Investigation of control region sequences of mtDNA in Naqu Tibetan population from Northwestern China.

BACKGROUND: The sequence polymorphisms of mitochondrial DNA (mtDNA) are valuable in forensic medicine and anthropological genetics. AIM: We analysed the sequences of the mtDNA control region in 207 unrelated Tibetan individuals from the Naqu region, Tibet Autonomous Region in the People's Republic of China, and investigated the population structure of the region by population comparison with other groups. SUBJECTS AND METHODS: Genomic DNA was extracted and hypervariable regions (HVS-I and HVS-II) were amplified and sequenced. Subsequently, sequences were aligned and compared with the revised Cambridge sequence. Moreover, population comparison was performed between the Naqu Tibetan group and the other groups. CONCLUSION: Our study provided available data for exploring the mtDNA haplotype of the Tibetan population in the Naqu region, and population comparisons found that the Naqu Tibetan population has its own unique structure.

[Interpretation of the disaster response plans in the pediatric intensive care unit].

In April 2018, the Group of Pediatric Disasters, Pediatric Society, Chinese Medical Association and Pediatric Committee, Medical Association of Chinese People's Liberation Army issued the disaster response plans in the pediatric intensive care unit (PICU). This article outlines the development of the plans and the implementation of PICU disaster rescue, along with ethical issues in the context of disasters and psychological reconstruction after a disaster.

[Relationship between fever degree and prognosis in children with bacterial bloodstream infection].

OBJECTIVE: To study the relationship between the degree of fever within 48 hours of admission and the prognosis in children with bacterial bloodstream infection. METHODS: This study retrospectively analyzed the clinical data of all patients diagnosed with sepsis who were admitted to the pediatric intensive care unit (PICU) of Shengjing Hospital Affiliated to China Medical University between September 2008 and September 2016. The children with bacterial bloodstream infection were classified into 5 groups according to the maximum temperature within 48 hours of admission: <36.5°C group, ≥36.5°C group (normal control), ≥37.5°C group, ≥38.5°C group, and ≥39.5°C group. The mortality was compared between the five groups. Results A total of 213 children with bacterial bloodstream infection were enrolled, consisting of 5 cases in the <36.5°C group, 44 cases in the ≥36.5°C group, 73 cases in the ≥37.5°C group, 69 cases in the ≥38.5°C group, and 22 cases in the ≥39.5°C group. A total of 48 cases died among the 213 patients. A significant difference was observed in the mortality between the five groups (P<0.01). The <36.5°C group and ≥39.5°C group had significantly higher mortality than the normal control group. However, there were no significant differences in the mortality between the ≥37.5°C and ≥38.5°C groups and the normal control group. Conclusions In children with bacterial bloodstream infection, those with a maximum temperature below 36.5°C or above 39.5°C within 48 hours of admission have a significantly increased mortality.

[Risk factors for multidrug-resistant Klebsiella pneumoniae sepsis in children].

OBJECTIVE: To explore the risk factors for sepsis caused by multidrug-resistant Klebsiella pneumonia (MDR-KP) and to provide a reference for the prevention of MDR-KP sepsis and rational use of antibiotics. METHODS: A retrospective case-control study of 41 children with MDR-KP sepsis (case group) and 53 pediatric patients without MDR-KP sepsis (control group) between March 2010 and Febrary 2014 was conducted. Multiple logistic regression analysis was performed to estimate the independent risk factors for MDR-KP sepsis. RESULTS: Compared with the control group, the case group had a longer length of stay in the PICU before infection (P<0.05), more prolonged duration of mechanical ventilation before infection (P<0.05), a larger total number of days of mechanical ventilation (P<0.05), more days of antibiotic use before infection (P<0.05), more types of antibiotics used before infection (P<0.05), and a higher mortality (P<0.05). The logistic regression analysis showed that more types of antibiotics used before infection and use of third-generation cephalosporin and carbapenems were independent risk factors for MDR-KP sepsis (P<0.05). CONCLUSIONS: Rational use of antibiotics is an effective measure to prevent MDR-KP sepsis.

