Dynamic Assessment and Sustainability Strategies of Ecological Security in the Irtysh River Basin of Xinjiang, China.

The drylands of China are extensive, and they are home to more than one-third of the country's population. However, the watershed territories of the drylands, where the majority of human activities are concentrated have long experienced strained human-land relationships, culminating in ecological security concerns. Correspondingly, it is essential to carry out a comprehensive assessment of the ecological security of dryland watersheds and to identify the key factors influencing ecological security in order to formulate strategies that ensure the sustainability of drylands. Premised on the Driving-Pressure-State-Impact-Response (DPSIR) model, this study developed an ecological security index and applied it to the Irtysh River Basin of Xinjiang, China, from 2000 to 2020. The obstacle degree model was applied to reveal the obstacles in two dimensions: criterion level and indicator level. The findings suggested that the ecological security comprehensive index in the Irtysh River Basin has increased significantly from 2000 to 2020, irrespective of the fact that it decreased during the study period and then increased. The ecological security level changed from 'critically safe' in 2000 to 'general safety' in 2020, with the state subsystem and pressure subsystem becoming ecological security weaknesses. The primary factors influencing the ecological security of the study area were water consumption, the area of high-efficiency water-saving irrigation, the proportion of wetland area, vegetation coverage, and livestock population. The ecological security of different counties in the basin varies greatly, whereas the factors that influence ecological security showed both similarities and differences among the counties. In light of on the findings, we proposed that future strategies for ecological security enhancement should concentrate on enacting the policy of localizing spatial differentiation, optimizing industrial structure, strengthening scientific and technological support in the field of water conservation, bolstering the treatment capacity of environmental facilities, and implementing the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands System to support the sustainable development of dryland watersheds.

What Cause Large Spatiotemporal Differences in Carbon Intensity of Energy-Intensive Industries in China? Evidence from Provincial Data during 2000-2019.

China has been reported as the world's largest carbon emitter, facing a tough challenge to meet its carbon peaking goal by 2030. Reducing the carbon intensity of energy-intensive industries (EIICI) is a significant starting point for China to achieve its emission reduction targets. To decompose the overall target into regions, understanding the spatiotemporal differences and drivers of carbon intensity is a solid basis for the scientific formulation of differentiated regional emission reduction policies. In this study, the spatiotemporal differences of EIICI are described using the panel data of 30 provinces in China from 2000 to 2019, and a spatial econometric model is further adopted to analyze its drivers. As indicated by the results: (1) from 2000 to 2019, China's EIICI tended to be reduced continuously, and the spatial differences at the provincial and regional levels expanded continuously, thus revealing the coexistence of "high in the west and low in the east" and "high in the north and low in the south" spatial patterns. (2) There is a significant spatial autocorrelation in the EIICI, characterized by high and high agglomeration and low and low agglomeration types. Moreover, the spatial spillover effects are denoted by a 1% change in the local EIICI, and the adjacent areas will change by 0.484% in the same direction. (3) Technological innovation, energy structure, and industrial agglomeration have direct and indirect effects, thus affecting the local EIICI and the adjacent areas through spatial spillover effects. Economic levels and firm sizes only negatively affect the local EIICI. Environmental regulation merely has a positive effect on adjacent areas. However, the effect of urbanization level on EIICI has not been verified, and the effect of urbanization level on the EIICI has not been verified. The results presented in this study show a scientific insight into the reduction of EIICI in China. Furthermore, policymakers should formulate differentiated abatement policies based on dominant drivers, spatial effects, and regional differences, instead of implementing similar policies in all provinces.

Spatiotemporal variations and determinants of water pollutant discharge in the Yangtze River Economic Belt, China: A spatial econometric analysis.

