Objective To investigate the effects of L-carnitine(L-CN)on electrophysiological changes induced by atrial ischemia in dogs.Methods Twelve dogs were divided into normal saline(NS)group and L-CN group.Atrial ischemia was induced by ligation of an atrial arterial branch of right coronary artery.Atrial effective refractory period(AERP)and conduction velocity(CV)of right atrium were measured before and after 3 hour's coronary artery ligation.Atrial wavelength(WL)and inducibility of atrial fibrillation(AF)were calculated.Histological examination was performed.Results (1)AERP and WL shortened dramatically after ligation of coronary artery in NS group;they showed no remarkable change in L-CN group.(2)There was no significant change of CV in the two groups.(3)AF was induced in 0 of 12 dogs under basic condition.(3)After ligation of the right coronary artery,AF was induced in all of the 6 dogs in NS group and 0 of 6 dogs in L-CN group.(5)Histological examination revealed that the ischemic changes occurred only in NS group.Conclusion Electrophysiological changes induced by atrial ischemia could be prevented by infusion of L-CN.

Objective To summarize the characteristics of treatment and outcomes of extremely low birth weight infants (ELBWI).Methods The clinical data of 81 cases of ELBWI admitted to Bayi Children's Hospital Affiliated to General Hospital of Beijing Military Command from October 1st.2008 to August 31st.2011 were retrospectively analyzed.The survival rate and mortality of ELBWI with different gestational age and birth weight were compared with Chi-square test.Results Of 81 ELBWI,43 were male and 38 were female; the mean gestational age at birth was (28.4 ±2.1) weeks; the average birth weight was (903.5 ± 95.4) g.Complications of them included respiratory distress syndrome (68/81,84.0％),patent ductus arteriosus (47/81,58.0％),retinopathy of prematurity (41/81,50.6％),intraventricular hemorrhage (23/81,28.4％),bronchopulmonary dysplasia (17/81,21.0％),sepsis (15/81,18.5％),periventricular leukomalacia (2/81,2.5％) and necrotizing enterocolitis (1/81,1.2％).Among 81 infants,96.3％ (n =78)received oxygen inhalation with the average time was 19.1 d (median 11 d,0-121 d) ; 70.4％ (n=57)received pulmonary surfactant; 27.2％ (n =22) received nasal continuous positive airway pressure;34.6％ (n =28) received normal frequency mechanicalfrequency ventilation.All 47 ELBWI with patent ductus arteriosus received ibuprofen treatment,among which 6 cases received arterial canal ligation after failure of ibuprofen treatment.20 out of 41 cases of retinopathy of prematurity received laser surgery.Total parenteral nutrition was required in 74 infants(91.4％),the average age of beginning enteral feeding was 5.2 d (median 6 d,0-17 d)and achieved full gastrointestinal feeding time was 31 d (median 28 d,7-65 d).The survival rate of ELBWI with gestational age of ≤26,-28 and ＞28 weeks was 25.0％ (4/16),72.0％ (18/25) and 77.5％ (31/40),respectively; the corresponding mortality was 12.5％ (2/16),8.0％ (2/25) and 2.5％ (1/40),respectively.The survival rate of ELBWI with birth weight ≤800,-900 and ＞900 g was 33.3％ (4/12),58.3％ (14/24) and 77.8％ (35/45),respectively; and corresponding mortality of them was 16.7％ (2/12),8.3％ (2/24) and 2.2％ (1/45),respectively.Conclusions The outcome of ELBWI is closely related to gestational age and birth weight.Professional and sophisticated treatment might improve the survival rate and general outcome of ELBWI.

Objective To determine the incidence and risk factors of retinopathy of prematurity (ROP) in preterm infants.Methods Fundus examinations were performed by RetCam Ⅱ ophthalmoscopy on 2185 premature infants (birth weight ≤ 2000 g or gestational age≤34 weeks)admitted into the neonatal intensive care unit of Beijing Bayi Children's Hospital from January 1st 2009 to December 31st 2010.According to the results,all infants were divided into ROP group and nonRO P group.Two-sample t test and Logistic regression analysis were used to investigate the risk factors of ROP.Results Among 2185 premature infants,287 (13.1 ％) cases were diagnosed with RO P.According to International Classification of RO P,34 cases (11.9 ％) were in zone Ⅰ,147 cases (51.2％) in zone Ⅱ,and 106 cases(36.9％) in zone Ⅲ.And there were 117 cases (40.8％) with stage 1 lesion,142 cases (49.5％) with stage 2 lesion,28 cases (9.7％) with stage 3 lesion,and no stage 4 or 5 lesion was identified.Thirty-six cases (12.5 ％) were accompanied by additional diseases.Logistic analysis showed that small gestational age (OR=0.859,95％CI:0.770-0.958,P=0.006),low birth weight (OR=0.729,95％CI:0.6340.838,P=0.000),long duration of oxygen supplement (OR=2.221,95％CI:1.904-2.592,P=0.000),assistant ventilation (OR=3.104,95％CI:2.0964.956,P=0.000),apnea (OR=1.767,95％CI:1.103 2.831,P=0.018) and=anemia (OR=2.242,95％CI:1.641-3.604,P=0.000) were independent risk factors of ROP.Conclusions The incidence of ROP in premature infants is high.Small gestational age and low birth weight,long duration of oxygen supplement,assistant ventilation,apnea and anemia are risk factors of ROP.Preventive measures should be taken against these factors.