[Diagnostic value of serum CRP and procalcitonin levels in children with bloodstream infection-associated sepsis and septic infection at other sites].

OBJECTIVE: To evaluate the diagnostic value of measuring serum C-reactive protein (CRP) and procalcitonin (PCT) levels, within 6 hours after admission to the pediatric intensive care unit (PICU) in children with bloodstream infection (BSI)-associated sepsis and septic infection at other sites. METHODS: A retrospective analysis was performed on 30 children with a confirmed diagnosis of systemic inflammatory response syndrome who were admitted to the Shengjing Hospital of China Medical University between January 2010 and January 2012. Clinical data on serum CRP, PCT and D-dimer levels were collected within 6 hours after admission. The diagnostic values of the indices were determined by comparative analysis. RESULTS: Serum CRP and PCT levels in children with BSI-associated sepsis were significantly higher than in children with septic infection at other sites (P<0.05), but there was no significant difference in serum D-dimer levels between the two groups (P>0.05). Serum PCT level was superior to serum CRP level in distinguishing children with BSI-associated sepsis from those with septic infection at other sites. Serum PCT level could not realistically be used for diagnosing BSI-associated sepsis when it was less than 2 ng/mL (negative predictive value: 100%), but could be reliably used when it was more than 10 ng/mL (positive predictive value: 77%). CONCLUSIONS: Serum PCT level is superior to serum CRP level in distinguishing children with BSI-associated sepsis from those with septic infection at other sites within 6 hours after admission to the PICU. Serum PCT level has a better diagnostic value for BSI-associated sepsis when it is more than 10 ng/mL.

[Investigation of disease spectrum in the PICU of Shengjing Hospital of China Medical University between 2005 and 2012].

OBJECTIVE: To summarize the spectrum of disease and common diseases that cause death in children admitted to the Pediatric Intensive Care Unit (PICU), Shengjing Hospital of China Medical University between 2005 and 2012. METHODS: A retrospective analysis was carried out on the clinical data of 4484 children admitted to the PICU of Shengjing Hospital between 2005 and 2012. RESULTS: Acute bronchopneumonia, which was found in 1099 (24.51%) of the 4484 cases, was the most common disease in the PICU between 2005 and 2012. The incidence of intracranial infection, sepsis, hand-foot-mouth disease and trauma showed an increasing trend from 2005 to 2012, but that of non-traumatic intracranial hemorrhage, epilepsy and congenital heart disease showed a decreasing trend. The mortality decreased from 11.5% in 2005 to 3.1% in 2012, and the overall mortality was significantly higher in 2005-2008 than in 2009-2012 (11.98% vs 4.41%; P<0.01). The main causes of death included severe acute bronchial pneumonia, severe sepsis, complex congenital heart disease, severe cerebral trauma, respiratory failure, severe hand-foot-mouth disease, acute poisoning and circulatory failure. CONCLUSIONS: Acute bronchopneumonia was the most common disease in the PICU of Shengjing Hospital between 2005 and 2012, but the spectrum of disease changed over time. The mortality showed a decreasing trend among the children in the PICU between 2005 and 2012, and the main causes of death included severe acute bronchial pneumonia and severe sepsis.

Multi-omics reveal neuroprotection of Acer truncatum Bunge Seed extract on hypoxic-ischemia encephalopathy rats under high-altitude.

