Safety and Effectiveness of Stellate Ganglion Cryoablation in Complex Regional Pain Syndrome.

This was a retrospective, observational, descriptive study to evaluate the safety and 6-month effectiveness of percutaneous cryoablation of the stellate ganglion for the treatment of complex regional pain syndrome (CRPS). Eight patients with CRPS diagnosed by Budapest criteria were treated with this procedure. CRPS symptom severity was assessed prior to the procedure and at 3-month intervals after the procedure using a novel CRPS scoring system-the Budapest score-created by the authors. The mean Budapest score prior to and 6 months (187 days, SD ± 43) after stellate ganglion cryoablation was 7.0 (SD ± 2.0) (n = 6) and 3.8 (SD ± 2.3) (n = 6), respectively, showing a decrease of 3.2 (SD ± 1.7) (n = 6; P = .006). There were no major adverse events due to the procedure, and there was only 1 minor adverse event. Stellate ganglion cryoablation is a feasible, safe, and minimally invasive procedure that may represent an efficacious adjunct treatment option for select patients with CRPS.

Genetically encoded protein sulfation in mammalian cells.

Tyrosine sulfation is an important post-translational modification found in higher eukaryotes. Here we report an engineered tyrosyl-tRNA synthetase/tRNA pair that co-translationally incorporates O-sulfotyrosine in response to UAG codons in Escherichia coli and mammalian cells. This platform enables recombinant expression of eukaryotic proteins homogeneously sulfated at chosen sites, which was demonstrated by expressing human heparin cofactor II in mammalian cells in different states of sulfation.

Resurrecting the Bacterial Tyrosyl-tRNA Synthetase/tRNA Pair for Expanding the Genetic Code of Both E. coli and Eukaryotes.

The bacteria-derived tyrosyl-tRNA synthetase (TyrRS)/tRNA pair was first used for unnatural amino acid (Uaa) mutagenesis in eukaryotic cells over 15 years ago. It provides an ideal platform to genetically encode numerous useful Uaas in eukaryotes. However, this pair has been engineered to charge only a small collection of Uaas to date. Development of Uaa-selective variants of this pair has been limited by technical challenges associated with a yeast-based directed evolution platform, which is currently required to alter its substrate specificity. Here we overcome this limitation by enabling its directed evolution in an engineered strain of E. coli (ATMY), where the endogenous TyrRS/tRNA pair has been functionally replaced with an archaeal counterpart. The facile E. coli-based selection system enabled rapid engineering of this pair to develop variants that selectively incorporate various Uaas, including p-boronophenylalanine, into proteins expressed in mammalian cells as well as in the ATMY strain of E. coli.