OBJECTIVE: Many studies have shown that glucocorticoids play a crucial role in the development of obesity and insulin resistance. This study investigated the therapeutic effects of long-term inhibition of glucocorticoid activity on obesity and insulin resistance. METHODS: Four-week-old male Sprague-Dawley (SD) rats were randomly fed with a high-fat diet (fat content accounting for 20% of total calorie) (control group, n=8) or with a high-fat diet along with glycyrrhetic acid (GE, 800 mg/L), an inhibitor of 11β-hydroxysteroid dehydrogenase (11β-HSD) for 24 weeks (GE-treated group, n=9). The body weights and the amount of food intake were monitored weekly and daily, respectively. After 24 weeks of GE treatment, oral glucose tolerance tests were performed. Blood glucose was measured by glucose oxidase method. The levels of plasma glucocorticoids, insulin and leptin were measured with radioimmunoassay. The levels of serum cholesterol and triglyceride were determined with an automatic measuring analyzer. RESULTS: The food intake amount decreased significantly in the GE-treated group from 6 weeks and body weight gain was markedly less from 8 weeks after GE administration compared with the control group. After 24 weeks of treatment, the plasma levels of leptin and insulin in GE-treated rats were significantly reduced compared with the control group. The serum levels of cholesterol and triglyceride decreased markedly compared with the control group and the levels of blood glucose were significantly lower 15, 30, 60 and 120 minutes after oral glucose load in the GE-treated group compared with the control group. CONCLUSIONS: Long-term GE treatment may contribute to resisting diet-induced obesity and insulin resistance.［Chin J Contemp Pediatr, 2007, 9 (3):183-187］

OBJECTIVE: The short-term efficacy of the transanal one-stage endorectal pull through operation for Hirschsprungs disease is satisfactory. However the long-term outcome of anorectal function has not been fully understood. The aim of this study was to evaluate the stooling pattern, colonic motility and anal sphincter performance after transanal one-stage pull through operation in children with Hirschsprung's disease. METHODS: Fifty-eight children who underwent transanal one-stage pull through operation for Hirschsprung's disease were followed up. The mean follow-up duration was 15.8 months (range, 6-24 months). The stooling patterns of the patients were investigated by the informed questionnaire. Barium enema, defecography, total and segmental colonic transit time and the anorectal vector manometry were performed. Thirty- three healthy children were used as controls. RESULTS: Most of patients had normal stool consistency and frequency. Postoperative enterocolitis occurred in 3 patients, and constipation was found in five patients. Postoperative soiling was observed in 9 patients. None of the 58 patients had incontinence, cuff infection, anastomotic leak and mortality. The barium enema showed that the configuration of the colon recovered well in most of patients. Postopertive defecography showed the anorectal angle of all the patients was open, fixed and bigger than that of preoperation and the healthy controls (P<0.01). Postoperatively, the mean total gastrointestinal transit time（TGITT）, the left colonic transit time (LCTT) and rectosigmoid colonic transit time (RSTT) in the 58 patients were significantly shorter than preoperatively (P<0.01) and were similar to those of the control group. The rectoanal inhibitory reflex was regained in 5 patients. The anal maximal pressure of the patients with constipation in resting and squeezing condition were significantly higher than those of the asymptomatic patients and controls (P<0.05）. The vector volume (VV) and vector symmetric index (VSI) in patients with soiling were significantly lower than those in preoperation and the controls (P<0.05). The VSI in the patients with constipation was significantly higher compared with the controls （P<0.05）. CONCLUSIONS: The stooling function, colonic motility and anal sphincter performance manifest well in most of the patients after the transanal endorectal pull through operation for Hirschsprung's disease. Stooling disorders in few cases are probably related to decrease or disappearance of the sigmoid loops, dysfunction of the "neorectosigmoid", an open and fixed anorectal angle and achalasia of the internal anal sphincter.［Chin J Contemp Pediatr, 2007, 9 (3):188-192］

