Relationship between Migraine and Patent Foramen Ovale Observed by Contrast-enhanced Transthoracic Echocardiography.

To observe the association between migraine and patent foramen ovale (PFO) using contrast-enhanced transthoracic echocardiography (cTTE). Eighty-five migraine with aura (MA) patients and 85 migraine without aura (MO) patients from January 2020 to February 2022 were divided into group A and group B, respectively. Sixty-five healthy people were included in normal control group. Difference of PFO positive rate among group A, group B, and normal control group was significant (p=0.002). Difference of PFO related right-to-left shunt (PFO-RLS), Grade 2 shunt, and Grade 3 shunt among group A, group B, and normal control group was significant (p=0.043 and p=0.013 respectively). PFO-RLS Grade 2 and 3 shunts may play an important role in MA patients and MO patients, and the size of PFO-RLS shunt may be associated with migraine. Key Words: Migraine, Patent foramen ovale (PFO), Right-to-left shunt (RLS), Contrast-enhanced transthoracic echocardiography (cTTE).

[Production of L-2-aminobutyric acid from L-threonine using a trienzyme cascade].

L-2-aminobutyric acid (L-ABA) is an important chemical raw material and chiral pharmaceutical intermediate. The aim of this study was to develop an efficient method for L-ABA production from L-threonine using a trienzyme cascade route with Threonine deaminase (TD) from Escherichia. coli, Leucine dehydrogenase (LDH) from Bacillus thuringiensis and Formate dehydrogenase (FDH) from Candida boidinii. In order to simplify the production process, the activity ratio of TD, LDH and FDH was 1:1:0.2 after combining different activity ratios in the system in vitro. The above ratio was achieved in the recombinant strain E. coli 3FT+L. Moreover, the transformation conditions were optimized. Finally, we achieved L-ABA production of 68.5 g/L with a conversion rate of 99.0% for 12 h in a 30-L bioreactor by whole-cell catalyst. The environmentally safe and efficient process route represents a promising strategy for large-scale L-ABA production in the future.