoglobulin (Ig) E levels, depressed cellular immunity, elevated blood eosinophilia, and increased interleukin (IL)-4 production. In addition, peripheral blood mononuclear cells of patients with atopic dermatitis produce reduced levels of interferon-gamma spontaneously and in response to stimuli. Due to this constellation of features, atopic dermatitis was initially viewed as a prototypical type 2 helper T lymphocyte (T(h2)) disease. These immunological findings led to a number of clinical trials with recombinant interferon-gamma in patients who had severe, unremitting atopic dermatitis. Treatment with recombinant interferon-gamma was postulated to be able to correct the immunological imbalances in patients with atopic dermatitis by decreasing serum IgE levels, IL-4 levels, restoring immune balance, and thereby leading to clinical improvement. Initial open-label studies, a double-blind placebo trial, and long-term open-label studies have demonstrated the clinical efficacy and tolerability of recombinant interferon-gamma in a subset of patients with severe, unremitting atopic dermatitis. Patients receiving treatment often had marked decreases in severity of clinical parameters: erythema, edema/indurations, pruritus, excoriations, dryness, lichenification and associated reduction in total body surface area involvement. Surprisingly, treatment with recombinant interferon-gamma did not lower serum IgE levels refuting the hypothesized mechanism by which interferon-gamma would bring about clinical improvement in patients with atopic dermatitis. Instead, decreases were noted in absolute white blood cell and eosinophil counts that tended to correlate with clinical improvement. Although the exact mechanism by which recombinant interferon-gamma brings about clinical changes in patients with atopic dermatitis is unknown, recombinant interferon-gamma should be considered a possible therapy for patients with atopic dermatitis.