Genetic Diversity of the Pear Scab Fungus Venturia nashicola in Korea

Scab disease caused by Venturia nashicola is of agroeconomic importance in cultivation of Asian pear. However, little is known about the degree of genetic diversity in the populations of this pathogen. In this study, we collected 55 isolates from pear scab lesions in 13 major cultivation areas in Korea and examined the diversity using sequences of internal transcribed spacer (ITS) region, β-tubulin (TUB2), and translation elongation factor-1α (TEF-1α) genes as molecular markers. Despite a low level of overall sequence variation, we found three distinctive subgroups from phylogenetic analysis of combined ITS, TUB2, and TEF-1α sequences. Among the three subgroups, subgroup 1 (60% of isolates collected) was predominant compared to subgroup 2 (23.6%) or subgroup 3 (16.4%) and was distributed throughout Korea. To understand the genetic diversity among the subgroups, RAPD analysis was performed. The isolates yielded highly diverse amplicon patterns and none of the defined subgroups within the dendrogram were supported by bootstrap values greater than 30%. Moreover, there is no significant correlation between the geographical distribution and the subgroups defined by molecular phylogeny. Our data suggest a low level of genetic diversification among the populations of V. nashicola in Korea.

Early Prediction of Bronchopulmonary Dysplasia in Premature Infants less than 34 Weeks of Gestational Age

PURPOSE: A variety of postnatal therapies have been and will be evaluated for prevention or treatment of neonatal chronic lung disease. A simple method for early selection of the highest risk infants would optimize intervention trials. The purpose of this study was to develop an scoring system to predict the bronchopulmonary dysplasia (BPD) in preterm infants. METHODS: A retrospective analysis of clinical, respiratory and radiographic variables of a 2.5-year experience was done with data of preterm infants less than 34 weeks of gestation admitted to Ewha Womans University Hospital from January 1998 to July 2000. RESULTS: Multiple regression analysis identified four independent predictors of BPD; longer duration of assisted ventilation, lower Apgar score at 5 minute, higher PaCO2 at birth, presence of patent ductus arteriosus after 7 days. A clinical predictive scoring system (CPSS) was developed with these four predictors. CONCLUSION: We have come up with a CPSS for early identification of preterm infants with high risk of BPD. A prospective study is on going to evaluate the predictivity of this scoring system.

Early Prediction of Bronchopulmonary Dysplasia in Premature Infants less than 34 Weeks of Gestational Age

PURPOSE: A variety of postnatal therapies have been and will be evaluated for prevention or treatment of neonatal chronic lung disease. A simple method for early selection of the highest risk infants would optimize intervention trials. The purpose of this study was to develop an scoring system to predict the bronchopulmonary dysplasia (BPD) in preterm infants. METHODS: A retrospective analysis of clinical, respiratory and radiographic variables of a 2.5-year experience was done with data of preterm infants less than 34 weeks of gestation admitted to Ewha Womans University Hospital from January 1998 to July 2000. RESULTS: Multiple regression analysis identified four independent predictors of BPD; longer duration of assisted ventilation, lower Apgar score at 5 minute, higher PaCO2 at birth, presence of patent ductus arteriosus after 7 days. A clinical predictive scoring system (CPSS) was developed with these four predictors. CONCLUSION: We have come up with a CPSS for early identification of preterm infants with high risk of BPD. A prospective study is on going to evaluate the predictivity of this scoring system.

Measurements of Cerebral Blood Flow Velocity Change Using Color Doppler in Asphyxiated Infants

PURPOSE: Alterations in cerebral blood flow are very important for understanding the neurological consequences of all varieties of perinatal asphyxia. The purpose of this study is to measure the change of cerebral blood flow velocity and resistance index (RI) of middle cerebral artery (MCA) according to the time in asphyxiated infants. METHODS: We studied 7 asphyxiated term infant and 27 normal term infant who were born at Ewha Womans University Hospital from January 1996 to August 1997. Using the Doppler ultrasound, we examined blood flow velocity and RI of the middle cerebral artery. RESULTS: Clinical characteristics were not significantly different in both groups. Peak systolic flow velocity (PSFV) in asphyxiated infants significantly decreased than control (P<0.05). End diastolic flow velocity (EDFV) was not significantly different in both groups. RI in asphyxiated infants significantly decreased for 24 hours (P<0.05). No control infant ever had a RI value of 0.55 or below, three (42.9%) asphyxiated infants had a RI value of 0.55 or below. The changes of the systemic BP and heart rate were not significant. Two (28.6%) asphyxiated infants were proven periventricular white matter ischemia by ultrasonography. CONCLUSION: It is therefore very important to monitor RI in asphyxiated infants even if the degree of asphyxia is mild.