Water pollution is an urgent problem that needs to be controlled via green transformation and the development of the Yangtze River Economic Belt (YREB). Based on the water pollutant discharge and socio-economic database of prefecture-level cities in the YREB from 2011 to 2015, this study explores the spatiotemporal variations in water pollutant discharge in the YREB via two main indicators: chemical oxygen demand (COD) and ammonia nitrogen (NH3-N). Further, the spatial effects and determinants of water pollutant discharge are quantitatively estimated. The results show that (1) the water pollutant discharge in the YREB has decreased significantly, with the COD and NH3-N discharge reduced by 10.46% and 10.79%, respectively, and the discharge reduction in the lower reaches was the most prominent; (2) the spatial pattern of water pollutant discharge in the YREB was generally stable and partially improved, and cities with a high rate of water pollutant reduction in the YREB were distributed in the main stream region of the Yangtze River and the intersection of the main stream and tributaries; (3) spatial effects had a significant impact on water pollutant discharge in the YREB, with regional cooperation and economic radiation through environmental management and control initially showing a combined reduction trend in regional water pollutants; and (4) determinants of population size and agricultural economic share declined to varying degrees at the end of the study period, although the urbanization level continued to increase, indicating that urbanization in the YREB occurred too quickly and that water pollutant discharge reduction was limited. However, economic development leading to the deterioration of the water environment was alleviated. In addition, foreign direct investment (FDI) inflows and rapid industrialization processes must be monitored to increase the reduction in characteristic water pollutants.

Silencing of Long Non-Coding RNA X Inactive Specific Transcript (Xist) Contributes to Suppression of Bronchopulmonary Dysplasia Induced by Hyperoxia in Newborn Mice via microRNA-101-3p and the transforming growth factor-beta 1 (TGF-ß1)/Smad3 Axis.

BACKGROUND Bronchopulmonary dysplasia (BPD) is a chronic lung disease mostly affecting premature infants. Long non-coding RNA (lncRNA) X inactive specific transcript (Xist) is actively involved in pulmonary disease development. The present study explored the potential mechanism of Xist in BPD development. MATERIAL AND METHODS First, newborn BPD mouse models were successfully established. lncRNAs and genes with differential expression were identified using microarray analysis. Various injuries and radial alveolar counts of lung tissues of BPD mice were detected by hematoxylin-eosin staining. Functional assays were utilized to detect alterations of superoxide dismutase (SOD), malondialdehyde (MDA), vascular endothelial growth factor, collagen I, alpha-smooth muscle Actin, TGF-ß1, and Smad3. Then, dual-luciferase reporter gene assay and RNA pull-down assay were performed to clarify the targeting relationship between Xist and miR-101-3p and between miR-101-3p and high-mobility group protein B3 (HMGB3). RESULTS In BPD mice, radial alveolar counts value and SOD activity declined while MDA level increased. Results of microarray analysis found that Xist and HMGB3 were highly expressed in BPD mice. Next, silenced Xist alleviated lung damage in BPD mice. Xist competitively bound to miR-101-3p to activate HMGB3, and overexpressed miR-101-3p mitigated lung damage in BPD mice. Additionally, silenced Xist downregulated the TGF-ß1/Smad3 axis. CONCLUSIONS Our study demonstrated that silencing of Xist suppressed BPD development by binding to miR-101-3p and downregulating HMGB3 and the TGF-b1/Smad3 axis. Our results may provide novel insights for BPD treatment.

Exploring regional differences in the impact of high energy-intensive industries on CO2 emissions: Evidence from a panel analysis in China.

China is currently the largest CO2 emitter in the world. Within China, more than 60% of CO2 emissions originate from high energy-intensive (HEI) industries. Therefore, controlling and reducing CO2 emissions from HEI industries is crucial if China is to achieve its 2030 emission reduction targets. This study aims to investigate regional differences in the impact of HEI industries on CO2 emissions in China. This paper presents an analysis of the impact of HEI industries on CO2 emissions at the national and regional levels using a modified STIRPAT model and provincial panel data from 2000 to 2015 in China. The results show that HEI industries are significant contributors to China's CO2 emissions owing to the growth in industries, coal-based energy structure, low level of technology, and outstanding conduction effects. The impact intensity of HEI industries on CO2 emissions decreases from the western to the central and eastern regions in China because of a huge regional difference in industrial structure, energy structure, R&D investment, and industrial transfer. Our findings have important implications for policymakers in China by indicating that regional policies concerning HEI industries should be differentiated to successfully reduce CO2 emissions and meet national targets.

