Myocardial infarction following held antiplatelet therapy for lumbar radiofrequency neurotomy: A letter to the editor.

Objectives: Describe a catastrophic complication of holding antiplatelet therapy (APT) prior to lumbar radiofrequency neurotomy (RFN). Setting: Bilateral L4-5 and L5-S1 RFN was performed 72 hours after the patient was instructed to hold APT. Discussion: Several hours after the lumbar RFN, the patient experienced substernal chest pain unresponsive to oral nitroglycerin. He presented to a local emergency department and was found to have ST-elevated myocardial infarction (STEMI), for which he underwent emergent cardiac catheterization. Almost all current literature and guidelines recommend continuing APT throughout the timeframe surrounding lumbar RFN yet the practice of holding these medications continues to be utilized by physicians. Conclusion: APT should not be discontinued in patients undergoing lumbar RFN due to the increased possibility of thromboembolic events such as a myocardial infarction.

Sample preparation for MALDI mass spectrometry using an elastomeric device reversibly sealed on the MALDI target.

A new method for improving low-concentration sample recovery and reducing sample preparation steps in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) is presented. In the conventional approach, samples are typically desalted and/or concentrated with various techniques and deposited on the MALDI target as small droplets. In this work, we describe a new approach in which an elastomeric device is reversibly sealed on the MALDI target to form a multi-well plate with the MALDI target as the base of the plate. The new format allows a larger volume (5-200 microL) of samples to be deposited on each spot and a series of sample handling processes, including desalting and concentrating, to be performed directly on the MALDI target. Several advantages have been observed: (i) multiple sample transferring steps are avoided; (ii) recovery of low-concentration peptides during sample preparation is improved using a novel desalting method that utilizes the hydrophobic surface of the elastomeric device; and (iii) sequence coverage of the peptide mass fingerprinting map is improved using a novel method in which proteins are immobilized on the hydrophobic surface of the elastomeric device for in-well trypsin digestion, followed by desalting and concentrating the digestion products in the same well.