Autophagy-Related Protein MAP1LC3C Plays a Crucial Role in Odontogenic Differentiation of Human Dental Pulp Cells

BACKGROUND@#Autophagy plays important roles in odontogenic differentiation of dental pulp cells (DPCs) in the developmental stage of tooth bud. Few studies have reported the role of autophagy during reparative dentin formation process. The objective of this study was to discover gene expression pattern correlated to autophagy and their role during odontogenic differentiation process in DPCs. @*METHODS@#After tooth cavities were prepared on the mesial surface of lower first molar crown of rats. Odontogenic differentiation and reparative dentin formation were assessed based on detection of morphology change with hematoxylin and eosin staining. @*RESULTS@#After tooth cavities were prepared on the mesial surface of lower first molar crown of rats, odontogenic differentiation and reparative dentin formation were assessed based on detection of morphology change with hematoxylin and eosin staining and dentin sialophosphoprotein (DSPP), whereas autophagy inhibitor 3-methyladenine (3MA) reversed. @*Results@#of quantitative polymerized chain reaction array of autophagosome formation related genes revealed that GABARAPL2 was prominently upregulated while expression of other ATG8 family members were moderately increased after tooth cavity preparation. In addition, human DPCs incubated in differentiation medium predominantly upregulated MAP1LC3C, which selectively decreased by 3MA but not by autophagy enhancer trehalose. Knock-down of MAP1LC3C using shRNA resulted in strong downregulation of dentin matrix protein 1 and DSPP as well-known odontogenic marker compared to knock-down of MAP1LC3B during odontogenic differentiation process of human DPCs. @*CONCLUSION@#Our results suggest that MAP1LC3C plays a crucial role in odontogenic differentiation of human DPCs via regulating autophagic flux.

Autophagy-Related Protein MAP1LC3C Plays a Crucial Role in Odontogenic Differentiation of Human Dental Pulp Cells

BACKGROUND@#Autophagy plays important roles in odontogenic differentiation of dental pulp cells (DPCs) in the developmental stage of tooth bud. Few studies have reported the role of autophagy during reparative dentin formation process. The objective of this study was to discover gene expression pattern correlated to autophagy and their role during odontogenic differentiation process in DPCs. @*METHODS@#After tooth cavities were prepared on the mesial surface of lower first molar crown of rats. Odontogenic differentiation and reparative dentin formation were assessed based on detection of morphology change with hematoxylin and eosin staining. @*RESULTS@#After tooth cavities were prepared on the mesial surface of lower first molar crown of rats, odontogenic differentiation and reparative dentin formation were assessed based on detection of morphology change with hematoxylin and eosin staining and dentin sialophosphoprotein (DSPP), whereas autophagy inhibitor 3-methyladenine (3MA) reversed. @*Results@#of quantitative polymerized chain reaction array of autophagosome formation related genes revealed that GABARAPL2 was prominently upregulated while expression of other ATG8 family members were moderately increased after tooth cavity preparation. In addition, human DPCs incubated in differentiation medium predominantly upregulated MAP1LC3C, which selectively decreased by 3MA but not by autophagy enhancer trehalose. Knock-down of MAP1LC3C using shRNA resulted in strong downregulation of dentin matrix protein 1 and DSPP as well-known odontogenic marker compared to knock-down of MAP1LC3B during odontogenic differentiation process of human DPCs. @*CONCLUSION@#Our results suggest that MAP1LC3C plays a crucial role in odontogenic differentiation of human DPCs via regulating autophagic flux.

Two-Stage Total Knee Arthroplasty for Prosthetic Joint Infection

PURPOSE: This retrospective review was conducted to identify prognostic factors for two-stage reimplantation for infected total knee arthroplasty (TKA) and the rate of reinfection following revision TKA. MATERIALS AND METHODS: Out of 88 patients diagnosed with post-TKA infection between 1998 and 2011, 76 underwent two-stage reimplantation and were reviewed in this study. The 76 patients were divided into two groups-those who experienced reinfection and those who did not. Comorbidities, culture results, and inflammation indices were analyzed and compared between the two groups. RESULTS: Of the 76 patients who underwent a two-stage reimplantation, 18 (23.7%) experienced reinfection. Patients with more than three comorbidities had significantly higher reinfection rates than those with less than three comorbidities (47.1% vs. 4.8%, p=0.032). The reinfection rate between the culture positive prosthetic joint infection group and the culture negative prosthetic joint infection group was not significantly different (p=0.056). Inflammation indices (erythrocyte sedimentation rate [ESR] and C-reactive protein [CRP]) showed a statistically significant difference between patients with reinfection and those without reinfection at 4 weeks after the first-stage surgery. CONCLUSIONS: Reimplantation must be carefully performed when the risk of reinfection is high, particularly in patients with more than three systemic or local comorbidities and higher inflammation indices (ESR and CRP) prior to revision TKA.

