Protective effects of IGF-1 on cortical nerve cells of neonatal rats under oxidative stress / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the protective effects of insulin-like growth factor-1 (IGF-1) on the nerve cells of neonatal rats under oxidative stress.</p><p><b>METHODS</b>Primary cortical neurons, oligodendrocytes, and astrocytes from newborn rats were cultured. An oxidative stress model was established with different concentrations of H2O2 (0-60 μmol/L); the degree of damage of nerve cells was evaluated by lactate dehydrogenase assay, and the viability of nerve cells was tested by MTT assay. An oxidative stress model was established with different concentration of H2O2 (0-80 μmol/L). Expression of Akt/p-Akt (Ser473) in neurons was measured by Western blot before and after IGF-1 (25 ng/mL) administration.</p><p><b>RESULTS</b>Compared with those not treated with H2O2, the cortical neurons, oligodendrocytes, and astrocytes treated with different concentrations of H2O2 for 24 hours showed increased damage and decreased cell viability; compared with oligodendrocytes and astrocytes, neurons showed significantly more changes (P<0.01). Compared with those not treated with H2O2, the cortical neurons treated with different concentrations of H2O2 for 5 minutes showed a significant decrease in p-Akt (Ser473) level (P<0.01), which was dependent on the concentration of H2O2. For the neurons treated with low-concentration H2O2, the addition of IGF-1 could reverse the inhibition of Akt phosphorylation, eliminating the difference in p-Akt level compared with the neurons not treated with H2O2, (P>0.05); however, it had no significant effect on the inhibition of Akt phosphorylation by high-concentration H2O2, and the treated neurons still had a lower p-Akt level than untreated neurons (P<0.01 for all). For the cortical neurons that had been treated with different concentration of H2O2 for 1 hour, the addition of IGF-1 (25 ng/mL) could eliminate thedifference in p-Akt level between the treated neurons and untreated neurons (P>0.05).</p><p><b>CONCLUSIONS</b>Cortical neurons are more sensitive to oxidative stress induced by H2O2 than other nerve cells. IGF-1 has protective effects on cortical nerve cells under oxidative stress.</p>

Effect of hyperoxia on A549 cells suppressed with surfactant protein-A suppressed by small RNA interference-mediated gene silencing / 中华实用儿科临床杂志

Objective To explore the effect of hyperoxia on A549 cells suppressed with surfactant protein A (SP-A) suppressed by small interference RNA(SiRNA)-mediated gene silencing,and discuss the function of SP-A in hyperoxic lung injury.Methods A549 cells were gained by serial sub cultivation in vitro and randomly divided into 2 groups,silenced of SP-A group and the control group.A549 cells were transfected with synthetic SP-A sequence-specific SiRNA by Lipofectamine 2000,continuously exposed to hyperoxia(950 mL/L 02,50 mL/L CO2).After exposure to hyperoxia for 48 hours,72 hours and 96 hours,total protein and culture supernatant were gained.SP-A protein was detected by Western-blot,the capacity of proliferation was detected by methyl thiazolyl tetrazolium,and thiobarbituric acid colorimetric method was used to detect the malondialdehyde (MDA) in culture supernatant.Results Sequence-specific SiRNA targeted SP-A2 and significantly down-regulated its expression in A549 cells.Compared with the control group in hyperoxia,the expression of SP-A significantly decreased after 48 hours,72 hours in the silenced group (all P ＜ 0.05),and the capacity of proliferation in A549 cells silenced by SP-A were obviously decreased after 48 hours,72 hours and 96 hours(all P ＜0.05).But there was no significant difference in the MDA in culture supernatant between 2 groups(all P ＞ 0.05).Conclusions The capacity of resisting hyperoxia decreased in A549 cells silenced by SP-A,which indicates that SP-A can protect hyperoxic lung injury.

