Detection of 23 Gastrointestinal Pathogens Among Children Who Present With Diarrhea.

BACKGROUND: Diarrheal diseases are a major cause of ambulatory care visits and hospitalizations among children. Because of overlapping signs and symptoms and expensive and inefficient testing methods, the etiology of pediatric diarrhea is rarely established. METHODS: We identified children <18 years of age who were evaluated for diarrhea at Primary Children's Hospital in Salt Lake City, Utah, between October 2010 and September 2012. Stool specimens submitted for testing were evaluated by using the FilmArray gastrointestinal diagnostic system, which is a rapid multiplex polymerase chain reaction platform that can simultaneously detect 23 bacterial, viral, and protozoal agents. RESULTS: A pathogen was detected in 561 (52%) of 1089 diarrheal episodes. The most commonly detected pathogens included toxigenic Clostridium difficile (16%), diarrheagenic Escherichia coli (15%), norovirus GI/GII (11%), and adenovirus F 40/41 (7%). Shiga toxin-producing E coli were detected in 43 (4%) specimens. Multiple pathogens were identified in 160 (15%) specimens. Viral pathogens (norovirus, adenovirus, rotavirus, and sapovirus) were more common among children <5 years old than among those 5 to 17 years old (38% vs 16%, respectively; P < .001). Bacterial pathogens were identified most commonly in children 2 to 4 years of age. Children with 1 or more underlying chronic medical conditions were less likely to have a pathogen identified than those without a chronic medical condition (45% vs 60%, respectively; P < .01). Viral pathogens were detected more commonly in the winter, whereas bacterial pathogens were detected more commonly in the summer. CONCLUSIONS: Toxigenic C difficile, diarrheagenic E coli, and norovirus were the leading organisms detected among these children with diarrhea. Viral pathogens are identified frequently among young children with acute gastroenteritis.

In vivo impedance imaging with total variation regularization.

We show that electrical impedance tomography (EIT) image reconstruction algorithms with regularization based on the total variation (TV) functional are suitable for in vivo imaging of physiological data. This reconstruction approach helps to preserve discontinuities in reconstructed profiles, such as step changes in electrical properties at interorgan boundaries, which are typically smoothed by traditional reconstruction algorithms. The use of the TV functional for regularization leads to the minimization of a nondifferentiable objective function in the inverse formulation. This cannot be efficiently solved with traditional optimization techniques such as the Newton method. We explore two implementations methods for regularization with the TV functional: the lagged diffusivity method and the primal dual-interior point method (PD-IPM). First we clarify the implementation details of these algorithms for EIT reconstruction. Next, we analyze the performance of these algorithms on noisy simulated data. Finally, we show reconstructed EIT images of in vivo data for ventilation and gastric emptying studies. In comparison to traditional quadratic regularization, TV regularization shows improved ability to reconstruct sharp contrasts.

Clinical and electrophysiologic features of CMT2A with mutations in the mitofusin 2 gene.

BACKGROUND: Axonal neuropathy linked to the CMT2A locus was originally associated with a mutation in the KIF1B gene. However, mutations in this gene have not been described associated with any other CMT2A families. Recently, mutations in the MFN2 gene, encoding the mitochondrial GTPase mitofusin 2 (Mfn2), have been identified as causative of CMT2A in seven families. The authors report three additional CMT2A families associated with novel mutations in highly conserved regions of the Mfn2 GTPase domain. METHODS: The authors performed a standardized neuromuscular and nerve conduction examination, genotyped known CMT loci, and analyzed the MFN2 gene by direct sequencing in three pedigrees and 10 additional probands affected by axonal CMT. RESULTS: Sequencing of the MFN2 gene revealed a novel mutation in each family (c.818T>G, c.638T>C, and c.314C>T). The largest family demonstrated an age-independent variable expression such that approximately one quarter of individuals with the mutation presented with features mild enough as to remain occult even with electrophysiologic evaluation. CONCLUSION: These results confirm that the majority of cases of CMT linked to the CMT2A locus are due to MFN2 mutations. The phenotype is largely indistinguishable from KIF1B-related CMT and from CMT2E and CMT2F. At least in some families, as many as 25% of individuals with MFN2 mutations may be asymptomatic and have a normal electrophysiologic examination, although a detailed neuromuscular examination may suggest the trait. Given the frequency of MFN2 mutations among CMT2 probands (3/13, or 23%), genetic testing of CMT2 patients should begin with a screen of the MFN2 gene.

Varicella-zoster virus transfer to skin by T Cells and modulation of viral replication by epidermal cell interferon-alpha.

Primary infection with varicella-zoster virus (VZV) causes the characteristic syndrome of varicella, or chickenpox. Experiments in severe combined immunodeficiency mice with human skin grafts (SCIDhu mice) indicate that VZV infection of T cells can mediate transfer of infectious virus to skin. VZV-infected T cells reached epithelial sites of replication within 24 h after entering the circulation. Memory CD4+ T cells were the predominant population recovered from skin in SCIDhu mice given uninfected or infected mononuclear cells, suggesting that immune surveillance by memory T cells may facilitate VZV transfer. The increased susceptibility of memory T cells to VZV infection may further enhance their role in VZV pathogenesis. During VZV skin infection, viral gene products down-regulated interferon-alpha to permit focal replication, whereas adjacent epidermal cells mounted a potent interferon-alpha response against cell-cell spread. Interleukin-1alpha, although activated in VZV-infected cells, did not trigger expression of endothelial adhesion molecules, thereby avoiding early recruitment of inflammatory cells. The prolonged varicella incubation period appears to represent the time required for VZV to overcome antiviral responses of epidermal cells and generate vesicles at the skin surface. Modulation of VZV replication by cutaneous innate immunity may avoid an incapacitating infection of the host that would limit opportunities for VZV transmission.

