Silk-Hyaluronic Acid for Vocal Fold Augmentation: Safety Profile and Long-Term Voice Outcomes.

OBJECTIVES: Silk-hyaluronic acid (silk-HA) is a novel vocal fold augmentation material used in humans since July 2020. We aim to describe indications, voice outcomes, and longevity data for silk-HA injectable when used for vocal fold injection (VFI) augmentation in a large cohort of patients with longer-term follow-up than preliminary clinical studies. METHODS: Retrospective chart review of Silk-HA injections for glottic insufficiency (GI) and follow-up between July 2020 and November 2023. Subject demographics, diagnoses, volume of material injected, VHI-10 data, time from injection, need for reinjection, and complications were collected. Blinded perceptual voice analysis of randomly selected pre- and post-intervention voice samples for unilateral vocal fold paralysis patients was performed by three voice-specialized speech-language pathologists, and changes in VHI-10 determined at various time intervals up to 1year and beyond. RESULTS: A total of 160 silk-HA injection procedures were performed: 59% female, with a mean age of 66± 13 (range 21-90) years. Ninety-four subjects had unilateral paralysis (58.4%); the remainder had scar, atrophy, paresis, or a combination thereof. Mean volume of silk-HA injected was 0.24± 0.14 cc. Major complications were rare, most notable for laryngoscopic evidence of hemilaryngeal edema (n = 6, 3.8%), with a readmission rate to hospital of 1.3% (n = 2). There was a statistically significant decrease in paired ΔVHI-10 and CAPE-V ratings for each of the postoperative follow-up intervals. A total of 24 (27.2%) repeat medialization procedures were recommended following silk-HA injection for unilateral paralysis. CONCLUSIONS: This study demonstrates that silk-HA is a safe product for VFI augmentation, and effective injectable for the treatment of GI due to unilateral vocal fold paralysis. Based on the current data, it is reasonable to counsel patients that they should expect benefit for several months following the injection. If patients reach 1year from their injection with a stable and satisfactory outcome, the majority experience ongoing benefit without need for additional procedures, however, the final duration of clinical effect appears to be years, but it is yet to be determined.

Not just snot: Local inflammatory profiles in patients with aspirin-exacerbated respiratory disease differ from patients with aspirin-tolerant chronic rhinosinusitis.

KEY POINTS: IL-5, CCL2, and CXCL8 in sinus mucous are higher in patients with AERD relative to aspirin-tolerant patients with CRS These mediators are pleiotropic, leading to widescale inflammatory processes contributing to AERD AERD is not only a T2 disease but heterogeneous: this may explain the refractory nature of AERD.

Local cytokine levels associate with SNOT-22 and UPSIT scores in chronic rhinosinusitis.

KEY POINTS: Elevated IL-5, IL-13, IL-33, and CCL2 correlate with lower UPSIT scores in CRS and AERD patients. Elevated IL-5, IL-13, TNF-α, CCL2, and CXCL-8 correlate with higher SNOT-22 scores in CRS and AERD patients.

The Impact of Ambient and Wildfire Air Pollution on Rhinosinusitis and Olfactory Dysfunction.

PURPOSE OF REVIEW: With increasing industrialization, exposure to ambient and wildfire air pollution is projected to increase, necessitating further research to elucidate the complex relationship between exposure and sinonasal disease. This review aims to summarize the role of ambient and wildfire air pollution in chronic rhinosinusitis (CRS) and olfactory dysfunction and provide a perspective on gaps in the literature. RECENT FINDINGS: Based on an emerging body of evidence, exposure to ambient air pollutants is correlated with the development of chronic rhinosinusitis in healthy individuals and increased symptom severity in CRS patients. Studies have also found a robust relationship between long-term exposure to ambient air pollutants and olfactory dysfunction. Ambient air pollution exposure is increasingly recognized to impact the development and sequelae of sinonasal pathophysiology. Given the rising number of wildfire events and worsening impacts of climate change, further study of the impact of wildfire-related air pollution is a crucial emerging field.

New Concepts in Barrier Dysfunction in CRSwNP and Emerging Roles of Tezepelumab and Dupilumab.

