Hypoxic-ischemic encephalopathy (HIE) in the newborn is a cerebral hypoxi-ischemic injury caused by perinatal asphyxia. It presents with various clinical manifestations of central nervous system. Diagnosis of HIE may be confirmed based on the following four criteria: A) Well-defined episode of fetal distress and evidence of severe fetal distress before delivery with fetal heart rate of < 100 beats per minute lasting for over 5 minutes and with or without severe meconium stained amniotic fluid, or an evidence of obvious asphyxia history during delivery. B) Severe birth asphyxia, defined as an Apgar scores of ≤ 3 at 1 minute and ≤ 5 at 5 minutes or an umbilical arterial pH of ≤7.00. C) Onset of abnormal neurological symptoms and signs in immediate newborn period and persisting for longer than 24 hrs. D) Exclusion of convulsions caused by electrolyte disturbances, intracranial hemorrhage and birth trauma, as well as the exclusion of brain injury resulted from intrauterine infection, genetic metabolic diseases, and other inborn errors of diseases. The infants who met the first three criteria but did not necessarily exhibit the fourth one may be diagnosed as suspected HIE. The diagnostic criteria for HIE are only suitable for term infants.［Chin J Contemp Pediatr, 2005, 7(2): 97-98］

ObjectiveGlucocorticoid is a first-selected medicine for the treatment of nephrotic syndrome (NS). But glucocorticoid can repress ossification and result in osteoporosis. This research examined the concentrations of biochemical markers of osteoblasts at different differentiation stages to explore the effects of glucocorticoid on osteoblast function in children with NS.Methods Serum procollagen type I c-terminal propeptide (PICP), bone Gla protein (BGP) and total alkaline phosphatase (AKP) were detected in 30 healthy children, 30 prednisone-treated NS children (2 mg/kg·d for 4-8 weeks) and 30 untreated NS children.Results Serum concentrations of PICP (165 ±56 μg/L vs 205 ±81 μg/L)and BGP (15±9 ng/L vs 19±12 ng/L)were significantly lower in untreated NS children than those in healthy controls (P<0.05). There was no significant difference in serum total AKP between the two groups. As compared with the untreated NS children, PICP (85 ±56 μg/L), BGP (8±5 ng/L) and AKP (104 ±59 U/L) in the prednisone-treated NS children were significantly lower (P<0.01). Conclusions There is a decreased bone composition in NS children. High-dose of glucocorticoid treatment for NS can further inhibit osteoblast composition.

OBJECTIVE: To explore the role of 5,10-methylenetetrahydrofolate reductase (MTHER) C677T polymorphisms in Chinese children with conotruncal heart defects (CTD). METHODS: A total of 97 children with CTD and 118 healthy controls were recruited into the study. MTHER genetic C677T polymorphisms were determined by PCR-RFLP. The 677TT genotype was compared between the two groups. RESULTS: The frequency of the TT genotype and T allele in CTD patients was 24.7% and 52.6%, respectively, which was significantly higher than that of controls ( 13.6% and 42.8%) (P = 0.036, P = 0.043, respectively). In patients with tetralogy of Fallot, coarctation of aorta or interruption of aortic arch, the frequency of the TT genotype varied between 29.7% and 40.0%. CONCLUSIONS: MTHFR gene is associated with CTD, and 677TT genotype might be a risk factor for congenital heart malformations.

