Knockdown of survivin expression increases chemosensitivity of glioma cells to temozolomide / 解放军医学杂志

Objective To study the effect of survivin on temozolomide (TMZ) resistance of glioma cells and possible mechanism.Methods Survivin RNA and survivin shRNA plasmids were transfected into U87 cells,respectively.The cell growth curve drawn by MTT was used to test the changes in the proliferation of glioma cells.Colony forming assay was used to calculate cell surviving fraction.The Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining were applied to detect the apoptosis rate by flow cytometer (FCM).Western blotting was used to detect the expression of activated caspase-3.Results The cell proliferation and cell surviving fraction were inhibited by TMZ,and it was more significantly inhibited in TMZ plus down-regulation of survivin.Compared with parental cells,U87/sur si cells,treated by TMZ,showed a decrease in proliferation and colony forming efficiency and an increase in apoptosis rate,whereas U87/sur cells,treated by TMZ,showed an increase in proliferation and colony forming efficiency and a decrease in apoptosis rate.Western blotting showed that compared with TMZ alone,the expression of activated caspase-3 protein was promoted in TMZ plus down-regulation of survivin.Conclusion Down-regulation of survivin could enhance the sensitivity of glioma cells to TMZ,which may be related to survivin promoting cell apoptosis.

Culture of glial lineage progenitor cells derived from white matter and establishment of its oxygen-glucose deprivation models / 中华神经医学杂志

Objective To in vitro culture glial lineage progenitor cells derived from periventricular white matter in neonatal rats,and establish oxygen-glucose deprivation models of progenitor cells to further explore the mechanism of neurogenesis in the ischemic white matter injury.Methods The progenitor cells were isolated and cultured from the white matter of 3-d-old neonatal rats.Cells were passaged every 3 or 4 d,and were further induced differentiation.The primary and passaged neurospheres and their differentiated cells were respectively identified by immunocytochemical stanning of NG2 (Neurospheres marker) and O4 (oligodendrocyte precursor marker).The third-or fourth-generation progenitor cells were used to establish the ischemic model of oxygen-glucose deprivation (OGD).The influence of different OGD periods (30,45 and 60 min,2 and 3 h) in the survival rates of progenitor cells was assessed 24 h after success of model making by both CCK-8 and Hoechst 33342/PI stainning.Results The progenitor cells obtained from the white matter had the capacity of forming neurospheres and reproduction which showed NG2 immunoreactive positivity,and could be induced differentiation into O4-positive oligodendrocyte precursors.No apoptotic or necrotic cells were observed in normal cultured NG2-positive progenitor cells.The apoptotic and necrotic cells tended to increase significantly with the extension of OGD period gradually.The survival rates of progenitor cells in turn were (85.94±3.06) ％ for 30 min OGD,(62.68±2.66) ％ for 45 min OGD,(45.09±2.24) ％ for 60 min OGD,(36.70±2.84) ％ for 2 h OGD and (22.01±3.00) ％ for 3 h OGD,respectively,with significant differences between each two groups (P＜0.05).Conclusion The oxygen-glucose deprivation models of glial lineage progenitor cells derived from periventricular white matter of neonatal rats are successfully established,which may provide the foundation for further exploring the mechanism of neurogenesis in the ischemic white matter injury.

Study of subependymal ventricular zone and white matter as an endogenous source of cells for white matter repair in neonatal rats with periventricular leukomalacia in vitro / 中华实用儿科临床杂志

