• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.716-722
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• 2005

Purpose : A full view of the spectrum of all bacterial diseases in healthy children is essential to the establishment of public health priorities. Accurate information on the relative importance of the various pathogens in terms of the age of the affected patients, the site of infection and the case fatality rate are valuable to the clinician in choosing antimicrobial treatments. Methods : Fifty-nine episodes of bacteremia were analysed. Data were collected at Ilsan Paik Hospital from January 2000 to December 2003. Analysis of each collected episode included isolating pathogen from blood culture, diagnosis, hospital course, isolating pathogens from other tissue sites, and studying results of antimicrobial sensitivity tests. Results : Fifty-nine cases of community-acquired bacteremia were reviewed. The most common pathogen was Staphylococcus aureus(11 cases, 18.6 percent), followed by Salmonella(10 cases, 16.9 percent), E. coli(7 cases, 11.9 percent), Streptococcus pneumoniae(five cases, 8.5 percent), Streptococcus viridans(5 cases 8.5 percent). The most common diagnosis was bacteremia without an indentified focus(61 percent), followed by meningitis(12 percent), bacteremia with enteritis(10.2 percent) and bacteremia with urinary tract infection(8.5 percent). Salmonella was still an important causative agent of bacteremia. The relative importance of Haemophilus influenza and Streptococcus pneumoniae was lower than in other studies. The most common organism responsible for bacteremia without an identified focus was Staphylococcus aureus. The case-fatality was 3.4 percent for all cases of bacteremia. Conclusion : We reviewed the etiology of community-acquired bacteremia. These data may be useful in the establishment of public health priorities and serve as a reference for selection of antibiotics in the empirical therapy of suspected invasive bacterial infection.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.473-481
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• 2002

Purpose : Ascending cholangitis is the most common complication after Kasai operations. The aim of this study is to evaluate the therapeutic efficacy of cefotaxime as an empirical antibiotic on ascending cholangitis after Kasai operations. Methods : Thirty-nine episodes of cholangitis in twenty-nine children who underwent Kasai operations at Seoul National University Children's Hospital from January 1991 to December 2000 were included in this study. Empirical cefotaxime treatments were divided into three groups : cefotaxime and amikacin treatment group(CA group), cefotaxime and gentamicin treatment group(CG group) and cefotaxime treatment group(C group). A diagnosis of cholangitis was made on the basis of unexplained fever(>$38^{\circ}C$) and either development of acholic stool or elevation of serum total bilirubin (>1.5 mg/dL). Therapeutic efficacy was judged by elimination of fever up to 72 hours, 120 hours, and 168 hours after antibiotic treatment. Results : There were therapeutic responses in 51%(20/39) up to 72 hours after antibiotic treatment : 54%(13/24) in CA group, 43%(3/7) in CG group and 50%(4/8) in C group. There were therapeutic responses in 69%(27/39) up to 120 hours, in 79%(31/39) up to 168 hours and in 82%(32/39) up to 2 weeks. There were no differences in therapeutic efficacy among the three regimens. In 12 of 39 episodes, the etiologic pathogens including Escherichia coli and enterococcus were cultured from the blood. Conclusion : Cefotaxime can be tried as an initial antibiotic in Korean children with ascending cholangitis after Kasai operation prior to the identification of microorganism on culture. However, further evaluation of pathogen and its resistant strain to cefotaxime should be done.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.462-474
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• 1994