Efficacy and Safety of Stem Cell Therapies for Patients with Stroke: a Systematic Review and Single Arm Meta-Analysis

BACKGROUND AND OBJECTIVES: Stem cell-based therapy is a potential new approach in the treatment of stroke. However, the efficacy and safety of these treatments are not yet fully understood. Therefore, we performed a meta-analysis of available single-arm studies using stem cell-based therapy in patients with stroke. METHODS: We searched MEDLINE, EMBASE, and the Cochrane database for studies of stem cell therapy in patients with stroke from its inception through July 2014. The articles included in the search were restricted to the English language, studies with at least 5 patients, and those using cell-based therapies for treating stroke. RESULTS: Fourteen studies included in the meta-analysis. The pooled mean difference in National Institutes of Health Stroke Scale (NIHSS) scores from baseline to follow-up points was 5.7 points (95%CI: -8.2 to -3.2, I2=91.5%) decreased. Also the pooled mean difference in modified Bathel index (BI) score was increased by 31.5 points (95%CI: 35.6~14.9, I2=52.7%) and the pooled incidence rate to achieve on modified Rankin score (mRS)< or =2 was 40% (95% CI: 30%~51%, I2=35.4%) at follow-up points. The pooled incidence rates of death, seizure, and infection were 13% (95%CI, 8~23%), 15% (95%CI, 8~25%), and 15% (95%CI, 8~23%), respectively. CONCLUSIONS: The published data suggest that stem cell-based therapy for patients with stroke can be judged as effective based on single arm clinical studies. However, clinical benefits of stem cell therapy for patients with stroke need further investigation and reevaluation to test the clinical efficacy.

Association Between Work Conditions and Smoking in South Korea

BACKGROUND: A variety of sociodemographic factors, such as gender, age, household income, and educational level, influence individuals' likelihood of smoking. Work-related factors may also be linked to smoking behavior. We sought to investigate the relationship between smoking and work environment in South Korea. METHODS: We analyzed data from the Fifth Korean National Health and Nutrition Examination Survey to determine whether there was an association between smoking and occupation type (e.g., manual, nonmanual, or service work), night-shift work, and hours worked/week (e.g., 60 hours) for 4,685 workers. Regression models were adjusted for sociodemographic variables such as age, recent alcohol consumption, hours slept, educational level, and household income. RESULTS: The prevalence of smoking was 50.1% in men and 7.2% in women. For women, manual workers had 2.34 times [95% confidence interval (CI): 1.02-5.36] greater odds of smoking compared with nonmanual workers, whereas service workers had 2.37 times greater odds (95% CI: 1.28-4.40). Furthermore, women who worked 49-60 hours had 2.21 times greater odds of smoking (95% CI: 1.10-3.75) as compared with women who worked 40-48 hours. CONCLUSION: Women who work long hours or who are employed in service or manual positions are more likely to smoke. These results indicate a need in South Korea to target these specific groups when creating nonsmoking policies.

Comparisons of Oxidative Stress during Laparoscopic Cholecystectomy and Open Cholecystectomy

PURPOSE: During oxidative stress, the levels of oxygen free radical increase dramatically, which plays a role in apoptosis, aging and is chemic injury, but also leads to positive effects such as induction of host defense genes and mobilization of ion transport systems. It has been suggested that the advantages of laparoscopic surgery are closely related to the reduced oxidative stress that occurs during laparoscopic cholecystectomy (LC) when compared to open cholecystectomy (OC). This study was conducted to compare oxidative stress markers including total antioxidant status (TAS), superoxide dismutase (SOD) and gluthathione reductase (GR) between the LC group and OC group to determine if these surgical procedures result in different patterns of oxidative stress. METHODS: Our prospective study included fifty patients with symptomatic cholelithiasis and cholecystitis, of whom 25 underwent LC and 25 underwent OC. The plasma levels of oxidative stress markers (TAS, SOD, and GR) were measured preoperatively and on the 1st, 2nd and 3rd postoperative days. RESULTS: The postoperative hospitalization days differed significantly between the two groups (p0.05). An acceptable postoperative decrease in SOD was observed in the OC group, especially after the 2nd postoperative day (p0.05) upon analysis of covariance. A significant postoperative decrease in the level of SOD was observed in the OC group, especially after the 2nd postoperative day (p<0.01), and there was also a significant difference in the serial change in SOD between groups (p=0.020). The level of GR in the OC group decreased significantly on the 2nd postoperative day (p=0.022). Moreover, ANCOVA revealed a significant difference in the serial changes in thelevel of GR between the two groups (p=0.039). CONCLUSION: Our study compared oxidative stress between LC and OC groups based on the levels of TAS, SOD, and GR. We found that minimally invasive surgery, such as laparoscopic cholecystectomy, produced less oxidative stress than open surgery.