Objective To explore an endogenous self-repair potentiality for injured cerebral white matter from both of subependymal ventricular zone and white matter cell cultures in neonatal rats with oxygen glucose deprivation (OGD) in vitro.Methods The white matter and subependymal ventricular zone tissues from the neonatal rats within 5 days old were separately used to prepare primary glia-derived cell cultures,and these cell cultures were randomly divided into the control group and the OGD group.The double-label fluorescent immunoanalysis was used to observe the proliferation and differentiation of the glia-derived cells came from both of subependymal ventricular zone and white matter activated by OGD.The Hoechst33342/propidium iodide (PI) staining and the flow cytometry technology were used to assess the apoptotic rates of the newborn cells.Results More apoptotic and necrotic cells appeared in the OGD group than those in the control group both in subependymal ventricular zone and white matter cell cultures in the flow cytometry test and Hoechst33342/PI staining at 24 h,48 h,72 h,7 d and 14 d after OGD (all P ＜ 0.01).Furthermore,fluorescence microscope showed that the number of the NG2 + progenitor cells,the O4 + oligodendrocyte precursor cells in the OGD group were all significantly more than those in the control group during 72 h after OGD (all P ＜ 0.05,0.01),while the number of the immature and mature oligodendrocytes in the OGD group decreased significantly compared with those in the control group on 7 d and 14 d after OGD (all P ＜ 0.05,0.01).Conclusions OGD may activate 2 endogenous self-repair pathways from subependymal ventricular zone and white matter in vitro.The activated subependymal ventricular zone and white matter-glial progenitor cells appear to proliferate markedly,and differentiate along an oligodendroglial pathway.However,only a few newly generated precursor cells can be differentiated into the immature or mature oligodendrocytes and OGD may induce the newborn cells to appear apoptotic and necrotic.

Effect of single or combined application of UDP-glucose, GDNF and memantine on improvement of white matter injury in neonatal rats assessed with light and electron microscopy pathologically / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To evaluate pathologically the effect of the single or combined application of UDP-glucose, GDNF and memantine on the improvement of white matter injury in neonatal rats with periventricular leukomalacia (PVL) under light and electron microscopy.</p><p><b>METHODS</b>A five-day-old neonatal rat model for PVL was established by ligation of the lateral common carotid artery following 120-minute hypoxia. Rats were randomly divided into six groups (30 rats in each group): sham-operated, PVL, UDP-glucose (UDP-glucose 2000 mg/kg intraperitoneally after PVL), GDNF (GDNF 100 μg/kg intracerebrally after PVL), tmemantine (memantine 20 mg/kg intraperitoneally after PVL), and a combination administration of three drugs (UDP-glucose, GDNF and memantine). The rats were sacrificed 7 or 21 days after PVL for assessment of pathological changes in the white matter under both light and electron microscopy. The number and thickness of the myelin sheath in the white matter were measured under electron microscopy, and both of pathological grading and scoring were undertaken under light microscopy.</p><p><b>RESULTS</b>There was rare and sparse myelinogenesis with a loose arrangement of nerve fibers in the white matter under electron microscopy in the PVL group at 7 and 21 days after PVL. The number and thickness of the myelin sheath in the PVL group were significantly less than in the sham-operated, UDP-glucose, GDNF, memantine and combination administration groups (P<0.01). The results of pathological grading of white matter under light microscopy showed that all rats in the PVL group manifested either mild injury (38%-50%) or severe injury (50%-62%) at 7 and 21 days after PVL. The majority of rats (50%-88%) in the four drug administration groups had normal white matter at 7 and 21 days after PVL. The pathological scores at 7 and 21 days after PVL in the PVL group were the highest, and they were significantly higher than in the other five groups (P<0.05).</p><p><b>CONCLUSIONS</b>The single or combined application of UDP-glucose, GDNF and memantine may significantly improve pathological changes in the white matter of rats with PVL. The favorable effect is inferred to be closely correlated with the improvement of brain microenvironment and the enhancement of nerve regeneration promoted by the three drugs.</p>

Effects of single or combined application of UDP-glucose, glial cell line derived neurotrophic factor and memantine on long-term prognosis of neonatal rats with periventricular leukomalacia / 中华神经医学杂志