Effectiveness and Renal Functions Safety of Treatments Used for Neonates with Patent Ductus Arteriosus: A Prospective Cohort Study.

BACKGROUND Neutrophil gelatinase-associated lipocalin plays an important role in renal dysfunctions. The objective of this study was to test the hypothesis that indomethacin used in treating patent ductus arteriosus protects infants from renal dysfunction. MATERIAL AND METHODS This prospective cohort study assessed data on urine prostaglandin metabolites, urinary neutrophil gelatinase-associated lipocalin, and the renal functions of preterm infants with confirmed patent ductus arteriosus who had been injected with indomethacin (n=144, ID group) or acetaminophen (n=144, AP group). RESULTS A reduction of neutrophil gelatinase-associated lipocalin in urine samples was found in the ID group (993±48 µG/L vs. 103±5 µG/L, p<0.0001). The reduction in prostaglandin (673±32 pg/mL vs. 139±7 pg/mL, p<0.0001) and the closure of ductus (2.64±0.89 mm vs. 2.31±0.81 mm, p=0.001) were found in the ID group after the first dose of indomethacin, but the closure of ductus (2.47±0.54 mm vs. 2.32±0.55 mm, p=0.02) and prostaglandin reduction (667±31 pg/mL vs. 129±7 pg/mL, p<0.0001) were found after the second dose of acetaminophen. Indomethacin had greater effect in reducing the risk of acute kidney injury than did acetaminophen (p=0.042). CONCLUSIONS Indomethacin treatment used in treating patent ductus arteriosus protects infants from renal dysfunction.

[Clinical effect of exogenous pulmonary surfactant in the treatment of severe neonatal infectious pneumonia: a multicenter prospective clinical trial].

OBJECTIVE: To study the clinical effect of calsurf, a domestic exogenous pulmonary surfactant, in the treatment of severe neonatal infectious pneumonia. METHODS: A total of 208 neonates with severe infectious pneumonia who hospitalized in 5 hospitals of China were enrolled. According to their parents' wishes on admission, these neonates were administered with conventional treatment (control group; n=81) and calsurf treatment + conventional treatment (calsurf treatment group, n=127). The two groups were compared in terms of the degree of oxygen dependence on admission, blood gas parameters before and after treatment, lung ultrasound results, duration of mechanical ventilation, length of hospital stay, hospital costs, complications and prognosis. RESULTS: Compared with the control group on admission, the calsurf treatment group had significantly higher inhaled oxygen concentration and partial pressure of carbon dioxide and significantly lower arterial partial pressure of oxygen and oxygenation index (P<0.01). After 1 hour of treatment, both groups had significant improvements in the above indices (P<0.05), and the improvements were more significant in the calsurf treatment group (P<0.05). After 4-6 hours of calsurf administration, there was a significant reduction in the degree of pulmonary consolidation. The calsurf treatment group had significantly shorter duration of mechanical ventilation and length of hospital stay than the control group, while there was no significant difference in the incidence rate of complications between the two groups. The neonates of both groups had a good prognosis. CONCLUSIONS: In neonates with severe infectious pneumonia, calsurf treatment can significantly improve oxygenation, reduce the degree of pulmonary consolidation, and shorten the duration of mechanical ventilation and length of hospital stay. Therefore, it should be considered in neonates with severe infectious pneumonia.

[Effect of intrauterine growth retardation on insulin sensitivity and plasma adiponectin level in neonates].

