Inverting the enantioselectivity of a carbonyl reductase via substrate-enzyme docking-guided point mutation.

Substrate-enzyme docking-guided point mutation of a carbonyl reductase from Sporobolomyces salmonicolor led to mutant enzymes, which reversed the enantiopreference and enhanced the enantioselectivity toward the reduction of para-substituted acetophenones. Such a dramatic change in the enantioselectivity indicates that the 245 residue in the catalytic site plays a critical role in determining the enantioselectivity of these ketone reductions, providing valuable insight into our understanding of how residues involved in substrate binding affect the orientation of bound substrate and thus control the reduction stereoselectivity.

Left upper lobe torsion in pneumothorax.

We report a case of left upper lobe torsion in a patient who had a pneumothorax as a complication of subclavian venous access for an elective neurosurgical operation. Despite appropriate management of the pneumothorax, the patient's chest radiograph did not improve. Computed tomography of the chest was concerning for left upper lobe torsion. Fiberoptic bronchoscopy revealed near complete obstruction of the left upper lobe bronchus. Review of computed tomography imaging before and after bronchoscopy and subsequent thoracotomy confirmed lobar torsion. Consideration of lobar torsion in the differential diagnosis of patients with persistently abnormal chest imaging despite appropriate management after complications of routine procedures is important for early recognition and intervention of a potentially life-threatening problem.

Adrenal crisis and autoimmune polyglandular syndromes.

We report a 67-year-old woman who presented with adrenal crisis as a manifestation of autoimmune polyglandular syndrome 2, a polygenic disorder characterized by concurrent primary adrenal insufficiency and either autoimmune thyroid disease or type 1 diabetes mellitus.