The Effect of Water Exercise Program for Treating the Gestational Edema / 대한주산의학회잡지

PURPOSE: To confirm the effect of water exercise program for treating the gestational edema. METHODS: Both low leg volume, body weight and urine specific gravity were measured in thirty women with gestational edema before and after water exercise program. Fetal heart rate, maternal heart rate and maternal blood pressure were measured before and after water exercise program. RESULTS: Right leg volume was decreased by 286 ml from 1714 to 1428 mL (P<.0001), left leg volume was decreased by 267 mL from 1,644 to 1,377 mL (P<0.0001), and total leg volume was decreased by 553 mL from 3,359 to 2,805 mL (P<0.0001). Urine specific gravity was decreased by 0.0047 from 1.0197 to 1.0150 (P=0.004). Maternal body weight, heart rate, blood pressure, and fetal heart rate were showed no significant change. CONCLUSION: Water exercise program is effective and safe method for treating the gestational edema.

A Case of Sarcoidosis in a Stonemason Exposed to Crystalline Silica / 대한산업의학회지

BACKGROUND: Sarcoidosis is a systemic granulomatous disease that can affect any organ, the exact cause of which is uncertain. Currently, investigations of crystalline silica improve the mechanism how it works the course of autoimmune diseases and some hypothesis supports that it also can attribute to sarcoidosis. CASE REPORT: The patient was a 53-year-old male, who works as a stonemason for 30 years. Sarcoidosis was suspected based on his chest X-ray and CT(Computed tomography). A biopsy was performed and he was indeed diagnosed with sarcoidosis. CONCLUSION: It is thought that sarcoidosis is more prevalent in the people who work at places with a risk of exposure to crystalline silica. This case suggests that if a patient gets sarcoidosis after being exposed to crystalline silica, or after once being diagnosed with silicosis, his or her sarcoidosis may have occurred due to exposure to crystalline silica.

The Relationship between the Experience of an Accident and Post Traumatic Stress Disorder in Bus Drivers / 대한산업의학회지

OBJECTIVES: Mental fitness issues have recently become a point of dispute in the field of health. Drivers are occupationally in danger of a possible accident, and are also exposed to other factors aside from accidents that threaten their mental health. The purpose of this research is to examine the level and state of post traumatic stress disorder (PTSD) and overall mental fitness in bus drivers. In addition, we wish to understand the various causes that can influence PTSD. METHODS: From April 1 to June 30, 2009, taking the region and number of workers into consideration, survey sheets were distributed to selected bus drivers who belonged to the public transportation union. The questionnaire included questions on experiences, details of accidents, the characteristics of the working environment, and the status of mental health. We used the Davidson Trauma Scale to investigate PTSD symptoms and the Center for Epidemiological Studies Depression Scale to evaluate depression. RESULTS: Regardless of the type of accident, the group of bus drivers with accident experience showed stronger signs of suffering from PTSD. It seemed that the experience of an accident that caused the death of passengers or conflict with passengers were important factors for PTSD. Within the PTSD group, we found more symptoms of depression, and also this group is more likely to take time off work. CONCLUSIONS: The experience of an accident threatens the mental health of bus drivers. Since bus drivers are responsible for the safety of many citizens, we must work towards finding ways to protect their mental health.

A case of minimal change nephrotic syndrome with polycythemia vera / 대한내과학회지

The cause of secondary polycythemia is known to be renal diseases such as renal tumors, renal cysts, hydronephrosis, renal artery stenosis, renal transplantation and Bartter's syndrome. Yet this disease rarely reported in conjunction with nephrotic syndrome, nephrosclerosis, pyelonephritis or chronic glomerulonephritis. There are only rare reports of glomerulonephritis with polycythemia vera. We report here on a case of a minimal change nephrotic syndrome with polycythemia vera. A 60-year-old man visited our hospital due to his elevated hemoglobin level and proteinuria and his elevated neuron specific enolase. The blood hemoglobin level was 22.4 g/dL. The blood level of neuron specific enolase was 36.7 ng/mL. The bone marrow aspirate showed hypercellularity and panmyelosis. Electron microscopy showed diffuse effacement of the epithelial foot processes and microvillous transformation of the foot processes. Treatment was done by performing phlebotomy and administering hydroxyurea. There was decreased urinary protein and normalization of the hemoglobin level following treatment with phlebotomy and hydroxyurea.