Objective To explore the effects of the single or combined application of UDP-glucose,glial cell line derived neurotrophic factor (GDNF) and memantine on the long-term prognosis (physical development,learning and memory and limb function) of rats with periventricular leukomalacia (PVL).Methods Five-day-old SD rats were randomly divided into the sham-operated group,PVL group,PVL plus UDP-glucose group,and PVL plus UDP-glucose combining GDNF and memantine group (three drugs group).The rats in the sham-operated group were performed dissociation but not ligation of the right common carotid artery and given no hypoxia; those in the PVL group were given ligation and hypoxia; those in the PVL plus UDP-glucose group were given intraperitoneal injection of UDP-glucose after ligation and hypoxia and those in the three drugs group were given intracranial injection of GDNF and intraperitoneal injection of UDP-glucose and memantine after ligation and hypoxia.The rats were weighed before and immediately after the establishment of PVL models,and the day age of first time opening eyes was recorded.Both tests of Morris water maze and Rivlin inclined plane were performed in all rats of the 4 groups on 26 day age; the escape latency (EL),swimming distance and scores in different inclined angle were recorded and compared,respectively.Results The weight at each time interval reduced and the day age of first time opening eyes delayed significantly in the PVL group as compared with those in the sham-operated group,PVL plus UDP-glucose group and three drugs group (P＜0.05).The average EL and swimming distance in four quadrants in the PVL group were obviously longer than those in the other 3 groups (P＜0.05).The scores of inclined plane degrees at 45° and 50° decreased remarkably in the PVL group as compared with those in the other 3 groups (P＜0.05).No significant differences in the weight,day age of first time opening eyes,values of EL and swimming distance,and scores of inclined plane were observed either between PVL plus UDP-glucose group and three drugs group or between PVL plus UDP-glucose group/three drugs group and sham-operated group,respectively (P＞0.05).Conclusion The single or combined application of UDP-glucose,GDNF and memantine can improve significantly the long-term prognosis in rats with PVL; the combined use of UDP-glucose,GDNF and memantine tends to have much obvious improvement in these rats.

Endogenous self-repair in immature white matter induced by ischemia in neonatal rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study in vivo the endogenous self-repair mechanism in immature white matter induced by ischemia in neonatal rats with periventricular leukomalacia (PVL).</p><p><b>METHODS</b>Five-day-old neonatal Sprague-Dawley (SD) rats were randomly divided into sham and PVL groups. Rat model of PVL was prepared by ligation of the right common carotid artery following 2 hours of exposure to 8% oxygen. Pathological changes and myelination in the white matter were assessed under light and electron microscopy at 7 and 21 days after PVL. O4-positive OL precursor cells in the white matter were determined with immunofluorescence staining. Activation, proliferation, migration and differentiation of glial progenitor cells in SVZ were observed using immunofluorescent double labeling of either NG2 (marker of progenitor cells) and 5-bromodeoxyuridine (BrdU), or O4 (marker of OL precursor cells) and BrdU.</p><p><b>RESULTS</b>All rats in the PVL group manifested either mild or severe white matter injury under light microscopy, and had higher pathological scores of white matter compared with the sham group at 7 and 21 days after PVL (P<0.05). Electron microscopy showed that the number and thickness of myelin sheath in the PVL group were significantly reduced compared with the sham group (P<0.01). O4-positive OL precursor cells in the white matter observed under fluorescence microscopy were significantly reduced in the PVL group compared with the sham group (P<0.05). BrdU/NG2-positive cells in the SVZ increased significantly in the PVL group 48 hours after PVL and migrated into the periventricular area, reaching a peak on day 7 after PVL. BrdU/O4-positive newborn cells began to appear in the periventricular area 72 hours after PVL, and the number of BrdU/O4-positive cells in the PVL group was statistically more than in the sham group on day 21 after PVL (P<0.05).</p><p><b>CONCLUSIONS</b>Ischemia may induce brain self-repair in neonatal rats, resulting in activation and proliferation of NG2 glial progenitor cells in the SVZ migration and differentiation into OL precursor cells in periventricular white matter.</p>

Effects of glial cell line-derived neurotrophic factor and memantine on long-term prognosis in neonatal rats with periventricular leukomalacia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To evaluate the effects of glial cell line-derived neurotrophic factor (GDNF) and memantine on the long-term prognosis in neonatal rats with ischemia-induced periventricular leukomalacia (PVL).</p><p><b>METHODS</b>Thirty-two 5-day-old neonatal rats were randomly divided into 4 groups: sham-operated, PVL, GDNF-treated and memantine-treated. PVL was induced by right carotid artery ligation and hypoxia in the PVL, GDNF-treated and memantine-treated groups. GDNF (100 μg/kg) or memantine (20 mg/kg) was injected in the two treatment groups immediately after PVL inducement. The weight of the rats was measured immediately before and after hypoxia ischemia (HI). Both of Morris water maze test and Rivlin inclined plane test were performed at 26 days old (21 days after HI). The values of the escape latency (EL) and swimming distance, and the maximum inclined plane degree which the rats could stand at least 5 seconds were compared among the four groups.</p><p><b>RESULTS</b>The lower weight, the prolonged mean values of EL and swimming distance and the reduced maximum inclined plane degree were observed in the PVL group compared to those in the sham-operated, GDNF-treated and memantine-treated groups. There were no significant differences in the weight, the values of EI and swimming distance and the maximum inclined plane degree between the two treatment groups and the sham-operated group.</p><p><b>CONCLUSIONS</b>The administration of either GDNF or memantine can markedly increase the abilities of spatial discrimination,learning and memory, and motor coordination, promote weight gain, and improve long-term prognosis in rats with PVL.</p>