Background : In acute lung injury, activated neutrophils play an important role in tissue damage. For neutrophils to participate in lung inflammation, chemotactic factors released from mononuclear phagocytes are needed to bring these cells to the local site of inflammation, with interleukin-8 (IL-8) being one of the most specific and important chemotactic factors for neutrophils. IL-8 also induces the expression of adhesion molecules and activates neutrophils to release various inflammatory mediators. Lipopolysaccharide(LPS) is one of the most important causes of adult respiratory distress syndrome and can cause release of many inflammatory cytokines including IL-8 leading to acute lung injury. But little is known about the regulatory mechanism of LPS-induced IL-8 gene expression in mononuclear phagocytes. Method : Human alveolar macrophages(HAM) and peripleral blood monocytes(PBMC) were isolated from healthy volunteers. Time and dose relationship of LPS-induced IL-8 mRNA expression was observed by Northern blot analysis. To evaluate the regulatory mechanism of LPS-induced IL-8 gene expression, pretreatment of actinomycin D(AD, $5{\mu}g/ml$) and cycloheximide(CHX, $5{\mu}g/ml$) was done and Northern blot analysis for IL-8 mRNA and ELISA for immunoreactive IL-8 protein in culture supernatant were performed. Results : 1) In HAM, dose and time dependent LPS-induced IL-8 mRNA expression was observed with peak mRNA level at 8 hours post-stimulation. 2) In PBMC, dose and time dependent LPS-induced IL-8 mRNA expression was also observed with peak mRNA level at 4 hours post-stimulation. 3) AD decreased expression of LPS-induced IL-8 gene expression at both mRNAand protein levels in both types of cells. 4) CHX decreased expression of LPS-induced IL-8 gene expression at protein level in both cell types but in HAM, superinduction of IL-8 mRNA was observed while decreased expression of IL-8 mRNA was observed in PBMC. Conclusion : Time and dose dependent LPS-induced IL-8 gene expression was observed in mononuclear phagocytes which is at least partly regulated pretranslationally. LPS-induced IL-8 mRNA expression in HAM needs no de novo protein synthesis and may be under the control of a labile repressor protein while de novo protein synthesis may be needed in PBMC.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.967-972
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• 2002

Purpose : A retrospective study was undertaken to evaluate the usefulness of low risk criteria for identifying febrile infants younger than three months unlikely to have serious bacterial infection. Methods : We conducted a retrospective study of 527 infants younger than three month with a axillary temperature ${\geq}37.4^{\circ}C$. If they met the following all four criteria, appear well, WBC $5,000-20,000/mm^3$, urine stick WBC(-) and nitrite(-), CSF WBC < $10/mm^3$, they were considered at low risk for serious bacterial infection(SBI). SBI was defined as a positive culture of urine, blood, or cerebrospinal fluid. The sensitivity, specificity, negative predictive value and positive predictive value of the low risk criteria were calculated. Results : Of 527 febrile infants, 110(21.0%) had serious bacterial infections. The 2.7% who met the low risk criteria had SBI and negative predictive value was 97.3%. SBI was diagnosed in 103 infants(38.6%) who didn't meet the low risk criteria including urinary tract infection(78.6%), most commonly, bacteremia(16.5%), bacterial meningitis(8.7%), Salmonella gastroenteritis(1%), osteomyelitis( 1%), septic arthritis of hip joint(1%). There were no differences in the sensitivity and negative predictive value according to the monthly-age-group. Conclusion : This low risk criteria to identify infants unlikely to have SBI early is available, however low risk infants must be carefully observed.

• Pediatric Infection and Vaccine
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• v.10 no.2
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• pp.215-222
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• 2003

Purpose : This study was to analyze serious bacterial infections in infants younger than three months of age and to review the direction of treatments for these patients. Methods : 378 febrile infants with a rectal temperature ${\geq}38.0^{\circ}C$ visited from Jan. 2001 through Dec. 2002 were retrospectively studied. Infants with the following criteria belonged to the low risk group. WBC $5,000{\sim}15,000/mm^3$, WBC negative in urine stick test and negative for nitirite test, CSF WBC < $10/mm^3$ and negative in CSF gram stain, negative chest X-ray, stool WBC <5/HFP(high power field), and focal infection. If any of the above criteria were not met, they belonged to the high risk group. SBI was defined as a positive culture of urine, blood or CSF. SI was defined as aseptic meningitis or pneumonia including above laboratory tests of SBI. SBI patients were separately compared with two groups, high risk and low risk. Results : Of the 378 infants that were tested 216(57.1%) were in the high risk group and 162(42.9%) in the low risk group. Among 105 SBI(27.8%) and 172 SI(45.5%), there were 98 urinary tract infection(25.2%), 10 bacteremia(2.6%), 2 bacterial meningitis(0.6%), and 77 aseptic meningitis(22.8%). There were 76 SBI(35.2%) from the high risk group and 29 SBI(17.9%) from the low risk group identified. The results of the sensitivity(72.4%), the specificity(48.7%), the negative predictive value(82.1%) and the positive predictive value (35.2%) were calculated. Conclusion : Even though the probability of SBI in the low risk group is insignificant, it should still be considered in febrile infants younger than 3 months of age. I believe the CSF study is necessary because of the moderate high incidence of abnormal finding in our study.