Hypoxic-ischemic encephalopathy (HIE) at high-altitudes leads to neonatal mortality and long-term neurological complications without effective treatment. Acer truncatum Bunge Seed extract (ASO) is reported to have effect on cognitive improvement, but its molecular mechanisms on HIE are unclear. In this study, ASO administration contributed to reduced neuronal cell edema and improved motor ability in HIE rats at a simulated 4500-meter altitude. Transcriptomics and WGCNA analysis showed genes associated with lipid biosynthesis, redox homeostasis, neuronal growth, and synaptic plasticity regulated in the ASO group. Targeted and untargeted-lipidomics revealed decreased free fatty acids and increased phospholipids with favorable ω-3/ω-6/ω-9 fatty acid ratios, as well as reduced oxidized glycerophospholipids (OxGPs) in the ASO group. Combining multi-omics analysis demonstrated FA to FA-CoA, phospholipids metabolism, and lipid peroxidation were regulated by ASO treatment. Our results illuminated preliminary metabolism mechanism of ASO ingesting in rats, implying ASO administration as potential intervention strategy for HIE under high-altitude.

Lipidomics reveal the cognitive improvement effects of Acer truncatum Bunge seed oil on hypoxic-ischemic encephalopathy rats.

Hypoxic-ischemic encephalopathy (HIE) is one of the leading causes of acute neonatal death and chronic neurological damage, and severe HIE can have secondary sequelae such as cognitive impairment and cerebral palsy, for which effective interventions are lacking. In this study, we found that continuous 30-day intake of Acer truncatum Bunge seed oil (ASO) reduced brain damage and improved cognitive ability in HIE rats. Using lipidomic strategies, we observed that HIE rats had decreased unsaturated fatty acids and increased lysophospholipids in the brain. However, after 30 days of ASO treatment, phospholipids, plasmalogens, and unsaturated fatty acids increased, while lysophospholipids and oxidized glycerophospholipids decreased in both serum and the brain. Enrichment analysis showed that ASO intake mainly affected sphingolipid metabolism, fat digestion and absorption, glycerolipid metabolism and glycerophospholipid metabolic pathways in serum and the brain. Cluster, correlation, and confirmatory factor analyses showed that cognitive improvement after ASO administration was attributed to increased essential phospholipids and ω3/6/9 fatty acids, coupled with decreased oxidized glycerophospholipids in HIE rats. Our findings indicate that ASO has the potential to be developed as an effective food supplement for ischemic hypoxic newborns.

Distribution of enteroviruses in hospitalized children with hand, foot and mouth disease and relationship between pathogens and nervous system complications.

BACKGROUND: To explore the relationship between enteroviruses and hospitalized children with hand, foot and mouth disease (HFMD) complicated with nervous system disease. 234 hospitalized HFMD patients treated in Shengjing Hospital, Liaoning Province were analyzed retrospectively. Based on the presence and severity of nervous system disease, the patients were grouped as follows: general patients, severely ill patients, critically ill patients and fatal patients. Based on the detected pathogen, the patients were grouped as follows: Enterovirus 71 (EV71) infection, coxsackie A16 (CA16) infection and other enterovirus (OE) infection. RESULTS: Of the 423 hospitalized patients, most were admitted in July 2010(129/423, 30.5%). Enteroviruses were detected in 177(41.8%). 272/423 patients were male (64.3%), and fatal patients had the greatest proportion of male patients (p < 0.05). EV71 infection was found in 89/423 patients (21%). CA16 infection was detected in 8/423 patients (16.1%). Compared to group CA16, patients in group EV71 were hospitalized earlier, and the duration of hospitalization was longer (p < 0.05). Of the 92 patients with nervous system damage, 65 were infected with EV71 and 19 were infected with CA16. Among these CA16 infected patients, 2 had brainstem encephalitis and 1 had AFP. There were more patients with nervous system dysfunction in group EV71 than in groups CA16 or OE (p < 0.05). The 5 fatalities all occurred in group EV71 patients (p < 0.05). Infection with EV71 was most likely to cause neurogenic pulmonary edema (p < 0.05). Patients in group EV71 had a higher rate of suffering from coma and limb movement disorder than patients in groups CA16 or OE (p < 0.05). CONCLUSION: The disease progresses faster in EV71-infected HFMD patients. These patients are more likely to suffer nervous system damage, neurogenic pulmonary edema, severe sequelae or death. CA16 and other enteroviruses can also cause HFMD with severe nervous system complications.

