Repetition of Apoptosis Induced by Amiloride Derivatives in Human Umbilical Vein Endothelial Cells

PURPOSE: Human umbilical vein endothelial cells(HUVECs) play an important role in regulating blood flow by releasing vasoactive substances. It has been reported that endothelial impairment and dysfunction might be a primary cause of placental vascular disease, which is manifested clinically as preeclampsia in mother and intrauterine growth restriction in fetus. Furthermore, the frequency of apoptotic changes is increased in umbilical and placental tissues from growth-restricted pregnancies. However, the various mechanisms of umbilical endothelial cell apoptosis have not been broadly proposed. We investigate the effects of amiloride derivatives on apoptotic death of HUVECs and identify their ionic mechanism. METHODS: HUVECs were purchased from Clonetics, and cultured on endothelial cell growth medium. MTT assay and flow cytometry were used for assessing cytotoxic effect and confirming the apoptosis. Changes in intracellular ion concentrations were measured with specific fluorescent dyes and fluorescence imaging analysis system. RESULTS: Amiloride derivatives elicited cytotoxic effects on HUVECs with dose-dependent manners and the rank order of potency is HMA(IC50 11.2 micrometer), MIA>EIPA>>amiloride. HMA-induced cytotoxicity is dependent on extra- and intracellular pH, that is, increase extra- and intracellular pH augmented the cytotoxic effects of HMA. HMA dose-dependently reduced intracellular major ions, such as K+ and Cl-. Interestingly, the depletion of intracellular ions induced by HMA was also significantly enhanced at alkaline extracellular pH. CONCLUSION: Amiloride derivatives induce apoptosis of HUVECs with dose and pH dependent manners. They reduce intracellular K+ and Cl- concentration, which is also extracellular pH dependent.

A Study of Serum Total and House Dust Mite-Specific IgE, and ECP Levels in Healthy Korean Children Under 7 Years of Age / 소아알레르기및호흡기학회지

PURPUSE: Serum IgE have been shown to be related to allergic disease and used for an initial diagnosis of allergic diseases. House dust mite such as Dermatophagoides pteronyssinus(Dp) and D. farinae(Df) is very important for inhalant allergens, which may be a cause and/or triggering factor of atopic diseases. On the other hand, eosinophil cationic protein (ECP) causes epithelial damages of the airway, and bronchial hyperresponsiveness has been used as a useful indication of allergic inflammation. To date, there are few studies on the longitudinal patterns of total and inhalant allergen-specific IgE, and ECP in normal children in Korea. The present study was performed to determine the reference levels of serum total and Dp- and Df-specific IgE and ECP in healthy children under 7 years of age by the groups of different age and gender. METHODS: Total, and Dp- and Df-specific IgE and ECP concentrations were measured by fluoroimmunoassay(UniCAP, Pharmacia-UpJohn, Sweden) in serum from 449 healthy children under 7 years of age by using a population-based cohort followed from 1996 through 1997. All subjects were enrolled from eight large health organizations in geographically defined area such as Seoul and four local cities. RESULTS: Serum total IgE concentration showed steady increase with age from birth to 4 years, and a plateau. In contrast, Dp- and Df-IgE levels showed apparently continuous increments after 4 years of age. ECP showed variable increase until 4 years of age and slow decrease afterwards. There were no statistically significant differences in those results by gender and/or the living area, but much higher increments of Dp- and Df-IgE of boys from 3 years of age through 6 years were found. CONCLUSION: We found feasible results of total, Dp- and Df-specific IgE, and ECP in serum from healthy children under seven years of age, which may be useful for a reference.

Two Cases of Seckel Syndrome / 대한소아내분비학회지

Seckel syndrome is a rare, autosomal recessive disorder of severe growth retardation and distinct craniofacial, orodental, and skeletal anomalies. We report hereby the first two Korean cases of typical Seckel syndrome who had characteristic symptoms of intrauterine growth retardation, small head, large eyes, sharp facial features (beaked nose, dysplastic ears and narrow face) with underdeveloped chin, dwarfism, severe mental retardation, and other malformation. We report two cases of Seckel syndrome with a brief review of related literatures.