Association of asymmetric dimethylarginine with the pathological process of persistent pulmonary hypertension of the newborn / 中国当代儿科杂志

OBJECTIVES@#To study the change in asymmetric dimethylarginine (ADMA) in the circulation system of full-term infants with persistent pulmonary hypertension of the newborn (PPHN) and its association with treatment response, as well as the possibility of ADMA as a therapeutic target and a marker for treatment response.@*METHODS@#A prospective study was performed. A total of 30 full-term neonates who were diagnosed with PPHN within 3 days after birth were enrolled as the PPHN group, and the neonates without PPHN, matched for gestational age and age, who were treated or observed in the department of neonatology were enrolled as the control group. Serum samples were collected on days 1, 7, and 14 of treatment. The high-performance liquid chromatography-tandem mass spectrometry was used to measure the serum concentrations of L-arginine, ADMA, and its isomer symmetric dimethylarginine (SDMA).@*RESULTS@#For the neonates in the control group, the serum concentrations of ADMA and L-arginine continuously increased and the serum concentration of SDMA continuously decreased within the first 14 days of treatment. On days 1 and 14, there was no significant difference in the serum concentration of ADMA between the control and PPHN groups (P>0.05). On day 7, the PPHN group had a significantly higher serum concentration of ADMA than the control group (P<0.05), while there were no significant differences in serum concentrations of SDMA or L-arginine (P>0.05). Moreover, after 7 days of treatment, the PPHN neonates with a systolic pulmonary arterial pressure (sPAP) of >35 mmHg had a significantly higher serum concentration of ADMA than those with an sPAP of ≤35 mm Hg.@*CONCLUSIONS@#There are continuous increases in the ADMA concentration and the ADMA/SDMA ratio in the circulation system of full-term infants within the first 2 weeks after birth, and this process is accelerated by the pathological process of PPHN, suggesting that ADMA may be involved in the pathologic process of PPHN. A high level of ADMA is associated with the resistance to PPHN treatment, suggesting that inhibition of ADMA might be a potential target of drug intervention to improve the treatment response of PPHN.

Detection of Amino Acids and Polypeptides by Electrospray Ionization-Ion Mobility Spectrometry / 分析化学

The electrospray ionization-ion mobility spectrometric (ESI-IMS) technique has the potential as an analytical separation tool in analyzing polypeptides and amino acids for fast screening unknown samples in anti-chemical and biological terror attacks. A method for detecting several polypeptides and amino acids was developed based on ESI-IMS using air as drift gas at room temperature. The ion mobility of four amino acids and two polypeptides dissolved in methanol was determined on the system at elution rate of 2 mL/ min. The spectra of these compounds had characteristics of finger-printing maps. The limit of detection of this instrument for Substance P could reach 855 ng / mL in 1 min. The results showed that a small, self-contained ESI-IMS instrument with reservoirs of air could be used to quickly detect and accurately identify polypeptides and amino acids.