[Correlation between the blood serum BNP level and the left cardiac function in children with congenital heart disease].

OBJECTIVE: To study the correlation between the blood serum brain natriuretic peptide (BNP) level and the left cardiac function in children with congenital heart disease (CHD). METHODS: The clinical data of 41 CHD children were retrospectively analyzed. Patients were divided into two groups based on the existence of congestive heart failure (CHF): CHD+CHF (n=21) and CHD alone (n=20). The blood serum BNP level was determined using chemiluminescence immunoassay, and the left ventricular ejection fraction (LVEF) was measured with echocardiogram. RESULTS: The serum BNP level was 1353 pg/mL (range: 926-2978) in the CHD+CHF group, which was significantly higher than in the CHD alone group[149 pg/mL (range: 75-242)] (P<0.01). The LVEF was 60% (range: 53%-65%) in the CHD+CHF group, which was significantly lower than in the CHD alone group[68% (range: 64%-72%)] (P<0.01). The serum BNP level showed a negative correlation with the LVEF level (r=-0.652, P<0.01). CONCLUSIONS: The blood serum BNP level is related to the cardiac function. For children with severe CHD+CHF, serum BNP level can be used as a sensitive indicator for evaluating cardiac function damage.

Cognitive improvement effect of nervonic acid and essential fatty acids on rats ingesting Acer truncatum Bunge seed oil revealed by lipidomics approach.

Acer truncatum Bunge seed oil (ASO) is rich in ω-9 (53.93%) and ω-6 (30.7%) fatty acids (FAs) and characterized by 3-7% nervonic acid (NA, C24:1ω-9). Evidence suggests that ω-9 FAs such as NA participate in processes of cognitive improvement; however, their mechanism remains ambiguous. In this study, we investigated the effect of ASO on rat memory and the change in lipid profiling and underlying metabolism. After ASO was administrated to rats for one, three and seven days, their capacity for learning and memory significantly increased via the MWM test. Lipid profiling showed alterations in a wide range of metabolic features after ASO was administrated to the rats, in which sphingolipids (SP) in the serum and glycerophospholipids (GP) in the brain were regulated significantly. The changes in the fatty acids in the serum and brain showed the synergetic effects of NA, EA, OA and DHA, where NA, EA and OA exhibited similar change trends. The enrichment analysis based on KEGG indicated that ASO supplementation evoked the pathways of neurotrophin signaling, glycerophospholipid metabolism and sphingolipid metabolism, which are related to memory and cognition improvement. Among the metabolites with different molecular forms, the biomarkers with C24:1ω-9 chains exhibited a positive correlation with others both in the serum SP and brain GP. These results suggest the synergistic effects of ω-9 FAs and that their conversion into each other may result in enhanced cognition in rats ingesting Acer truncatum Bunge seed oil.

Surfactant Therapy for Respiratory Distress Syndrome in High- and Ultra-High-Altitude Settings.

