Study on Learning and Memory Ability of Mice Induced by Different Doses of D-galactose

Aim:To explore the influence of different doses of D-galactose on learning memory capacity in mice.Methods:The 2-month-old KM mice were randomly divided into D-galactose-treated groups (75,100,150,300 mg·kg^-1) and normal control group,with 12 mice in each group.The corresponding dose of D-galactose was administered subcutaneously to the back of the neck,and normal control group was injected subcutaneously with saline for 8 weeks.Learning memory capacity of mice was detected through Morris water maze,step-down passive avoidance test and new object recognition test.Meanwhile,the enzymatic indicators in the brain were determined to detect the damage degree in mice with different doses of D-galactose.Results:Compared with the normal control group,the spatial and non-spatial cognitive functions and brain enzyme levels of D-galactose in each dose group was damaged to varying degrees,especially the dose of 100 mg·kg-1 group.In the water maze experiment,D-galactose groups significantly prolonged the time of crossing the platform for the first time and decreased the number of crossing platforms,especially at the dose of 100 mg·kg-1 (P < 0.05);in the new object recognition experiment,discrimination index was significantly decreased in each D-galactose group (P < 0.01),and the dose of 100 mg·kg-1 was most obvious;in addition,D-galactose could significantly increase the level of acetylcholinesterase (AChE)(P < 0.01),decrease the levels of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px),and total antioxidant capacity (T-AOC)(P < 0.05 or P < 0.01) in the mice brain.Conclusion:Subcutaneous injection of low-medium-high dose of D-galactose for 8 weeks in the back of the neck can cause changes in brain parameters in mice,but the effects of different doses of D-galactose on some indicators are significantly different.D-galactose model is effective and stable at the dose of 100 mg·kg-1.

Causes of severe neonatal hyperbilirubinemia: a multicenter study of three regions in China

Background Available evidence suggests that our country bear great burden of severe hyperbilirubinemia.However,the causes have not been explored recently in different regions of China to guide necessary clinical and public health interventions.Methods This was a prospective,observational study conducted from March 1,2018,to February 28,2019.Four hospitals in three regions of China participated in the survey.Data from infants with a gestational age≥35 weeks,birth weight>2000 g,and total serum bilirubin(TSB)level≥17 mg/dL(342μmol/L)were prospectively collected.Results A total of 783 cases were reported.Causes were identified in 259 cases.The major causes were ABO incompatibility(n=101),glucose-6-phosphate dehydrogenase deficiency(n=76),and intracranial hemorrhage(n=70).All infants with glucose-6-phosphate dehydrogenase deficiency were from the central south region.Those from the central south region had much higher peak total bilirubin levels[mean,404μmol/L;standard deviation(SD),75μmol/L]than those from the other regions(mean,373μmol/L;SD,35μmol/L)(P<0.001).Conclusions ABO incompatibility was the leading cause in the east and northwest regions,but cases in the central south region were mainly caused by both ABO incompatibility and glucose-6-phosphate dehydrogenase deficiency,and infants in this region had a much higher peak total bilirubin level.Intracranial hemorrhage may be another common cause.More thorough assessments and rigorous bilirubin follow-up strategies are needed in the central south region.