OBJECTIVE: To explore the effect of intrauterine growth retardation (IUGR) on insulin sensitivity in neonates and the relationship between insulin sensitivity and plasma adiponectin level. METHODS: Eighty-two term neonates with IUGR and 90 term neonates born appropriate for gestational age (AGA) were enrolled. Weight, height, head circumference and abdomen circumference of the neonates were measured within 24 hours after birth. Fasting serum glucose (FG), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), plasma insulin and adiponectin were detected in two groups on the 7th day after birth. Homeostasis model assessment for insulin resistance (HOMA-IR) index and insulin sensitivity index (ISI) were calculated. RESULTS: There were no significant differences in the levels of FG, TG, HDL and LDL between the IUGR and AGA groups (P>0.05). The plasma insulin level in the IUGR group was higher than that in the AGA group, but the plasma adiponectin level was lower than that in the AGA group (P<0.05). HOMA-IR index in the IUGR group was higher than that in the AGA group, but ISI was lower than that in the AGA group (P<0.05). Both Pearson correlation analysis and multiple linear regression analysis showed HOMA-IR index was negatively correlated with plasma adiponectin level and birth weight (P<0.05). CONCLUSIONS: The neonates with IUGR display a higher plasma insulin level and decreased insulin sensitivity. The decreased plasma adiponectin level may be associated with the decreased insulin sensitivity.

[Value of arterial blood lactic acid in the evaluation of disease severity and prognosis in neonatal shock].

OBJECTIVE: To evaluate the value of blood lactic acid (BLA) as a predictor for the severity and prognosis of neonatal shock. METHODS: A total of 326 neonates with shock were enrolled and divided into three groups based on the severity, namely mild group (n=147), moderate group (n=105), and severe group (n=74). BLA level was measured during and early after (about 6 hours later) fluid resuscitation, and lactate clearance rate (LCR) was calculated. The receiver operating characteristic (ROC) curve was applied to evaluate the predictive value of BLA in neonatal shock. RESULTS: BLA level was high in all subjects prior to treatment, and was highest in the severe group and lowest in the mild group (P<0.01). BLA level was significantly higher among patients with septic shock than among those with hypovolemic, cardiogenic, and asphyxiating shock (P<0.05). BLA level was significantly reduced in patients in recovery after treatment (P<0.05). Mortality was significantly lower in patients with BLA level ≤4 mmol/L or LCR ≥10% than in those with BLA level >4 mmol/L or LCR <10% (P<0.01). BLA at 11.15 mmol/L had 100% sensitivity and 96.8% specificity in predicting severe shock. BLA at 10.65 mmol/L had 88.9% sensitivity and 74.1% specificity in predicting the prognosis (survival or dead) of newborns with shock. CONCLUSIONS: In neonates with shock, arterial BLA level increases as the disease severity increases and is associated with prognosis, so it is a useful predictor of the severity and prognosis of neonatal shock.

LncRNA MEG3 ameliorates respiratory syncytial virus infection by suppressing TLR4 signaling.

Maternally expressed gene 3 (MEG3), a long noncoding RNA (lncRNA) has been dysregulated in various tumors. However, the expression level and functional role of MEG3 in the progression of respiratory syncytial virus (RSV) infection remains to be elucidated. The present study quantified the expression level of MEG3 in the nasopharyngeal (NPA) samples of RSV­infected patients and in BEAS­2B cells infected with RSV. The findings of the present study demonstrated that the expression level of lncRNA MEG3 was reduced in the NPA samples of RSV­infected patients and in BEAS­2B cells infected with RSV. In vitro transfection revealed increased mRNA expression levels of toll­like receptor 4 (TLR4), tumor necrosis factor­α (TNFα) and interleukin (IL)­8 following RSV infection in BEAS­2B cells. Additionally, ectopic expression of MEG3 reduced the expression level of TLR4, subsequently suppressing the mRNA expression levels of TNFα and IL­8, indicating the protective role of MEG3 in the process of RSV infection. It is of note, that RSV infection­induced p38 mitogen activated protein kinase (MAPK) and nuclear factor­κB (NF­κB) activation was partly abolished by overexpression of MEG3. In conclusion, to the best of our knowledge, the present study provided the first evidence that lncRNA MEG3 expression level was reduced in the NPA samples of patients with RSV infection and RSV­infected cells. Additionally, it was demonstrated that MEG3 protected human airway epithelial cells from RSV infection, primarily by suppressing TLR4­dependent p38 MAPK and NF­κB signaling.

