The effects of multiple trace elements injection (I) on the stability of fat emulsion in neonatal parenteral nutrition solutions / 中华临床营养杂志

Objective:To investigate the effects of multiple trace elements in neonatal parenteral nutrition (PN) on the stability of fat emulsion, and to assess the changes of stability indexes after filtration.Methods:With the standard body weight of 1.5 kg, seven groups of neonatal PN solutions with different concentrations of multiple trace elements were designed, including blank group (without multiple trace elements), normal dose group (1 ml/kg, i.e., 0.75 ml per 100 ml PN) and five experimental groups (i.e., 1.5 ml, 3 ml, 4.5 ml, 6 ml, and 7.5 ml per 100 ml PN respectively). Macroscopic observation was performed 0 h and 24 h after preparation. The mean droplet diameter (MDD) of lipid emulsion was determined with dynamic light scattering before and after filtration. The percentage of fat residing in globules larger than 5 μm (PFAT5) and the globule size distribution before and after filtration were determined with light blockage method.Results:Macroscopic examination of the 7 groups of PN solutions identified neither changes in color nor stratification within 24 hours after solution preparation. Within 24 hours after solution preparation, the MDDs of all PN solutions before filtration were between (338.67±6.11) nm and (370.00±15.13) nm, and the PFAT5 values before filtration ranged from (32.00±1.00) ×10 -3% to (85.67±6.81) ×10 -3%. The MDDs of all PN solutions after filtration were between (310.67±8.62) nm and (362.33±19.86) nm, and the PFAT5 values after filtration ranged from (4.67±1.15) ×10 -3% to (17.33±0.58) ×10 -3%. The concentration of multiple trace elements was positively correlated with PFAT5 ( P<0.05). There was statistically significant difference in PFAT5 values at 0 h and 24 h after preparation ( P=0.004). The difference of PFAT5 values before and after filtration was also statistically significant ( P=0.000). Conclusions:Within 24 hours after solution preparation at room temperature, the appearance of neonatal PN solutions with different concentrations of trace elements supplementation was unchanged, and the MDDs of fat emulsions were all within the safe range. However, when the concentration of monovalent cations (Na +, K +) was 38.9 mmol/L, the concentration of divalent cation (Ca 2+) was 5 mmol/L, and the concentration of trace elements (Zn 2+, Cu 2+, Mn 2+, and Se 4+) was higher than 0.063 mmol/L, the PFAT5 value was higher than 0.05%. In this case, filtration with a 1.2 μm filter was necessary, which could significantly reduce the PFAT5 value and the globule size distribution, and improve the safety and standardization of the clinical application of PN solutions. It is suggested that the neonatal PN solutions supplemented with multiple trace elements injection (I) may be administered through a terminal filter.

G protein-coupled receptor 17 is involved in CoCl-induced hypoxic injury in RGC-5 cells / 浙江大学学报·医学版

OBJECTIVE@#To investigate the effect of G protein-coupled receptor 17 (GPR17) on hypoxia injury in retinal ganglion cells .@*METHODS@#CoCl (400 μmol/L) was used to induce hypoxic injury in RGC-5 cells. The expression of GPR17 and the effect of GPR17 ligands were investigated, and the role of GPR17 in hypoxia injury was further studied by transfection of RGC-5 cells with GPR17 small interfering RNA (siRNA). The cell viability was determined by MTT and the cell apoptosis rate was detected by flow cytometry analysis. The expression of GPR17 mRNA was determined with RT-PCR.@*RESULTS@#mRNA expressions of GPR17 in RGC-5 cells with and without CoCl treatment were 0.36±0.05 and 0.26±0.08(<0.01). Compared with hypoxia without any treatment, pretreatment with GPR17 agonists (LTD, UDP, UDP-G) significantly reduced cell viability (the survival rates of cells decreased by 29.6%, 31.8% and 33.9%, all <0.01), while the effect of GPR17 antagonist (cangrelor) was the opposite (the survival rates of cells increased by 33.2%, <0.01). Transfection with GPR17 SiRNA inhibited hypoxia-induced up-expression of GPR17 mRNA (<0.01)and reduced cell apoptosis[rates of cell apoptosis were(39.73±2.06)%,(42.50±3.64)% and (24.98±2.16)% for blank control, NC siRNA and GPR17 siRNA groups, <0.01].@*CONCLUSIONS@#GPR17 may mediate hypoxia injury in RGC-5 cells, while the knockdown of GPR17 can reduce the hypoxia injury.

Stability assessment of neonatal parenteral nutrition solutions with various amino acid concentrations / 中华临床营养杂志

Objective To explore the influence of various concentrations of amino acid on the stability of neonatal parenteral nutrition solutions .Methods Five formulations were designed with 5 different amino acid concentrations containing the same components .The final amino acid concentrations of admixtures were 0%, 1%, 2%, 3%, and 3.5%, respectively .The appearance , pH, and osmolality were observed or meas-ured after preparation (0 hour) and at 12, 24, 48 and 72 hours after preparation.The average size and the size distribution of the lipid globules were also evaluated by laser nanometer particle size analyzer .Results There was no observable alteration in color , phase separation , precipitate , and flocculation in any admixture at any of the observation time points.The mean pH values for all groups were between (5.49 ±0.01) to (6.19 ±0.01) within 72 hours.The mean osmolalities for all groups were between (774 ±3) to (1106 ±13) mOsm/kg.The mean diameters of lipid globules for all groups were between (280.6 ±0.7 ) mm to (332.2 ±2.0 ) nm.The mean polydispersity for all groups were between (0.200 ±0.011) to (0.245 ±0.012).The enrichment of ami-no acid concentration was linked to lower pH ( P=0.000 ) , higher osmolality ( P=0.000 ) and larger average lipid globules size ( P=0.000 ) .However , there was no distinct linear dependence between amino acid concen -tration and polydispersity value ( P=0.628 ) .Conclusion After 72 hours of storage at room temperature , the appearance, pH, osmolality, and the average lipid globules diameter of the parenteral nutrition solutions are within the safe range when the amino acid is not contained or the concentrations are no more than 3.5%.