Culture and identification of microglias and preoligodendrocytes / 中华神经医学杂志

Objective To explore the isolated and in vitro cultural methods of preoligodendrocytes (preOLs) and microglias (MGs) obtained from the brain tissues of neonatal rats.Methods The MGs and preOLs isolated from the brain tissues of the 2-d-old SD neonatal rats were primarily cultured by using the nutrition-deficient method with the combination of shaking and the modified shaking and adherence method, respectively. The purity of the cultured cells was identified by immunocytochemical analysis. Results After cultured for 7 d, the mixed glias formed 3 cell layers consisting of the microglias in the upper layer, O2A progenitor cells in the middle layer and the astrocytes in the basal layer, respectively. It was observed under fluorescence microscope that the cultured preOLs were small and round with bi-polar or tri-polar prominence, and the cultured microglias displayed amebiform or round morphologies, sometimes with the burr rim shape. The immunocytochemical analysis identified that the purities of the cultures were consistently ＞95% for O4 positive labeled preOLs and ＞90% for FITC-labeled IB4 positive MG. Conclusion By using the nutrition-deficient method with the combination of shaking and the modified shaking and adherence method, the massive highly-pure and alive microglia and preOLs are obtained successfully.

1400W blocks death pathway of LPS-induced activated-microglia to preOLs / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the efficacy of inductible nitric oxide synthase (iNOS) inhibitor 1400W in vivo in blocking the death pathway of lipopolysaccharide (LPS)-induced activated-microglia to preoligodendrocytes (preOLs) in neonatal rats with infective-type periventricular leukomalacia (PVL) induced by LPS.</p><p><b>METHODS</b>Two-day-old neonatal rats were randomly divided into: a sham-operated group, an untreated PVL group, and four 1400W-treated PVL groups that were subcutaneously administrated with 20 mg/kg of 1400W at 0 h, 8 hrs, 16 hrs, and 24 hrs after LPS induction, respectively. The brain specimens were obtained 5 days after LPS induction. The pathological assessment of cerebral white matter was performed under a light microscope. Concentrations of nitric oxide (NO) were measured by nitric acid-deoxidize colorimetry. Synthesis of iNOS was determined by Western blot analysis. Peroxynitrite (ONOO(-)) level and the amount of preOLs were determined by immunocytochemistry. RETHODS: The obvious injuries of periventricular white matter, massive loss of positive O4-labelled preOLs, and increased levels of NO, ONOO(-) and iNOS were observed in neonatal rats with PVL. Compared to the untreated PVL group, the use of 1400W at 0 h, 8 hrs and 16 hrs after LPS induction significantly improved white matter injuries, reduced the levels of NO, ONOO(-) and iNOS, and increased the amount of O4-labelled preOLs. However, the use of 1400W at 24 hrs after LPS induction did not result in the improvements.</p><p><b>CONCLUSIONS</b>iNOS inhibitor 1400W can effectively block the toxicity of LPS-activated microglia to preOLs and protect cerebral white matter through inhibiting iNOS and reducing the production of NO and ONOO(-). The use of 1400W within 16 hrs after LPS induction may provide cerebral protections in neonatal rats with PVL.</p>