Association of surfactant protein B gene polymorphisms (C/A-18, C/T1580, intron 4 and A/G9306) and haplotypes with bronchopulmonary dysplasia in chinese han population / 华中科技大学学报（医学）（英德文版）

This study aimed to investigate the association between surfactant protein B (SP-B) polymorphisms and bronchopulmonary dysplasia (BPD) in Chinese Han infants. We performed a casecontrol study including 86 infants with BPD and 156 matched controls. Genotyping was performed by sequence specific primer-polymerase chain reaction (PCR) and haplotypes were reconstructed by the fastPHASE software. The results showed that significant differences were detected in the genotype distribution of C/A-18 and intron 4 polymorphisms of SP-B gene between cases and controls. No significant differences were detected in the genotype distribution of C/T1580 or A/G9306 between the two groups. Haplotype analysis revealed that the frequency of A-del-C-A haplotype was higher in case group (0.12 to 0.05, P=0.003), whereas the frequency of C-inv-C-A haplotype was higher in control group (0.19 to 0.05, P=0.000). In addition, a significant difference was observed in the frequency of C-inv-T-A haplotype between the two groups. It was concluded that the polymorphisms of SP-B intron 4 and C/A-18 could be associated with BPD in Chinese Han infants, and the del allele of intron 4 and A allele of C/A-18 might be used as markers of susceptibility in the disease. Haplotype analysis indicated that the gene-gene interactions would play an important part in determining susceptibility to BPD.

Association of surfactant protein B gene polymorphisms (C/A-18, C/T1580, intron 4 and A/G9306) and haplotypes with bronchopulmonary dysplasia in chinese han population / 华中科技大学学报（医学）（英德文版）

This study aimed to investigate the association between surfactant protein B (SP-B) polymorphisms and bronchopulmonary dysplasia (BPD) in Chinese Han infants. We performed a casecontrol study including 86 infants with BPD and 156 matched controls. Genotyping was performed by sequence specific primer-polymerase chain reaction (PCR) and haplotypes were reconstructed by the fastPHASE software. The results showed that significant differences were detected in the genotype distribution of C/A-18 and intron 4 polymorphisms of SP-B gene between cases and controls. No significant differences were detected in the genotype distribution of C/T1580 or A/G9306 between the two groups. Haplotype analysis revealed that the frequency of A-del-C-A haplotype was higher in case group (0.12 to 0.05, P=0.003), whereas the frequency of C-inv-C-A haplotype was higher in control group (0.19 to 0.05, P=0.000). In addition, a significant difference was observed in the frequency of C-inv-T-A haplotype between the two groups. It was concluded that the polymorphisms of SP-B intron 4 and C/A-18 could be associated with BPD in Chinese Han infants, and the del allele of intron 4 and A allele of C/A-18 might be used as markers of susceptibility in the disease. Haplotype analysis indicated that the gene-gene interactions would play an important part in determining susceptibility to BPD.

Oxidative stress inhibits the protective effects of insulin-like growth factor-1 on cortical neurons of neonatal rat / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the protective effects of insulin-like growth factor-1(IGF-1) on the survival and apoptosis of cortical neurons of neonatal rat under oxidative stress and its significance.</p><p><b>METHOD</b>Primary cortical neurons from newborn rat were cultured and the oxidative stress model was established. Then cells were randomly divided into IGF-1 group and control group. The concentration of LDH in supernatant was detected. Cell survival was determined with MTT assay and the expression of active Caspase-3 was measured using Western Blotting.</p><p><b>RESULT</b>(1) The values of LDH gradually decreased with the increasing IGF-1 added to the cells [(0.5065 ± 0.0064) to (0.435 ± 0.0065), (P < 0.01)], but when the concentration of IGF-1 reached a certain level (> 25 ng/ml), there were no longer obvious effects on the level of LDH [(0.42 ± 0.012) to (0.418 ± 0.0098), (P > 0.05)]; Western blot showed that the level of active Caspase-3 was significantly decreased after treatment with IGF-1 [(0.662 ± 0.033) to (0.199 ± 0.01), (P < 0.01)]. (2) Compared with control group, without or with low concentration of H2O2 (0 - 40 µM), the values of LDH and the expression of active Caspase-3 in IGF-1 group were significantly decreased[(1.518 ± 0.137) to (1.068 ± 0.067), (P < 0.05) and 0.850 ± 0.042 to 0.597 ± 0.03, P < 0.01, respectively] while the values of MTT obviously elevated [(0.773 ± 0.062) to (1.196 ± 0.057), (P < 0.05)]; but with higher concentration (≥ 60 µM) of H2O2, the values of LDH and MTT and the expression of active Caspase-3 in IGF-1 group all had no significant difference (P > 0.05). (3) When the concentration of H2O2 reached 60 µM and higher, whatever concentration of IGF-1 could not lower the level of LDH compared with control group [(2.376 ± 0.04) to (2.442 ± 0.046), (P > 0.05)].</p><p><b>CONCLUSIONS</b>Oxidative stress can induce IGF-1 resistance of cortical neurons in neonatal rat, and even increasing the concentration of IGF-1 can not restore their sensitivity to IGF-1.</p>