OBJECTIVE: To investigate the neurodevelopmental outcome of preterm infants who were discharged from neonatal intensive care unit (NICU) at 1 year of age and the impact factors contributing to the neurodevelopmental outcome and to study whether early intervention can improve the neurodevelopmental outcome in preterm infants. METHODS: Early intervention guidance and follow-up visits were performed after the preterm infants discharged from NICU. The infants received the infant development test of Child Development Centre of China (CDCC) for neurological development at 1 year of age. The neurodevelopmental outcome was evaluated based on mental development index (MDI) and physical development index (PDI). MDI and PDI > 85 was defined as normal, MDI or PDI between 70 and 85 as critical and MDI or PDI <70 as abnormal. Social-domestic and clinical factors related to neurological development were analyzed by ANOVA or chi-square test. Potential high risk factors were analyzed with logistic regression. To investigate the effects of intervention compliance on neurological development, the infants were classified into two groups according to different intervention compliances. The good compliance group included infants who received a through familial intervention for more than 4 days weekly (30 minutes daily) and consulted with physicians more than 5 times in 1 year. The infants who did not receive the interventions as the good compliance group served as the bad compliance group. RESULTS: This study consisted of 210 infants, with a mean gestational age of 33.2±2.6 weeks and a mean birth weight of 1 923.3±558.8 g. Normal, critical and abnormal neurological development occurred in 123 cases (58.6%), 61 cases (29.0%) and 26 cases (12.4%) respectively. Eighteen infants (8.6%) had mental lag and 9 (4.3%) had cerebral palsy (CP). The MDI and PDI scores of the good compliance group (111 cases) were 97.15±17.38 and 94.23±18.55 respectively, which were markedly higher than those of the bad compliance group (89.87±18.92 and 87.20±19.12; P<0.05). The incidence of CP (3/111, 2.7%) in the good compliance group was lower than that of the bad compliance group (5/99, 6.1%) although there were no statistical differences. Parents' education level, multiple birth, serious intracranial hemorrhage and apnea were risk factors for adverse neurodevelopmental outcome. CONCLUSIONS: Preterm infants discharged from NICU are a high risk group of neurodevelopmental disablement. Early intervention can improve the neurodevelopmental outcome of perterm infants at high risk.［Chin J Contemp Pediatr, 2007, 9 (3):193-197］

OBJECTIVE: This study analyzed the clinical data of newly diagnosed childhood leukemia from various hospitals in the cities or counties of Hunan Province between 2002 and 2005 in order to provide references for further epidemiologic survey of childhood leukemia. METHODS: The clinical data of children with newly diagnosed leukemia from hospitals of various cities or counties of Hunan Province between 2002 and 2005 were collected and reviewed. RESULTS: There were 803 children with leukemia during 2002-2005. Acute lymphoid leukemia was most commonly seen (597/803, 74.35%), followed by acute non-lymphoid leukemia (192/803, 23.91%) and chronic myelocytic leukemia (14/803, 1.74%). There were no significant differences in the clinical type and the prevalence of leukemia between males and females. The prevalence of newly diagnosed childhood leukemia in the urban area was noticeably higher than that in the rural area (2.02/105 vs 1.50/105, P<0.05). 41.79% of children with newly diagnosed leukemia from the urban area received treatments but only 22.80% of patients from the rural area received treatments (P<0.05). CONCLUSIONS: This study of patients-based hospitals showed some features of the morbidity of childhood leukemia in Hunan Province. It provides references for further epidemiologic investigation of this disease in Hunan Province.［Chin J Contemp Pediatr, 2007, 9 (3):198-200］