[Change of Thrombelastography in Children's DIC and Analysis of Its Sensitivity and Specificity for Diagnosis of DIC].

OBJECTIVE: To investigate the influence of thrombelastography index changes on its sensitivity and specificity for diagnosis of disseminated intravascular coagulation (DIC) in children. METHODS: A total of 149 children with DIC in our hospital from June 2013 to June 2016 were selected in DIC group, while 106 cases of non-DIC, including healthy children and children with diseases easily confused with DIC, were selected as non-DIC(control) group. The thrombelastography, D-dimer, coagulation functions including prothrombintime (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB) and fibin degradation product (FDP), congental coagulation disorders and platelet count were detected in DIC and non-DIC groups; the statistics of data was performed and the sensitivity and specificity of thromelastraphy indexes such as R time, α angle MA value and A value were evaluated; the relationship of DIC with indexes was analyzed. Moreover, the result difference of thromelastography and routine coagulation function test was compared at diagnosis of DIC. RESULTS: According to statistical analysis of clinical data in 2 groups, the average R time in non-DIC group was significantly less than that in DIC group (P<0.05); the average α angle in non-DIC group was larger than that in DIC group (P<0.05), both the MA and A values in the non-DIC group were significantly higher than those in DIC group (P<0.05). The specificity of routine coagulation function test for diagnosis of DIC was as follow: PT-27.2%, APTT-42.2%, international normalized ratio(INR)-47.9%, FIB-44.4%, FDP-42.7% and D-dimer-68.3%, which were significantly lower than that of R time,α angle and MA value for diagnosis of DIC (85.1%, 74.1% and 73%). The α angle and MA value of healthy children were greater than those of children with severe liver disease(P<0.05). while the average R time of healthy children was less than that of children with severe liver disease(P<0.05), but the difference of A value between them did not statistically significant (P>0.05) . The average R time of healthy children was less than that of children with congenital coagulation disorders (P<0.05). but there was no significant differences in α angle MA and Avalues between them. CONCLUSION: As compared with routine coagulation function test, the thrombelastography shows more high specificity for diagnosis of DIC, and can more precisely diagnose the DIC; moreover, the thrombelastography combined with roatime coagulation function test can more early find and diagnose the DIC in children, therefore it can improve the survival rate of children with DIC.

Risk and protective factors of intraventricular hemorrhage in preterm babies in Wuhan, China.

OBJECTIVE: The aim of this study is to identify prenatal and perinatal risk and protective factors for the development of IVH, using a retrospective and case-control clinical study. METHODS: Prenatal and perinatal data were collected from three NICUs between January 2010 and December 2010. Univariate analysis was performed between case and control groups, and multivariate analysis was done to find out risk and protective factors for development of IVH. Further analysis of these variables was undertaken for gestational age strata <30, 30-34, and 35-37 weeks. RESULTS: By univariate analysis, factors related with IVH were C-section, prenatal steroid, pregnancy-induced hypertension, transport from other hospital, hypothermia, Apgar score at 1 and 5 min < 4, luminal, pathological jaundice, RDS, hypotension, volume expansion/inotropics, PO(2), repeat suctioning, and mechanical ventilation (P < 0.05). Five variables remained significant in multivariate analysis. C-section and prenatal steroid use were protective variables while mechanical ventilation, hypotension, and transport from other hospital were risk factors. Further analysis of these variables was undertaken for gestational age strata <30, 30-34, and 35-37 weeks. Prenatal steroid use remained significant as a protective variable in gestational age less than 35 weeks; hypotension was shown to be a risk factor just in the time period between 30-34 weeks; transport from other hospital was a risk factor in gestational age more than 30 weeks; mechanical ventilation remained non-significant during the gestational age strata studied. CONCLUSION: In the present study, factors that related to neonatal IVH included hypotension, prenatal steroid use, and transportation.

[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].

OBJECTIVE: 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). METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Relation of insulin-like growth factor binding protein-2 with hyperoxia-induced lung injury in term and premature neonatal rats].