Measurements of Cerebral Blood Flow Velocity Change Using Color Doppler in Asphyxiated Infants

PURPOSE: Alterations in cerebral blood flow are very important for understanding the neurological consequences of all varieties of perinatal asphyxia. The purpose of this study is to measure the change of cerebral blood flow velocity and resistance index (RI) of middle cerebral artery (MCA) according to the time in asphyxiated infants. METHODS: We studied 7 asphyxiated term infant and 27 normal term infant who were born at Ewha Womans University Hospital from January 1996 to August 1997. Using the Doppler ultrasound, we examined blood flow velocity and RI of the middle cerebral artery. RESULTS: Clinical characteristics were not significantly different in both groups. Peak systolic flow velocity (PSFV) in asphyxiated infants significantly decreased than control (P<0.05). End diastolic flow velocity (EDFV) was not significantly different in both groups. RI in asphyxiated infants significantly decreased for 24 hours (P<0.05). No control infant ever had a RI value of 0.55 or below, three (42.9%) asphyxiated infants had a RI value of 0.55 or below. The changes of the systemic BP and heart rate were not significant. Two (28.6%) asphyxiated infants were proven periventricular white matter ischemia by ultrasonography. CONCLUSION: It is therefore very important to monitor RI in asphyxiated infants even if the degree of asphyxia is mild.

Serogroup and Antimicrobial Resistance of Streptococcus pneumoniae Isolated from Oropharynx in Children Attending Day Care Center

PURPOSE: Penicillin- and multidrug-resistant S. pneumoniae poses a serious threat to clinicians because the rate of resistance of S. pneumoniae to penicillin in Korea has surged up to the world's highest level. This study was performed to assess the carriage rate, serogroups and antimicrobial susceptibility of S. pneumoniae isolated from oropharynx in children. METHODS: From March to July 1998, 209 children under 5 years of age were recruited from five day care centers. The carriage rate for pneumococci was obtained. Antimicrobial susceptibilities were determined with the E-test and agar dilution methods. Serogrouping was performed on 48 of the pneumococcal isolates by the Quellung reaction. RESULTS: The carriage rate of S. pneumoniae was 30.1%. Antimicrobial susceptibility profiles were available for 59 of the isolates. Sixty-six percent of isolates were not susceptible to penicillin, and multidrug-resistance was observed in 76.3% of the isolates. A high proportion of the penicillin-resistant strains showed associated resistance to trimethoprim-sulfamethoxazole, tetracycline, erythromycin, and oxacillin. The most prevalent oropharyngeal serogroups were 19, 6, 3, 23, and 29. Resistance of the pneumococcal isolates to penicillin was different according to the serogroups. All of the strains of serogroup 19, 23, and 29 was resistant to penicillin but 87.5% of serogroup 3 strains were susceptible to penicillin. CONCLUSION: The resistance rate of S. pneumoniae isolated from oropharynx in children was very high to penicillin and other antimicrobial agents. For the reduction of the drug-resistant rate of S. pneumoniae, clinicians should be required to be more judicious in their use of antimicrobial agents.