Effects of Matrigel on expression of focal adhesion kinase and on proliferation and apoptosis of alveolar epithelial cell II of premature rat exposed to hyperoxia / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the effects of Matrigel on expression of focal adhesion kinase and on proliferation and apoptosis of alveolar epithelial cell II of premature rat exposed to hyperoxia.</p><p><b>METHODS</b>The primary premature rat AECII (gestation 19 d) were cultured in vitro. For establishing hyperoxia-exposed cell model, purified AECII were cultured for 12 hours after culture flasks were filled with 95% oxygen-5% CO2 at 5 L/min, and then sealed for 12 hours. DNA content, phosphor and total protein of FAK were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively after 12 hours of air or hyperoxia exposure in the presence or absence of Matrigel. To investigate the relationship between FAK activated and proliferation or apoptosis of type II alveolar epithelial cells, levels of proliferation and apoptosis of AECII were measured by immunohistochemical assay of proliferating cell nuclear antigen (PCNA) and TUNEL method respectively.</p><p><b>RESULTS</b>FAK and FAK-Tyr(397) activity of AECII on Matrigel-coated substrate increased: compared with air group, the expression of PCNA decreased and apoptotic index increased markedly in hyperoxia group (0.1498 ± 0.009 vs. 0.0953 ± 0.006, P < 0.05; 1.232 ± 0.6 vs. 13.40 ± 3.2, P < 0.01), but the expression of PCNA of AECII on Matrigel-coated substrate increased significantly (0.1498 ± 0.009 vs. 0.1921 ± 0.008, P < 0.01) and apoptotic index did not change. The expression of PCNA increased significantly (0.0953 ± 0.006 vs. 0.1125 ± 0.012, P < 0.05) and apoptotic index decreased markedly in hyperoxia + Matrigel group as compared with hyperoxia group (13.40 ± 3.2 vs. 7.641 ± 1.6, P < 0.05).</p><p><b>CONCLUSION</b>Hyperoxia decreased the level of FAK and FAK-Tyr(397) in AECII, which may be a contributory mechanism of impaired proliferation and apoptosis of AECII in hyperoxia induced lung injury in premature rat. Matrigel could inhibit apoptosis and promote proliferation of AECII resulted from hyperoxia in vitro. Matrigel may play a protective role in hyperoxia-induced lung injury partly due to activated FAK.</p>

Dynamic expression of CyclinD1 and p21CIP1 during lung development in rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>CyclinD1 and p21CIP1 are major proteins to regulate lung cell proliferation and involved in lung development and lung injury reparation. This study aimed to explore the expression manners of CyclinD1 and p21CIP1 at canalicular, saccular and alveolar stages during lung development in Sprague-Dawley rats.</p><p><b>METHODS</b>Lung tissues were obtained from fetal rats of 20 and 21 days gestational ages, and neonatal rats at 0, 3, 7, 14 and 21 days (n=6). Lung tissues were used for histopathology and the protein analysis of CyclinD1 and p21CIP1 (immunohistochemistry and Western blot).</p><p><b>RESULTS</b>The strongest expression of CyclinD1 and the weakest expression of p21CIP1 occurred at 20-21 days gestation (canalicular stage). At the canalicular stage, CyclinD1 was mainly expressed in epithelial cells, and the expression of p21CIP1was negative. At the saccular stage, the expression of CyclinD1 decreased significantly and the p21CIP1 expression increased significantly. Positive expression of CyclinD1 and p21CIP1 was found in epithelial cells and interstitial cells. At the alveolar stage, the CyclinD1 expression was the lowest and the p21CIP1 expression was the highest. The positive expression of CyclinD1 was found in interstitial cells and that of p21CIP1 was found in epithelial cells.</p><p><b>CONCLUSIONS</b>The location and quantity of CyclinD1 and p21CIP1 expression are different at various stages during lung development in rats. A strongest CyclinD1 expression found in the canalicular stage may be associated a high lung cell proliferation. A strongest p21CIP1 expression found in the alveolar stage may be associated with alveolar maturity.</p>