• Tuberculosis and Respiratory Diseases
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• v.66 no.3
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• pp.178-185
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• 2009

Background: Epigallocatechin-3-gallate (EGCG) is the major catechin in green tea, and has shown antiproliferative, antiangiogenic, antimetastatic and cell cycle pertubation activity in various tumor models. Hypoxia can be induced because angiogenesis is insufficient for highly proliferating cancer. Hypoxia-inducible factor-1$\alpha$ (HIF-1$\alpha$) and its downstream target, vascular endothelial growth factor (VEGF), are important for angiogenesis, tumor growth and metastasis. The aim of this study was to determine how hypoxia could cause changes in the cellular phenomena and microenvironment in a non-small cell culture system and to examine the effects of EGCG on a HIF-1$\alpha$ and VEGF in A549 cell line. Methods: A549 cells, a non-small cell lung cancer cell line, were cultured with DMEM and 10% fetal bovine serum. A decrease in oxygen tension was induced using a hypoxia microchamber and a $CO_2-N_2$ gas mixture. Gas analysis and a MTT assay were performed. The A549 cells were treated with EGCG (0, 12.5, 25, 50 ${\mu}mol/L$), and then examined by real-time-PCR analysis of HIF-1$\alpha$, VEGF, and $\beta$-actin mRNA. Results: Hypoxia reduced the proliferation of A549 cells from normoxic conditions. EGCG inhibited HIF-1$\alpha$ transcription in A549 cells in a dose-dependent manner. Compared to HIF-1$\alpha$, VEGF was not inhibited by EGCG. Conclusion: HIF-1$\alpha$ can be inhibited by EGCG. This suggests that targeting HIF-1$\alpha$ with a EGCG treatment may have therapeutic potential in non-small cell lung cancers.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.173-177
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• 2010

Purpose : Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen that causes nosocomial infection in NICU. It contributes to neonatal morbidity and mortality with variable complications. This study was conducted to identify the risk factors associated with complicated MRSA bacteremia in neonates. Methods : We reviewed the medical records of 44 neonates with positive blood culture for MRSA who were admitted to the NICU of Pusan National University Hospital from January 2002 to December 2007. We compared various factors of the complicated and uncomplicated MRSA bacteremia cases. Results : Of the 44 neonates, 31 were male and 13, female. The mean gestational age and birth weight were $33.2{\pm}4.9$ weeks and $1,859.9{\pm}962.2g$, respectively. Twenty-one of infants were treated with a mechanical ventilator during a mean of $8.8{\pm}13.8$ days. There were 13 cases of complicated and 31 cases of uncomplicated MRSA bacteremia. Between the 2 groups, we compared the following variables: gestational age, birth weight, ventilator use, umbilical catheter use and central catheter insertion, $O_2$ inhalation, first oral feeding day after birth, underlying disease, transfusion, and initial vancomycin use. The underlying disease and transfusion were the risk factors related to complicated MRSA bacteremia. Conclusion : Complicated MRSA bacteremia is related to underlying disease and transfusion. Since this was a retrospective study with a small sample size, it offered limited capacity to compare complicated and uncomplicated MRSA bacteremia. A prospective study with a larger population is needed to determine the exact characteristics of MRSA bacteremia in NICU.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.13 no.1
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• pp.30-35
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• 2010

Purpose: Infectious ileocecitis is an infection confined to the ileocecal area and one of the most common causes of pediatric abdominal pain. This study was performed to demonstrate the clinical features of infectious ileocecitis in children. Methods: The medical records and radiologic findings of 37 patients with ileocecitis diagnosed by ultrasonography and/or computed tomography, who were admitted to Pusan National University Hospital from January 2004 and July 2008, were reviewed retrospectively. Viral gastroenteritis and secondary ileocecitis were excluded. Results: The mean age of the patients was 4.8${\pm}$3.4 years. One-half of the patients were preschool children. The chief complaint was abdominal pain (75.7%), diarrhea (10.8%), and vomiting (8.1%). Accompanying symptoms were fever (56.8%), vomiting (21.6%), and diarrhea (16.2%). The mean duration of abdominal pain, fever, diarrhea, and vomiting was 3.8${\pm}$2.1, 3.0${\pm}$1.9, 3.4${\pm}$1.9, and 2.4${\pm}$2.3 days, respectively. The frequency of diarrhea and vomiting was 5.8${\pm}$2.2 and 4.0${\pm}$2.8 per day, respectively. Diagnosis was made by abdominal ultrasonography in 22 patients (59.5%), abdominal CT in 2 patients (5.4%), and both modalities in 13 patients (35.1%). Besides the radiologic finding of thickening of the bowel wall, mesenteric lymphadenitis (59.5%), ascites (5.4%), and both mesenteric lymphadenitis and ascites (16.2%) were revealed. The mean duration of illness was 7.5${\pm}$5.0 days. There were no specific laboratory findings, and culture studies with stool or blood were negative. All of the patients recovered completely without specific treatment. Conclusion: Infectious ileocecitis has acute appendicitis-mimicking symptoms, but is self-limited within a few days, thus unnecessary treatment and work-up is avoided. However, distinguishing infectious ileocecitis from appendicitis, inflammatory bowel disease, and mesenteric lymphadenitis is important.