Effects of Thioredoxin on Apoptosis-Inducing Neuronal Cell Injury

PURPOSE: Thioredoxin is an endogenous antioxidant. It regulates the activities of transcriptional factors such as NF-kB(nuclear factor kappa B)and AP-1(activator protein-1) and it increases the synthesis of cytokines, preventing cellular proliferation and apoptosis. The aim of this study was to clarify the role of thioredoxin on apoptosis-inducing neuronal cell injury. We investigated the protective effects of thioredoxin against apoptosis-inducing neuronal cell injury through intracellular mechanism by 6-hydroxydopamine and serum deprivation. METHODS: PC 12 cells were cultured in RPMI 1640 media containing 10% fetal calf serum and subcultured in 96-well plates. Each well contained 30,000 cells. Cells were treated with hydrogen peroxide, diamide or 6-hydroxydopamine 30 minutes after thioredoxin treatment and then incubated for 24 hours. Cytotoxicity and cellular viability were assessed by measuring lactate dehydrogenase(LDH) release and MTT reduction. RESULTS: Thioredoxin increased cytotoxicity of PC cells treated with 6-hydroxydopamine by increasing LDH release and decreasing MTT reduction. In the serum deprivation condition, thioredoxin increased cytotoxicity of PC cells by increasing LDH release. CONCLUSION: Thioredoxin potentiates oxidative injury through intracellular mechanisms by 6-hydroxydopamine and serum deprivation instead of protecting. The cytotoxicity of thioredoxin may be mediated by decreasing the activity of NF-kB, which has been reported recently to protect against cellular apoptosis. Evidence suppors that the cytotoxic effect was not increased in the presence of serum in this study. Therefore, we found that the antioxidant effects of thioredoxin depended on mechanisms of injuries.

Effects of Thioredoxin on Oxidative Neuronal Cell Injury

PURPOSE: Thioredoxin is an endogenous antioxidant which directly scavenges reactive oxygen species(ROS) and regenerates oxidatively damaged protein by reducing potential at the redox active disulfide(-Cys-Gly-Pro-Cys-) site. Under oxidative stress, thiredoxin plays a protective and adaptative role by inducing expressions. The aim of this study was to clarify the role of thioredoxin on oxidative neuronal cell injury. We investigated the protective effects of E. coli thioredoxin, also acting as a substrate for mammalian thioredoxin reductase, against oxidative neuronal cell injury under oxidative stresses such as hydrogen peroxide and diamide. METHODS: PC 12 cells were cultured in RPMI 1640 media containing 10% fetal calf serum and subcultured in 96-well plates. Each well contained 30,000 cells. Cells were treated with hydrogen peroxide or diamide 30 minutes after thioredoxin treatment and then incubated for 24 hours. Cytotoxicity and cellular viability were assessed by measuring of lactate dehydrogenase(LDH) release and MTT reduction. RESULTS: Thioredoxin not only decreased the cytotoxicity of PC 12 cell treated with hydrogen peroxide by decreasing LDH release and preventing the decrease of MTT reduction but also thioredoxin showed greater protective effects when simultaneously treated with hydrogen peroxide. Also, thioredoxin decreased cytotoxicity by decreasing LDH release from PC 12 cells damaged by diamide. Thioredoxin did not prevent the decrease of MTT reduction on PC 12 cells damaged by diamide. CONCLUSION: Thioredoxin protected PC 12 cells under oxidative stresses by directly scavenging and inhibiting oxidants such as hydrogen peroxide and diamide.

Fcr Receptor and Mac-1 Expression and Functional Differentiation of HL-60 Cells by All-trans Retinoic Acid

PURPOSE: During differentiation of HL-60 cells by all-trans retinoic acid(ATRA), we analyzed the expression of Fcr receptors and Mac-1 by molecules of equivalent soluble fluorochromes(MESF) and functional studies. METHODS: HL-60 cells were induced to differentiate by adding 1micrometer ATRA. On the 4th and 7th day after stimulation as well as before stimulation, the cells were analyzed for phenotypic and functional differentiation. Phenotypic analysis was performed by flow cytometry after staining the cells with PE-conjugated anti-human CD64(FcrRI), CD32(FcrRII), CD16(FcrRIII), CD11b, CD18. The measured fluorescent intensity was transformed into MESF. Phagocytic activity was measured by flow cytometry after incubation of the cells with fluorochrome-conjugated beads. Respiratory burst was measured by chemiluminescence assay. ADCC was measured by hemoglobin release assay. Opsonophagocytic activity was measured by fungicidal assay. Correlation between MESF of FcrR and Mac-1 and function of HL-60 was measured. RESULTS: Percent positive cells and MESF of CD11b and FcrRI increased on the 4th day and decreased on the 7th day. Percent positive cells of CD18 was 99% regardless of differentiation. But MESF of CD18 was increased on the 4th day and decreased on the 7th day. Percent positive cells of FcrRII were above 90% regardless of differentiation. MESF of FcrRII showed no significant change. FcrRIII expression was not induced. Phagocytic activity of HL-60 cells was increased twofold. Chemiluminescence of HL-60 cells was increased up to 60-fold on the 7th day. ADCC of HL-60 cells was incerased up to 2.5-fold on the 7th day. Opsonophagocytic activity increased twice on the 4th day. ADCC and opsonophagocytic activity correlates with the expression of CD11b/CD18 and FcrRII. CONCLUSION: Differentiation of HL-60 cells with ATRA induces several functional maturations until 7 days with expression of FcrR and Mac-1.