Effect of 1400W, an inhibitor of inducible nitric oxide synthetase, on blocking the toxicity of lipopolysaccharide-induced activated microglia to preoligodendrocytes / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the toxicity of LPS-induced activated microglia to preoligodendrocytes (preOLs) and the effect of 1400W, a selective inhibitor of inducible nitric oxide synthetase (iNOS), on the blockage of the toxicity.</p><p><b>METHODS</b>Co-cultured microglia and preOLs obtained from two-day-old Sprague-Dawley (SD) rats were divided into three groups: co-culture control group, co-culture LPS group and co-culture LPS plus 1400W group. After cultured cells were induced by LPS (100 ng/ml) for 48 hours, the concentration of nitric oxide (NO) was measured by nitric acid-oeoxidize-colorimetry, the level of peroxynitrite (ONOO(-)) was determined by immunocytochemistry, and the synthetic level of iNOS was detected by Western blotting, respectively. The morphologic observation of apoptotic preOLs stained with Hoechst 33342/PI and the apoptotic rate of preOLs detected by flow cytometry were processed simultaneously. Data were analyzed with SPSS 11.0 software.</p><p><b>RESULTS</b>Compared to co-culture control group, there was significant increase in levels of NO [(82.27+/-3.41) micromol/L vs. (167.86+/-9.87) micromol/L, t=8.593, P<0.01], ONOO(-)[(6.14+/-1.27) x 10(7)/L vs. (34.38+/-7.75) x 10(7)/L, t=5.892, P<0.01], and iNOS [(0.18+/-0.027) vs. (0.79+/-0.068), t=9.26, P<0.01] induced by LPS in co-culture LPS group, and with a higher apoptotic rate of preOLs [(6.73+/-1.39)% vs. (24.77+/-2.05)%, t=12.619, P<0.01]. However, all levels of NO [(69.55+/-5.07) micromol/L, t=8.896, P<0.01], ONOO(-) [(10.33+/-3.47) x 10(7)/L, t=14.96, P<0.01] and iNOS (0.35+/-0.042, t=5.506, P<0.01) decreased significantly with the use of 1400W at a dose of 10 micromol/L in co-culture LPS plus 1400W group, and the apoptotic rate of preOLs [(11.8+/-2.06)%, t=7.715, P<0.01] was also reduced evidently.</p><p><b>CONCLUSIONS</b>NO, ONOO(-) and iNOS, etc. play important roles in the death pathway of preOLs induced by LPS. 1400W can block effectively the toxicity of LPS-activated microglia toxicity to preOLs through inhibiting iNOS selectively and reducing the production of NO and ONOO(-), and improve the survival rate of preOLs.</p>

Multicenter follow-up report of 147 premature infants with brain injuries from 6 hospitals in China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Sponsored by the Subspecialty Group of Neonatology of Pediatric Society, China Medical Association, more than 10 large-scale hospitals participated in the near two-year multicenter investigation for Brain Injuries in Premature Infants in China. The present study presents the follow-up results of 147 premature infants with brain injuries from 6 Third Class A Level hospitals.</p><p><b>METHODS</b>All premature infants with intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL) diagnosed in the early neonatal period in the 6 hospitals were followed-up between January 2005 and August 2006. Based on the synthetic results of physical development, examination of nervous system, intelligence tests and cranial ultrasound, the premature infants with brain injuries were classified as normal development, marginal development and retarded development.</p><p><b>RESULTS</b>One hundred and forty-seven premature infants with brain injuries from the 6 hospitals consisted of 141 cases of IVH and 36 cases of PVL (30 cases having IVH and PVL). Based on the synthetic follow-up results, 51.4% of premature infants with brain injuries were generally assessed as normal development, 38.4% as marginal development and 10.7% as retarded development. Among them, delayed growth in head circumference, height and weight was 13.4%; the occurrence frequency of cerebral paralysis (CP) was 7.1% in PVL grade I, 28.6% in PVL grade II and 100% in PVL grade III; 12.7% showed retarded development of intelligence; and 30% presented post-injurious changes on cranial sonography.</p><p><b>CONCLUSIONS</b>The data of the multicenter follow-up can basically reflect the short-term prognosis of premature infants with brain injuries in major big cities of China. About 10% of them have retarded physical, motor-and mental developments. The long-term regular follow-up study is expected for more premature infants with brain injuries, and behavioral sequelae of brain injuries which may occur in peri-school age and adolescence should be paid particularly close attention.</p>