Objective: The objective of this study is to investigate the therapeutic effect of surfactant replacement therapy (SRT) on respiratory distress syndrome (RDS) in premature infants in the Qinghai-Tibet Plateau. Materials and Methods: This multi-center retrospective cohort study collected and screened reasonable clinical data of 337 premature infants with RDS from 10 hospitals in the Qinghai-Tibet Plateau from 2015 to 2017. We grouped the cases by rationally analyzing their baseline characteristics, using logistic analysis to evaluate each factor's effect on the prognosis of the infants, and comparing the short-term improvement in blood gas and mortality after SRT treatment at different altitudes, in high-altitude (1,500-3,500 m) and ultra-high-altitude (3,500-5,500 m) groups. Results: Independent of altitude, the mortality rate of children with RDS in the SRT group was significantly lower than that of children in the non-SRT group (both P < 0.05). The effect of SRT on preterm infants with RDS in the high-altitude group [odds ratio (OR) = 0.44, 95% confidence interval (CI) = 0.22-0.87, P = 0.02] was better than that in the infants in the ultra-high-altitude group (OR = 0.26, 95% CI = 0.13-0.58, P < 0.01), with death rates of 34.34 and 49.71%, respectively. Similarly, after SRT, the improvement of PaO2/FiO2 and pH of children at high altitude was significantly better than those of children at ultra-high altitude (all P < 0.01). Conclusions: SRT plays a prominent role in curing infants with RDS in both high- and ultra-high-altitude regions, although with better effects at high rather than ultra-high altitude. This study provides a basis for further large-scale studies on SRT for RDS treatment at high altitudes.

Lactate levels and clearance rate in neonates undergoing mechanical ventilation in Tibet.

OBJECTIVE: This study aimed to examine the characteristics of blood lactate in neonates undergoing mechanical ventilation in Tibet. METHODS: We recruited 67 neonates undergoing mechanical ventilation in Naqu People's Hospital as the plateau observation group and 94 neonates undergoing mechanical ventilation in Shengjing Hospital as the control group. We analyzed the differences in lactate levels between the two groups. RESULTS: The lactate clearance rates of neonates with asphyxia and those with respiratory distress syndrome were significantly lower in the plateau group than in the control group. Lactate levels in neonates who died in the plateau group were significantly higher and the lactate clearance rate was significantly lower than those in neonates who survived. The cut-off point for the lactate clearance rate at 6 hours for predicting mortality was 6.09% in the plateau group. CONCLUSION: The lactate clearance rate of neonates on mechanical ventilation in the plateau area is lower than that in neonates in the non-plateau area. The lactate clearance rate at 6 hours is important for evaluating the prognoses of critical neonates in plateau areas.

Factors Influencing Vitamin D Levels in Neonatal Umbilical Cord Blood: A Two-Center Study From Tibet and Shenyang.

Objective: To investigate the factors influencing the levels of vitamin D (vitD) in the umbilical cord blood of neonates born in Naqu, Tibet (4,500 m above sea level), and Shenyang, Liaoning Province (500 m above sea level). Methods: This prospective study was conducted from June 2017 to October 2018 in Naqu (the plateau group) and Shenyang, (the non-plateau group). Healthy mothers that gave birth to healthy neonates of >2,000g after 38 weeks' gestation were enrolled in the study, as were their neonates. After separation of serum from the umbilical cord and mothers for routine biochemical tests, discarded samples were remained for analyses of vitD, calcium, phosphorus, alkaline phosphatase (ALP) and parathyroid hormone (PTH). Questionnaires were developed covering the demographic characteristics and possible risk factors for neonatal vitD deficiency of mothers. Statistical analysis was performed to identify associations between the calcium, phosphorus, ALP, PTH, maternal factors and neonatal vitD levels. Results: In total, 295 neonates and 225 mothers were enrolled in the study. VitD deficiency was common in neonates and mothers. The risk of vitD deficiency was higher in the plateau group than in the non-plateau group. The mean levels of 25-hydroxy vitD (25(OH)D) in mothers and neonates from the plateau group were 8.49 ± 4.12 ng/mL and 10.17 ± 5.07 ng/mL, respectively. Such levels were significantly lower than those in the non-plateau group (19.77 ± 9.57 ng/mL and 23.93 ± 11.01 ng/mL, respectively). The vitD levels of neonates and mothers were highest in the summer and lowest in the winter. Cord blood vitD was positively correlated with the vitD levels in mothers' serum (r = 0.75, P < 0.05). Increased PTH levels in mothers and decreased cord blood calcium levels were risk factors for neonatal vitD deficiency. A lack of vitD supplementation during pregnancy was associated with an 8.91-fold higher probability of neonatal vitD deficiency (OR = 8.91, 95% CI = 1.521-9.429, P < 0.001). Conclusions: The levels of neonatal and maternal vitD in the plateau group were generally lower than those in the non-plateau group. VitD supplementation during pregnancy could effectively reduce the risk of vitD deficiency in neonates.