Inhibitory Effects of Dexamethasone on Production IL-1alpha and TNF-alpha in Peripheral Blood Mononuclear Cells

PURPOSE: IL-1alpha and TNF-alpha have a seminal role in the intial events of inflammation. An area of intense interest is the assessment of new therapeutic modalities that regulate inflammatory response in acute bacterial infection. We conducted this study to compare the inhibitory effects of dexamethasone on the secretion of proinflammatory cytokines, such as IL-lalpha and TNF-alpha from cord blood mononuclear cells(MC) to those of adult blood MC during stimulation with S. aureus TSST-1 and E. coli LPS. METHODS: MC were isolated by differential centrifugation on Ficoll-Hypaque gradients. Each MC were incubated with TSST-1(2ug/ml) or LPS(0.2ug/ml), with various concentrations of dexamethasone for 72hr. And the other MC were incubated with TSST-1 or LPS, using the same concentration of dexamethasone, which was added 4hr before or simultaneously or 4hr, 24hr, 48hr after the stimulation. Concentration of IL-1alpha and TNF-alpha was measured by ELISA kit. RESULTS: Dexamethasone showed significant inhibitory effects on secretion of IL-1alpha and TNF-alpha. In comparison with both cytokines, secretion of IL-1alpha was suppressed more severely than TNF-alpha. In comparison with each stimulators, inhibition of TSST-1 induced cytokines production was greater than LPS. There was no difference between adult and cord blood MC. When dexamethasone was added to MC 4hr before the stimulation, it had the best inhibitory effects on the production of proinflammatory cytokines. CONCLUSION: Proinflammatory cytokine production in cord and adult blood MC were inhibited by dexamethasone in a dose-dependent manner. Early treatment of dexamethasone is more effective and can be used for modulating or suppressing excessive proinflammatory cytokine production in acute bacterial infection.

Functional Differentiation of HL-60 Cells by Dimethylsulfoxide and Phorbol 12-myristate 13-acetate

PURPOSE: During hematopoietic differentiation of HL-60 cells by DMSO and PMA, we demonstrated functional changes of HL-60 cells-phagocytic activity, respiratory burst, antibody-dependent cell-mediated cytotoxicity(ADCC) and opsonophagocytic activity. METHODS: HL-60 cells(ATCC CCL-240), cultured in RPMI 1640 and supplemented with 10% FBS, were induced to differentiate by adding 1.0% DMSO or 16nM PMA. On the 4th and 7th day after stimulation as well as before stimulation, the cells were analyzed for functional differentiation. Phagocytic activity was measured by flow cytometry after incubation of the cells with fluorochrome-conjugated beads. Respiratory burst was measured by chemiluminescence assay. ADCC was measured by hemoglobin release assay. Opsonophagocytic activity was measured by fungicidal assay using Candida albicans. RESULTS: Phagocytic activity of HL-60 cells was not increased by differentiation with DMSO. But PMA induced increase of phagocytic activity on 7th day. Respiratory burst studied by chemiluminescence was increased up to 4-fold on 7th day by DMSO. PMA induced increase upto 3-fold on 4th day. ADCC was increased upto 3-fold on 4th day by DMSO, but PMA induced little increase in ADCC. Opsonophagocytic activity was increased upto 3-fold on 4th day by DMSO or PMA. On differentiation with DMSO, respiratory burst correlates with FcgammaRI and FcgammaRII. ADCC and opsonophagocytic activity correlate with CD11b/CD18. On differentiation with PMA, phagocytic activity correlates with FcgammaRII. Respiratory burst correlates with CD11b. ADCC and opsonophagocytic activity of HL-60 cells correlate with CD18. CONCLUSION: Treatment of HL-60 cells with DMSO or PMA induces functional maturation differently. Phagocytic activity, respiratory burst, ADCC and opsonophagocytic activity of HL-60 cells correlated with expresson of FcgammaR and Mac-1.