Cerebral pathological evaluation following neural stem cells intraventricular transplantation in neonatal rats with periventricular leukomalacia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To evaluate the brain pathological changes following exdogenous neural stem cells (NSCs) intraventricular transplantation in neonatal rats with periventricular leukomalacia (PVL), and to explore the feasibility of NSCs transplantation for the treatment of PVL in premature infants.</p><p><b>METHODS</b>NSCs were prepared from E14 embryonic rat brain. Two-day-old neonatal rats were randomly divided into six groups: PVL, PVL+culture medium, PVL+NSCs, sham operation, sham operation+culture medium, and sham operation+NSCs (18-21 rats each group). Intraventricular transplantation of exdogenous NSCs was performed 72 hrs after PVL induction or sham operation. The cerebral pathological evaluation was undertaken by light microscopy 7, 14 and 21 days after transplantation.</p><p><b>RESULTS</b>The pathological changes in the cerebral white matter were gradually improved with the prolonged time after transplantation. After 21 days of transplantation, 50% of the cerebral white matter showed mild pathological changes and 50% of that showed severe pathological changes, with neuronal pathological scores of 1.28+/-0.86, in the untreated PVL group. In the PVL+NSCs group, 30% of normal white matter, 40% of mild and 30% of severe pathological changes in the white matter were observed, with neuronal pathological scores of 0.32+/-0.16, 21 days after transplantation. There were very significant differences in both of pathological changes in the cerebral white matter and neuronal pathological scores between the PVL and PVL+NSCs groups (x2=10.7, P<0.01; F=29.664, P<0.01).</p><p><b>CONCLUSIONS</b>Intraventricular transplantation of exdogenous NSCs can apparently improve cerebral white matter damage. It is suggested that intraventricular transplantation of NSCs is of a great potential feasibility for the treatment of PVL in premature infants.</p>

Multicenter investigation for incidence of periventricular leukomalacia in premature infants in China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Sponsored by the Subspecialty Group of Neonatology of Pediatric Society, China Medical Association, more than 10 large-scale hospitals participated in the near two-year multicenter investigation for brain injuries in premature infants in China. This study presented the investigation result for the incidence of periventricular leukomalacia (PVL) in premature infants from 10 Third Class A Level hospitals.</p><p><b>METHODS</b>The premature infants with a gestation age<37 weeks in the 10 hospitals were given routine cranial ultrasound scanning within seven days after birth, and then repeated every 3-7 days until discharge from January 2005 to August 2006. The severity of PVL was graded based on de Vries classification.</p><p><b>RESULTS</b>A total of 4 933 premature infants were enrolled. The total incidence of PVL and the incidence of cystic PVL were 2.3% (112/4 933) and 0.3% (16/4 933), respectively. Of the 112 PVL cases, 96 (85.7%) were with grade I, 14 (12.5%) with grade II, and 2 (1.8%) with grade III. The incidence of PVL in 4 maternal and child health care hospitals were significantly lower than that in 6 general or children's hospitals (1.4% vs 2.8%) (X2=10.284, P<0.01). Vaginal delivery and mechanical ventilation were possible high-risk factors for the development of cystic PVL.</p><p><b>CONCLUSIONS</b>The data of the multicenter investigation can basically reflect the situation about the occurrence of PVL in premature infants in major big cities of China. It is important to improve the ability to recognize the sonogram of non-cystic periventricular white matter injury.</p>

Maturation-dependent vulnerability of oligodendrocytes to oxidative injury / 中华神经医学杂志

Objective To explore the maturation-dependent vulnerability of oligodendrocytes (Ols) to oxidative injury and its relationship with the expressions of apoptosis-related proteins (Bcl-2/Bax, Caspase-3), and antioxidative abilities. Methods Cultured OL progenitors and mature Ols were exposed to H2O2 of different concentrations, and their cell viability was detected with MTT assay. Western blot was used to detect the expressions of Bcl-2, Box and Caspase-3 proteins in both of OL progenitors and mature Ols. Activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and level of malondialdehyde (MDA) were detected by chromatometry. Rusults H2O2 caused a concentration-dependent decrease in cell viability, and the viabilities of OL progenitors were significant lower than that of mature Ols. There were the higher expressions of either Box or Caspase-3 and lower expression of Bcl-2 in OL progenitors compared to those in mature Ols. Activities of T-SOD, GSH-Px and CAT were lower while MDA was higher in OL progenitors than those in mature cells. Conclusions Differences in either the expressions of Bcl-2, Box and Caspase-3 or the antioxidative ability in different developmental stages of Ols are correlated with the maturation-dependent vulnerability of Ols to oxidative injury.

