Reconstituting Plant Secondary Metabolism in Saccharomyces cerevisiae for Production of High-Value Benzylisoquinoline Alkaloids.

Benzylisoquinoline alkaloids (BIAs) constitute a diverse class of plant secondary metabolites that includes the opiate analgesics morphine and codeine. Collectively, BIAs exhibit a myriad of pharmacological activities, including antimicrobial, antitussive, antispasmodic, and anticancer properties. Despite 2500 known BIA products, only a small proportion are currently produced though traditional crop-based manufacturing, as complex stereochemistry renders chemical synthesis of BIAs largely unfeasible. The advent of synthetic biology and sophisticated microbial engineering coupled with recent advances in the elucidation of plant BIA metabolic networks has provided growing motivation for producing high-value BIAs in microbial hosts. Here, we provide a technical basis for reconstituting BIA biosynthetic pathways in the common yeast Saccharomyces cerevisiae. Methodologies outlined in this chapter include fundamental techniques for expressing and assaying BIA biosynthetic enzymes, bioprospecting large libraries of BIA enzyme variants, and reconstituting and optimizing complete BIA formation pathways in yeast. To expedite construction of superior BIA-producing yeast strains, we emphasize high-throughput techniques. Finally, we identify fundamental challenges impeding deployment of yeast-based BIA production platforms and briefly outline future prospects to overcome such barriers.

Application of Kunlin's technique in vascular micro-anastomosis: experimental and clinical study.

Vascular microanastomosis of vessels that presents marked discrepancy in size can be performed without difficulty by making a longitudinal incision of the end of the smallest vessel, forming a kind of "spatula," and joined to the vessel of greater diameter.

Lymphatic compression of the superficial branch of the radial nerve--a case report.

We report a case of radial sensory loss caused by entrapment neuropathy of the superficial branch of the radial nerve at the wrist. Lymphatic dilatations of unknown etiology caused the entrapment.

The reapplication of microvascular clamps after venous anastomosis: an experimental study.

Albino rats were used to determine the effects of the reapplication of microvascular clamps in veins after anastomosis. The results demonstrate that, if necessary, microvascular clamps can be reapplied either proximal, or both proximal and distal to a venous anastomosis for up to 30 minutes, thus allowing a suture to be redone or the lumen to be explored with no loss of patency.

Free latissimus dorsi myocutaneous flaps in the dynamic reconstruction of cheek defects: a preliminary report.

In the past, reconstruction of defects after cheek resection for such lesions as cancer or hemangioma was performed primarily by using local components. Two cases are reported in which free latissimus dorsi myocutaneous flaps with neurovascular microanastomoses were used to reconstruct cheek defects. Early follow-up has shown that the results are satisfactory.