OBJECTIVE: To study the relationship of the types of Helicobacter pylori (H. pylori) strains with the classification and the severity of chronic gastroduodenal diseases in children. METHODS: One hundred and fifteen children with chronic upper gastrointestinal symptoms who were diagnosed as H. pylori infection by gastroscopy were enrolled in this study. H. pylori strains were serotyped by immunoblot technique. The gastric biopsy specimens of all patients were studied histologically. RESULTS: Type I H. pylori strains were confirmed in 84 cases (73.0%), intermediate type strains in 21 cases (18.3%), and type II strains in 10 cases (8.7%). Type I H. pylori strains infection caused a moderate gastric mucosal inflammation in 83 cases and a severe inflammation in 1 case. Intermediate type H. pylori strains infection caused a moderate gastric mucosal inflammation in 21 cases. Type II H. pylori strains infection caused a mild gastric mucosal inflammation in 2 cases and a moderate inflammation in 8 cases. Different types of H. pylori strains resulted in different severity of gastric mucosal inflammation (χ2=15.444, P<0.01). The gastric mucosal inflammation due to type I H. pylori strains was the most severe, while the inflammation due to type II H. pylori strains was relatively mild. The incidence of nodulus lymphaticus of gastric mucosa due to type I, type II and intermediate type H. pylori strains infection was 76.2%, 47.6% and 40.0%, respectively（χ2=10.171, P<0.01）. The classification of chronic gastro-duodenal diseases was not associated with the types of H. pylori strains. CONCLUSIONS: Type I strains were the leading cause of H. pylori infection in children. All of types of H. pylori strains can cause pathohistologic changes of gastric mucosa. Type I H. pylori strains infection can result in the most severe gastric mucosal inflammation and the highest incidence of nodulus lymphaticus. The immunoblot serotyping of H.pylori strains may be useless for the classification of chronic upper gastrointestinal diseases but it is helpful for the evaluation of the severity of the diseases in children.［Chin J Contemp Pediatr, 2007, 9 (3):201-204］

OBJECTIVE: To study the efficacy of esomeprazole-based 1 week or 2 weeks triple therapy for Helicobactor pylori (H. pylori) infection in children. METHODS: One hundred and five children with H. pylori infection identified by 13C-UBT were randomly assigned into Group A (n=60) and Group B (n=45). The patients of the two groups were administered with 1 week or 2 weeks triple therapy consisting of esomeprazole, clarithromycin and amoxillin, respectively. They were followed up four weeks after drug withdrawal. RESULTS: Recurrent abdominal pain was relieved in all of patients. Fifty-five patients (91.7%) showed 13C-UBT negative in Group A and 42 (93.3%) presented negative in Group B. There was no significant difference in the eradication rate of H. pylori. CONCLUSIONS: Esomeprazole-based triple therapy for H. pylori infection is effective in children. The efficacy of esomeprazole-based 1 week or 2 weeks triple therapy for this disorder does not appear to be different.［Chin J Contemp Pediatr, 2007, 9 (3):205-206］

OBJECTIVE: An unhealthy food consumption habit attributes to one of the etiology of gastro-esophageal reflux. The purpose of this article was to study the influence of food intake before going to bed on the nighttime gastro-esophageal reflux. METHODS: hirty-eight children with upper gastrointestinal symptoms were divided into two groups on the basis of taking (Group A, n=16) or not taking (Group B, n=22) food (non-stimulating) within 2 hrs before going to bed. All of them underwent 24 hr esophageal pH monitoring. The times of reflux episode, the longest duration of reflux, the times of reflux duration >5 min, and the percentage of time of pH<4 were compared between the two groups. RESULTS: There were no significant differences in the parameters of pH monitoring between Groups A and B, with the times of reflux episode of 32 (21.5-43.5) vs 24 (15-37.3) , the longest duration of reflux of 6.6 ( 2.4-29.8) min vs 4.5 (2.5-13.2) min, the times of reflux episode longer than 5 min of 1.5 ( 0-3) vs 0 (0-3), and the percentage of time of pH < 4 of 4.3 (2.1-15.0)% vs 4.1 (2.0-7.2)% . CONCLUSIONS: Non-stimulating food intake before going to bed did not adversely affect the nighttime gastro-esophageal reflux.［Chin J Contemp Pediatr, 2007, 9 (3):207-209］

