ABSTRACT
OBJECTIVE@#To study the methylation level and dynamic change of 5-hydroxymethylcytosine (5hmC) in mitochondrial DNA (mtDNA) in the cerebral cortex of neonatal rats with hypoxic-ischemic brain damage.@*METHODS@#A total of 24 male Sprague-Dawley rats aged 7 days were randomly divided into control group, 24-hour model group and 48-hour model group (n=8 each). Common carotid artery ligation combined with hypoxic treatment was performed to establish an animal model of hypoxic-ischemic brain damage. The rats in the control group were not given ligation or hypoxic treatment. Oxidative bisulfite sequencing was used to measure the level of 5hmC in the cerebral cortex. Western blot was used to measure the expression of 5hmC-related enzymes TET1, TET2 and DNMT1.@*RESULTS@#The 24- and 48-hour model groups had a significantly higher level of 5hmC than the control group (P<0.05). Western blot showed a significant increase in the expression of DNMT1 in the 24- and 48-hour model groups (P<0.05). Compared with the control group, the 24- and 48-hour model groups had significant differences in the 5hmC level at multiple mitochondrial genetic loci (P<0.05).@*CONCLUSIONS@#The level of DNMT1, a key enzyme for 5hmC modification in mtDNA, in the cerebral cortex increases in neonatal rats with hypoxic-ischemic brain damage, suggesting that there is an abnormal methylation level of 5hmC after hypoxic-ischemic brain damage, which might be associated with the regulation of hypoxic-ischemic brain damage.
Subject(s)
Animals , Male , Rats , Animals, Newborn , Cerebral Cortex , DNA, Mitochondrial , Hypoxia-Ischemia, Brain , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To study the efficacy and safety of probiotics for the prevention of feeding intolerance in low birth weight (LBW) premature infants.</p><p><b>METHODS</b>Sixty eligible LBW premature infants were randomly divided into probiotics and conventional treatment groups (n=30 each). Both groups received treatment of the primary disease. Additionally, the probiotics treatment group was administered with probiotics (0.25 g, twice daily). The incidence of feeding intolerance, the time to regain birth weight and to reach full enteral nutrition and the length of hospitalization were compared between the two groups. The occurrence of adverse reactions was recorded.</p><p><b>RESULTS</b>The incidence of feeding intolerance in the probiotics treatment group was lower than that in the conventional treatment group (4% vs 14%; P<0.01). The time to regain birth weight (6.8±1.2 days vs 7.7±1.6 days; P<0.05) and the time to reach full enteral nutrition (8.0±1.4 days vs 9.0±2.0 days; P<0.05) in the probiotics treatment group were shorter than those in the conventional treatment group. No adverse reactions were observed in the probiotics treatment group.</p><p><b>CONCLUSIONS</b>Probiotics can reduce the incidence of feeding intolerance in LBW premature infants, can promote weight gain and shorten the time to reach full enteral nutrition. The application of probiotics appears to be safe in LBW premature infants.</p>