Association between vitamin D level at birth and respiratory morbidities in very-low-birth-weight infants / 소아과

PURPOSE: This study aimed to evaluate vitamin D status at birth in very-low-birth-weight infants (VLBWIs: <1,500 g) and to determine the association between vitamin D level and respiratory morbidity. METHODS: A retrospective study was conducted at Soonchunhyang University Bucheon Hospital between November 2013 and November 2017. We collected blood samples and data on respiratory morbidity from 230 VLBWIs on the first day of life. Patients who were transferred to other hospitals (n=19), died before 36 weeks of gestational age (n=18), or whose blood samples were not collected immediately after birth (n=5) were excluded. Finally, 188 patients were enrolled. VLBWIs with different vitamin D levels were compared with respect to demographic features, maternal diseases, respiratory morbidities, and other neonatal diseases. RESULTS: The mean serum vitamin D level, as measured by 25-hydroxyvitamin D (25(OH)D), was 13.4±9.3 ng/mL. The incidence of vitamin D deficiency (<20 ng/mL) was 79.8%, and 44.1% of preterm infants had severe vitamin D deficiency (<10 ng/mL). Logistic analysis shows that a low serum 25(OH)D level (<20 ng/mL) was a risk factor for respiratory distress syndrome (odds ratio [OR], 4.32; P=0.010) and bronchopulmonary dysplasia (OR, 4.11; P=0.035). CONCLUSION: The results showed that 79.8% of preterm infants in this study had vitamin D deficiency at birth. Low vitamin D status was associated with respiratory morbidity, but the exact mechanism was unknown. Additional studies on the association between vitamin D level and neonatal morbidity are required.

Comparison of Clinical Features between Noroviral and Rotaviral Gastroenteritis

OBJECTIVE: Rotavirus and norovirus are the most common pathogens causing acute gastroenteritis in children. As the incidence of noroviral gastroenteritis increases, it is becoming more important to identify the clinical features of noroviral infection. We compared the clinical features of noroviral gastroenteritis and rotaviral gastroenteritis. METHODS: This study included 79 children with noroviral and 151 children with rotaviral gastroenteritis, who were admitted to the Soonchunhyang University Gumi Hospital between January 2013 and December 2014. We reviewed their medical records and compared the clinical features of gastroenteritis between the two groups respectively. RESULTS: In those belonging to the norovirus group, the mean age was 29.65 months, which was younger than that of the rotavirus group, at 34.74 months. Patients suffering from noroviral gastroenteritis experienced more vomiting (5.6 episodes/day) than diarrhea (3.5 episodes/day). Vomiting, diarrhea, and fever were all less severe in those suffering from noroviral gastroenteritis. It is commonly noted that patients with noroviral infection have vomiting and diarrhea without fever (55.0%), while those with rotaviral infection present with vomiting, diarrhea, and fever (44.3%). CONCLUSION: Although noroviral gastroenteritis is less severe than rotaviral gastroenteritis, the incidence of noroviral infection is increasing, and the mean age group infected with this virus is getting younger; thus, noroviral infection must be considered in the differential diagnoses in young patients with gastroenteritis.

Radioimmunoassay for Determination of Serum Macrophage Migration Inhibitory Factor / 대한핵의학회잡지

PURPOSE: There has been a renewal of interest in Macrophage migration inhibitory factor (MIF), especially correlation in pathogenesis of sepsis by many infectious diseases and in regulation of host inflammatory and immune response. We developed immunoradiometric assay (IRMA) to determine serum human MIF concentration. MATERIALS AND METHODS: The IRMA system utilizes solid phase bound monoclonal anti-recombinant human MIF (rhMIF) antibody as a capture antibody, biotinylated polyclonal anti-rhMIF antibody as a detector antibody. We applied with rhMIF that concentration of standard solutions increased from 0 ng/ml to 100 ng/ml. We used 125I-streptavidin (SA) as radiotracer to determination of rhMIF concentration. Streptavidin was labeled with 125I by Chloramine-T method and 125I-SA was purified by ultracentrifugation. 125I-SA stability was evaluated by ITLC analysis at 4 degrees C and room temperatures until 60days. To validate IRMA system for MIF, we experimented intra-assay and inter-assay coefficients of variation, recovery test and dilution test. RESULTS: Radiolabeling yield of 125I-SA was 87% and purified 125I-SA retained above 99% radiochemical purity. 125I-SA showed above 93% stability in 4 degrees C until 60days that it is good for immunoradiometric assay as radiotracer. Plotted standard dose response curve showed that increased concentration of rhMIF linearly correlated (R2=0.99) with bound radioactivity of 125I-SA. The highest intra- and inter-assay coefficients of variation were 5.5% and 7.6%, respectively. The average of recovery of MIF in samples was 102%. In dilution test, linear response curves were obtained (R2=0.97). CONCLUSION: Radioimmunoassay using 125I-SA as radiotracer thought to be useful for the determination of serum MIF concentration, and further, its data will be used to evaluate the correlation between clinical significance and serum MIF concentration in patients with various inflammatory diseases.