Iatrogenic Pleural Effusion Due to Extravasation of Parenteral Nutrition via an Epicutaneo Cava Catheter in Neonates: A Prospective Cohort Study.

Background: Although Epicutaneo cava catheters (ECCs) are being routinely used for intravenous access for long-term parenteral nutrition and prolonged medication administration in neonates, ECC use can be associated with rare but acute life-threatening events such as pleural effusion (PE). It is important to identify and maintain the ECC tip in a central location for preventing complications. Recently, intracavitary electrocardiogram (IC-ECG) has been developed for the real-time monitoring and verification of ECC tip position. Objective: To investigate the causes and preventive measures of ECC-related PE in neonates. Methods: This prospective cohort study was conducted between January 2013 and December 2017. We observed and analyzed the clinical characteristics and causes of ECC-related PE. From January to December 2017, all ECCs were guided by IC-ECG. The incidence of ECC-related PE and first-attempt success rates were analyzed before and after the introduction of IC-ECG. Additionally, the sensitivity and specificity of IC-ECG were evaluated. Results: ECC-related PE was identified in 14 infants. Catheters were malpositioned in three cases; in the other 11 cases, catheters were located centrally on insertion but had migrated to non-central locations at the time of PE. After the introduction of IC-ECG, the incidence of PE was zero (P < 0.05). The incidence of ECC-related PE was lower when veins of the lower extremities were selected as the insertion site (P < 0.05). The first-attempt success rate was significantly higher in the group with IC-ECG-guided ECC placement than in the group without (P < 0.05). The sensitivity and specificity of IC-ECG were 97.9 and 84.6%, respectively. Conclusion: ECC-related PE can be associated with either primary malposition or migration of the catheter tip. IC-ECG can help detect malposition and migration of catheter tips and improve the first-attempt success rate. Choosing a lower extremity insertion site may help decrease the rate of ECC-related PE. In neonates, IC-ECG is a reliable positioning method for ECCs with superior sensitivity and specificity.

[Etiology of acute upper respiratory tract obstruction in infants: analysis of 12 cases].

OBJECTIVE: To study the etiology of acute upper respiratory tract obstruction in infants. METHODS: The medical data of 12 infants with acute upper respiratory tract obstruction were retrospectively reviewed. The patients received the examinations of laryngoscopy and CT scans for larynx and lungs. RESULTS: All of the 12 infants presented with laryngeal stridor. Eight infants (67%) were diagnosed as congenital simple laryngeal stridor before admission. Based on the clinical features, laboratory examinations, imaging examinations and laryngoscopy, 4 (33%) were definitely diagnosed with thyroglossal ductal cyst, 1(8%) with abscess-emphysema in the posterior wall of pharynx, 1(8%) with cervicallymphangioma, 2 (16%) with subglottic stenosis, and 4 (33%) with acute laryngitis. CONCLUSIONS: Acute upper respiratory tract obstruction is easily misdiagnosed in infants. Thyroglossal duct cyst is a common cause of upper respiratory tract obstruction/laryngeal stridor. It is recommend that laryngoscopy and CT scans for larynx should be performed in infants with laryngeal stridor.

[Treatment of congenital heart disease complicated by severe bronchopneumonia in infants].

