Objective To explore the influence of retinoic acid (RA) on the expressions of insulin-like growth factor (IGF)-Ⅱ,type 2 IGF receptor (IGF-2R) and IGF binding protein (IGFBP)-2 mRNA and polypeptides in lungs of hyperoxia-exposed premature rats and its possible molecular mechanism. Methods On the 2nd postnatal day, 260 Sprague-Dawley(SD)preterm rats were randomly divided into 4 groups. Group Ⅰ: air + normal saline (NS) group; Group Ⅱ: hyperoxia(85% O_2) + NS group; Group Ⅲ: air+ RA group; Group Ⅳ: hyperoxia(85% O_2) + RA group. RA was injected to group Ⅲ, Ⅳ intraperitoneally (500 ?g/kg) since the 3rd day after birth, while NS was given to group Ⅰ,Ⅱ daily at the same time as group Ⅲ and Ⅳ. On day 4, 7, 10, 14 and 21 after birth, 8 rats in each group were killed. The mortality of preterm rats was recorded and lung radical alveolar counts (RAC) were examined. The mRNA analysis (RT-PCR) and polypeptides analysis (Western Blot) of IGF-Ⅱ, IGF-2R and IGFBP-2 were performed. Results 1. On the 4～7th day of exposure, the survival rate in all groups were similar. After 7 days of 85% O_2 exposure, the survival rate in group Ⅱ, Ⅳ dropped sharply and there was a significant difference comparing to group Ⅰ, Ⅲ( P

To investigate role of Notch1 - 3 in hyperoxia-induced lung injury in newborn rat exposed to 85% O2, SD rat litters born on the 22th day were randomly divided into two groups: room air group and hyperoxia group. The animals were sacrificed 1, 4, 7, 10, 14 and 21 days after continued exposure to oxygen (n = 40, oxygen > 0.85) or room air (n = 40). 6 rats each group were used to assess lung histological changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from frozen lung tissues. Notch mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that 7, 14 and 21 days after O2 exposure, hyperoxia group showed lung injury characterized by pulmonary edema, hemorrhage and lung development arrest. Positive staining for Notch1, Notch 2 in hyperoxia group was much lower than those in room air group at all time points (P < 0. 01, P < 0.05), but compared with the controls, the hyperoxia group showed higher expression of Notch3 (P > 0.05). Immunostained cells were typically airways epithelia, alveolar epithelial and inflammatory cells, and fibroblasts in hyperoxia group (P < 0.01). Notch mRNA levels showed similar change as protein level (P < 0.01). It is concluded that the prolonged exposure to 85% O2 resulted in abnormal expression of Notch receptors, which might contribute to the pathogenesis of hyperoxia-induced lung injury in newborn rats. The decreased inhibition of Notch1 might be one of the protective reaction and major mechanisms for proliferation/differentiation of type II alveolar epithelial cells. The up-regulation of Notch3 activity might result in the lung development arrest of the newborn rats.
Aerobiosis ; Animals, Newborn ; Lung/*pathology ; Lung Diseases/etiology ; Lung Diseases/*metabolism ; Lung Diseases/pathology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Random Allocation ; Rats, Sprague-Dawley ; Receptors, Notch/*biosynthesis ; Receptors, Notch/genetics

0.85) or room air ( n =40) respectively, six rats of each group were used to assess lung histologic changes with HE staining and expression of Notch in lungs with immunohistochemistry. Total RNA was extracted by Trizol reagent from the frozen lung tissues. mRNA levels of Notch were measured by reverse transcription polymerase chain reaction (RT PCR). Results 1. Hyperoxia group showed lung injury characterized by subacute alveolitis and inhibition of lung development at 7,14 and 21 days after birth from the lung histology exam. 2 Positive staining for Notch 1, Notch 2 and Jagged in hyperoxia group was much lower than control at every time point ( P0.05 ). Notch was strongly expressed in airways epithelial, alveolar epithelial and inflammatory cells, and fibroblast in hyperoxia group ( P