OBJECTIVE: To study the value of the integrated visual and auditory continuous performance test (IVA-CPT) in the diagnosis of childhood attention deficit hyperactivity disorder (ADHD). METHODS: IVA-CPT was performed in 153 children (6-15 years old) with suspected ADHD. The "gold standard" for the diagnosis of ADHD was based on the Chinese Classification and Diagnostic Criteria of Mental Disease (3rd version) (CCMD-3) or the Diagnostic and Statistical Manual of Mental Disorders (4th version,USA) (DSM-IV). RESULTS: When CCMD-3 was used as the "gold standard", the sensitivity and specificity of IVA-CPT for the diagnosis of ADHD were 72.7% and 46.0% respectively. There were no significant differences in the diagnostic positive detection rate between the two diagnostic ways. When DSM-IV was used as the "gold standard", the sensitivity and specificity of IVA-CPT for the diagnosis of ADHD were 71.6% and 56.5% respectively. There were no significant differences in the diagnostic positive detection rate between the two diagnostic ways. There were similar results in the identification of subtypes of ADHD by the two diagnostic ways. The sensitivity and specificity of IVA-CPT for the diagnosis of ADHD in the 10-15 years old group were lower than those in the 6-9 years old group when either CCMD-3 or DSM-IV was used as the "gold standard". CONCLUSIONS: IVA-CPT can be used as an assisted tool for the diagnosis of ADHD. It is more effective for the diagnosis of ADHD in younger children.［Chin J Contemp Pediatr, 2007, 9 (3):210-212］

OBJECTIVE: To investigate the characteristics of 24-hr ambulatory electrocardiography (DCG) of children with myocarditis and to study the clinical value of DCG in the diagnosis of childhood myocarditis. METHODS: 24-hr DCG findings, including abnormal DCG rate, and number, grade and distribution of ventricular premature beat (PVC), as well as heart rate variability, from 59 children with myocarditis were retrospectively reviewed and compared with those detected in 41 children without heart disease. RESULTS: 86.4% of patients with myocarditis showed abnormal DCG, and compound arrhythmia was commonly seen, but only 46.3% showed abnormal DCG (P<0.01) and single arrhythmia was predominant in the control group. The number and grade of PVC/24 hrs were not significantly different between the two groups. Compared with the control group, the average pattern PVC was predominant in the myocarditis group (84.6% vs 48.7%; P<0.05). Monopeak pattern PVC was mostly seen (64.4%), followed by multiple-peak pattern (25.4%) and bi-peak pattern (8.4%) in the myocarditis group, which were significantly different from the control group: monopeak pattern 53.6%, bi-peak pattern 36.6% and multiple-peak pattern 7.3% (P<0.01). CONCLUSIONS: The 24-hr DCG characteristics of children with myocarditis are different from the normal controls, suggesting 24-hr DCG monitoring is useful to the diagnosis of childhood myocaditis.［Chin J Contemp Pediatr, 2007, 9 (3):213-215］

Leigh syndrome is a genetically heterogeneous disease caused by defects in enzymes involved in aerobic energy metabolism and the Krebs' cycle. Deficiency of pyruvate dehydrogenase complex E1 alpha subunit (PDHA1) is the common cause of Leigh syndrome. In this study, one Chinese case of PDHA1 deficiency was reported. The patient was a boy with normal mental development, retarded motor development, general weakness, hypotonia and areflexia. Muscle histopathological findings suggested axonal peripheral neuropathy. Brain magnetic resonance imaging at 5 years of age revealed bilateral putamina lesions and periventricular white matter demyelination, supporting the diagnosis of Leigh syndrome. A C214T mutation in exon 3 of the PDHA1 gene was detected. After the treatment of thiamin, coenzyme Q10, Lcarnitine and carbohydrates-restricted diet, his movement ability improved significantly. At present, the patient is 8 years old and has normal school life. PDHA1 deficiency is an X-linked inherited metabolic disease, which shares various clinical manifestations and leads to difficult diagnosis. This patient predominately presented with progressive weakness and was diagnosed by gene analysis.［Chin J Contemp Pediatr, 2007, 9 (3):216-219］