Retinoic acid diminished the expression of lung tissue matrix metalloproteinase-2 and matrix metalloproteinase-9 in hyperoxia-exposed premature rats through regulating mitogen-activated protein kinases / 中华儿科杂志

<p><b>OBJECTIVE</b>To further investigate the protective effect of retinoic acid (RA) on hyperoxia induced lung injury and the role of RA as a modulator on mitogen-activated protein kinases (MAPKs).</p><p><b>METHODS</b>Establishment of hyperoxia (85%) induced lung injury model of premature Sprague-Dawley (SD) rats: 21 d gestational age SD rat's fetuses (term = 22 d) were delivered by hysterectomy. Within 12 - 24 h after birth, the premature rat pups were randomly divided into 4 groups: Group I, air-exposed control group; Group II, hyperoxia-exposed group; Group III, air plus RA-exposed group, Group IV, hyperoxia plus RA-exposed group. Group I and III were remained in room air, and group II and IV were placed in 85% oxygen. The pups in Group III and IV were injected with RA (500 microg/kg, every day) intraperitoneally. The entire lung tissues of premature rat pups were collected at 4 d, 7 d and 14 d. The mRNA levels of MMP-2 and MMP-9 were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). MMP-2 and MMP-9 activities were measured by zymography. Western blot was used to detect phosphorylated and total nonphosphorylated form of ERKs, JNKs and p38.</p><p><b>RESULTS</b>Exposure to oxygen for 4 d, 7 d, and 14 d resulted in increased mRNA levels of MMP-2 and MMP-9 compared with air-exposed control group (P < 0.01 for all). The mean protein levels of active MMP-2 and pro/active MMP-9 after exposure to O2 were higher than air control groups on each experimental day (P < 0.01 or < 0.05). The phosphorylated ERK1/2, JNK1/2 and p38 proteins in hyperoxia-exposed group increased markedly compared with air-exposed control group (P < 0.01 for all). The pups treated with RA in the hyperoxic environment expressed significantly lower mRNA levels of MMP-2 and MMP-9 than the hyperoxic control pups on each experimental day (P < 0.05 for all). The levels of active MMP-2 and pro/active MMP-9 decreased to a different degree after RA treatment in hyperoxia exposure rat pups. In addition, RA treatment led to a decrease of p-JNK1/2 and p-38 (P < 0.01 for all) protein levels and a further elevation of p-ERK1/2 compared with hyperoxia-exposed group.</p><p><b>CONCLUSION</b>Hyperoxia exposure elevated the expression of MMP-2 and MMP-9 markedly, which played a role in oxygen-induced lung injury. RA could have a protective effect on hyperoxia induced lung injury by decreasing active levels of JNK and p38, which subsequently reduce the expression and activation of MMP-2 and MMP-9.</p>