OBJECTIVE: It was aimed to determine the concentration of urine 8-iso-PGF_ 2α in normal neonates and neonates with hypoxic-ischemic encephalopathy (HIE) and to study the value of urine 8-iso-PGF_ 2α in the assessment of the severity of neonatal HIE. METHODS: Urine samples from normal (n=126) and HIE (n=151) neonates were collected on the 1st, 3rd and 7th days after birth. ELISA was used to determine the urine 8-iso-PGF_ 2α contents. RESULTS: 1) Urine 8-iso-PGF_ 2α contents from normal neonates were 29.9 ± 7.9, 27.7 ± 9.8 and 27.5 ± 10.5 ng/mmol·Cr on the 1st, 3rd and 7th days after birth, respectively. There was no significant difference among the three days for the urine 8-iso-PGF_ 2α contents. 2) On the 1st day of HIE onset, neonates with mild, moderate and severe HIE had higher levels of urine 8-iso-PGF_ 2α (65.3 ± 13.2, 154.6 ± 31.6 and 241.7 ± 41.0 ng/mmol·Cr, respectively) compared with the normal neonates (P﹤0.001 ). 3) On the 3rd day, the urine 8-iso-PGF_ 2α content in neonates with moderate and severe HIE remained higher (34.2 ± 10.3 and 50.8 ± 12.8 ng/mmol·Cr, respectively) than the normal neonates (P﹤0.001 ), while that of the neonates with mild HIE regressed to normal. 4) On the 7th day, there was no significant difference in the urine 8-iso-PGF_ 2α level between all HIE and normal neonates. 5) The boundaries of 45.5, 89.9 and 217.5 ng/mmol·Cr of urine 8-iso-PGF_ 2α were defined to distinguish from normal to mild HIE, from mild to moderate HIE and from moderate to severe HIE. As defined, the corresponding sensitivity and specificity were 95.2% and 99.2%, 100% and 95.2%, 65.8% and 100%. CONCLUSIONS: The urine 8-iso-PGF_ 2α levels in neonates were stable within 7 days after birth. The urine 8-iso-PGF_ 2α contents in HIE neonates reached the peak within 24 hours after onset. There was a correlation between the urine 8-iso-PGF_ 2α contents and the severity of HIE, suggesting that urine 8-iso-PGF_ 2α may be a reliable and convenient index for the assessment of the severity of HIE.

OBBJECTIVE: To observe the changes of erythropoietinerythrogenin (Epo) in serum and cerebrospinal fluid (CSF) in neonates with hypoxic-ischemic encephalopathy (HIE), and to study the relationship between Epo levels and brain injury. METHODS: Serum Epo levels were measured by radioimmunoassay in 26 neonates with HIE (HIE group, 8 mild, 10 moderate and 8 severe ) and 8 normal neonates (Control group) at 0-24 hrs, 48-72 hrs and 7-10 days of their lives. CSF Epo levels were measured at 48-72 hrs of their lives and brain MRI scans were taken 7-10 days after birth in the HIE group. RESULTS: In the Control group, serum Epo levels decreased significantly within days after birth (P<0.05); However, in the HIE group serum Epo levels increased during 1-3 days then decreased thereafter; Significantly decreased levels were observed only in mild HIE neonates ( P< 0.05). In every time period, the serum Epo concentration in severe HIE neonates was significantly higher than in mild and moderate HIE neonates. It was also observed that CSF Epo levels in severe HIE neonates were significantly higher than those of mild and moderate HIE neonates (P<0.01). There was a significant linear and positive correlation between serum and CSF Epo levels at 48-72 hrs in severe HIE neonates (r= 0.76, P< 0.05), but not in mild and moderate HIE neonates. CSF Epo levels in neonates with severe cranial MRI abnormalities were significantly higher than those of neonates with mild and moderate cranial MRI abnormalities (P< 0.01). CONCLUSIONS: The maintained and increased serum Epo levels may be a marker of severe hypoxic-ischemia in neonates with HIE. CSF Epo levels can reflect the severity of cerebral hypoxia-ischemia; Impaired blood-brain barrier might account for the increased CSF Epo levels.

OBJECTIVE: To study the relationship between telomerase activity and p15INK4b (p15) expression in the development of childhood acute leukemia (AL). METHODS: Telomerase activity and p15 expression in bone marrow (BM) of 27 cases of childhood AL were evaluated using a modified telomeric repeat amplification protocol assay and reverse-polymerase chain reaction respectively. For comparative analysis, BM from control donors (n = 9) were analyzed. RESULTS: At diagnosis, the telomerase activity detected in BM from AL children was significantly higher than that from control donors (34.5±37.0 TPG vs 2.4±2.2 TPG, P < 0.001). The p15 expression in BM of AL children was significantly lower than that of the controls (9.8±16.2% vs 45.8±16.9%, P < 0.001). No significant correlation was observed between p15 expression and telomerase activity (r = - 0.01304, P >0.05). CONCLUSIONS: The telomerase up-regulation and lower expression of p15 gene may play an important role in the development of AL by different mechanisms.