Establishment of a neonatal rat model of periventricular leukomalacia and its concomitant cataract / 中国当代儿科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Long-term effects of memantine therapy on neonatal rats with hypoxic-ischemic brain damage / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Animal trials have demonstrated that memantine has neuroprotective effects on hypoxic-ischemic (HI) brain damage. Whether memantine can improve the long-term prognosis of rats with HI brain damage has not been reported. This study was designed to investigate the long-term effect of memantine therapy on neonatal rats with HI brain damage.</p><p><b>METHODS</b>Sixty postnatal 7-day-old newborn rats were randomly assigned into Normal control, HI and Memantine treated groups. Memantine (20 mg/kg) was administered immediately after HI in the Memantine-treated group. All subjects received a 5-day training of Morris water maze test from 23 days old. The escape latency (EL) was recorded at 28 and 35 days old.</p><p><b>RESULTS</b>The EL values of the Normal control, HI and Memantine-treated groups at 28 days old were 23.1 +/- 21.8, 35.1 +/- 5.3, and 20.6 +/- 3.4 seconds, respectively. There was a significant difference in the EL value between the HI and the Normal control groups (P < 0.05). The EL value of the Normal control, HI and Memantine-treated groups at 35 days old were 19.7 +/- 16.7, 35.6 +/- 32.3, and 16.3 +/- 13.2 seconds, respectively. A prolonged EL induced by HI still existed (P < 0.05 vs Normal controls) but memantine treatment shortened the EL (P < 0.01 vs HI group) at 35 days old.</p><p><b>CONCLUSIONS</b>Administering memantine immediately after HI can markedly increase the abilities of spatial discrimination, learning and memory and improve the long-term prognosis in rats with HI brain damage.</p>

Effect of different blood glucose levels on the expression of cerebral GLUT3 mRNA in neonatal rats with hypoxia-ischemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Concerns of the effect of glucose on perinatal hypoxic-ischemic brain damage are increasing. It was previously considered that the glucose transporter (GLUT) genes and their productions played an important role in the regulation of cerebral energy metabolism. The present study aimed to explore the effect of different blood glucose levels on the expression of cerebral GLUT3 mRNA in neonatal rats with hypoxia-ischemia (HI), and to evaluate the neuroprotective effect of glucose against HI insults.</p><p><b>METHODS</b>A total of 250 7-day-old neonatal SD rats were randomly divided into 10 groups (n=25 each): Normal control, Sham-operated, HI, Hypoglycemia, Hypoglycemia pre- and post-HI, Mild hyperglycemia pre- and post-HI, Severe hyperglycemia pre- and post-HI. Blood glucose levels of normal, hypoglycemia, mild hyperglycemia and severe hyperglycemia were defined as 5-7 mmol/L, 3-4 mmol/L, 10-15 mmol/L and 16-25 mmol/L, respectively. The expression of GLUT3 mRNA was detected with RT-PCT technique at 2, 24, 48 and 72 hrs and at 7 days after HI.</p><p><b>RESULTS</b>There was a correlation between increases in GLUT3 mRNA expression and postnatal age in the Normal control group. HI significantly enhanced the expression of GLUT3 mRNA from 2 hrs, peaking at 24 hrs after HI, and then significantly decreased at 72 hrs and 7 days after HI when compared with the Normal Control group (P < 0.01). GLUT3 mRNA expression in the Hypoglycemia pre-HI group was the lowest among all groups with HI at each time point after HI, and a statistically significant difference was found at 72 hrs after HI when compared with the HI group (P < 0.05). The expressional levels of GLUT3 mRNA in the Severe hyperglycemia pre-HI group were strikingly higher than those in any other groups with HI (P < 0.05 or 0.01). The GLUT3 mRNA expression patterns in the Mild and Severe hyperglycemia post-HI and the Hypoglycemia post-HI groups were similar to the Hypoglycemia pre-HI group.</p><p><b>CONCLUSIONS</b>GLUT3 mRNA expression and the synthesis of GLUT3 can be down-regulated by hypoglycemia pre-HI, coupled with aggravation of cerebral pathology, but up-regulated by higher hyperglycemia pre-HI, coupled with improvement of cerebral pathology. This suggested that adequate glucose supplement before HI can improve the cerebral function against HI insults in neonatal rats.</p>

