Inner ear exosomes and their potential use as biomarkers.

Exosomes are nanovesicles involved in intercellular communications. They are released by a variety of cell types; however, their presence in the inner ear has not been described in the literature. The aims of this study were to determine if exosomes are present in the inner ear and, if present, characterize the changes in their protein content in response to ototoxic stress. In this laboratory investigation, inner ear explants of 5-day-old Wistar rats were cultured and treated with either cisplatin or gentamicin. Hair cell damage was assessed by confocal microscopy. Exosomes were isolated using ExoQuick, serial centrifugation, and mini-column methods. Confirmation and characterization of exosomes was carried out using transmission electron microscopy (TEM), ZetaView, BCA protein analysis, and proteomics. Vesicles with a typical size distribution for exosomes were observed using TEM and ZetaView. Proteomic analysis detected typical exosome markers and markers for the organ of Corti. There was a statistically significant reduction in the exosome protein level and number of particles per cubic centimeter when the samples were exposed to ototoxic stress. Proteomic analysis also detected clear differences in protein expression when ototoxic medications were introduced. Significant changes in the proteomes of the exosomes were previously described in the context of hearing loss and ototoxic treatment. This is the first report describing exosomes derived from the inner ear. These findings may present an opportunity to conduct further studies with the hope of using exosomes as a biomarker to monitor inner ear function in the future.

Comparison of the classic and Broms methods of rhinomanometry using model noses.

Calculation of nasal airway resistance (NAR) using rhinomanometry can be obtained using different methods of analysis of the pressure-flow curve. The two commonest methods for measuring NAR in rhinomanometry are the classic method at 75 and 150 Pa and the Broms method at radius 200. The objective of this study was to compare the unilateral NAR values measured using both classic and Broms method over four artificial model noses (R1, R2, R3 and R4). The study found that at low resistances (R1 and R2), NAR measurements of Broms were not significantly different from measurements of classic method at 75 Pa but were significantly different from measurements of classic method at 150 Pa. At high resistances (R3 and R4), NAR measurements of Broms were not significantly different from measurements of classic method at 150 Pa but were significantly different from measurements of classic method at 75 Pa. The magnitude of any change in resistance due to surgery or medical intervention is therefore also dependent on the method used to analyze the pressure-flow curves, with bigger change observed in Broms method at certain level of nasal resistances compared to classic measurements in the same patient. In conclusion, nasal airway resistance is not a standardized measurement like blood pressure. Clinicians need to be careful when comparing unilateral measurements of resistance from the classic and Broms methods because the two methods can give either similar or different measurements depending on the level of nasal resistance.

Comparison of classic and 4-phase rhinomanometry methods, is there any difference?

BACKGROUND: There are various different parameters used to measure nasal airway resistance (NAR) in rhinomanometry, which include the classic method at fixed pressure of 150Pa or 75Pa and 4-phase rhinomanometry. This study aims to determine if there is any difference between the measurements of NAR obtained by the classic and 4-phase rhinomanometry methods. METHODOLOGY: In-vitro study with measurements of NAR using both methods when applied across four artificial nose models. RESULTS: No statistically significant differences were found between NAR values obtained from both methods. Strong, positive correlations were found between NAR measured with both methods, which were statistically significant. Bland-Altman method also showed good agreement between both methods with narrow limits of agreement. CONCLUSION: There is high level of conformity between the values of nasal airway resistance measured using both methods.

Unilateral non-Hodgkin's lymphoma of the frontal sinus presenting as Pott's puffy tumour.

Malignant lymphoma of the paranasal sinuses and nasal cavity is very rare and can mimic those of infectious, non-lymphomatous neoplastic and granulomatous process in their initial presentation, thus delaying its diagnosis. This report describes a case of unilateral frontal sinus B-cell lymphoma presenting as Pott's puffy tumour. Key features to differentiate the two conditions are discussed. A 61-year-old woman presented with 4 weeks history of a gradually enlarging right-sided forehead swelling, which was smooth and firm with no tenderness, fluctuation or overlying skin changes. Initial computed tomography (CT) of the paranasal sinuses revealed a mildly opacified right frontal sinus with an overlying soft tissue swelling. A repeat CT scan one week later showed evidence of osteomyelitis of the medial wall of the right frontal bone and orbit, suggesting diagnosis of Pott's puffy tumour. A third CT scan was performed as the swelling continued to enlarge despite antibiotics, which demonstrated a collection over the frontal sinus. No pus was found from a frontal sinus trephine. Histopathologic analysis of the frontal sinus biopsy showed diffuse large B cell lymphoma. The patient was treated successfully with 6 cycles of chemotherapy. In conclusion, it is not easy to differentiate Pott's puffy tumour from frontal sinus lymphoma at their initial presentation. With clearer understanding of both conditions, we can raise the index of suspicion among clinicians of the possibility of frontal sinus lymphoma even when evidence of osteomyelitis is present, therefore prompting earlier tissue biopsies for confirmation of diagnosis.

First-bite syndrome complicating carotid endarterectomy: a case report and literature review.

First-bite syndrome (FBS) is an infrequently encountered complication of parapharyngeal space surgery. Patients experience excruciating pain in the ipsiltateral parotid gland region at the first bite of each meal, which improves with subsequent mastication. This is thought to be due to parotid gland sympathetic denervation from surgery with resultant hypersensitivity to parasympathetic impulses. There is no consensus on best treatment for FBS although symptoms tend to improve with time. There are only 2 case reports linking carotid endarterectomy and FBS so far. We report the third case of FBS after carotid endarterectomy to raise awareness among vascular surgeons of the possibility of this complication.