Tonsillectomy Outcomes in Children After Solid-Organ Transplantation: A 15-Year Single-Center Experience.

OBJECTIVE: Solid-organ transplantation (SOT) has become the standard of care for children with terminal organ failure. Long-term immunosuppression has improved survival substantially but is associated with secondary malignancies and impaired wound healing. Our goal was to review the incidence, outcomes, complications, and rate of posttransplant lymphoproliferative disorder on pathologic examination following tonsillectomy/adenotonsillectomy (T/AT) in children after SOT. STUDY DESIGN: A retrospective cohort study. SETTING: Tertiary care children's hospital. METHODS: Data were extracted from charts of children with a history of kidney, heart, or liver transplantation, who underwent T/AT between 2006 and 2021. RESULTS: A total of 110 patients met the inclusion criteria, including 46 hearts, 41 kidneys, 19 livers, and 4 liver-and-kidney transplants. The mean age at transplantation was 4.2 years, and the mean transplantation-to-T/AT time interval was 28.8 months. The posttransplant lymphoproliferative disorder was diagnosed in 52 (47.3%) patients, and 25% of these had no tonsillar hypertrophy. There was no difference in age at transplantation, organ received, transplantation-to-T/AT time interval, immunosuppressive medications, tonsil size, or tonsillar asymmetry between patients diagnosed with the posttransplant lymphoproliferative disorder and patients with benign tonsillar/adenotonsillar hypertrophy. Posttonsillectomy complications were similar between the groups. CONCLUSION: The incidence of posttransplant lymphoproliferative disorder undergoing tonsillectomy for any indication was 47.3%. There was no association between preoperative signs and symptoms and the histopathological diagnosis of posttransplant lymphoproliferative disorder. Stratification by organ received and immunosuppressive medications did not identify differences among the groups relative to the incidence of posttransplant lymphoproliferative disorder and other postoperative complications.

Endoscopic endonasal optic nerve decompression: treatment of fibrous dysplasia in a pediatric population.

OBJECTIVE: Patients with fibrous dysplasia (FD) of the anterior skull base can experience progressive visual loss and impairment. The authors reviewed their experience with endonasal decompression of the optic nerve (ON) in this patient population. Endoscopic ON decompression (EOND) is a feasible surgical approach for children with FD and visual deficit due to structural ON compression. METHODS: Electronic medical records of children between 1 and 17 years of age with unilateral FD of the anterior skull base and concomitant ON compression, who required EOND between 2017 and 2022 (n = 4), were reviewed for demographic data, both pre- and postoperative imaging, and evaluations by an otolaryngologist, neurosurgeon, and ophthalmologist in a multidisciplinary fashion. RESULTS: EOND was found to be a safe and effective surgery for children with FD. Visual acuity was stable in 80% of the eyes postoperatively. Visual fields improved in 40% of the eyes and remained stable in the rest. CONCLUSIONS: EOND is beneficial for progressive optic neuropathy that is unresponsive to steroid therapy and can prevent permanent disability if performed prior to irreversible damage to the nerve. EOND can decompress the edematous ON with proper exposure of the optic canal and orbital apex, without any major complications.

Assessing the Impact of a Training Initiative for Nasopharyngeal and Oropharyngeal Swabbing for COVID-19 Testing.