Effects of Two Different Surfactants on RBC Membrane and Type II Alveolar Epithelial Cell in Vitro

PURPOSE: Respiratory distress syndrome(RDS) is a major cause of death in premature babies. For the treatment of RDS, various artificial pulmonary surfactants have been used. The incidence of pulmonary hemorrhage is increased in association with surfactant therapy in extremely low birth weight infants. But the pathogenesis of this increased incidence is not clear. So we conducted this study to prove whether exposure of RBC or type II alveolar epithelial cell membrane to Surfacten(R) or Exosurf(R) or additive component of Exosurf(R) may lead to increased membrane permeability. METHODS: Washed packed RBC(30microliter) with various concentrations of Surfacten(R), Exosurf(R), hexadecanol and tyroxapol(concentration similar to their content in each Exosurf(R)), were incubated for 2, 24 and 48 hour at 37degrees C. Hemolysis was measured by spectrophotometry. Type II alveolar epithelial cell(HTB-181)(106cell/mL) with 2, 4, 6 and 8mg of Surfacten(R) or Exosurf(R) were incubated for 24 hour at 37degrees C. Lactate dehydrogenase(LDH) release was measured as an indicator of cytotoxicity. RESULTS: RBC hemolysis was increased in a time and dose-dependent manner with both artificial surfactants and additive components of Exosurf(R). This trend, especially, was typically seen in the sample which was incubated for 24 hours, where more hemolysis was seen with Exosurf(R) and tyroxapol than Surfacten(R) and hexadecanol with the above concentration of 2.5mg/2mL(P<0.05). LDH released from type II alveolar epithelial cell with Exosurf(R) was greater than with Surfacten(R), especially at the concentration of 6mg/106cell(P<0.05). CONCLUSION: Artificial surfactant may be associated with in vitro cytotoxicity on RBC membrane and aveolar epithelial cell, and this property was more prominent with Exosurf(R) and the additive components of Exosurf(R), especially with tyroxapol.

Effects of Two Different Surfactants on RBC Membrane and Type II Alveolar Epithelial Cell in Vitro

PURPOSE: Respiratory distress syndrome(RDS) is a major cause of death in premature babies. For the treatment of RDS, various artificial pulmonary surfactants have been used. The incidence of pulmonary hemorrhage is increased in association with surfactant therapy in extremely low birth weight infants. But the pathogenesis of this increased incidence is not clear. So we conducted this study to prove whether exposure of RBC or type II alveolar epithelial cell membrane to Surfacten(R) or Exosurf(R) or additive component of Exosurf(R) may lead to increased membrane permeability. METHODS: Washed packed RBC(30microliter) with various concentrations of Surfacten(R), Exosurf(R), hexadecanol and tyroxapol(concentration similar to their content in each Exosurf(R)), were incubated for 2, 24 and 48 hour at 37degrees C. Hemolysis was measured by spectrophotometry. Type II alveolar epithelial cell(HTB-181)(106cell/mL) with 2, 4, 6 and 8mg of Surfacten(R) or Exosurf(R) were incubated for 24 hour at 37degrees C. Lactate dehydrogenase(LDH) release was measured as an indicator of cytotoxicity. RESULTS: RBC hemolysis was increased in a time and dose-dependent manner with both artificial surfactants and additive components of Exosurf(R). This trend, especially, was typically seen in the sample which was incubated for 24 hours, where more hemolysis was seen with Exosurf(R) and tyroxapol than Surfacten(R) and hexadecanol with the above concentration of 2.5mg/2mL(P<0.05). LDH released from type II alveolar epithelial cell with Exosurf(R) was greater than with Surfacten(R), especially at the concentration of 6mg/106cell(P<0.05). CONCLUSION: Artificial surfactant may be associated with in vitro cytotoxicity on RBC membrane and aveolar epithelial cell, and this property was more prominent with Exosurf(R) and the additive components of Exosurf(R), especially with tyroxapol.

