Prevalence of allergic sensitization to imported fire ants in children living in an endemic region of the southeastern United States.

BACKGROUND: Imported fire ant (IFA) stings are common in children in the southeastern United States, but little is known about antibody responses to stings. OBJECTIVES: To examine the prevalence of detectable IgE and IgG antibodies to IFA venom (IFAV) and to assess the frequency of IFA stings in children in an endemic region. METHODS: We measured IFAV specific IgE using the ImmunoCAP assay and IgG anti-IFAV using protein G solid-phase radioimmunoassay in 183 serum samples from children living in the southeastern United States. A questionnaire was used to collect information about insect stings and bites from 182 children in a general pediatric clinic. RESULTS: Serum IgE anti-IFAV was detected (0.1 kUa/L) in 7.1% of 0- to 1-year-olds, 57.1% of 2- to 5-year-olds, and 64.4% of 6- to 10-year-olds. The prevalence of IgG anti-IFAV antibodies increased from 11.9% in 0- to 1-year-olds to 97.5% in 11- to 20-year-olds. Of children in the pediatric clinic, almost 40% had been stung by an IFA in the past month, with 23.9% receiving more than 6 stings per month. CONCLUSIONS: In endemic areas, the onset of sensitization (IgE positivity) to IFAV occurs in the first years of life, with more than half of the children demonstrating sensitization by 2 to 5 years of age. Exposure to IFAV as evidenced by a positive IgG anti-IFAV antibody increased with age, and by the second decade, more than 97% of children had detectable antibody. Children living in an endemic region frequently encounter IFAs and, when stung, often receive multiple stings.     

Objectives to direct the training of emergency medicine residents on off-service rotations: Emergency medical services

Emergency Medical Services are an area of special interest in emergency medicine. Many emergency physicians are called upon to direct, train, or manage emergency medical services. Residents training in emergency medicine have a need for a defined curriculum in emergency medical services. Residency training should provide a basic foundation in EMS including on- and off-line medical control, medicolegal aspects, communications, disaster management, and EMS history, structure, and function. The resident must gain experience through on-scene observation, EMT/Paramedic education, medical direction, and quality assurance activities. This paper is one in a continuing series of goals and objectives to direct resident training in off-service rotations. Specific resources, learning objectives, and experiences are suggested.     

Prenatal diagnosis of congenital non-bullous ichthyosiform erythroderma (lamellar ichthyosis)

We report the first positive prenatal diagnosis of congenital non-bullous ichthyosiform erythroderma or lamellar ichthyosis. Fetal skin samples were obtained by fetoscopy at 21 weeks' gestation and examined by light and electron microscopy. Light microscopy revealed a thickened interfollicular epidermis with multiple layers of flattened cells and excessive keratinization of the epidermal lining of the follicular infundibulum. Electron microscopy of the thickened epidermis revealed granular cells that contained larger-than-normal keratohyalin granules and multiple layers of parakeratotic cornified cells. Although there was regional variation in the degree of interfollicular keratinization, follicles from all regions showed greater and more complete keratinization, indicating that they express the abnormality early enough in development to permit prenatal diagnosis at about 20 weeks' gestation.     

Pharmacokinetic modeling of the lung burden from repeated inhalation of nickel aerosols

The saturable nature of the clearance of soluble nickel compounds from the lung was studied by repeated exposures of rats to respirable submicron-size nickel aerosols. Using Michaelis-Menten type kinetics for removal of nickel lung burdens and a constant rate of deposition, the lung nickel burdens were simulated by computer. The computer simulation was used to design a repeated exposure regimen to test further the hypothesis of saturable clearance. Male Sprague-Dawley rats were exposed for 2 h/day to nickel chloride aerosols at either 90 or 400 micrograms Ni/m3 for up to 14 days. During the 22 h between exposures and up to 3 days post-exposure rats were kept in clean air. The particle size of the aerosol ranged from 0.7 to 0.9 micron mass median aerodynamic diameter with a geometric standard deviation of 1.2-1.4. A steady-state nickel lung burden was observed at 90 micrograms/m3, as predicted from computer modeling, while lung burdens continued to increase with repeated exposure to 400 micrograms Ni/m3. The best fit for the experimental data was obtained with a maximum clearance velocity (Vmax) of 34.6 ng Ni/g X h and a Michaelis-Menten constant for transport (Kt) of 1380 ng Ni/g. The percentage of submicron nickel chloride aerosols retained in the lung was 6.9%. These data support the hypothesis of a saturable clearance mechanism for soluble nickel and provide physiological constants useful for estimating human health risks from nickel inhalation.     

Australian doctors and the visual arts. Part 6. Photography

This is the final article in this series. In previous articles the contributions of doctors in Australia as painters, sculptors, writers on art and supporters of art galleries and artists have been discussed. Photography is very much a fine art form, and several outstanding doctor-photographers are discussed in this article.