Temporal expression and significance of caspase-3 and interleukin-8 in the lungs of preterm rats exposed to hyperoxia / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the temporal expression and significance of Caspase-3 and interleukin-8 (IL-8) in hyperoxia-induced lung injury in preterm rats.</p><p><b>METHODS</b>Two-day-old Sprague-Dawley preterm rats were randomly divided into Air group and Hyperoxia group (each rats in each group). Rats in the Hyperoxia group were exposed to 85% O(2), while rats in the Air group were exposed to air. The rats in each group were sacrificed at 1, 4, 7, 14 and 21 days after exposure (8 rats at each time point), and lung tissues were collected. Pathomorphology of lungs was observed by hematoxylin-eosine staining. The contents of IL-8 in the homogenate of lungs were detected using ELISA. The expression of Caspase-3 was detected by immunohistochemistry and Western blot.</p><p><b>RESULTS</b>(1) Lung histopathology: after hyperoxia exposure 1 day, no significant effects on alveoli were found; but on days 4 and 7, alveolitis appeared: there were necrotic abscission cells in alveolar space, increased inflammatory cells infiltration, lung interstitial edema; on days 14 and 21, lung structure derangement, decreased number of alveoli, simplified and vesicular lung structure, all of which showed the retardation of alveolar formation. (2) the contents of IL-8 in the homogenate of lungs had no significant change on day 1 but increased significantly on days 4, 7 and 14 compared with air control group (P < 0.01 for all). (3) Immunohistochemistry detected the expression of Caspase-3 in the lung: the intensity of Caspase-3 expression increased significantly on days 4, 7 and 14 compared with air control group (P < 0.01). (4) Western blotting detected the expression of caspase-3 in the lung: the pattern of dynamic expression of Caspase-3 was similar to the results of immunohistochemistry.</p><p><b>CONCLUSIONS</b>Both apoptosis and necrosis contribute to cell death during hyperoxia. Apoptosis and necrosis may both play an important role in hyperoxia-induced lung injury in preterm rats.</p>

Value of magnetic resonance imaging in the early evaluation of prognosis for hypoxic-ischemic encephalopathy in full-term infants / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To understand the clinical characteristics of hypoxic-ischemic encephalopathy (HIE) in full-term infants and to explore the value of magnetic resonance imaging (MRI) for the early prediction of HIE prognosis.</p><p><b>METHODS</b>The medical data, including histories, clinical manifestations, MRI findings and follow-up outcomes, of 348 full-term infants with HIE between January 2001 and December 2005 were retrospectively reviewed.</p><p><b>RESULTS</b>HIE patients (348 cases) accounted for 8.25% of in-patients (4220 cases) over the five years. The etiology of HIE mainly attributed to birth asphyxia (76.2%), consisting of mild asphyxia (59.2%) and severe asphyxia (40.8%). A poor outcome was confirmed in 10.1% of these patients, including 27.3% in severe HIE, 10.0% in moderate HIE and 1.5% in mild HIE cases. All of patients whose MRI showed diffusion intraparenchymal hemorrhages and cerebral infarctions had poor outcomes. Fourteen (87.5%) out of the 16 cases with basal ganglia and thalamic or internal capsule injury and 9 (81.8%) out of the 11 cases with cytotoxic brain edema diagnosed by diffusion weighted imaging had poor outcomes.</p><p><b>CONCLUSIONS</b>HIE is one of common diseases in newborn infants. The etiology of neonatal HIE mainly attributed to birth asphyxia, mild asphyxia accounting for a greater proportion. MRI findings can be helpful for the early prediction of HIE prognosis.</p>

A preliminary study on diagnosis and grading of hypoxic-ischemic brain damage of premature infants / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Hypoxic-ischemic brain damage (HIBD) occurs frequently in premature infants, resulting death or neurological sequela in some survivors. Up to now, however, there are no diagnostic criteria for this disease. The aim of this study was to explore the diagnostic criteria and the grading principle for HIBD of premature infants.</p><p><b>METHODS</b>The clinical data of 453 premature infants who were diagnosed with HIBD based on the diagnostic criteria for HIBD of term infants, including medical history, clinical manifestations, laboratory results and imaging findings, were studied retrospectively.</p><p><b>RESULTS</b>A preliminary diagnostic criteria for HIBD of premature infants was propounded based on clinical and pathologic features of brain damage of premature infants. Of the 453 premature infants, 346 (76%) matched the diagnostic criteria. Of the 346 cases, PaO2 (42.21 +/- 8.33 mmHg) and /or SaO2 (68.49 +/- 5.19%) decreased in 208 patients and the BE value (-10.86 +/-3.41 mmol/L) decreased in 138 patients. The sensitivity and specificity of cranial computer tomography for the diagnosis of HIBD in premature infants was 100% and 17.8%, respectively. Cranial ultrasound displayed a sensitivity of 87.9% and specificity of 100% for the diagnosis of HIBD in premature infants.</p><p><b>CONCLUSIONS</b>The diagnostic criteria used for HIBD for term infants is not suitable for premature infants. This study puts forward the reference diagnostic criteria of premature HIBD as following: 1) evidence of hypoxia; 2) neurological symptoms and signs; 3) imaging findings: severe brain edema, germinal matrix intraventricular hemorrhage (GMH-IVH), periventricular leukomalacia (PVL), or brain infarction, and/or the resistance index (RI) > 0.75 or < 0.55 showed by cranial ultrasound; 4) Brain damage caused by infection, electrolyte disturbance and congenital metabolic disease was excluded. The grading principle of premature HIBD is proposed as follows: MILD HIBD when cranial ultrasound shows grade I-II of GMH-IVH or PVL, and SEVERE HIBD when cranial ultrasound shows grade III-IV of GMH-IVH or PVL.</p>