Diagnostic Sensitivity in Predicting Hyperlipidemia by Bioelectrical Impedance Analysis in Obese Children

PURPOSE: Childhood obesity is currently on the rise. The complications of childhood obesity are depression, adult obesity, hypertension, diabetes, hyperlipidemia, coronary artery disease and fatty liver. Therefore, accurate diagnosis of obesity is important. The purpose of this study was to assess diagnostic sensitivity to predict hypelipidemia by bioelectrical impedance analysis (BI) in obese children. METHODS: One hundred fifteen healthy subjects who have received health care services at Ewha Womans University Hospital were enrolled. Obesity was diagnosed by an obesity index (OI), Rohrer index (RI), body mass index (BMI), skinfold thickness (ST) of the triceps and subscapularis, and bioelectrical impedance analysis. The correlation coefficients between BI and other variable methods were obtained. The sensitivity and specificity to predict hyperlipidemia in obese children by several methods were studied.RESULTS: The incidence of obesity was 20.9% by bioelectrical impedance analysis. The BI highly correlated with ST (r=0.828), RI (r=0.826), BMI (r=0.821) and OI (r=0.619). The blood level of total cholesterol and triglyceride were statistically higher in obese children diagnosed by BI compared to non-obese children. In obese children, sensitivity in predicting hyperlipidemia was higher in RI than in other methods, the specificity for low density lipoprotein was higher in BI. CONCLUSION: Bioelectrical impedance analysis highly correlated with several other methods to assess obesity. The sensitivity and specificity to predict hyperlipidemia in obese children by BI was similar to other methods.

Study of Seroprevalence of Antimycoplasma Antibody in Healthy Children and its Diagnostic Value

PURPOSE: To evaluate the diagnostic reliability of the single serum titers of the specific serum antibody determiantion method, we compared antimycoplasma antibody titers of 177 healthy children with 353 children who had respiratory symptoms indicative of Mycoplasma pneumoniae infection. METHODS: We used Serodia-Myco II particle agglutination test and the titers of > or = 1:40 were regarded as positive. RESULTS: Age distribution of 177 healthy children was between 4-17 years and among these children there were 105 males and 75 females. Age distribution of 353 children with respiratory symptoms was between 2-17 years and consisted of 187 males and 166 female children. The results of antimycoplasma antibody titers of healthy 177 children were 95 cases (53.7%) of negative AMA, 30 cases (16.9%) of 1:40, 27 cases (15.3%) of 1:80, 19 cases (10.7%) of 1:160, 6 cases (3.4%) of 1:320 and there were no cases of > or = 1:640. The results of antimycoplasma antibody titers of 353 children with respiratory symptoms were 195 cases (55.2%) of negative antimycoplasma antibody 19 cases (5.4%) of 1:40, 28 cases (7.9%) of 1:80, 30 cases (8.5%) of 1:160, 33 cases (9.3%) of 1:320, and there were a total of 48 cases (13.6%) that were > or = 1:640. In healthy children the antimycoplasma antibody titers above 1:40 were 14% at 4 years of age, 7% at 5 years, 40% at 6 years and leveled out until 16 years of age. CONCLUSION: Antimycoplasma antibody titer distribution in healthy children ranged from negative to 1:320, therefore, if the single serum sample titer is < or = 1:320, for a definitive diagnosis it is necessary to compare antibody levels after 2-3 weeks.

Immunologic Changes of HL-60 Cells by Differentiation Inducing Agents I : Phenotypic Differentiation of FcgammaR and Mac-1

