Risk Factors of Rapid FEV1 Decline in a Real-World Chronic Obstructive Pulmonary Disease Cohort.

BACKGROUND: Rapid forced expiratory volume in 1 s (FEV1) decliners have been considered a unique subgroup of patients with chronic obstructive pulmonary disease (COPD). Rapid FEV1 decline manifests early and is associated with poor prognosis. This necessitates the pre-emptive identification of risk factors for rapid FEV1 decline. OBJECTIVES: We aimed to determine the risk factors and clinical outcomes in patients with COPD. METHODS: This longitudinal, observational study was based on the Korea COPD Subgroup Study cohort (NCT02800499) from January 2012 to December 2019 across 54 medical centers in South Korea. Eligible patients were followed up for 3 years with serial spirometric tests. We calculated the annualized percentage change in FEV1 from baseline. Rapid decliners were defined as the quartile of patients with the highest annualized percentage FEV1 decline. RESULTS: Of the 518 patients, 130 were rapid decliners who lost 6.2%/year and 100 mL/year of FEV1. The multivariable logistic regression identified male sex, current smoking, blood eosinophil count <150/µL, and high forced vital capacity as the independent risk factors for rapid FEV1 decline. Among rapid decliners, the lung function deteriorated more rapidly in current smokers and patients with severe dyspnea, while triple combination therapy attenuated lung function decline in comparison with mono-bronchodilator therapy. Rapid decliners had a higher rate of severe exacerbation than nonrapid decliners (0.2/year vs. 0.1/year, p value = 0.032). CONCLUSIONS: We identified the independent risk factors for rapid FEV1 decline. This information may assist physicians in the early detection and pertinent management of rapid decline among patients with COPD.

Production of 10-hydroxy-12,15(Z,Z)-octadecadienoic acid from α-linolenic acid by permeabilized cells of recombinant Escherichia coli expressing the oleate hydratase gene of Stenotrophomonas maltophilia.

Recombinant Escherichia coli, expressing the oleate hydratase gene of Stenotrophomonas maltophilia, was permeabilized by sequential treatments with 0.125 M NaCl and 2 mM EDTA. The optimal conditions for the production of 10-hydroxy-12,15(Z,Z)-octadecadienoic acid from α-linolenic acid by permeabilized cells were 35 °C and pH 7.0 with 0.1 % (v/v) Tween 40, 50 g permeabilized cells l(-1), and 17.5 g α-linolenic acid l(-1). Under these conditions, permeabilized cells produced 14.3 g 10-hydroxy-12,15(Z,Z)-octadecadienoic acid l(-1) after 18 h, with a conversion yield of 82 % (g/g) and a volumetric productivity of 0.79 g l(-1) h(-1). These values were 17 and 168 % higher than those obtained by nonpermeabilized cells, respectively. The concentration, yield, and productivity of 10-hydroxy-12,15(Z,Z)-octadecadienoic acid obtained by permeabilized cells are the highest reported thus far.

ß-glucosidase from Penicillium aculeatum hydrolyzes exo-, 3-O-, and 6-O-ß-glucosides but not 20-O-ß-glucoside and other glycosides of ginsenosides.

A novel ß-glucosidase from Penicillium aculeatum was purified as a single 110.5-kDa band on SDS-PAGE with a specific activity of 75.4 U mg⁻¹ by salt precipitation and Hi-Trap Q HP and Resource Q ion exchange chromatographies. The purified enzyme was identified as a member of the glycoside hydrolase 3 family based on its amino acid sequence. The hydrolysis activity for p-nitrophenyl-ß-D-glucopyranoside was optimal at pH 4.5 and 70 °C with a half-life of 55 h. The enzyme hydrolyzed exo-, 3-O-, and 6-O-ß-glucosides but not 20-O-ß-glucoside and other glycosides of ginsenosides. Because of the novel specificity, this enzyme had the transformation pathways for ginsenosides: Rb1 → Rd → F2 → compound K, Rb2 → compound O → compound Y, Rc → compound Mc1 → compound Mc, Rg3 → Rh2 → aglycone protopanaxadiol (APPD), Rg1 → F1, and Rf → Rh1 → aglycone protopanaxatriol (APPT). Under the optimum conditions, the enzyme converted 0.5 mM Rb2, Rc, Rd, Rg3, Rg1, and Rf to 0.49 mM compound Y, 0.49 mM compound Mc, 0.47 mM compound K, 0.23 mM APPD, 0.49 mM F1, and 0.44 mM APPT after 6 h, respectively.