Prospective study on prognosis of infants with neonatal subependymal cysts / 中华儿科杂志

<p><b>OBJECTIVES</b>It is confirmed that most neonatal subependymal cysts (SEC) are closely correlated with intrauterine infection and the short-term prognosis of SEC is not very good. Little information about the long-term prognosis of SEC is available. The purpose of the present study was to explore the short-term and long-term prognosis of neonatal SEC cases via a 6-year follow up.</p><p><b>METHODS</b>Seventy SEC neonates detected by cranial ultrasound between October 1993 and October 1994 were enrolled into SEC group and 70 healthy neonates into control group. Serum antibodies (IgG and IgM) to cytomegalovirus (CMV), toxoplasma and rubella virus and PCR for these pathogens (except for rubella virus) were measured in the two groups. CMV-PCR was also performed for urine specimens. Cranial sonography assessment, physical growth evaluation, Bayley developmental scale or Wyeth developmental scale, brain-stem auditory evoked potential (BAEP) and vision examination were undertaken at 3, 6, 12 months and 6 years in the two groups.</p><p><b>RESULTS</b>The positive rate of CMV-IgM and blood CMV-PCR in SEC group was significantly higher than those of control group (19.1% vs. 5.7%, 12.9% vs. 2.9%). The positive rate of urine CMV-PCR in SEC group was also significantly higher (40% vs 17.1%). No significant difference could be found in the positive rate of PCR for toxoplasma and rubella-IgM between the two groups. The weight and height of infants with SEC were obviously lower than those in control group during the first year after birth. The parameters of the physical development in SEC infants reached the similar level as controls till 6 years old. However, the index of mental development below 80 was more often seen in infants with SEC comparing to that in control group during the whole six years. There were no abnormal findings either in BAEP or vision examination in the two groups.</p><p><b>CONCLUSION</b>Infants with SEC may show a transient retardation of physical growth after birth, while their mental developmental retardation might last for longer time. It is suggested that cranial ultrasound examination should be performed in all neonates for the detection of SEC, and a longer follow-up should be done for infants with SEC.</p>

Toxic Reactions of Memantine in Acute Toxicologic Experiment in Neonatal Rats / 实用儿科临床杂志

Objective To explore the acute toxic reactions of memantine in neonatal rats. Methods Based on Completely Lethal dose(LD_(100)) and median lethal dose (LD_(50))of memantine in SD neonatal rats acquired in a preliminary test of death dose, 60 neonatal rats were randomly divided into normal group which were given water injection intraperitoneally and 5 study groups which were given different doses of memantine intraperitoneally.LD_(50) was calculated with Bliss method and the toxic reactions of memantine were observed in all neonatal rats of 6 groups after administration of memantine. Results LD_(50) of memantine in SD neonatal rats was((74.386?2.811)) mg/kg with 95% confidence at the range of 59.334-93.257 mg/kg.Side effects occurred at 1-4 minutes after administration. Excitatory jitteriness,ataxia,decreased respiratory rate and passivity were usually observed in groups with a lower dosage (52.0 mg/kg,61.2 mg/kg,72.0 mg/kg);some of them also manifested side lying, cyanosis and respiratory failure.While neonatal rats with a higher dosage (85 mg/kg,100 mg/kg)mainly manifested visible symptoms of inhibition, respiratory failure,side (lying) and cyanosis.However,no jitteriness and ataxia were observed in them.The neonatal rats usually died around 1 hour after memantine administration;survival rats usually returned to normal 4-5 hours after administration.Conclusion There is a positive correlation between toxic reactions and the mortality with memantine dosage in neonatal rats.

Research Progress of Relationship between Ureaplasma Urealyticum Infection and Perinatal Disease / 实用儿科临床杂志

Ureaplasma urealyticum(UU)is one of the most common pathogen in childbearing age women.The proportion of neonate especially premature baby infected with UU is increasing yearly.UU infaction is related with premature labour,low birth weight,bronchopulmonary dysplasia,chronic lung disease,respiratory distress syndrome and other perinatal diseases by promoted the expression of inflammatory cytokines,increasing the inflammatory response and interfering inflammation clear.There still has controversial point to treat perinatal diseases caused by UU infection by erythromycin,azithromycin,pulmonary surfactant,steroid.