Effects of LED irradiation on the expression of apoptosis-related molecules in human SH-SY5Y neuroblastoma cells

To verify the inhibitory or protective effects of light-emitting diode(LED) irradiation on apoptotic cell death induced by CoCl2, human SH-SY5Y cells were treated with CoCl2 and LED were used to irradiate the cells. In the cell viability assay, cells were died slowly from 50 micrometer to 250 micrometer and about 50% of cells died after 12 hours at 400 micrometer of CoCl2. The Diff-Quik staining revealed that cells showed condensation of DNA and blebbing of the cell membrane. The DNA fragmentation assay revealed the DNA fragmentation, which is another apoptosis marker, occurred in cells treated with 400 micrometer CoCl2 for 16 hours. In the western blot for HIF-1 alpha, HIF-1 alpha was expressed after 3 hours from induction and peaked maximally at 16 hours. In the cell viability assay of the effects of LED irradiation (at 590 nm for 1 hour 20 minutes), the cells showed more proliferation (about 20%) than the control group. The RPA assay of various apoptosis-related molecules showed that pro-apoptosis molecules such as Bax, Bak, and Bid were upregulated in the CoCl2 treatment group. This means that the apoptotic cell population was increased. However there was some significant changes in LED irradiated cells. In the CoCl2-treated LED irradiation group, those molecules were down-regulated more than in the only CoCl2-treated group. These results have shown that CoCl2 may induce apoptotic cell death in human SH-SY5Y neuroblastoma cells. And LED irradiation has a positive effect on apoptotic cells by down-regulation of pro-apoptotic molecules.

The Clinicopathologic Significance of a p63 Expression in Invasive Breast Cancer

PURPOSE: p63 is a recently described as p53 homologue. Despite their structural homologies, they have different activities. p63 is a specific myoepithelial cell marker in normal breast tissue and it is expressed in a minority of breast cancers. The aim of this study was to evaluate the prognostic significance of the p63 expression in breast cancer. METHODS: The expression of p63 in breast cancer was determined by performing immunohistochemistry on 350 patients who underwent mastectomy at the Department of Surgery at Korea University Medical Center between January 1992 and September 2004. A retrospective analysis was conducted using the medical records. A tissue microarray was constructed, and immunohistochemical analysis for p63 was performed according to the usual methods. RESULTS: Among 350 patients, 40 (11.4%) showed a p63 expression. There was a significant correlation between p63 and the histologic grade. There were significant correlations of p63 with p53 and HER2/neu, respectively. In the basal type of breast cancer, the p63 expression was significantly higher than in the luminal type of breast cancer. The 5 year disease free survival rates were 69% in the patients with a p63 expression and 76% in the patients without a p63 expression, but there was no statistical difference. CONCLUSION: The present results indicate that a p63 expression is associated with a high grade tumor, a p53 expression and a HER2/neu expression in breast cancer, which are the known poor prognostic factors of breast cancer. Immunohistochemical subtyping shows that the p63 expression is a useful predictor for the basal type of breast cancer. In addition, this study suggests that the p63 expression in the basal type of breast cancer is associated with a poor prognosis.

Prognostic Factors of Resected Stage IV Gastric Cancer Patients

PURPOSE: The prognosis of stage IV gastric cancer is poor with the 5-year survival rate still being about 10%. We investigated the prognostic factors of stage IV gastric cancer patients who underwent resection. MATERIALS AND METHODS: A retrospective study of 383 patients with stage IV gastric cancer who underwent surgery in our department between September 1983 to December 2000 was conducted. We classified the 383 patients into two groups: patients surviving 2 years or more (n=77) and those surviving less than 2 years (n=306). Clinicopathologic differences were analyzed between the two groups. We also performed univariate and multivariate analyses of various clinicopathologic factors concerning survival. RESULTS: Statistically significant clinicopathologic differences between the two groups were observed in regard to macroscopic type, distant metastasis, lymph node dissection, curability, and histology. Curability and histology were significant survival factors in 2-year survival. The 5-year survival rate was 5.4% in stage IV gastric cancer. Significant differences in survival among macroscopic type, distant metastasis, lymph node dissection, curability and histology were observed in the univariate analysis. In the Multivariate analysis, Curability, lymph node dissection, and histology were significantly beneficial factors for survival. CONCLUSION: Lymph node dissection, curability, and histology were independent prognostic factors in stage IV gastric cancer, and radical treatment is recommended to improve survival.

