Objective To explore the clinical features and risk factors of poor prognosis in neonatal necrotizing enterocolitis(NEC).Methods A retrospective study was carried out in the infants with NEC admitted to 6 cooperative hospitals in Guangdong Province between January 2005 and December 2014.The clinical features and risk factors of poor prognosis in preterm and full-term infants diagnosed NEC,early onset and late onset NEC were analyzed.Results A total of 449 cases who met the criteria were admitted during the study time.The mortality was 23.6％ (106/449 cases),of which the preterm group was 24.6％ (58/238 cases) while the full-term group was 22.7％ (48/211 cases),the early onset group was 22.1％ (45/204 cases) while the late onset group was 24.3％ (57/235 cases).The median number of NEC onset in preterm group was 11 d after birth while the number of the full-term group was 6 d.Full-term infants who diagnosed NEC were more likely to manifest themselves as abdominal distension (52.1％ vs.42.0％,x2 =4.597,P =0.032),vomiting(36.5％ vs.17.2％,x2 =21.428,P =0.000) and bloody stool(30.3％ vs.21.4％,x2 =4.653,P =0.031);but in the onset of NEC,preterm infants more likely to have feeding intolerance (21.0％ vs.12.8％,x2=5.309,P =0.021).The early onset group of full-term NEC was much common in twins or multiplets(9.4％ vs.1.1％,x2 =6.226,P =0.013),which rate of surgical therapy was much higher (41.0％ vs.27.0％,P =0.036) and the breast-feeding rate before NEC was lower than the late onset group(14.5％ vs.32.6％,x2 =9.500,P =0.002),the differences were statistically significant.The gestational age and birth weight were bigger in the early onset group of preterm NEC[(33.8 ±2.5) weeks vs.(32.2 ±2.8) weeks,t =4.261,P =0.000;(2.1 ±0.5) kg vs.(1.7 ± 0.5) kg,t =4.735,P =0.000)],but length of stay was shorter than the late onset group (18.0 d vs.26.5 d,P =0.000).Logistic regression analysis showed that the risk factors of poor prognosis of full-term NEC were shock,peritonitis and sepsis;while risk factors of poor prognosis of preterm NEC were small for gestational age infant,pulmonary hemorrhage,shock,intestinal perforation and sepsis;the risk factors of poor prognosis of the early onset group of full-term NEC was shock;while those of the late onset group were shock and peritonitis;the risk factors of poor prognosis in the early onset group of preterm NEC were shock and sepsis,while those in the late onset group were pulmonary hemorrhage,shock,intestinal perforation and sepsis.Conclusions Compared to the preterm NEC,the onset time of full-term NEC was earlier and the clinical manifestations were more typical.Early identification and management of shock,peritonitis,intestinal perforation,sepsis and pulmonary hemorrhage can reduce the risk of poor prognosis of neonate NEC.

OBJECTIVETo observe the effects of manganese sulfate on blood pressure, myocardial ultrastructure and heart organ index of rats.

METHODSForty male SPF SD rats were randomly divided into 4 groups: control group (0 mg/kg), 5 mg/kg dose group, 15 mg/kg dose group and 25 mg/kg dose group, 10 rats each group. Intraperitoneal injection was performed for six months, by five times each week, the rat blood pressure was measured by tail cuff method, and the heart organ index of the rats was computed. Three rats were selected from each group randomly, and the myocardial ultrastructure of the rats was observed by using transmission electron microscopy (TEM). The BMD and BMDL between manganese sulfate injected dose and the rats heart organ index were evaluated by BMD (Benchmark Dose).

RESULTSThere was no significant of blood pressure between the experimental group and the control group (P > 0.05).The heart organ indexes of the four groups were 0.24% ± 0.10%, 0.25% ± 0.02%, 0.26% ± 0.02%, and 0.24% ± 0.02%. Statistical significance of heart organ indexes was found between the 15 mg/kg dose group and the control group (P < 0.05). Observed by TEM, we found that-different degrees of mitochondrial crest fracture or disappear, mitochondria swelling, hydropic change and myocardial fibers degeneration happened in the rats of the three exposed groups, but not the control group. The BMD and BMDL were calculated as 9.33 mg/kg and 4.28 mg/kg in the study of manganese sulfate injected dose and the rats heart organ index.

CONCLUSIONChronic manganese poisoning can lead to myocardial mitochondria superfine lesions, myocardial fiber damage and heart organ index change in rats.

Animals ; Male ; Manganese Compounds ; Mitochondria ; drug effects ; ultrastructure ; Myocardium ; ultrastructure ; Myocytes, Cardiac ; drug effects ; ultrastructure ; Rats ; Rats, Sprague-Dawley ; Sulfates ; toxicity ; Toxicity Tests