Leigh syndrome is a severe early-onset progressive neurodegenerative disorder due to mitochondrial oxidative phosphorylation defects. Nuclear SURF1 mutations are the main causes of Cytochrome C oxidase deficiency resulting in Leigh syndrome. This study reviewed the clinical and genetic characteristics of a Chinese girl with Leigh syndrome due to 604G>C heterozygous mutation in SURF1. The female patient fell ill at age of 9 months, manifesting with feeding difficulty, malnutrition, progressive motor degeneration, hypotonia and nystagmus. She was hospitalized at 17 months and died of respiratory failure at 23 months. Her blood lactate and pyruvate levels detected during admission were significantly increased. Brain MR imaging showed characteristic focal, bilateral lesions in brain stem, thalamus, and basal ganglia. Brain stem and cerebellar atrophy were also found. Mitochondrial gene mutations were excluded. All of the exons of SURF1 amplified by polymerase chain reaction (PCR) sequencing and PCR-Restriction Fragment Length Polymorphism (RFLP) showed a 604G>C heterozygous mutation of SURF1 in the proband. Her mother and uncle had the mutations of SURF1 but no mutations were identified in her father and in 100 normal controls aged 14-18 years. This is the first reported case in China of Leigh syndrome due to 604G>C heterozygous mutation in SURF1 and it will be helpful for the diagnosis of Leigh syndrome and genetic counseling of the patient′s pedigree in future.

OBJECTIVE: To explore the clinical features and diagnosis of neonatal cerebrovascular disorder. METHODS: The medical documents of 26 cases of neonatal cerebrovascular disorder (parenchymal hemorrhage, n=9; cerebral infarction, n=17) were analyzed retrospectively. RESULTS: Based on clinical neurological symptoms, the diagnosis of neonatal cerebrovascular disorder was confirmed with different imaging techniques. Parenchymal hemorrhage in 9 cases occurred in frontal, temporal and occipitals lobules. Seven out of 9 cases presented within 72 hrs after birth. Of the 17 cases of cerebral infarction, 10 resulted from cerebrovascular malformation and infarction occurred in different blood supply areas: anterior cerebral artery, middle cerebral artery and posterior cerebral artery. Another 7 cases of cerebral infaction were secondary to systemic diseases and presented with branch cerebral artery blood flow disorder. Repeated convulsion was the characteristic symptom in all cases with neonatal cerebrovascular disorder. CONCLUSIONS: This study reported the clinical features of neonatal cerebrovascular disorder. Imaging examination can provide a definitive diagnosis of this disorder.

OBJECTIVE: Digestive tract malformation is most common in neonatal surgical diseases, for which early surgery is required. The purpose of this study was to show the importance of perioperative biochemical monitoring in newborns. METHODS: Forty neonates with surgical diseases (digestive tract malformation accounting for 40%) aged 13.8±12.7 days were included in this study. Serum biochemical parameters, including blood routine, electrolytes and blood sugar were determined before and after operation. RESULTS: The white blood cell count was within normal range but the ratio of lymphocyte in the differential count significantly increased from 0.34±0.15 to 0.40±0.17 after operation ( P < 0.05 ). In contrast, the hemoglobin level decreased significantly after operation (from 142.11±33.09 g/L to 130.89±27.17 g/L, P < 0.05 ). The levels of serum Na+, K+ and Ca 2+ were not significantly different, while blood sugar contents increased significantly from 6.90±6.24 mmol/L to 10.20±6.89 mmol/L post-operatively (P < 0.05 ). CONCLUSIONS: Post-operatively, neonates may be prone to developing anemia and hyperglycemia. It is important to monitor the changes of biochemical parameters during perioperation.