Sweet's syndrome masquerading as facial cellulitis.

Sweet's syndrome, or acute febrile neutrophilic dermatosis, is a cutaneous condition that typically occurs as tender red plaques or nodules. However, atypical presentations may occur and, in our case, Sweet's syndrome masqueraded as facial cellulitis and soft tissue infections of the extremities in a sporotrichoid pattern. Despite treatment with broad-spectrum antibiotics, the cutaneous lesions progressed. Results of skin biopsy specimens of the facial plaque and a nodule on the right upper extremity were diagnostic of Sweet's syndrome. Simultaneous to diagnosis, the patient also was found to have acute myelogenous leukemia (AML).

Sacral hemangioma with sinus tract in an infant.

Congenital midline cutaneous lesions should always alert the clinician to the possibility of spinal dysraphism. These lesions can take many different forms. The physician should be cognizant of such lesions in order to avoid potential neurologic complications. We present a patient with a midline sacral hemangioma associated with a congenital enteric sinus cyst, a previously unreported association.

Rapidly growing mycobacterial infections after pedicures.

BACKGROUND: Rapidly growing mycobacteria (RGM) can cause a variety of cutaneous and systemic diseases. The causative organisms are typically Mycobacterium fortuitum or Mycobacterium chelonae (also known as Mycobacterium abscessus). Primary cutaneous lesions may develop after a variable latent period, from weeks to several months, and usually result from direct inoculation after trauma, from injections, or during surgery via contaminated medical instruments. Recently, investigators from the Centers for Disease Control and Prevention, Atlanta, Ga, and the California Department of Health Services, Berkeley, documented a large, unprecedented outbreak of community-acquired RGM infection, during which more than 100 patrons of a northern California nail salon contracted furunculosis in their legs as a result of exposure to whirlpool footbaths that were contaminated with M fortuitum. OBSERVATIONS: We report the clinical and epidemiological findings in 3 cases of lower extremity RGM infections that occurred after similar whirlpool footbath exposure at several different nail salons in southern California. These infections typically presented as recurrent furunculosis, causing considerable morbidity as a result of scarring, delayed diagnosis, and the need for long-term polymicrobial therapy. CONCLUSIONS: Rapidly growing mycobacterial infections related to pedicures may continue to occur in a sporadic fashion. Clinicians should consider the possibility of RGM infection and inquire about recent pedicures in a patient with recurrent lower extremity furunculosis and abscesses that are unresponsive to conventional antibiotic therapy.

Flagellate hyperpigmentation following intralesional bleomycin treatment of verruca plantaris.

BACKGROUND: Flagellate hyperpigmentation is a well-documented complication of systemic bleomycin sulfate therapy when using doses of 100 U or more as an antineoplastic agent. Two cases occurred after using systemic doses from 15 to 30 U injected intravenously or intrapleurally; however, it has not been described as a complication following intralesional treatment of verruca plantaris. OBSERVATIONS: We report a case of flagellate hyperpigmentation after intralesional injection of 14 U of bleomycin for verrucae plantaris and review the literature associated with this cutaneous complication. CONCLUSIONS: Flagellate hyperpigmentation from extremely low doses of intralesional bleomycin is a previously undescribed complication. Although the mechanisms of reaction are not clearly understood, the clinician should be mindful of this uncommon complication.

Treatment of pseudofolliculitis barbae in skin types IV, V, and VI with a long-pulsed neodymium:yttrium aluminum garnet laser.

BACKGROUND: Pseudofolliculitis barbae affects a large number of individuals with coarse curly hair, and present treatment options are suboptimal. OBJECTIVE: We evaluated the safety and efficacy of a long-pulsed neodymium:yttrium aluminum garnet (Nd:YAG) laser in the treatment of pseudofolliculitis barbae. METHODS: This was a two-phase observational study conducted at a military tertiary medical facility. The study group included 37 patients (skin types IV, V, and VI) referred from primary care physicians with a diagnosis of pseudofolliculitis barbae refractory to conservative therapy. In phase I, one treatment with a Nd:YAG laser was performed on a tattooed area of the thigh with 3 light doses. Epidermal tolerance was evaluated, and hair counts were performed 3 months after treatment for each light dose. In phase II, the highest dose tolerated by the epidermis from phase I was applied to a small submental region of skin with an adjacent site as a control. Subsequently, papule counts were performed 90 days after treatment in the laser-irradiated and control areas. RESULTS: Phase I: When normalized for controls, there was 33%, 43%, and 40% hair reduction on the thigh for the 50, 80, and 100 J/cm(2) fluences, respectively, after 90 days. Overall, the highest doses tolerated by the epidermis were 50, 100, and 100 J/cm(2) for type VI, V, and IV skin, respectively. Phase II: Mean papule counts after 90 days were 6.95 and 1.0 for the control and treatment sites, respectively. CONCLUSION: Nd:YAG laser treatment may represent a safe and effective option for reducing hair and subsequent papule formation in patients with pseudofolliculitis barbae.