OBJECTIVE: To establish a reliable neonatal rat model of periventricular leukomalacia (PVL) which is expected to be similar to PVL of human preterm infants pathologically, and to explore the concomitant eye lesions in the PVL model. METHODS: Two-old-day neonatal rats were randomly divided into a PVL group and a sham-operated group (n=19 each). The PVL model was established by the ligation of bilateral common carotid arteries, followed by a 30-min exposure to 8% oxygen. The cerebral infarction area was assessed with TTC staining 1 day after operation. Cerebral pathology was examined under a light micsrocope 2 and 21 days after operation. The examinations of eyes under a slip lamp and the pathology of eyeballs under a light microscope were performed 21 days after operation. RESULTS: The TTC staining cerebral slices showed there were extensive white areas of infarction in the brain of the PVL group, with an infarction area of 53.45±33.90 mm3 and a percentage of infarction of (24.98±15.44)％. Significant cystic necrosis and apoptosis around the periventricular and subcortical white matter and mild damage in cortical neurons were observed in the PVL group 2 days after operation. The more obvious cystic necrosis around the periventricular area was found in the PVL group 21 days after operation. There were no pathological changes in the brain of the sham-operated group. All of rats in the PVL group had bilateral cataracts, however, no pathological changes were observed in their postbulbar tissues. The sham-operated group did not show eye abnormal. CONCLUSIONS: The PVL animal model that was similar to PVL of human preterm infants pathologically was successfully established by the ligation of bilateral common carotid arteries, followed by 30-min hypoxia exposure, with a positive effect and a good repeatability. Cataract can also be induced by the method.［Chin J Contemp Pediatr, 2007, 9 (3):220-224］

OBJECTIVE: The oligodendrocyte is a key cell component of brain white matter. It is important to understand the pathology of oligodendrocyte injury to better understand the mechanisms leading to white matter injury in the premature brain. This study investigated the ultrastructural changes of oligodendrocytes following ischemic brain injury in 3-day-old premature rats. METHODS: One hundred and eight 3-day-old Sprague-Dawley (SD) premature rats were randomly divided into experimental and control groups. Ischemic brain injury was induced by ligation of bilateral carotid arteries. The control group underwent a sham operation without carotid ligation. At 6, 12 and 24 hrs after operation, 8 rats were randomly selected from surviving rats of both groups. The brain tissues were sampled for transmission electron microscopy. RESULTS: The survival rate of the control and the experimental groups was 100% and 51%, respectively. At 6 hrs of ischemia, swollen oligodendrocytes were observed in all 8 experimental rats. Organelles, including mitochondria, endoplasmic reticulum, and the Golgi apparatus, were swollen and the number of organelles in all 8 rats decreased noticeably compared with control animals. The swollen and decreased mitochondria were the most frequent change. Vacuolated mitochondria were seen in one rat and degranulated rough endoplasmic reticulum was seen in another rat from the experimental group. At 12 hrs of ischemia, oligodendrocyte swelling and decreased number of organelles became more severe in the experimental group. The oligodendrocyte nuclear chromatin was unevenly distributed and karyopycnosis began to appear in experimental animals. At 24 hrs of ischemia, oligodendrocytes generally displayed karyopycnosis and karyolysis, and organelles disappeared in experimental animals. CONCLUSIONS: Progressive oligodendrocyte damage occurred in 3-day-old premature rats subjected to permanent cerebral ischemia. The organelles injury was observed at 6 hrs of ischemia and evolved to oligodendrocyte apoptosis at 24 hrs of ischemia.［Chin J Contemp Pediatr, 2007, 9 (3):225-228］