OBJECTIVE: Neonatal polycythemia has a complicated etiology, for which monovariable analysis was generally used in the most previous studies.This paper investigated the independent risk factors for neonatal polycythemia by multivariable analysis and studied the interactions between the risk factors. METHODS: A case-control study was conducted to investigate 27 potential risk factors for neonatal polycythemia. These risk factors were significant in monovariable analyses and were selected for the non-conditional logistic regression analysis. The interactions of the risk factors were evaluated using an additive model. RESULTS: Monovariable analyses showed that pregnancy-induced hypertension syndrome, fetal asphyxia, fetal distress, small for gestational age, premature rupture of membranes, premature birth, placental abruption, multiple pregnancies and low birth weight were significant(P<0.05).Non-conditional logistic regression analysis indicated fetal asphyxia (OR=7.8255), premature rupture of membranes (OR= 2.7007),pregnancy-induced hypertension syndrome (OR=2.8313),premature birth (OR=7.7394) and low birth weight (OR=7.4803) as independent risk factors for neonatal polycythemia.The interaction analyses showed that there were positive interactions between low birth weight and small for gestational age, low birth weight and fetal distress,as well as premature birth and small for gestational age (synergy index>1). CONCLUSIONS: Risk for neonatal polycythemia is multifactorial. The coexistence of multiple risk factors may increase the incidence of this disorder. Clinically it is important to monitor and manage all potential risk factors.

OBJECTIVE: To understand the clinical and pathological characteristics of the membranoproliferative glomerulonephritis (MPGN) and to explore the therapeutic methods. METHODS: The clinical characteristics, laboratory data, pathological findings and therapeutic methods were investigated retrospectively in the 5 patients with MPGN (aged 8-13 years). RESULTS:  ①All five patients presented with nephritic-range proteinuria (>50 mg/kg· d) and haematuria, 4 patients had hypertension and low serum C_3 levels; and 2 patients, azotemia. ②Renal biopsies revealed mesangial hypercellularety and expanded mesangial matrix in 5 cases, glomerular lobulation, in 3 cases, and crescent formation, in 2 cases. The double contour of basement membrane occurred in 4 cases. Different degrees of tubulointerstitial damage occurred in 5 cases. Immunofluoroscence showed C_3 deposition in 5 cases. ③ All the 5 patients received prednisone combined with intravenous cyclophosplamide (CTX ) alone or added methyprednisolone together with pulse therapy. After treatment, 1 patient achieved a complete remission; 3, partial remission, and persistent nephropathy in 1 case. CONCLUSIONS: The study suggested that clinical manifestation in children with MPGN is characterized by nephritic nephrosis. The pathological changes are characterized by mesangial cells proliferation, expanded mesangial matrix and double contour of basement membrance. High dosage corticosteroids combined with CTX pulse therapy may be effective for improving the short outcome of MPGN.

OBJECTIVE: The degree of renal tubulointerstitial injury determines the prognosis of renal disease. This research studied the relationship among mononuclear cells infiltration, the degree of renal tubulointerstitial injury and the prognosis of renal disease, so as to explore the effect of mononuclear cells infiltration in prognosis of renal disease. METHODS: The renal biopsy specimens from 42 children with primary or secondary kidney disease were studied. Mononuclear cells were detected by CD4+, CD8+ or CD68+ immunohistochemistry. The relationship among the expressions of CD4+, CD8+ and CD68+ in the renal interstitium, renal tubulointerstitial pathological changes and prognosis of renal diseases were analyzed. RESULTS: There were positive correlations between the expressions of CD4+, CD8+ and CD68+ in the renal interstitium and renal tubulointerstitial pathological changes (r_s=0.570,P=0.029;r_s=0.368,P=0.009, r_s=0.468, P=0.003). The renal tubulointerstitial pathological changes were also positively correlated to the prognosis of renal diseases (r_s=0.467, P= 0.001). The expressions of CD8+ and CD68+ in renal interstitium and the prognosis of kidney diseases were correlated (r_s=0.398,P=0.004;r_s=0.328,P=0.036). CONCLUSIONS: There is a close relationship between the density and varieties of infiltrated mononuclear cells in renal interstitium and the prognosis of renal diseases. The mononuclear cells filtration may induce the renal tubulointerstitial fibrosis and result in a poor prognosis of kidney diseases.