Effect of Intravenous Nutrition on Immune Function in Premature Infants / 实用儿科临床杂志

Objective To observe the effect of intravenous nutrition on blood serum triglyceride (TG),humoral immunity and cellular immunity function in premature infants.Methods Sixty premature infants were randomly divided into 3 groups:amino acid group (group A),amino acid plus medium-long chain fatty group (group B) and amino acid plus long chain fatty group (group C).Amino acid and the fatty were used on them from 24 hours after their birth,started from 1.0 g/(kg?d),increased progressively 0.5 g/(kg?d) until 3.0 g/(kg?d),totally 7 days.TG and immunoglobulin IgA,IgM,IgG,complement C3,C4 and T-lymphocyte subsets CD3,CD4,CD4/CD8 and NK cell were checked in the first day before treatment and the ninth day after treatment.Results Compared with before treatment,TG of 3 groups were elevated(Pa0.05).Compared with group A and B,NK cell in group C were decreased obviously(Pa

Protective effects of amygdalin on hyperoxia-exposed type II alveolar epithelial cells isolated from premature rat lungs in vitro / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the effect of hyperoxia on the proliferation and surfactant associated protein messenger RNA levels of type II alveolar epithelial cells (AECIIs) of premature rat, and to investigate the effect of amygdalin on the change resulted from hyperoxia in AECIIs isolated from premature rat lung in vitro.</p><p><b>METHODS</b>The lung tissue of 20-day fetal rat was digested by trypsin and collagenase. AECIIs and lung fibroblasts (LFs) were isolated and purified at different centrifugal force and different adherence, then cultured. The nature of the cultures was identified by cytokeratin staining, vimentin staining and transmission electron micrography. For establishing hyperoxia-exposed cell model, purified AECIIs were cultured for 24 hours after culture flasks were filled with 95% oxygen-5% CO2 at 3 L/min for 10 min, and then sealed. Oxygen concentrations were tested in CYS-1 digital oxygen monitor after 24 hours of exposure. A sample was discarded if its oxygen concentration was < 90%. Cell proliferating vitality was examined by MTT assay after treatment with amygdalin at various concentrations. DNA content, protein expression of proliferating cell nuclear antigen (PCNA) and mRNA levels of SPs of AECIIs were analyzed with flow cytometric assay, Western blot and reverse transcription polymerase chain reaction (RT-PCR) respectively after 24 hours of air or hyperoxia exposure in the presence or absence of 200 micromol/L amygdalin.</p><p><b>RESULTS</b>Excellent yields of highly purified, culturable AECIIs could be obtained from 20-day fetal lungs. The expression of cytokeratin in AECIIs was positive and that of vimentin negative by immunocytochemistry. Those, however, in LFs were just opposite. Lamellar bodies in purified AECIIs were revealed by transmission electron micrography. The established hyperoxia-exposed cell model assured the oxygen concentrations of culture flasks more than 90%. Amygdalin at the concentration range from 50 micromol/L to 200 micromol/L stimulated the proliferation of AECIIs in a dose-dependent manner; however, at the concentration of 400 micromol/L inhibited the proliferation of AECII. Flow cytometric analysis showed that the apoptosis rate and G0/G1 phase percentage increased significantly (P < 0.01), S phase and G2/M phase percentage decreased significantly (P < 0.01), in hyperoxia group compared with that of air group. The apoptosis rate of air plus 200 micromol/L amygdalin group, compared with air group, was not significantly different (P > 0.05); however, G0/G1 phase percentage decreased markedly, S phase percentage increased significantly, G2/M phase percentage did not significantly change (P > 0.05). The apoptosis rate of hyperoxia plus 200 micromol/L amygdalin group was not significantly different (P > 0.05) from that of hyperoxia group, S phase and G2/M phase percentage increased significantly (P < 0.01), G0/G1 phase percentage decreased significantly (P < 0.01). Western blot analysis showed that the protein expression levels of PCNA in all group was significantly different, in turn, hyperoxia group < hyperoxia plus 200 micromol/L amygdalin < air group < air puls 200 micromol/L amygdalin (P < 0.01). SPs mRNA levels were significantly decreased in hyperoxia group, as compared with air group (P < 0.01). After amygdalin was added, SPs mRNA levels were elevated in air plus amygdalin group and hyperoxia plus amygdalin group, as compared with hyperoxia group (P < 0.01, P < 0.05, respectively), but compared with air group, SP mRNA levels were not significantly elevated (P > 0.05).</p><p><b>CONCLUSION</b>AECIIs of premature rats were isolated, purified and cultured successfully. Hyperoxia-exposed cell model was established in AECIIs of premature rat in this experiment. Amygdalin promotes the proliferation of premature rat AECII exposed to air or hyperoxia, the concentration of amygdalin with the best effect was 200 micromol/L. Hyperoxia inhibited the proliferation and decreased SPs mRNAs levels in AECIIs in vitro, which may contribute to hyperoxia-induced lung injury in premature rats. Amygdalin could inhibit the changes of SPs mRNAs levels and cell proliferation of AECIIs resulted from hyperoxia and may play partial protective role in hyperoxia-induced premature lung injury.</p>