OBJECTIVE: To study the effects of topiramate (TPM) and valproate acid (VPA) on serum insulin and leptin levels in young and adult rats. METHODS: Thirty healthy female young rats (21 days old) and thirty healthy female adult rats (2 months old) were randomly administered with TPM (50 mg/kg daily), VPA (200 mg/kg daily) or normal saline (control group) by intragastric administration for 5 weeks. After 5 weeks, serum leptin and insulin levels were detected by radioimmunoassay (RIA). RESULTS: Serum leptin and insulin levels in both the young and adult TPM groups were remarkably lower than those of the corresponding control group (P<0.05). The adult TPM group had significantly lower serum leptin and insulin levels than the young TPM group (P<0.05). In contrast, serum leptin and insulin levels in both the young and adult VPA groups were remarkably higher than those of the corresponding control group (P<0.05). The young TPM group had significantly higher serum leptin and insulin levels than the adult TPM group (P<0.05). CONCLUSIONS: TPM decreases serum leptin and insulin levels in young and adult rats, especially in adult rats. VPA increases serum levels of both in young and adult rats, especially in young rats.［Chin J Contemp Pediatr, 2007, 9 (3):229-232］

OBJECTIVE: To investigate the protective effect of amrinone against experimental lung ischemia /reperfusion (I/R) injury. METHODS: Twenty-four Sprague-Dawley rats were randomly divided into 3 groups (n=8 each): sham- operated group, I/R group, and amrinone-treated I/R group (AMR group).The left lung of rats was subjected to ischemia for 90 minutes, followed by reperfusion for 2 hrs, to induce an I/R lung injury model. The rats of the AMR group received amrinone (10 mg/kg) intravenously 30 minutes before ischemia and 5 minutes before reperfusion. After 2 hrs of reperfusion, carotid artery blood was collected for blood-gas analysis and detection of serum levels of IL-1β, IL-8 and TNF-α. The left lung was removed for detection of the lung wet/dry ratio, the erythrocuprein (SOD) activity and the malonaldehyde (MDA) content as well as the pathological changes. RESULTS: After 2 hrs of reperfusion, there were no significant differences in artery partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2) among the three groups. The lung wet/dry ratio (5.3±0.5 vs 4.8±0.1) and the MDA content (0.66±0.16 nmol/mg prot vs 0.47±0.06 nmol/mg prot) in the I/R group were significantly higher than those of the sham-operated group (P<0.05).The administration of amrinone markedly reduced the lung wet/dry ratio (4.8±0.2) and the MDA content (0.51±0.09 nmol/mg prot) and increased the SOD activity (54.7±6.8 vs 39.3±3.0 U/mg prot) when comparing the I/R group (P<0.05).The serum levels of IL-1β, IL-8 and TNF-α in the I/R group were 22.08±3.85, 21.92±5.56 and 30.50±3.77 pg/mL respectively, which were significantly higher than those of the sham-operated group. The AMR group showed lower serum levels of IL-1β, IL-8 and TNF-α (16.66±3.02,14.73±2.75 and 22.48±3.82 pg/mL, respectively) compared with the I/R group (P<0.01). The pathologic examination displayed that the lung tissue structure was normal and there was no hyperemia in the sham-operated and the AMR groups. The lung tissue structure of the I/R group was nearly normal but there were hyperemia and more inflammatory cells than the sham-operated and the AMR groups. CONCLUSIONS: Amrinone has protections against lung I/R injury, possibly through its anti-oxidation effects and an inhibition of inflammation factors releasing.［Chin J Contemp Pediatr, 2007, 9 (3):233-236］