OBJECTIVE: To study the treatment and the treatment outcome in infants with congenital heart disease complicated by severe pneumonia and heart failure. METHODS: The clinical data of 24 infants with congenital heart disease (left to right shunt) complicated by severe pneumonia and heart failure between January 2007 and December 2007 were retrospectively reviewed. RESULTS: Twenty-two infants recovered and 2 died. Severe pneumonia and heart failure were refractory even after 1-2 months medical treatment in 6 infants at ages of <6 months. They then underwent an open heart surgery under the mechanical ventilation and tracheal intubations and were successfully cured. The other 18 infants underwent a selective heart surgery after pneumonia and heart failure had been improved. Sixteen infants were successfully cured and 2 died of postoperative low cardiac output syndrome and diffuse intravascular clotting. CONCLUSIONS: The heart surgery should be performed early when the medical treatment does not work in infants with congenital heart disease complicated by severe pneumonia and heart failure. This may improve their outcome.

Mechanical Ventilation in Neonatal Respiratory Distress Syndrome at High Altitude: A Retrospective Study From Tibet.

Objective: To explore the characteristics of mechanical ventilation parameters and the arterial partial pressure of oxygen in neonatal respiratory distress syndrome (RDS) at high altitude. Methods: From the 1st May 2017 to the 31st December 2018, we recruited 33 neonates with severe RDS who were undergoing mechanical ventilation in the NICU of Naqu People's Hospital in Tibet (4,580 m above sea level); these neonates formed a plateau observation group. We also recruited a non-plateau control group: 66 neonates with severe RDS undergoing mechanical ventilation of Shengjing Hospital in Liaoning (51 m above sea level). Various ventilation parameters and the arterial partial pressure of oxygen were then compared between the two groups, between the survivors of the two groups, and between those who died and survived in the plateau group. Results: In terms of initial ventilator parameters, peak inspiratory pressure (PIP), positive end expiratory pressure (PEEP), and the fraction of inspired oxygen (FiO2) in the plateau group were significantly higher than those in the non-plateau group (P < 0.01). PIP, PEEP, and FiO2 in the survivors from the plateau group were also significantly higher than those in the non-plateau group (P < 0.01). In addition, the arterial partial pressure of oxygen in the non-plateau group was higher (P < 0.05) than that in the plateau group during the early postnatal period, and the arterial partial pressure of oxygen at 6 and 12 h was lower than that in the plateau group (P < 0.05). Conclusion: Mechanical ventilation can effectively improve the arterial oxygen partial pressure and reduce the mortality of newborns with RDS in a plateau environment. It was clearly evident that ventilation parameters are closely related to altitude. It is therefore not advisable to apply mechanical ventilation parameters used in a non-plateau area as a guide for the treatment of newborns with RDS in plateau areas.

[Changes of pulmonary surfactant protein A in young rats with acute lung injury induced by lipopolysaccharide].

OBJECTIVE: Pulmonary surfactant protein A (SP-A) plays an important role in the maintenance of pulmonary surfactant function and innative immune defence. This study aimed to explore the changes of SP-A concentration in the lungs of young rats with acute lung injury. METHODS: Sprague-Dawley rats were randomly assigned to control and lung injury groups. Acute lung injury was induced by intraperitoneal injection of lipopolysaccharide (LPS) (4 mg/kg) in the lung injury group. The same amount of normal saline was given for the control group. The two groups were subdivided into 6 groups sacrificed at 6, 12, 24, 36, 48 and 72 hrs of injection (n=8 each). Western blot was employed to detect SP-A concentration in the lung tissues. RESULTS: SP-A concentration in the lung injury group was not different from the the control group within 12 hrs after LPS injection. SP-A concentration in the lung injury group was elevated significantly during 24-48 hrs after LPS injection, peaking at 36 hrs (6.94+/-0.80 vs 5.01+/-0.36; P< 0.01), compared with the controls. However, SP-A concentration in the lung injury group was significantly reduced 72 hrs after LPS injection compared with the controls (P< 0.01). CONCLUSIONS: The changes of lung SP-A concentration in rats following acute lung injury were time-dependent. The transient elevation of SP-A concentration in the lungs indicated a strong compensation ability of SP-A in the host defence against acute lung injury.