OBJECTIVE: The accuracy and reliability of COVID-19 testing are critical to limit transmission. After observing variability in testing techniques, we otolaryngologists at a tertiary medical center initiated and evaluated the impact of nasopharyngeal and oropharyngeal swabbing training, including video instruction, to standardize sampling techniques and ensure high-quality specimens. METHODS: Participants in the training were employees (N = 40). Training consisted of an instructional video on how to perform nasopharyngeal and oropharyngeal swabs and a live demonstration. Participants completed pre- and posttraining surveys assessing their knowledge and confidence in performing nasopharyngeal and oropharyngeal swabs. They then performed swabbing on partners, which was graded per a standardized checklist. RESULTS: Mean scores for knowledge-based questions and confidence in swabbing were significantly higher after the training session (both P < .001). All participants scored ≥6 of 8 on the posttraining checklist. Ninety-five percent rated the video as very or extremely useful. DISCUSSION: Specialized instruction for nasopharyngeal swabbing improved participants' knowledge-specifically, the appropriate head position and minimum swab time in nasopharynx-and their confidence. After the training, their swabbing execution scores were high. IMPLICATIONS FOR PRACTICE: Video-assisted hands-on instruction for nasopharyngeal swab sampling can be used to standardize teaching. When prompt and accurate testing is paramount, this instruction can optimize procedural technique and should be used early and often. In addition, there may be a professional responsibility of otolaryngologists to participate in such initiatives.

Surgical Management of Nasal Valve Collapse.

Nasal valve collapse has multiple causes, including congenital, traumatic, and, unfortunately, iatrogenic. Recognition of the causes of nasal valve collapse and the methodology for treatment is paramount not only for the otolaryngologist but also for any physician managing the nasal airway. This article focuses on the cause and surgical management of internal and external nasal valve collapse.

Multiple States of Nitrile Hydratase from Rhodococcus equi TG328-2: Structural and Mechanistic Insights from Electron Paramagnetic Resonance and Density Functional Theory Studies.

Iron-type nitrile hydratases (NHases) contain an Fe(III) ion coordinated in a characteristic "claw setting" by an axial cysteine thiolate, two equatorial peptide nitrogens, the sulfur atoms of equatorial cysteine-sulfenic and cysteine-sulfinic acids, and an axial water/hydroxyl moiety. The cysteine-sulfenic acid is susceptible to oxidation, and the enzyme is traditionally prepared using butyric acid as an oxidative protectant. The as-prepared enzyme exhibits a complex electron paramagnetic resonance (EPR) spectrum due to multiple low-spin (S = 1/2) Fe(III) species. Four distinct signals can be assigned to the resting active state, the active state bound to butyric acid, an oxidized Fe(III)-bis(sulfinic acid) form, and an oxidized complex with butyric acid. A combination of comparison with earlier work, development of methods to elicit individual signals, and design and application of a novel density functional theory method for reproducing g tensors to unprecedentedly high precision was used to assign the signals. These species account for the previously reported EPR spectra from Fe-NHases, including spectra observed upon addition of substrates. Completely new EPR signals were observed upon addition of inhibitory boronic acids, and the distinctive g1 features of these signals were replicated in the steady state with the slow substrate acetonitrile. This latter signal constitutes the first EPR signal from a catalytic intermediate of NHase and is assigned to a key intermediate in the proposed catalytic cycle. Earlier, apparently contradictory, electron nuclear double resonance reports are reconsidered in the context of this work.

Identification of an active site-bound nitrile hydratase intermediate through single turnover stopped-flow spectroscopy.

Stopped-flow kinetic data were obtained for the iron-type nitrile hydratase from Rhodococcus equi TG328-2 (ReNHase) using methacrylonitrile as the substrate. Multiple turnover experiments suggest a three-step kinetic model that allows for the reversible binding of substrate, the presence of an intermediate, and the formation of product. Microscopic rate constants determined from these data are in good agreement with steady state data confirming that the stopped-flow method used was appropriate for the reaction. Single turnover stopped-flow experiments were used to identify catalytic intermediates. These data were globally fit confirming a three-step kinetic model. Independent absorption spectra acquired between 0.005 and 0.5 s of the reaction reveal a significant increase in absorbance at 375, 460, and 550 nm along with the hypsochromic shift of an Fe(3+)←S ligand-to-metal charge transfer band from 700 to 650 nm. The observed UV-visible absorption bands for the Fe(3+)-nitrile intermediate species are similar to low spin Fe(3+)-enzyme and model complexes bound by NO or N3((-)). These data provide spectroscopic evidence for the direct coordination of the nitrile substrate to the nitrile hydratase active site low spin Fe(3+) center.