To investigate role of Notch1-3 in hyperoxia-induced lung injury in newborn rat exposed to 85% O2, SD rat litters born on the 22th day were randomly divided into two groups: room air group and hyperoxia group. The animals were sacrificed 1, 4, 7, 10, 14 and 21 days after continued exposure to oxygen (n=40, oxygen＞0.85) or room air (n=40). 6 rats each group were used to assess lung histological changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from frozen lung tissues. Notch mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that 7, 14 and 21 days after O2 exposure, hyperoxia group showed lung injury characterized by pulmonary edema, hemorrhage and lung development arrest. Positive staining for Notch1,Notch 2 in hyperoxia group was much lower than those in room air group at all time points (P＜0.01, P＜0.05), but compared with the controls, the hyperoxia group showed higher expression of Notch3 (P＞0.05). Immunostained cells were typically airways epithelia, alveolar epithelial and inflammatory cells, and fibroblasts in hyperoxia group (P＜0.01). Notch mRNA levels showed similar change as protein level (P＜ 0.01). It is concluded that the prolonged exposure to 85 % O2 resulted in abnormal expression of Notch receptors, which might contribute to the pathogenesis of hyperoxia-induced lung injury in newborn rats. The decreased inhibition of Notch1 might be one of the protective reaction and major mechanisms for proliferation/differentiation of type Ⅱ alveolar epithelial cells. The up-regulation of Notch3 activity might result in the lung development arrest of the newborn rats.

The influence of platelet-derived growth factor (PDGF) on lung development in newborn rats and the effect of retinoic acid (RA) on PDGF in lung development were investigated. Newborn Sprague-Dawley (SD) rats were randomly assigned to two groups: control group and RA group. The rats in RA group was intraperitoneally injected with all trans-retinoic acid (500 microg/kg every day) for consecutive 3 days after birth, while those in the control group were not subjected to intervention. Immunohistochemical assay was performed to locate the expression of PDGF. mRNA levels of PDGF were measured by reverse transcription polymerase chain reaction (RT-PCR) at age of 1, 3, 5, 7, 10, 14, 21 days. The method of radial alveolar counts (RAC) was used to measure the amount of the alveoli of the lungs. It was found that with increasing days, levels of PDGF-A and PDGF-B changed to verying degrees. RA could elevate significantly the expression levels of PDGF-A mRNA and protein (P<0.01), but not affect the expression levels of PDGF-B mRNA and protein markedly (P>0.05). It is suggested that PDGF might play an important role in lung development. RA can stimulate lung development through increasing the expression levels of PDGF-A mRNA and protein.
Animals ; Animals, Newborn ; Lung ; growth & development ; metabolism ; Platelet-Derived Growth Factor ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tretinoin ; pharmacology

To explore the relationship between Insulin-like growth factor (IGF)-I , -II and lung development in neonatal rats. 80 timed pregnant Sprague-Dawley (SD) rats were randomly divided into 4 groups (n=20): group A (Control group), group B (Dexamethasone (DEX) 1 group), group C (DEX 2 group), group D (retinoic acid (RA) group). 20 pregnant rats in group A, B and D were injected subcutaneously or intraperitoneally with vehicle (NS), DEX, or RA respectively during gestational day 16 to 18. All newborn rats in group C were subcutaneously injected with DEX at day 1 to 3 after birth. The lung tissue was obtained at the following times: fetuses at gestational ages of 18, 20 and 21 days, and 1, 3, 5, 7, 10, 14 and 21 days after birth. Lung tissues were used for histopathological study, the polypeptides analysis of IGF- I, -II (immunohistochemistry and Western blot) and mRNA analysis ( RT- PCR). The results showed that the strongest expression of IGF- I in group A and D occurred at ages of 5-7 days (alveolar stage). The stronger their expressions, the better the alveolar develop. The peak stage of expression in group B occurred earlier, on the day 3 after birth. Compared with group A, the expression of IGF-I during gestation age of 18 days to age of 3 days in group B were significantly higher (P<0.01), but significantly lower at other time points (P<0.01). The expression of IGF-I was lower in group C all the time and always higher in group D than those in group A (P<0.01). The peak expression of IGF-II took place at the gestation age of 18 days, then gradually dropped to trace. During 18 days of gestation to age of 3 days, the expression of IGF-II in group B was significantly higher than that in group A (P<0.01). No difference was found among all other groups. The change in the expression of IGF-I, -II mRNA in all 4 groups was similar to that of their polypeptides. The results suggested that there is a close linking between IGF-I , -II and lung development in newborns. The IGF-II works at early stage and the that of IGF- I works at the stage of new septa formation and alveoli maturation. The stronger their expressions, the more mature the lung development.
Animals ; Animals, Newborn ; Dexamethasone ; pharmacology ; Female ; Insulin-Like Growth Factor I ; biosynthesis ; genetics ; Insulin-Like Growth Factor II ; biosynthesis ; genetics ; Lung ; embryology ; growth & development ; metabolism ; Male ; Pregnancy ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tretinoin ; pharmacology