OBJECTIVE: To study the deleterious effect of prolonged hyperoxic exposure on term and premature neonatal rat lungs and investigate the relationship between insulin-like growth factor binding protein (IGFBP)-2 and hyperoxia-induced lung injury in neonatal rats. METHODS: At the 22nd postnatal day Sprague-Dawley (SD) term-newborn or preterm-newborn rats were randomly divided into 4 groups. group I: term-rats+air group; group II: term-rats+hyperoxia group; group III: preterm-rats+air group; group IV: preterm-rats+hyperoxia group. The rats in group II and IV were exposed to about 85% (in volume) O(2). The rats in group I and III were exposed to air in the same rooms. At 4, 7, 10, 14 and 21 days after birth, eight rats in each group were killed. The mortality of newborn rats was also recorded and lung radical alveolar counts (RAC) were examined. Lung histopathology with hematoxylin and eosin (HE) staining was examined; The protein and mRNA of IGFBP-2 in the lung tissue were determined by Western blotting and by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: After 7 days of 85% O(2) exposure, the survival rate in group II, IV were significant lower compared with group I, III (all P<0.01), but no difference was found between group IV and group II (P>0.05). No inflammatory change in lung tissue was found in group I and III. After 7-14 days of hyperoxia exposure, blood vessels in group II, IV were dilated. Red blood cells and inflammatory cells were seen infiltrating into the alveolar space, and interstitium was thickened. After 21 days of hyperoxic exposure, inflammatory changes in group II became more marked, and the alveolar walls or alveolar septa were markedly thickened. The formation of alveoli in group II, IV was retarded and RACs at all time points were significantly lower than those in group I, III (all P<0.01). After 4 days and 14 days, the expression of IGFBP-2 in the group II and IV were significantly higher than those in group I, III (all P<0.01). The expression of mRNA of IGFBP-2 showed the same tendency of the protein in all 4 groups. CONCLUSION: The prolonged exposure to hyperoxia may cause subacute lung injury and the retardation of lung development in term-neonatal or preterm-neonatal rats. The abnormal expressions of IGFBP-2 correlate with hyperoxia-induced lung injury in neonatal rats.

Relationship between Notch receptors and hyperoxia-induced lung injury in newborn rats.

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.

[Protective effects of amygdalin on hyperoxia-exposed type II alveolar epithelial cells isolated from premature rat lungs in vitro].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Association of insulin-like growth factors with lung development in neonatal rats.

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.

Effect of amygdalin on the proliferation of hyperoxia-exposed type II alveolar epithelial cells isolated from premature rat.

The pathogenesis of hyperoxia lung injury and the mechanism of amygdalin on type 2 alveolar epithelial cells (AEC2) isolated from premature rat lungs in vitro were investigated. AEC2 were obtained by primary culture from 20-days fetal rat lung and hyperoxia-exposed cell model was established. Cell proliferating viability was examined by MTT assay after treatment of amygdalin at various concentrations. DNA content and the proliferating cell nuclear antigen (PCNA) protein expression of AEC2 were measured by using flow cytometry and immunocytochemistry respectively after 24 h of hyperoxia exposure or amygdalin treatment. The results showed that hyperoxia inhibited the proliferation and decreased PCNA protein expression in A-EC2 of premature rat in vitro. Amygdalin at the concentration range of 50-200 micromol/L stimulated the proliferation of AEC2 in a dose-dependent manner, however, 400 micromol/L amygdalin inhibited the proliferation of AEC2. Amygdalin at the concentration of 200 micromol/L played its best role in facilitating proliferation of AEC2s in vitro and could partially ameliorated the changes of proliferation in hyperoxia exposed AEC2 of premature rat. It has been suggested that hyperoxia inhibited the proliferation of AEC2s of premature rat, which may contribute to hyperoxia lung injury. Amygdalin may play partial protective role in hyperoxia-induced lung injury.

Effect of retinoic acid on platelet-derived growth factorand lung development in 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.

Clinical implication of the changes of cAMP, TXA2 and PGI2 in CSF of asphyxiated newborns.

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.