OBJECTIVE: Gastrointestinal dysfunction often occurs in the clinical course of many critical illnesses. In order to explore the relationship between gastrointestinal dysfunction and critical illness and to study the role of inflammatory response in the development of gastrointestinal dysfunction and critical illness, this study examined the changes of TNF-α, IL-1β and IL-6 levels in critically ill children and made the regression analysis on systemic inflammatory response syndrome (SIRS), multiple organ failure (MOF), gastrointestinal dysfunction and death. METHODS: The medical data of 2 632 critically ill children admitted to the PICU of The Second Clinical Hospital, China Medical University between 2000 and 2003 were analyzed retrospectively. Logistic regression analysis was used to evaluate the relationship between SIRS classification and gastrointestinal dysfunction as well as the relationship of SIRS classification, MOF classification and gastrointestinal dysfunction with death. The Chi-square test was used to evaluate the relationship between gastrointestinal dysfunction and MOF classification. The levels of TNF-α, IL-1β and IL-6 were expressed as ±s. The Student T- test was used to evaluate the differences between groups. RESULTS: Logistic regression analysis showed that SIRS was a risk factor for gastrointestinal dysfunction (OR=4.711, P<0.05). The prevalence of MOF was not significantly associated with gastrointestinal dysfunction. A significant correlation was found between the number of involved organs in MOF and gastrointestinal dysfunction(χ2=75.6, P<0.05). SIRS classification, MOF classification and gastrointestinal dysfunction were all the risk factors for death(OR =19.642,58.252,63.800 respectively, all P<0.05). The levels of TNF-α, IL-1β and IL-6 in children with gastrointestinal dysfunction were significantly higher than in those without(90.51±3.32 ng/L vs 27.48±2.53 ng/L, 8.13±2.34 ng/L vs 6.03±1.81 ng/L,75.86±7.24 ng/L vs 10.96±2.24 ng/L, respectively, all P<0.05). CONCLUSIONS: Gastrointestinal dysfunction is closely related to critical illness. Cytokines may be involved in the development of gastrointestinal dysfunction. Early diagnosis and active intervention of gastrointestinal dysfunction are needed for children with critical illness.

OBJECTIVE: Cytochrome P450 3A4(CYP3A4) is involved in the metabolisms of many environmental toxins as well as over 50% of drugs including commonly used chemotherapeutic drugs. Polymorphism studies have demonstrated that there are significant individual variations in CYP3A4 activity as well as various distributions in different ethnicities and diseases. Currently there was no reported method in the large scale analysis of CYP3A4 activity. This study aimed to develop a simple, stable and reliable method for the analysis of CYP3A4 activity, and to explore the distributions of the CYP3A4 activity in Chinese children. METHODS: High performance liquid chromatograpy (HPLC) was used to determine the CYP3A4 activity in 85 healthy children and 120 children with acute leukemia. RESULTS: The standard curve had the linear range of 0.01-5 mg/L. The minimal detectable amount was 0.01 mg/L for hydrocortisol and 0.03 mg/L for 6β-hydroxycortisol. Intra- and inter-day assay precisions for hydrocortisol were less than 2% and 5%, respectively, while those for 6β-hydroxycortisol were less than 7% and 10%,respectively. The recovery rate was 98%-106%. The activity range of CYP3A4 in the healthy controls was 2.34 - 48.88,with the average activity of 9.76±6.99. Compared with that of children with acute myelogenous leukemia (AML) (13.97±10.84), there was no statistical difference. The range of CYP3A4 activity in children with acute lymphocytic leukemia (ALL) varied from 2.00 to 585.72, with the average activity of 53.52. It was significantly higher than that of AML (P = 0.0066) and healthy children (P = 0.0065). CONCLUSIONS: This method is rapid and convenient for determining CYP3A4 activity with high sensitivity,accuracy and reproducibility. ALL children have higher CYP3A4 activity than AML and healthy children, while the CYP3A4 activity was similar in the latter two groups.