To evaluate the changes of 3', 5'-cyclic adenosine monophosphate (cAMP), thromboxane A2(TXA2) and prostacyclin (PGI2) in cerebrospinal fluid (CSF) in the asphyxiated newborn and explore their roles in hypoxic-ischemic brain damage (HIBD). Thirty-six full term newborns were divided into 3 groups, including 12 with moderate-severe hypoxic-ischaemic encephalopathy (HIE), 13 with mild HIE, 11 without HIE (control group). The levels of cAMP, TXB2 (TXA2 metabolite) and 6-keto-PGF1 alpha (PGI2 metabolite) in CSF and plasma were measured 36-72 h after birth by RIA, and the concentrations were expressed as nM/L (cAMP), ng/L(TXB2 and 6-keto-PGF1 alpha). The infants were followed-up at 6 and 12 month of age and Mental Development Index (MDI) and Psychomotor Development Index (PDI) were measured using Bayley Scales of Infant Development (BSID). The CSF cAMP level in moderate-severe HIE group was 8.60 +/- 2.40, significantly lower than that of the mild HIE group (14.83 +/- 2.84) and the control group (24.43 +/- 2.39) (for both P < 0.01). The levels of TXB2 and 6-keto-PGF1 alpha in CFS in the moderate-severe HIE group (206.06 +/- 29.74, 168.47 +/- 23.02, respectively) were significantly higher than in the mild HIE group (83.37 +/- 28.57, 131.42 +/- 16.57, respectively, P < 0.01) and the control group (41.77 +/- 21.58, 86.23 +/- 13.05, respectively, P < 0.01). The level changes of cAMP, TXB2 and 6-keto-PGF1 alpha in plasma in all groups were similar to those in CSF, but no significant difference was found between mild HIE group and the control group (P > 0.05). The follow-up results showed that MDI and PDI of the moderate-severe HIE group were the lowest (84.79 +/- 13.34, 83.50 +/- 13.28, respectively), followed by mild HIE group (102.19 +/- 7.02, 99.94 +/- 9.08, respectively), with the control group being the highest (116.63 +/- 12.08, 116.69 +/- 10.87, respectively). Univariate analysis showed some significant difference (the moderate-severe HIE group vs. the mild HIE group or the control group, P < 0.01; the mild HIE group vs. the control group P < 0.05). The results suggested that the concentration of cAMP, TXA2 and T/K ratio in CSF after neonatal asphyxia might be sensitive markers in evaluating the severity of brain damage in early stage and predicting the future outcome.
6-Ketoprostaglandin F1 alpha ; cerebrospinal fluid ; Asphyxia Neonatorum ; cerebrospinal fluid ; Biomarkers ; Cyclic AMP ; cerebrospinal fluid ; Epoprostenol ; cerebrospinal fluid ; Female ; Follow-Up Studies ; Humans ; Hypoxia-Ischemia, Brain ; cerebrospinal fluid ; Infant, Newborn ; Male ; Thromboxane A2 ; cerebrospinal fluid ; Thromboxane B2 ; cerebrospinal fluid

Objective To explore the influencing factors of the onset of autism spectrum disorder in male children.Methods Totally 151 male children with autism spectrum disorder were selected as case group and 119 healthy male children matched with the age of the case group in the same administrative region were taken as the control group.All children were assessed with the questionnaire for children's autism etiology and risk factors.Results (1) The differences in children having anorexia and partial eclipse (x2 =50.763,P＜0.01),father's age during pregnancy (x2 =11.441,P=0.043),place of pregnancy (x2 =50.763,P＜0.01),hypertension of pregnancy (x2 =5.693,P=0.026),intrauterine hypoxia (x2 =9.332,P=0.002),umbilical cord around the neck(x2 =18.483,P＜0.01),parents smoking and drinking history during pregnancy (x2 =13.660,P=0.008),parental smoking (x2 =12.901,P=0.005) and alcohol consumption (x2 =8.386,P=0.039) during pregnancy,birth height of child (x2 =8.870,P=0.031),amniotic fluid pollution (x2 =4.561,P=0.043),participation time of artificial feeding,major caregivers,delayed development indicators in infants and young children and whether or not the harmonious parent-child relationship were statistically significant(P＜0.05).(2) Children with anorexia and partial diet (OR =12.284,95％ CI =2.768-54.507),living in rural areas during pregnancy (OR =17.251,95％ CI =1.899-1 56.745),parents' history of smoking and drinking (OR =6.191,95％ CI =1.678-22.838),and intrauterine hypoxia during pregnancy (OR=38.859,95％CI=2.944-512.930) may be risk factors for male autism spectrum disorder.Conclusion To correct children's anorexia bias,improve the living environment in pregnancy,reduce pregnancy complications and avoid exposure to tobacco and alcohol pollution during maternal pregnancy can be an effective entry point for the prevention and control of autism spectrum disorders in male children.