Noise-Induced Hearing Loss in Orthopaedic Surgery: A Review Article.

There are many sources of noise production in the operating room, including conversations among the surgical team, background music, electric monitors and alarms, surgical power tools, surgical instrument clattering and hammering, and suction devices. These sources introduce occupational hazards by producing damaging noise levels that exceed noise exposure level guidelines set by the National Institute of Occupational Safety and Health and the Health and Safety Executive. Noise-induced hearing loss affects up to 50% of orthopaedic staff, but few preventative measures are regularly followed in the orthopaedic setting.

Intraoperative Neuromonitoring for Spines at Risk During Nonspine Surgery: A 9-Year Review.

Background: Patients with certain spinal anomalies are at risk for rare but devastating spinal cord injuries under anesthesia. We created a Spine at Risk (SAR) program to evaluate and recommend precautions for such patients, including intraoperative neuromonitoring (IONM) use for the highest-risk patients. We aimed to review all monitored nonspine procedures to determine rate of potential spinal cord injuries avoided in those who would otherwise have been unmonitored.

Computational engineering of previously crystallized pyruvate formate-lyase activating enzyme reveals insights into SAM binding and reductive cleavage.

Radical S-adenosyl-l-methionine (SAM) enzymes are ubiquitous in nature and carry out a broad variety of difficult chemical transformations initiated by hydrogen atom abstraction. Although numerous radical SAM (RS) enzymes have been structurally characterized, many prove recalcitrant to crystallization needed for atomic-level structure determination using X-ray crystallography, and even those that have been crystallized for an initial study can be difficult to recrystallize for further structural work. We present here a method for computationally engineering previously observed crystallographic contacts and employ it to obtain more reproducible crystallization of the RS enzyme pyruvate formate-lyase activating enzyme (PFL-AE).

The pediatric "Spine at Risk" program: 9-year review of a novel safety screening tool.

Purpose: We implemented an EMR-based "Spine at Risk" (SAR) alert program in 2011 to identify pediatric patients at risk for intraoperative spinal cord injury (SCI) and prompt an evaluation for peri-operative recommendations prior to anesthetic. SAR alerts were activated upon documentation of a qualifying ICD-9/10 diagnosis or manually entered by providers. We aimed to determine the frequency of recommended precautions for those auto-flagged by diagnosis versus by provider, the frequency of precautions, and whether the program prevented SCIs during non-spinal surgery.

HydG, the "dangler" iron, and catalytic production of free CO and CN: implications for [FeFe]-hydrogenase maturation.

The organometallic H-cluster of the [FeFe]-hydrogenase consists of a [4Fe-4S] cubane bridged via a cysteinyl thiolate to a 2Fe subcluster ([2Fe]H) containing CO, CN-, and dithiomethylamine (DTMA) ligands. The H-cluster is synthesized by three dedicated maturation proteins: the radical SAM enzymes HydE and HydG synthesize the non-protein ligands, while the GTPase HydF serves as a scaffold for assembly of [2Fe]H prior to its delivery to the [FeFe]-hydrogenase containing the [4Fe-4S] cubane. HydG uses l-tyrosine as a substrate, cleaving it to produce p-cresol as well as the CO and CN- ligands to the H-cluster, although there is some question as to whether these are formed as free diatomics or as part of a [Fe(CO)2(CN)] synthon.

Radical S-adenosylmethionine maquette chemistry: CxCxC peptide coordinated redox active [4Fe-4S] clusters.

The synthesis and characterization of short peptide-based maquettes of metalloprotein active sites facilitate an inquiry into their structure/function relationships and evolution. The [4Fe-4S]-maquettes of bacterial ferredoxin metalloproteins (Fd) have been used in the past to engineer redox active centers into artificial metalloenzymes. The novelty of our study is the application of maquettes to the superfamily of [4Fe-4S] cluster and S-adenosylmethionine-dependent radical metalloenzymes (radical SAM).