PURPOSE: Fc receptors and Mac-1 play an important role in the protective response of granulocytes and monocytes against microbial infection. FcgammaRl, FcgammaRll, FcgammaRlll as well as CD11b/ CD18 have never been measured in a quantitative way during hemopoiesis. Thus we quantified the expression of Fc Rl, Fc Rll, Fc Rlll, and CD11b/CD18 during hematopoietic differentiation using HL-60 cells, which was induced to differentiate by DMSO, or PMA. METHODS: HL-60 cells (ATCC CCL-240) were induced to differentiate by adding 1.0% DMSO, or 16nM PMA. On the 4th and 7th day after stimulation as well as before stimulation, phenotypic analysis was performed by flow cytometry after staining the cells with PE-conjugated anti- human CD64, CD32, CD16, CD11b, CD18, and isotype controls. And the measured fluorescent intensity was transformed into Molecules of Equivalent Soluble Fluorochromes (MESF). RESULTS: Percent positive cells and MESF of CD11b on HL-60 cells increased upon induction by DMSO, but not by PMA. Percent positive cells of CD18 on HL-60 cells was 99% regardless of differentiation. But MESF of CD18 was increased on the 4th day and decreased on the 7th day by DMSO or PMA. Percent positive cells and MESF of FcgammaRl on HL-60 cells increased upon induction by DMSO or PMA. Percent positive cells of FcgammaRll on HL-60 cells was above 90% regardless of differentiation. MESF of FcgammaRll showed no significant change by DMSO or PMA. CONCLUSION: Quantitative expression of FcgammaRl, FcgammaRll, FcgammaRlll, and CD11b/CD18 of HL-60 cells changed during induction of differentiation by DMSO or PMA. MESF of FcgammaR and CD11b/ CD18 a better indicator than percent positive cells to compare the differentiation of HL-60cells.

Inhibitory Effects of Actinomycin-D and Pentoxifylline on the Production of IL-1alpha and TNF-alpha by Human Cord and Adult Blood Mononuclear Cells

PURPOSE: An area of intense intrest is assessment of new therapeutic modalities that regulate the inflammatory response in acute bacterial infection is proving to be an area of interest these days. So we conducted this study to compare the inhibitory effects of actinomycin-D and pentoxifylline on the production of IL-lalpha and TNF-alpha from cord blood mononuclear cells (MC) to those from adult blood MC stimulated with S. aureus toxic shock syndrome toxin (TSST)-1 and E. coli lipopolysaccharide (LPS). METHODS: Cord and adult blood MC were isolated by differential centrifugation on Ficoll-Hypaque gradients. Each mononuclear cells were incubated with TSST-1 (2 microgram/ml) or LPS (0.2 microgram/ml), simultaneously with various concentrations of actinomycin-D or pentoxifylline added for inhibition. Concentration of interleukin-1alpha (IL-lalpha) and tumor necrosis factor-alpha (TNF-alpha) were measured by means of ELISA. RESULTS: In comparison with each inhibitory drug, actinomycin-D showed more potent inhibitory effects on the production of IL-1alpha and TNF-alpha from adult and cord blood MC stimulated by TSST-1 and LPS, than pentoxifylline (P<0.05). There was no difference between adult and cord blood MC. In comparison with each stimulator, inhibition of TSST-1 induced cytokines production with actinomycin-D was greater than pentoxifylline, in contrast to inhibition of LPS induced cytokines production with pentoxifylline which was greater than actinomycin-D in adult blood MC (P<0.05). CONCLUSION: Proinflammatory cytokine production in cord and adult blood MC were inhibited by each drug in the same manner except, the inhibition of pentoxifylline for LPS in cord blood MC. So it is possible that these drugs can be used to modulate or suppress excessive proinflammatory cytokine production in acute bacterial infection.

Normal Predicted Values of Pulmonary Function Test in Healthy Korean Children

PURPOSE: We performed a pulmonary function test with simple, computerized spirometry composed of pneumotachometry and evaluated the predicted normal values of air flow rates and lung volumes in healthy Korean children. We calculated each of the simple and complex linear and logarithmic regression equations setting the predicted values. METHODS: Four hundred and fifty-two healthy children were enrolled from December, 1994 to August, 1995. We measured air flow rates (FVC, FEV1, PEFR, FEF25-75) and lung volumes (VC, ERV, IC, VE). Data was analyzed according to sex, age, height, weight, and body surface area. RESULTS: In 452 children (male : 282, female : 170), the age distribution was from 8 through 19 years, the height from 121cm to 180cm and the weight from 21kg to 79kg. We could get determinant coefficients between parameter and air flow rates. In boys, height showed the highest determinant coefficient in examing air flow rates, followed by age, body surface area and weight in order. In girls, body surface area showed the highest determinant coefficient in examing air flow rates, followed by height, weight, and age in order. A determination coefficient to the parameter was the highest with FVC. We could get determinant coefficients between parameter and lung volumes. Boys showed high determinant coefficient with only IC, girls with VC and IC. In examing IC, height showed the highest determinant coefficient, followed by body surface area and weight in order. Predicted values of pulmonary function test were generally higher in boys than in girls. CONCLUSION: After performing the pulmonary function test in healthy Korean children, we report their normal values of air flow rates, lung volumes and regression equations for the predicted values.