BACKGROUND: Epithelial barrier disturbances in CRSwNP patients play an important role in both the innate and adaptive immune responses, contributing to chronic inflammation, olfactory dysfunction, and impairments in quality of life. OBJECTIVE: To evaluate the role of the sinonasal epithelium in disease and health, review the pathophysiology of epithelial barrier dysfunction in CRSwNP, and the immunologic targets for treatment. METHODS: Literature review. RESULTS: Blockade of cytokines such as thymic stromal lymphopoietin (TSLP), IL-4, and IL-13 have shown promise in barrier restoration and IL-13, specifically may be central to olfactory dysfunction. CONCLUSION: The sinonasal epithelium plays a crucial role in the health and function of the mucosa and immune response. Increased understanding of the local immunologic dysfunction has led to several therapeutics that can potentially restore epithelial barrier function and olfaction. Real world and comparative effectiveness studies are needed.

Roles of vascular endothelial and smooth muscle cells in the vasculoprotective effect of insulin in a mouse model of restenosis.

BACKGROUND: Insulin exerts vasculoprotective effects on endothelial cells (ECs) and growth-promoting effects on vascular smooth muscle cells (SMCs) in vitro, and suppresses neointimal growth in vivo. Here we determined the role of ECs and SMCs in the effect of insulin on neointimal growth. METHODS: Mice with transgene CreERT2 under the control of EC-specific Tie2 (Tie2-Cre) or SMC-specific smooth muscle myosin heavy chain promoter/enhancer (SMMHC-Cre) or littermate controls were crossbred with mice carrying a loxP-flanked insulin receptor (IR) gene. After CreERT2-loxP-mediated recombination was induced by tamoxifen injection, mice received insulin pellet or sham (control) implantation, and underwent femoral artery wire injury. Femoral arteries were collected for morphological analysis 28 days after wire injury. RESULTS: Tamoxifen-treated Tie2-Cre+ mice showed lower IR expression in ECs, but not in SMCs, than Tie2-Cre- mice. Insulin treatment reduced neointimal area after arterial injury in Tie2-Cre- mice, but had no effect in Tie2-Cre+ mice. Tamoxifen-treated SMMHC-Cre+ mice showed lower IR expression in SMCs, but not in ECs, than SMMHC-Cre- mice. Insulin treatment reduced neointimal area in SMMHC-Cre- mice, whereas unexpectedly, it failed to inhibit neointima formation in SMMHC-Cre+ mice. CONCLUSION: Insulin action in both ECs and SMCs is required for the "anti-restenotic" effect of insulin in vivo.

Insulin decreases atherosclerotic plaque burden and increases plaque stability via nitric oxide synthase in apolipoprotein E-null mice.

It has been argued whether insulin accelerates or prevents atherosclerosis. Although results from in vitro studies have been conflicting, recent in vivo mice studies demonstrated antiatherogenic effects of insulin. Insulin is a known activator of endothelial nitric oxide synthase (NOS), leading to increased production of NO, which has potent antiatherogenic effects. We aimed to examine the role of NOS in the protective effects of insulin against atherosclerosis. Male apolipoprotein E-null mice (8 wk old) fed a high-cholesterol diet (1.25% cholesterol) were assigned to the following 12-wk treatments: control, insulin (0.05 U/day via subcutaneous pellet), N(ω)-nitro-l-arginine methyl ester hydrochloride (l-NAME, via drinking water at 100 mg/l), and insulin plus l-NAME. Insulin reduced atherosclerotic plaque burden in the descending aorta by 42% compared with control (plaque area/aorta lumen area: control, 16.5 ± 1.9%; insulin, 9.6 ± 1.3%, P < 0.05). Although insulin did not decrease plaque burden in the aortic sinus, macrophage accumulation in the plaque was decreased by insulin. Furthermore, insulin increased smooth muscle actin and collagen content and decreased plaque necrosis, consistent with increased plaque stability. In addition, insulin treatment increased plasma NO levels, decreased inducible NOS staining, and tended to increase phosphorylated vasodilator-stimulated phosphoprotein staining in the plaques of the aortic sinus. All these effects of insulin were abolished by coadministration of l-NAME, whereas l-NAME alone showed no effect. Insulin also tended to increase phosphorylated endothelial NOS and total neuronal NOS staining, effects not modified by l-NAME. In conclusion, we demonstrate that insulin treatment decreases atherosclerotic plaque burden and increases plaque stability through NOS-dependent mechanisms.

Local insulin application on the carotid artery inhibits neointima formation.