OBJECTIVE: To study the value of isotype-specific IgM, IgA, IgG and IgE antibodies against Mycoplasma pneumoniae (MP) in the diagnosis of childhood MP infection and the relationship between MP-IgE and asthma attack. METHODS: Specific MP-IgA, MP-IgE and MP-IgG antibodies were measured by ELISA; and specific MP-IgM, with pellet agglutination assay in children with suspected MP infection. Fifty-seven cases with definitive diagnosis of MP infection were followed up for 2-5.5 months. Thirty healthy age-matched children were used as the controls. RESULTS: Of the 372 patients with suspected MP infection, 184 were MP-IgA positive (49.5%), 241 MP-IgM positive (64.8%) and 140 were both MP-IgA and MP-IgM positive. The Chi-squared test showed a significant coincidence between the positive rates of MP-IgA and MP-IgM. MP-IgG positive was found in 105 patients (70.5%) out of 149 cases tested. In the 30 normal controls, only 2 were MP-IgG positive and none, MP-IgA and IgM positive. It was in the second week of the disease course that the positive rates of MP-IgA, MP-IgM and MP-IgG were the highest in 57 patients with definitive diagnosis of MP infection. Recurrent respiratory infection occurs in 25 out of 57 followed-up MP patients. The positive rate of MP-IgA increased significantly in the 25 cases compared the initial positive rate and the titer of MP-IgM also remained high. In the 32 cases without recurrent respiratory infection, the titer of MP-IgM was significantly reduced and the positive rate of MP-IgA did not show differences compared with the initial findings. The positive rate of MP-IgE in patients with MP infection was significantly higher than that in the normal controls and the asthmatic patients without MP infection, but was the same as the asthmatic patients accompanied by MP infection. CONCLUSIONS: The determination of MP-IgA, IgM, IgG and IgE is of importance in increasing the specificity and sensitivity of the diagnosis of MP infection, and especially in the diagnosis of the repeated MP infection. MP-IgE may be associated with the development of asthma attack.

OBJECTIVE: To identify the expressed sequence tags (EST) associated with childhood acute lymphoblastic leukemia (ALL) at chromosome 6q16.3, so as to clone candidate genes at the locus. METHODS: The expression of EST at 6q16.3 in lymphocytes was detected using EST homology analysis in bioinformatics along with reverse transcription-polymerase chain reaction in 10 children with ALL and 5 healthy children. RESULTS: The EST AA403058 expression decreased in seven of ten ALL children compared with that in healthy children (P<0.001). CONCLUSIONS: The EST AA403058 expression is down-regulated in childhood ALL, suggesting it may be involved in the development of childhood ALL. This study provided important information toward cloning childhood ALL associated genes.

OBJECTIVE: It was aimed to study the expression of redoxfactor-1 (APE/Ref-1) protein in the cerebral tissues of neonatal rats after hypoxic-ischemic brain damage (HIBD) and its relationship to apoptosis. METHODS: Seven-day-old neonatal rats were randomly assigned into a Normal control group, a Sham-operation group and a Hypoxic-ischemic (HI) group. The HIBD model was established through the ligation of left common carotid artery along with hypoxic exposure. The expression of APE/Ref-1 protein and apoptosis were determined by immunohistochemistry and terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL) staining at 1, 3, 6, 12, 24 and 48 hrs after HI. RESULTS: Immunohistochemistry results showed extensive nuclear expressions of APE/Ref-1 in the Normal control and Sham-operation groups, and there was no significant difference between the two groups. In the HI group, the nuclear expression of APE/Ref-1 protein decreased significantly with the HI time. The APE/Ref-1 protein expression in the cerebral cortex was significantly different at different HI time points. In contrast, apoptotic cells increased with the HI time and reached a peak 24 hrs after HI. Significant differences were observed in both the APE/Ref-1 protein expression and the number of apoptotic cells between the HI group and the Normal group as well as the Sham-operation group. CONCLUSIONS: The results suggested that the reduction of APE/Ref-1 protein and the failure of DNA repairing might have contributed to apoptosis after cerebral hypoxia and ischemia.