Change of Cytochrome Oxidase Expression in Type Ⅱ Alveolar Epithelial Cell of Rats Exposed to Hyperoxia / 实用儿科临床杂志

Objective To observe the expression of mitochondrial encoding cytochrome oxidase subunitⅠ(COXⅠ) and subunitⅡ(COXⅡ) in type Ⅱalveolar epithelial cell(AEC Ⅱ) of rats exposed to hyperoxia and explore the role of COXⅠand COXⅡ in hyperoxia-induced lung injury.Methods AECⅡ were gained by primary culture from 19-days fetal rats lung.After purified,AECⅡ were randomly assigned to hyperoxia group and air group.Hyperoxia group was flushed the flake with 950 mL/L O2 and 50 mL/L CO2 at 3 L/min for 10 min,then sealed.Both groups were in CO2 culture chamber(37 ℃,50 mL/L CO2).After 6,12 and 24 hours of exposure,AECⅡ were harvested and extracted for total RNA.COXⅠand COXⅡ mRNA were detected by reverse transcription polymerase chain reaction(RT-PCR).The results were analyzed by SPSS 12.0 softwore.Results Compared with air group,COXⅠmRNA expression in hyperoxia group increased significantly at 6 hours(t=3.832 P=0.019) and 12 hours(t=10.431 P=0),respectively,then decreased to the equivalent level in 24 hours(t=0.360 P=0.731).Compared with air group,COXⅡmRNA expression in hyperoxia group increased significantly at 6 hours(t=2.795 P=0.035),then decreased to the equivalent level at 12 hours(t=0.892 P=0.40) and 24 hours(t=2.018 P=0.071).Conclusions Exposure of hyperoxia up-regulate the expressions of COXⅠmRNA and COXⅡmRNA in AECⅡ,which may be a protective mechanism of hyperoxia-induced lung injury.

