Chronic Administration of Monosodium Glutamate under Chronic Variable Stress Impaired Hypothalamic-Pituitary-Adrenal Axis Function in Rats

The hypothalamic-pituitary-adrenal (HPA) axis is the primary endocrine system to respond to stress. The HPA axis may be affected by increased level of corticotrophin-releasing factors under chronic stress and by chronic administration of monosodium glutamate (MSG). The purpose of this study was to investigate whether chronic MSG administration aggravates chronic variable stress (CVS)-induced behavioral and hormonal changes. Twenty-four adult male Sprague-Dawley rats, weighing 200~220 g, were divided into 4 groups as follows: water administration (CON), MSG (3 g/kg) administration (MSG), CVS, and CVS with MSG (3 g/kg) administration (CVS+MSG). In addition, for the purpose of comparing the effect on plasma corticosterone levels between chronic stress and daily care or acute stress, 2 groups were added at the end of the experiment; the 2 new groups were as follows: naive mice (n=7) and mice exposed to restraint stress for 2 h just before decapitation (A-Str, n=7). In an open field test performed after the experiment, the CVS+MSG group significant decrease in activity. The increase in relative adrenal weights in the CVS and CVS+MSG group was significantly greater than those in the CON and/or MSG groups. In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS+MSG group as compared to all other groups, except the naive group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.

A Case of Encephalitis with a Reversible Splenial Lesion on a Diffusion Weighted MRI Image

Reversible splenial lesion may occur in encephalitis rarely. A 21-year-old man was admitted with viral encephalitis. High signal on the diffusion MRI and low signal on the ADC map image was showed in the splenium. As the patient improved, the lesion suggestive of cytotoxic edema was completely resolved one month later. Although the concrete pathophysiology of focal cytotoxic edema in encephalitis is unclear yet, MRI is valuable diagnostic tool to manage encephalitis in the view of prognosis.

A Three-year Follow-up of D.f- and D.p-Specific Conventional Immunotherapy in Asthmatic Children / 소아알레르기및호흡기학회지

PURPOSE: Immunotherapy (IT) with Dermatophagoides farinae (D.f) or Dermatophagoides pteronyssinus (D.p) has proven to be clinically effective treatment for patients with asthma, but the mechanism and prognostic index of IT are not completely understood. We evaluated the long-term effect of conventional IT with D.f or D.p, and also investigated whether IT could prevent new sensitizations to other new allergens. METHODS: The patient group included 23 asthmatic patients with D.f- and D.p-sensitivities who visited Asan Medical Center and were treated with conventional IT (Allergopharma, Germany). The control group contained 27 asthmatic patients with D.f- and D.p-sensitivities who were not treated with IT. We compared skin test reactivity, total IgE, specific IgE, total eosinophil counts, eosinophils fraction and bronchial hyperreactivity before and three years after IT. RESULTS: The skin test reactivity to D.p and total eosinophil counts were decreased significantly three years after IT. But total IgE, D.f- and D.p-specific IgE, and eosinophils fraction were not changed three years after IT. The bronchial hyperreactivity by methacholine was decreased in both groups after three years. In addition, development of sensitization to new allergens happened in 13.0 percent of the IT group and 22.2 percent of the control group, but did not reach statistical significance. CONCLUSION: The conventional IT with D.f and D.p could change the allergic responsiveness of the target organs, such as skin, but it could not prevent the development of new sensitizations in asthmatic children.