OBJECTIVE: Exposure to high concentrations of oxygen may impair the pulmonary development in premature neonates and ultimately result in chronic lung disease (CLD). But its precise mechanism has not been identified. This study aimed to investigate the role of alveolar epithelial type Ⅱ cells (AECⅡ) apoptosis and its signaling pathways in the development of hyperoxia-induced CLD in premature rats. METHODS: Ninety-three premature newborn rats were randomly assigned into a Control group (exposed to air,n = 45) and a Model group (exposed to ≥95% O_2,n = 48). Apoptosis and relative factor expression were determined with the terminal deoxynucleotidyl transferase-mediated nick end labelling (TUNEL), electron microscopy, and reverse transcriptase PCR (RT-PCR). RESULTS: The apoptotic index increased in the Model group from day 7 to day 21 of hyperoxia inducement(P <0.05). The apoptotic cells were AECⅡ. Bax mRNA levels in the Model group were higher than those in the Control group after the 3rd day(P <0.05), while Bcl-2 expression in the Model group was lower on the 7th, 14th and 21st days than that in the Control group(P <0.05). There was no difference in the Fas mRNA expression between the two groups. CONCLUSIONS: Apoptosis of AECⅡis present in the process of hyperoxia-induced CLD and may be one of major causes of poor alveoli development related to hyperoxia-induced CLD . The changes in the Bax and Bcl-2 ratio may be involved in the initiation of the signaling pathway of AECⅡapoptosis, while Fas transcriptional expression may be irrelevant.

OBJECTIVE: This study examined the effect of mild hypothermia on amplitude integrated electroencephalogram (aEEG) recordings in neonatal pigs with hypoxic-ischemic brain damage (HIBD) and investigated the role of aEEG in the assessment of the effect of mild hypothermia on HIBD. METHODS: Thirty-four 5-day-old piglets were randomly divided into four groups: a Normal control group (normal temperature, n = 7), a Hypothermic-control group (n = 9), a Normothermic hypoxic-ischemic (HI) group (n = 9) and a Hypothermia-treated HI group (n = 9). HIBD was induced by a temporary occlusion of both carotid arteries, followed by mechanical ventilation with low concentration of oxygen (FiO_2 = 0.06) for 30 minutes. The nasopharyngeal and rectal temperature maintained at 35℃±2℃ and 36.0℃±2℃ respectively by head cooling in the two hypothermia-treated groups. The aEEG was recorded before HI and 15 mins, 2 hrs, 12 hrs, 24 hrs, 48 hrs, 72 hrs and 6 days after HI. RESULTS: The normal piglets presented with continuous normal voltage (CNV). The incidence of abnormal waves reflecting the severity of brain damage, continuous low voltage (CLV), burst-suppression (BS) and flat tracing (FT), significantly increased 24 hrs after HI. The incidence of three abnormal waves in the Hypothermia-treated HI group was significantly lower than that in the normothermic HI group. A significant difference was also observed in the incidence of CNV between the two groups 6 days after HI. CONCLUSIONS: The incidence of CLV, BS and FT recorded by aEEG decreased significantly after mild hypothermia treatment, suggesting that mild hypothermia has a neuroprotecive effect against HIBD.

OBJECTIVE: Recent clinical studies have shown that arsenic trioxide (As_2O_3) at low concentrations induces a complete remission with minimal toxicity in patients with refractory acute promyelocytic leukemia (APL). Studies suggest that As_2O_3 induces apoptosis and possible differentiation in APL cells. Like APL cells, neuroblastoma (NB) cells are thought to be arrested at an early stage of differentiation, and cells of highly malignant tumors fail to undergo spontaneous maturation. This study was designed to investigate the effect of (As_2O_3) on apoptosis of neuroblastoma cells in vitro and its mechanism. METHODS: The effect of a wide range of concentrations of As_2O_3 on the proliferation of neuroblastoma cells was measured by the colorimetric method. Morphological changes of the cells were observed under the optical microscope in Giemsa stain. Cell apoptosis was determined by the flow cytometry assay in Annexinⅴ/PI stain. Bcl-2 was detected by the immunocytochemical method. RESULTS: 0.5- 4.0 μmol/L As_2O_3 significantly inhibited the proliferation of the neuroblastoma cell line SK-N-SH and the inhibitory effect was dose- and time-dependent, which was accompanied by the appearance of morphologic characteristics of apoptosis. After 4.0 μmol/L As_2O_3 treatment for 72 hrs, the percentage of apoptotic cells [(9.9±0.8)%] increased significantly when compared with the untreated controls [(3.7±0.2)%] (P<0.05). The expression level of bcl-2 was down-regulated as the concentration of As_2O_3 increased. SK-N-SH cells treated with 1.0 μmol/L, 2.0 μmol/L, and 4.0 μmol/L As_2O_3, the percentage of bcl-2 positive cells [( 26.3±8.0)%, (15.0±4.5)% and (4.8±3.2)% respectively] decreased significantly when compared with the untreated controls [(73.6±6.1)%] (P<0.01). CONCLUSIONS: As_2O_3 may inhibit the proliferation and induce apoptosis of the neuroblastoma cells, in which bcl-2 is involved.

