ABSTRACT
Objective To investigate the sensitivity of mouse models of chronic restraint stress to conditions that induce epileptic seizures.Methods Male C57BL/6J mice were randomized into chronic restraint stress(CRS)group and normal control(NC)group. The modeling results were evaluated by sucrose preference test and forced swimming test. Kainic aicd(KA)was intraperitoneally injected to induce acute seizures. Seizure onset time,duration,and scores were recorded and compared.Results During the forced swimming test,the immobility time was(120.9±13.5)s in CRS group and only(59.1±9.8)s in NC group(t=3.700,P=0.0019). During the sucrose preference test,the water consumption proportion at 0-24 h and 0-48 h were(64.7±4.7)% and(73.3±3.0)%,respectively,in CRS group,significantly lower than those[(77.2±2.5)%(t=2.672,P=0.0167)and(83.0±2.8)%(t=2.386,P=0.0297)] in NC group. Although there was no significant difference in the total number of acute seizures[(11.5±1.1)times vs.(13.7±2.1)times;t=0.9767,P=0.3465],mice in CRS group had significantly higher severe seizure score than in control group[(66±10)scores vs.(37±5)scores;t=2.777,P=0.0157]. The seizure onset time was(138±26)s in CRS group,which was significantly shorter than that in NC group[(234±28)s;t=2.485,P=0.0274]. The seizure duration of the CRS group was(61±16)min,which was significantly longer than that of the NC group[(37±5)min;t=3.342,P=0.0053].Conclusion CRS mice are more susceptible to KA-induced acute epileptic seizures.
ABSTRACT
<p><b>OBJECTIVE</b>To explore an optimal oxygen saturation for extremely preterm infants based on a systemic review of the published studies.</p><p><b>METHODS</b>A Meta analysis of the published studies by the NeOProM Group which compared the outcomes of extremely preterm infants (gestational age <28 weeks) maintained in either a low (85%-89%) or high (91%-95%) oxygen saturation (SpO2) by using the STATA 12.0. The outcomes measured included the mortality and the incidences of retinopathy of prematurity (ROP), necrotizing enterocolitis of newborn (NEC), broncho-pulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) and patent ductus arteriosus (PDA).</p><p><b>RESULTS</b>Three studies were included, in which 2 460 infants were assigned into the low SpO2 group and 2 459 infants in the high SpO2 group. The Meta analysis demonstrated that the risk of mortality before discharge or at the age of 18 months increased in the low SpO2 group compared with the high SpO2 group (RR: 1.19; 95%CI: 1.05-1.35); the risk of ROP decreased in the low SpO2 group (RR: 0.73; 95%CI: 0.53-1.00); the risk of NEC increased in the low SpO2 group (RR: 1.26; 95%CI: 1.06-1.49). There was no significance in the incidences of BPD, IVH and PDA between the two groups.</p><p><b>CONCLUSIONS</b>Maintaining SpO2 at 85%-89% may decrease the incidence of ROP, but increase the mortality rate and the incidence of NEC in extremely premature infants.</p>