Anti-mitogenic agents currently used to prevent restenosis in drug-eluting stents delay re-endothelialization. Delayed re-endothelialization is now considered as the main cause of late stent thrombosis with drug-eluting stents, which emphasizes the need for new treatments. We have shown that systemic insulin treatment decreases neointimal growth and accelerates re-endothelialization after arterial injury in a rat model of restenosis. However, systemic insulin treatment cannot be given to non-diabetic individuals because of the risk of hypoglycemia. Thus, we investigated whether local insulin treatment is also effective in reducing neointimal growth after arterial injury. Rats were given local vehicle or local insulin delivered via Pluronic gel applied around the carotid artery immediately following balloon injury. Plasma glucose and systemic insulin levels were not affected by local insulin treatment. Insulin decreased intimal area at 28 days (P < 0.05) and also inhibited vascular smooth muscle cell migration by 60% at 4 days (P < 0.05). NPH (a longer-lasting insulin) also decreased neointimal area. These results indicate that local insulin treatment can lead to decreased restenosis, suggesting a protective vascular effect of insulin in vivo and that local insulin treatment, possibly via insulin-eluting stents, may be clinically relevant.

In vitro and in vivo testing of glucose-responsive insulin-delivery microdevices in diabetic rats.

We have developed glucose-responsive implantable microdevices for closed-loop delivery of insulin and conducted in vivo testing of these devices in diabetic rats. The microdevices consist of an albumin-based bioinorganic membrane that utilizes glucose oxidase (GOx), catalase (CAT) and manganese dioxide (MnO(2)) nanoparticles to convert a change in the environmental glucose level to a pH stimulus, which regulates the volume of pH-sensitive hydrogel nanoparticles and thereby the permeability of the membrane. The membrane is integrated with microfabricated PDMS (polydimethylsiloxane) structures to form compact, stand-alone microdevices, which do not require tethering wires or tubes. During in vitro testing, the microdevices showed glucose-responsive insulin release over multiple cycles at clinically relevant glucose concentrations. In vivo, the microdevices were able to counter hyperglycemia in diabetic rats over a one-week period. The in vitro and in vivo testing results demonstrated the efficacy of closed-loop biosensing and rapid response of the 'smart' insulin delivery devices.

Quantitative and qualitative differences in protein expression between papillary thyroid carcinoma and normal thyroid tissue.

In order to better understand basic mechanisms of tumor development and identify potential new biomarkers, we have performed difference gel electrophoresis (DIGE) and peptide mass fingerprinting on pooled protein extracts from patients with papillary thyroid carcinoma (PTC) compared with matched normal thyroid tissue. Image analysis of DIGE gels comparing PTC and matched normal thyroid tissue protein indicated that 25% of the protein spots were differentially expressed at a 2.5-fold cutoff and 35% at two-fold. Comparison between two different pools of protein from normal thyroid tissues revealed differential protein expression of only 4% at 2.5-fold and 6% at two-fold cutoff. One hundred ninety-two protein spots were identified by MALDI-TOFMS, representing 90 distinct proteins. Excluding albumin, globins and thyroglobulin, imaging software determined 31 proteins to be differentially expressed at the two-fold (or greater) level. Individual gel comparisons (PTC vs. matched normal) from five patients established that 15/31 (48%) of these proteins exhibited statistically significant differential expression. Previously identified molecular markers in this group of proteins include cathepsin B, cytokeratin 19, and galectin-3. Novel differentially expressed proteins include S100A6, moesin, HSP70 (BiP), peroxiredoxin 2, protein phosphatase 2, selenium binding protein 1, vitamin D binding protein, and proteins involved in mitochondrial function. The use of two-dimensional gel electrophoresis (2DGE) revealed a significantly altered protein mass and/or pI in 10%-15% of proteins, suggesting alternatively spliced forms and other posttranslational modification of proteins revealed by this approach. We confirmed S100A6 as a potentially useful biomarker using immunohistochemical analysis (85% sensitivity and 69% specificity for distinguishing benign from malignant thyroid neoplasms). In summary, proteomic analysis of PTC using DIGE and mass spectrometry has confirmed several known biomarkers, uncovered novel potential biomarkers, and provided insights into global pathophysiologic changes in PTC. Many of the differences observed would not have been detected by genomic or other proteomic approaches.