OBJECTIVE: Severe infection is a common cause of gastrointestinal dysfunction in children, the mechanism of which is closely related to endotoxemia and impairment of gut mucosal barrier function. The study was undertaken to investigate intestinal epithelial apoptosis and its possible signal-conducting pathway in rats with endotoxemia. METHODS: The model of endotoxemia was established by intraperitoneal injection of endotoxin (4 mg/kg of Escherichia coli O_ 55∶B_5 lipopolysaccharide) in 40 18-day-old rats (Endotoxin group). Another 40 rats, served as controls and received normal saline (1 mL/kg). Both groups of rats were sacrificed at 2, 4, 6, 24 and 72 hrs after injection. A segment, 4-cm-long, of lower ileum was then removed. The pathologic changes of small intestine villus were observed under an optical microscope (hematoxylin-eosin staining). Apoptosis was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. Caspase-3 expression was measured by immunohistochemistry staining. RESULTS: The structure of small intestinal villi of the Control group remained normal at various time points, while inflammation cells infiltration was observed in the Endotoxin group 4-72 hrs after injection. The apoptotic cells significantly increased 2 hrs after endotoxin injection, and peaked at 24 hrs. The apoptotic index of the Endotoxin group at each time point was significantly higher than that of the Control group (P<0.001). Similarly, the Caspase-3 expression in the Endotoxin group at each time point was significantly higher than that of the Control group. The Caspase-3 expression increased 2 hrs after endotoxin injection and reached a peak at 6 hrs. CONCLUSIONS: Intestinal epithelial apoptosis increases in rats with endotoxemia. Caspase-3 expression is one of its signal-conducting pathways. Cellular apoptosis might be the underlying mechanism of gut mucosal barrier impairment during severe infection.

OBJECTIVE: Necrotizing enterocolitis (NEC) is a common severe gastrointestinal disorder in premature infants. Reactive oxygen species (ROS) has been proved to have a close relationship with the pathogenesis of NEC. This study aimed to explore the relationship between xanthine oxidase (XO), one of the major sources of ROS, and intestinal injury using a neonatal rat model of NEC. METHODS: Forty-eight newborn rats were assigned randomly into two groups: NEC group (n=40, 8 each time point) and Control group (n=8). The rats of the NEC group were given gastric lavage with 5 mg/kg E coli O_ 55∶B_5 endotoxin (LPS) dissolved in 0.2 mL normal saline. The rats of the Control group received gastric lavage treatment with 0.2 mL normal saline alone, and were sacrificed 3 hrs later. The NEC rats were sacrificed 3, 6, 12, 24, and 72 hrs after treatment respectively. A part of lower ileum was removed, fixed, embedded in paraffin.and stained with hematoxylin and eosin for histological evaluation. The rest of the ileum was frozen in liquid nitrogen for XO activity measurements. The correlation between the histological changes and XO activity was studied. RESULTS: The intestinal injury scores were significantly higher in the NEC group 3, 6, 12 and 24 hrs after treatment (1.54±0.87, 1.79±0.75, 1.92±0.43 and 2.29±0.60) than that of the Control group (0.08±0.15) (P<0.05). Increased XO levels were observed in the NEC group at each time point (1.15±0.09, 1.24±0.15, 1.30±0.18 and 1.42±0.21 U/mgprot) when compared with that of the Control group (0.95±0.13 U/mgprot) (P<0.05). Spearman correlation analysis showed a significantly positive correlation between XO levels and intestinal injury scores within 24 hrs of LPS treatment . CONCLUSIONS: XO may play an important role in the development of necrotizing enterocolitis.