• Pediatric Infection and Vaccine
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• v.11 no.1
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• pp.112-120
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• 2004

Purpose : Methicillin Resistant-Coagulase Negative Staphylococcus(MR-CNS) infection has become an increasingly important cause of morbidity in NICU infants. We investigated the c linical characteristics of MR-CNS sepsis. Methods : This study included 40 neonates with MR-CNS sepsis who were admitted to the neonatal intensive care unit of Kangnam Sacred Heart Hospital, Hallym University from January 1998 to July 2002. MR-CNS sepsis was defined as MR-CNS recovery from blood with clinical symptoms and signs of infection. Retrospective analyses of the medical records of patients with MR-CNS sepsis were performed. The analyses included demographic findings, clinical features, hospital courses, risk factors for infection including invasive procedures and mortality. Results : From 1998 to 2002, there were 40 cases of MR-CNS sepsis, comprising 17.7% of late onset infections in NICU of Kangnam Sacred Heart Hospital. The male/female ratio was 1.5 : 1. The mean gestational age of infected babies was $32.4{\pm}4.3$ weeks at birth. And the first positive MR-CNS culture was done in the day $10.6{\pm}9.3$ after birth. Clinical symptoms such as fever, dyspnea, cyanosis, grunting, bradycardia, vomiting and diarrhea were frequent in MR-CNS. Mechanical ventilation was applied in 12 cases and catheter was inserted in 11 cases. The mortality(12.5%) directly attributable to MR-CNS sepsis was similar to other late onset infections. Conclusion : MR-CNS is a pathogen responsible for most late onset and nosocomial infections. And it will be life-threatening in high-risk neonate. Awareness of increasing infections due to MR-CNS in NICU is important not only for infection control but also placing a great limit in use of antibiotics and invasive procedures, especially in premature infants.

• Journal of Preventive Medicine and Public Health
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• v.27 no.1 s.45
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• pp.11-24
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• 1994

The studies reported here were undertaken to investigate the effects of mercury chloride on immune system of Balb/c mouse employing a flexible tier of in vitro and in vivo assays. Mercury chloride inhibited the proliferative responses of spleen cells to lipopolysaccharide, pokeweed mitogen, and phytohemagglutinin as a dose-dependent manner. This inhibitory effect was observed not only when $HgCl_2$ was added 2nd or 3rd day of 3 days culture period but also when spleen cells was pretreated with $HgCl_2$ for 2 hours. Mercury chloride, however, potentiated the production of IgM and IgG from spleen cells. During the $HgCl_2$ administration by drinking for 3 weeks, the weight gain of mice was significantly blunted than that o control group mice, while no overt signs related to mercury toxicity were noted in any mice of experimental group. There was no change in thymus and spleen weights, and in histological findings of kidney, bone marrow of femur, thymus, spleen, and popliteal lymph node after 3 weeks of mercury exposure. However, $HgCl_2$ induced a significant increase of total serum IgM, IgG including $IgG_1,\;IgG_{2a}\;and\;IgG_{2b}$, and IgE in Balb/c mice. Treatment in vivo with anti-IL-4 monoclonal antibody significantly abrogated the $HgCl_2$-induced increase in total serum IgG1 and IgE. Whereas $HgCl_2$ potentiated total serum IgM and IgG, there was no difference in total serum hemagglutinin to SRBC (Sheep Red Blood Cell) between experimental and control group mice when these mice were immunized with SRBC. All these findings observed in Balb/c mice suggest that mercury perturbates well-orchestrated regulation of immune responses before developing histopathological changes in lymphoid tissues.