Proton MR spectroscopy study in neonates with hypoxic ischemic encephalopathy / 中华放射学杂志

Objective To investigate the metabolic alterations in the brain of neonates with HIE and correlate those alterations with clinical grading and prognosis of HIE.Methods Fourty-six eases of full-term neonates diagnosed as HIE clinically were performed MRI and 1~H-MRS,9 healthy neonates without the evidence of asphyxia were studied as controls,1~H-MRS techniques included single voxel proton MRS and two dimensional muhi-voxel chemical shift spectroscopy imaging,point resolved spectroscopy sequence was used for 1~H-MRS.Metabolic changes in the spectroscopy were analyzed in neonates with HIE,and study the relationgship between MRS findings and prognosis.Results(1)The typical 1~H-MRS manifestations of full- term neonates suffering from HIE were as follows:the peaks of Lac were elevated,GLx-? were elevated and NAA were decreased.(2)GLx-?/Cr ratio in control,mild,moderate and severe HIE group was 0.16, 0.21,0.64,and 1.31,respectively.Lac/Cr ratio in control,mild,moderate and severe HIE group was 0.12,0.14,0.19,and 0.26,respectively.There was a significant difference in the ratio of GLx-? and Lac/Cr between HIE group and control group(t=5.01,P

Relative Factors of Glucose Metabolism Disorders in Newborn Infants / 实用儿科临床杂志

Objective To investigate the relative risk factors of glucose metabolism disorder in newborn infants.Methods Clinical information of 791 newborns suffered from glucose metabolism disorders who had been hospitalized in NICU from Jan.2004 to May 2007 were analyzed retrospectively.Four hundred and thirty-nine cases presented with hypoglycemia,275 cases presented with hyperglycemia,and 77 cases presented with both hypoglycemia and hyperglycemia.Data of risk factors were processed with both ?2 test and multiple Logistic regression analysis.Results The statistic analysis showed that low birth weight[258 cases(58.77%)],asphyxia[217 cases(49.43%)],acidosis[146 cases(33.26%)],hypothermia[128 cases(29.16%)],maternal gestational hypertension[83 cases(18.91%)],pneumonia[63 cases(14.35%)],anomaly of placenta[35 cases(7.97%)],maternal diabetes[17 cases(3.87%)] and septicaemia[10 cases(2.28%)]were significant hypoglycemia risk factors(according to the level of morbidity).Pneumonia[98 cases(35.64%)],asphyxia[129 cases(27.23%)],hypoxemia[61 cases(22.18%)]and septicaemia[24 cases(8.73%)]were significant hyperglycemia risk factors.Acidosis[33 cases(42.86%)],pneumonia[27 cases(35.06%)]and maternal diabetes[6 cases(7.79%)] were significant risk factors for neonates with both hypoglycemia and hyperglycemia.Conclusion Dynamic monitoring of blood glucose concentration and reasonable adjustment is recommended for neonates with risk factors to lower morbility and mortality.

Research Progress on Mitochondria-Located Thioredoxin / 实用儿科临床杂志

The thioredoxin system consists of thioredoxin(Trx),thioredoxin reductase(TrxR)and reduced nicotinamide adenine dinucleo-tide phosphate.Trx is a small redox-active multifunctional protein.Thioredoxin 2,which is localized in the matrix mitochondria,has been shown involved in not only oxidative stress,nucleic acid metabolism,cell grow and apoptosis,but also many diseases such as organism growth and development,oxidative stress damage,cancer and ischemical reperfusion injury.It participates in redox reactions by reversible oxidation of its active center dithiol to disulfide and catalyzes dithio-disulfide exchange reactions involving many thiol-dependent processes.As signaling molecule,Trx2 participates in many signaling pathways.

Expression of Notch2,Notch4 in Hyperoxia Induced Lung Injury in Premature Rats / 实用儿科临床杂志

Objective To explore the roles of Notch2,Notch4 in hyperoxia induced lung injury in premature rats.Methods At the postnatal 1 day Sprague-Dawley premature rats were randomly assigned to about 85% hyperoxia group and air group.At the 1,7,14,21 days after exposed,8 rats of each group were used to evaluate expressions of Notch2,Notch4 in lungs by immunohistochemistry and the level of Nothch2,Notch4 mRNA by reverse transcription polymerase chain reaction(RT-PCR).Results Expressions of Notch2,Notch4 had their rules in rats′ different stages of development;85% oxygen exposed would change their tracks.Conclusion Prolonged 85% oxygen exposure result in abnormal expressions of Notch2 and Notch4 ,which is likely to lead to the pathogenesis of hyperoxic lung injure in premature rats.