Ultrastructural study of the levator veli palatint muscle in cleft palate patients

Application of DNA chip techniques for Yq microdeletion analysis in infertile males

Our aim was to apply DNA chip technology as a diagnostic tool in infertility research and clinics. Six loci, including a sex-determining region on the Y chromosome and five sequence-tagged sites in azoospermia-factor regions were investigated in infertile male patients. Our method produced a sensitive signal, which showed the presence or absence of the STS regions on the Y chromosome. The results from 93 patients with non- obstructive azoospermia, oligoathenoteratozoospermia, or oligozoospermia were identical when analyzed with either the DNA chip technique or conventional PCR-gel electrophoresis. We have demonstrated its application in the molecular diagnosis of male infertility. This system provides an economic and high-throughput method for detecting the deletion of genomic DNA sequences of large groups of infertile patients, and a completely new approach to male infertility screening. The application of DNA chip technology to identify Yq deletions can also facilitate our understanding of male infertility.

Predictors of Clinical Outcome in the Newborns of Persistent Pulmonary Hypertension Treated with Inhaled Nitric Oxide

PURPOSE: Inhaled nitric oxide (iNO) has been known to improve oxygenation in newborns with persistent pulmonary hypertension (PPHN). This study was performed to evaluate the predictors of clinical outcome in the newborn infants with PPHN treated with iNO. METHODS: Between September 1998 and August 2002, 23 newborn infants with PPHN treated with iNO were enrolled in this study. Reduction of oxygenation index (OI) and AaDO2 to 30% or more were defined as clinical response. Accoding to the response time within or after 12 hours, the clinical response was sub-categorized as early or delayed response, respectively. RESULTS: The mean gestational age and birth weight of 23 newborn infants were 36.7+/-4.4 weeks and 2,644+/-907 g. The mean baseline OI and AaDO2 were 22.20+/-13.63 and 477.16+/-127.96. There were ten non-responsders, eight early responsders and five delayed responders. Eleven neonates showed sustained response for 24 hours. The mean AaDO2, and PaO2 were decreased after 12 hours (P<0.05), while there was no difference in oxygenation index, arteral pH and PaCO2. The mortality rates of non-responders or not- sustained responders were higher than those of responders or sustained responders (P< 0.05). The birth weight of death group was lower than that of survival group and AaDO2, and OI at 12 hours after iNO therapy in survival group were lower than those in death group. CONCLUSION: Predictors of the clinical outcome of iNO therapy were clinical response patterns after iNO therapy, time taken until clinical response, duration of response and change of oxygenation at 12 hours after iNO therapy.

Predictors of Clinical Outcome in the Newborns of Persistent Pulmonary Hypertension Treated with Inhaled Nitric Oxide

PURPOSE: Inhaled nitric oxide (iNO) has been known to improve oxygenation in newborns with persistent pulmonary hypertension (PPHN). This study was performed to evaluate the predictors of clinical outcome in the newborn infants with PPHN treated with iNO. METHODS: Between September 1998 and August 2002, 23 newborn infants with PPHN treated with iNO were enrolled in this study. Reduction of oxygenation index (OI) and AaDO2 to 30% or more were defined as clinical response. Accoding to the response time within or after 12 hours, the clinical response was sub-categorized as early or delayed response, respectively. RESULTS: The mean gestational age and birth weight of 23 newborn infants were 36.7+/-4.4 weeks and 2,644+/-907 g. The mean baseline OI and AaDO2 were 22.20+/-13.63 and 477.16+/-127.96. There were ten non-responsders, eight early responsders and five delayed responders. Eleven neonates showed sustained response for 24 hours. The mean AaDO2, and PaO2 were decreased after 12 hours (P<0.05), while there was no difference in oxygenation index, arteral pH and PaCO2. The mortality rates of non-responders or not- sustained responders were higher than those of responders or sustained responders (P< 0.05). The birth weight of death group was lower than that of survival group and AaDO2, and OI at 12 hours after iNO therapy in survival group were lower than those in death group. CONCLUSION: Predictors of the clinical outcome of iNO therapy were clinical response patterns after iNO therapy, time taken until clinical response, duration of response and change of oxygenation at 12 hours after iNO therapy.