Double-blind Randomized Dose Controlled Multicenter Study on Prevention of Anemia in VLBW Premature Infants Treated with High Dose rhEPO (recombinant human erythropoietin)

PURPOSE: Very low birth weight infants frequently suffer severe anemia. This study was designed to evaluate the effectiveness of rhEPO for prevention of anemia of prematurity and for reduction of the need for transfusion in very low birth weight infants. METHODS: Eighty very low birth weight infants(<1.5 kg) whose gestational age was under 33 weeks were enrolled at 9 university hospital in Korea. This study was conducted as a double-blind randomized, dose-controlled study. In high dose EPO group, 500 IU/kg of rhEPO was subcutaneously administered every other day for 17 times. In low dose EPO group, 250 IU/kg of rhEPO was subcutaneously administered every other day for 17 times. In control group, placebo was administered in the same manner. The effectiveness of rhEPO was evaluated for multiple parameters. RESULTS: 1) Infants receiving high dose rhEPO showed a significant increase in hemoglobin and hematocrit by 3 weeks(P<0.05). 2) Infants receiving high & low dose rhEPO showed an increase in reticulocyte count by 1 week(P<0.05). 3) There were no significant changes in platelet, WBC count, and ANC in each group. 4) Serum concentration of erythropoietin, iron, TIBC and ferritin were highly variable in study patients.5) Incidence of anemia k transfusion in high dose rhEPO group was lower than low dose and control group(P<0.05). 6) Number of patients who did not receive transfusion and whose hematocrit did not fall below 30% in high dose rhEPO group was significantly higher than in low dose and control group(P<0.01). CONCLUSION: High dose recombinant human erythropoietin(rhEPO) treatment for anemia of prematurity may minimize the decrease in hemoglobin and hematocrit, rapidly increase reticulocyte count and reduce the need for transfusion.

Lysis of RBc Membrane and Type II Alveolar Epithelial Cell Toxicity by Various Artificial Pulmonary Surfactants Used in Korea

PURPOSE: Surfactant replacement therapy is now recognized as a life saving and safe intervention in small premature infants with respiratory distress syndrome. The incidence of pulmonary hemorrhage is increased in association with artificial surfactant therapy in extremely low birth weight infants, but the pathogenesis is not clear. We conducted this study to prove whether exposure of RBC or type II alveolar epithelial cell membrane to various artificial pulmonary surfactants may lead to increased membrane permeability. METHODS: 1) Washed packed red blood cells(30 pl) with various concentration of SurfactenR, NewfactanR, CurosurfR, and ExosurfR were incubated for either 2 or 24 hours at 37 degrees C. Hemolysis was measured by spectrophotometry. 2) Type II alveolar epithelial cell(HTB-181) (105cell/Ml) with various concentrations of above artificial surfactants were incubated for 24 hours at 37 degrees C. Lactate dehydrogenase (LDH) release was measured as an indicator of cytotoxicity. RESULTS: 1) Concentrationdent hemolysis of RBC membrane with each artificial surfactant for 2 or 24 hours was observed. Especially for 24 hours incubation, hemolysis with ExosurfR was significantly higher than with other artificial surfactants at concentration up to 2.5 mg/2 mL(P<0.05). 2) Exposure of 105 cells to 6 mg of all artificial surfactants led to a maximum release of LDH from cells into the media. At the concentration of 6 mg, release of LDH with ExosurfR was significantly higher than SurfactenR and NewfactanR (P< 0,05). There was no difference between SurfactenR, NewfactanR, and control group. CONCLUSION: Artificial surfactant may be associated with in vitro cytotoxicity and this property differs for different dosage and exposure time. Especially purely synthetic artificial surfactant(ExosurfR) is more potent in inducing lysis of RBC and type II alveolar epithelial cell.