OBJECTIVE:Most of the therapeutic strategies for systemic inflammatory response syndrome (SIRS) is not effective. This study was to investigate the effect of continuous veno-venous hemodiafiltration (CVVHDF) on SIRS induced by cecum perforate peritonitis in piglets. METHODS: Twelve piglets (weighing 7-9 kg) were randomly divided into two groups: control and CVVHDF (n=6). The piglets of both groups were subjected to a cecum puncture to induce peritonitis which caused SIRS. After SIRS occurred the piglets of the CVVHDF group immediately received the CVVHDF therapy for 6 hrs, with a blood flow rate of 20 mL/min, a replacement rate of 300 mL/h, and a dialysis rate of 600 mL/h. The heart rate (HR), mean artery blood pressure (MABP), respiratory rate (RR), arterial blood gas analysis and blood cells count were measured and recorded at baseline and onset of SIRS, and 2, 4 and 6 hrs after SIRS occurred. RESULTS: When SIRS occurred, the HR and RR increased and the MABP, artery oxygen pressure (PaO2) and the count of white cells decreased in both groups. The HR of the CVVHDF group decreased significantly at 2 hrs (P< 0.05) and remained lower until 6 hrs after CVVHDF therapy (P< 0.01) compared with that of the control group. The RR of the CVVHDF group was significantly lower than that of the control group 6 hrs after CVVHDF therapy (P< 0.05). The MABP of the CVVHDF group increased significantly 4 and 6 hrs after therapy compared with that of the control group (P< 0.01, P< 0.05 respectively). There were no significant differences in temperature, PaO2 and blood cells count between the two groups during the experiment. CONCLUSIONS: CVVHDF has a positive effect on hemodynamics in piglets with SIRS induced by cecum perforate peritonitis.［Chin J Contemp Pediatr, 2007, 9 (3):237-240］

OBJECTIVE: Previous studies suggest that hyperbaric oxygen (HBO) treatment promotes the proliferation of neurocytes in neonatal rats following hypoxic-ischemic brain damage (HIBD). The Wnt signaling pathway is associated with neurogenesis. This study examined whether HBO promoted neural stem cells (NSCs) proliferation after HIBD, and whether that the proliferation correlated with Wnt-3 protein expression. METHODS: Seven-day-old Sprague-Dawley rats were randomly divided into three groups: normal control, hypoxia-ischemia (HI), and HI-HBO. HI was induced by the ligation of left common carotid artery, followed by a 2-hr exposure to 8% O2 in the latter two groups. HBO was administered 3 hrs after HI in the HI-HBO group for continuous 7 days (2 atmospheres absolute, once daily). The proliferating NSCs in the subventricular zone (SVZ) was examined by BrdU/nestin immunofluorescence and the expression of Wnt-3 protein in NSCs was examined by nestin/Wnt-3 immunofluorescence at 6 and 24 hrs and at 3, 7 and 14 days of HI. The cellular expressions of nestin and Wnt-3 protein were analyzed by laser scanning confocal microscopy. The linear regression analysis was used to evaluate the correlation between cellular Wnt-3 and nestin protein. The expressions of nestin and Wnt-3 protein in the ischemic cerebral hemisphere were analyzed with Western blotting. RESULTS: The number of BrdU/nestin positive cells in the SVZ increased 3 hrs after HBO therapy, peaked at 7 days and remained at a higher level until 14 days after HBO therapy in the HI-HBO group compared with the normal control and the HIBD groups. The level of Wnt-3 protein in NSCs increased significantly 3 hrs after HBO therapy, peaked at 3 days and remained at high levels until 14 days after HBO therapy in the HI-HBO group compared with the normal control and the HIBD groups. The level of cellular nestin protein was closely correlated with the level of cellular Wnt-3 protein (r = 0.893, P<0.05). The Western blotting analysis demonstrated increased Wnt-3 and nestin protein expressions in the ischemic cerebral hemispheres. CONCLUSIONS: HBO treatment promotes the proliferation of NSCs in HIBD neonatal rats, which is correlated with the activation of Wnt signaling.［Chin J Contemp Pediatr, 2007, 9 (3):241-246］