Two Cases of Cryptosporidiosis in Children Confirmed by Electron Microscopy / 대한소아소화기영양학회지

Cryptosporidiosis is an intestinal disease caused by the protozoan Cryptosporidium parvum. The most common manifestation in human is enteric symptoms, which in immunocompetent hosts are self-limiting but can be life threatening in immunocompromised hosts, characterized by profuse watery diarrhea, abdominal pain, severe weight loss. It's prevalence rate in immunocompetent host is variable by geographic locations (3~11%) but up to 15~40% in AIDS patients. Now it is considered as one of the important enteropathogens causing diarrhea not only in immunocompromised but also in immunocompetent hosts, especially in children. We experienced two cases of cryptosporidiosis in a 15 year old boy who was admitted due to diarrhea , abdominal pain and fever and in a 8 year old boy who was admitted due to watery diarrhea and vomiting. These are the first clinical cases of cryptosporidiosis confirmed by electron microscopy of the colonic mucosa among immunocompetent children in Korea.

Traumatic Carotid-Cavernous Fistula as a sequela of Mandibular Fracture

Traumatic carotid-cavernous fistula(CCF) is an uncommon situation resulting from trauma. The blood shunted from the internal carotid artery to the cavernous sinus results in pulsation exophthalmos,orbital headache, bruit, loss of visual acuity, diplopia, ophthalmoplegia. We were recently faced with such a case. The patient sustained fracture of the mandible during sports activity. Five months later, all the classic signs and symptoms of CCF had appeared. A carotid angiography confirmed the presence of a CCF. The management was achieved intravascularly by platinum electrothrombosis embolization. The main signs and symptoms of the CCF had resolved, but the patient remained in a visual loss of affected eye.

Statistical Study of Extremely Low Birth Weight (ELBW) Infants / 대한주산의학회잡지

PURPOSE: The purpose of our study was to review the perinatal clinical characteristics of extremely low birth weight(ELBW) infants and determine their risk factors of their deaths. METHODS: The medical records of 96 infants weighing less than 1,000g, who were born at Seoul National University Hospital and admitted to our neonatal intensive care unit(NICU) were analyzed retrospectively on the basis of clinical characteristics, obstetrical problems, postnatal complications and outcome. RESULTS: The annual birth rate of ELBW infants was 0.11% to 0.90% of total live births and the mean annual birth rate was 0.56% at Seoul National University Hospital. Preeclampsia was the most common obstetrical problem(34.4%), followed by incompetent internal os of cervix(IIOC) (13.5%), multiple pregnancy(13.5%) and in vitro fertilization(IVF)(13.5%). Respiratory distress syndrome(RDS) was the most common postnatal complication(78.1%), followed by sepsis(60.4%) and apnea(39.6%). Comparing the ELBW infants weighing less than 750g with those weighing more than 751g, sepsis was more frequent in the latter group(p<0.05), whereas high grade intraventricular hemorrhage(grade Ill) was more frequent in the former group(p<0.05). Otherwise there was no statistically significant difference concerning the frequency of perinatal complications between two groups. Comparing the ELBW infants born before the year 1991, when surfactant treatment started to be used routinely at our NICU, with those born after the year 1991, apnea and sepsis could be observed more frequent in the latter group(p<0.05). Otherwise there was no statistically significant difference in the frequency of perinatal complications between two groups, The survival rate of ELBW infants was 0.0% in 1986, 50.0% in 1991 and 40.0% in 1995. The risk factors of neonatal deaths of ELBW infants included birth weight, gestational period, mode of delivery, IIOC, RDS, apnea, pneumonia, pneumothorax, acute renal failure(ARF) and infections(except pneumonia), but analyzing these risk factors by multivariate logistic regression analysis, the resultant significant independent risk factors consisted only of birth weight, RDS and pneumonia(p<0.05). There was no statistically significant difference in survival rate between ELBW infants born before and after the year 1991, but there was a tendency toward increasing survival rates in the latter group. CONCLUSION: Recently, the survival rate of ELBW infants is improving steadily, but is still lower than that of western countries and postnatal morbidity remains high. Therefore, there is an urgent need to give more efforts to the neonatal intensive care of ELBW inFants in order to increase survival rates and reduce postnatal morbidity. But it is more important to reduce preterm birth by the treatment of preventable obstetrical risk factors.