Patent ductus arteriosus treatment trends and associated morbidities in neonates.

To evaluate national epidemiologic data on infants treated for patent ductus arteriosus (PDA) in Korea and analyze outcomes associated with different PDA treatments. We retrospectively evaluated data on 12,336 patients diagnosed with PDA (International Classification of Diseases-10 code: Q250) between 2015 and 2018 from the Health Insurance Review and Assessment database. Among them, 1623 patients underwent surgical ligation (code: O1671). We used birth certificate data from Statistics Korea to estimate the prevalence, diagnosis, and treatment of PDA. The prevalence of infants with PDA was 81 infants per 10,000 live births and 45.2% in very low birth weight (VLBW) infants, which increased from 2015 to 2018. PDA ligation was performed in 2571 infants and 22% VLBW infants. Medical treatment was administered to 4202 infants, which decreased significantly, especially in VLBW infants (62% to 53%). The proportion of treatment was as follows: conservative treatment (53.1%), intravenous ibuprofen (24.4%), surgery (20.4%), and oral ibuprofen (10.7%); that among 4854 VLBW infants was as follows: intravenous ibuprofen (46.3%), conservative treatment (33.2%), surgery (22.2%), and oral ibuprofen (14.2%). Surgical treatment had a significantly higher risk (odds ratio 1.36) of mortality than conservative treatment. Surgical and/or medical treatments were associated with a higher risk of morbidity. Recently, increased use of conservative management of PDA has contributed to improved neonatal outcomes in VLBW infants. Select patients may still benefit from surgical ligation following careful consideration.

Characterization of aldolase from Methanococcus jannaschii by gas chromatography.

The products of reactions catalyzed by Methanococcus. jannaschii (Mj) aldolase using various substrates were identified by gas chromatography (GC). Although Mj aldolase is considered a fuculose-1-phosphate aldolase based on homology searching after gene sequencing, it has not been proven to be a fuculose-1-phosphate aldolase based on its reaction products. Mj aldolase was found to catalyze reactions between glycoaldehyde or D, L-glyceraldehyde and DHAP (dihydroxyacetone phosphate). Before performing GC the ketoses produced were converted into peracetylated alditol derivatives by sequential reactions, i.e., dephosphorylation, NaBH(4) reduction, and acetylation. By comparing the GC data of final products with those of standard alditol samples, it was found that the enzymatic reactions with glycoaldehyde, D-glyceraldehyde, and D, L-glyceraldehyde produced D-ribulose-1-phosphate, D-psicose-1-phosphate, and a mixture of D-psicose and L-tagatose-1-phosphate, respectively. These results provide direct evidence that Mj aldolase is a fuculose-1-phosphate aldolase.

Synthesis of 2'-azidoethyl trisaccharide, alpha-D-Gal-(1-->2)-6d-alpha-D-altro-Hepp-(1-->3)-beta-D-GlcNAc, an O-antigenic repeating unit of C. jejuni O:23 and O:36.

A trisaccharide, the O-antigenic repeating unit of C. jejuni serotype O:23 and O:36, was synthesized as a 2'-azidoethyl glycoside by block addition of perbenzylated thiogalactoside donors to alpha-altroHepp-(1-->3)-GlcNPhth disaccharide acceptor in presence of IDCP promoter. The alpha-linked altroheptopyranoside moiety in the glycosyl acceptor was effectively prepared by Swern oxidation of alpha-mannohepp-(1-->3)-GlcNPhth disaccharide followed by mild reduction with NaCNBH3.