Physicochemical Properties of 20 Ionic Liquids Prepared by the Carbonate-Based IL (CBILS) Process

Ionic liquids (ILs) are an emerging materials' class with applications in areas such as energy storage, catalysis, and biomass dissolution and processing. Their physicochemical properties including surface tension, viscosity, density and their interplay between cation and anion chemistry are decisive in these applications. For many commercially available ILs, a full set of physicochemical data is not available. Here, we extend the knowledge base by providing physicochemical properties such as density (20 and 25 °C), refractive index (20 and 25 °C), surface tension (23 °C, including polar and dispersive components), and shear viscosity (ambient atmosphere, shear rate 1-200 s-1), for 20 commercial ILs. A correlation between the crystal volume, dispersive surface tension, and shear viscosity is introduced as a predictive tool, allowing for viscosity estimation. Systematic exploration of cation/anion alkyl side chain lengths reveals the impact on the IL's physicochemical attributes. Increasing the anion's headgroup decreases surface tension up to 35.7% and consequently shear viscosity. We further demonstrate that the dispersive part of the surface tension linearly correlates with the refractive index of the ionic liquid. While we provide additional physicochemical data, the screening and modeling efforts will contribute to better structure property predictions enabling faster progress in design and applications of ILs.

Ganglioside lipidomics of CNS myelination using direct infusion shotgun mass spectrometry

Gangliosides are present and concentrated in axons and implicated in axon-myelin interactions, but how ganglioside composition changes during myelin formation is not known. Here, we present a direct infusion (shotgun) lipidomics method to analyze gangliosides in small amounts of tissue reproducibly and with high sensitivity. We resolve the mouse ganglioside lipidome during development and adulthood and determine the ganglioside content of mice lacking the St3gal5 and B4galnt1 genes that synthesize most ganglioside species. Our results reveal substantial changes in the ganglioside lipidome during the formation of myelinated nerve fibers. In sum, we provide insights into the CNS ganglioside lipidome with a quantitative and sensitive mass spectrometry method. Since this method is compatible with global lipidomic profiling, it will provide insights into ganglioside function in physiology and pathology.

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A sensitive direct infusion mass spectrometry method for ganglioside lipidomics

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Quantification of gangliosides in CNS myelin development

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Generation of myelin in the absence of gangliosides

Study protocol P-MAPS: microbiome as predictor of severity in acute pancreatitis-a prospective multicentre translational study

Background

Acute pancreatitis (AP) is an inflammatory disorder that causes a considerable economic health burden. While the overall mortality is low, around 20% of patients have a complicated course of disease resulting in increased morbidity and mortality. There is an emerging body of evidence that the microbiome exerts a crucial impact on the pathophysiology and course of AP. For several decades multiple clinical and laboratory parameters have been evaluated, and complex scoring systems were developed to predict the clinical course of AP upon admission. However, the majority of scoring systems are determined after several days and achieve a sensitivity around 70% for early prediction of severe AP. Thus, continued efforts are required to investigate reliable biomarkers for the early prediction of severity in order to guide early clinical management of AP patients.

Methods

We designed a multi-center, prospective clinical-translational study to test whether the orointestinal microbiome may serve as novel early predictor of the course, severity and outcome of patients with AP. We will recruit 400 AP patients and obtain buccal and rectal swabs within 72 h of admission to the hospital. Following DNA extraction, microbiome analysis will be performed using 3rd generation sequencing Oxford Nanopore Technologies (ONT) for 16S rRNA and metagenomic sequencing. Alpha- and beta-diversity will be determined and correlated to the revised Atlanta classification and additional clinical outcome parameters such as the length of hospital stay, number and type of complications, number of interventions and 30-day mortality.

Discussion

If AP patients show a distinct orointestinal microbiome dependent on the severity and course of the disease, microbiome sequencing could rapidly be implemented in the early clinical management of AP patients in the future.

Trial registration: ClinicalTrials.gov Identifier: NCT04777812

Factors associated with relevant olfactory recovery after olfactory training: a retrospective study including 601 participants

OBJECTIVE

Olfactory training (OT) represents a therapeutic option for multiple etiologies of olfactory dysfunction (OD) that also benefits normosmic subjects. In this retrospective study, we report the effectiveness of OT and factors associated with relevant changes in olfactory function (OF) in large groups of normosmic participants and patients with OD, including a control group that performed no training.

METHODS

This was a retrospective pooled analysis including 2 treatment cohorts of 8 previously published studies. Adult participants that either presented with the major complaint of quantitative OD or normosmic volunteers were recruited at various ENT clinics and received OT or no training. The outcome was based on changes in objective olfactory test scores after OT.

RESULTS

A total of 601 patients with OD or normosmic subjects were included. OT was more effective compared to no training. No interaction was found between OT and OF. In multivariate analysis, higher baseline OF (adjusted odds ratio, aOR, 0.93) and posttraumatic (aOR, 0.29) or idiopathic OD (aOR, 0.18) compared to postinfectious causes were significantly associated with lower odds of relevant improvements in patients with OD receiving OT. Subgroup analysis of normosmic participants receiving OT further revealed a significant association of lower age and baseline olfactory function with improvements of overall OF.

CONCLUSIONS

This study demonstrated that OT was more effective than no training in patients with various causes of OD. Additionally, baseline olfactory performance and etiology of OD were identified as important factors associated with relevant improvements after OT.

Plasma lipidomics of monozygotic twins discordant for multiple sclerosis

Blood biomarkers of multiple sclerosis (MS) can provide a better understanding of pathophysiology and enable disease monitoring. Here, we performed quantitative shotgun lipidomics on the plasma of a unique cohort of 73 monozygotic twins discordant for MS. We analyzed 243 lipid species, evaluated lipid features such as fatty acyl chain length and number of acyl chain double bonds, and detected phospholipids that were significantly altered in the plasma of co‐twins with MS compared to their non‐affected siblings. Strikingly, changes were most prominent in ether phosphatidylethanolamines and ether phosphatidylcholines, suggesting a role for altered lipid signaling in the disease.

Factors associated with relevant olfactory recovery after olfactory training: a retrospective study including 601 participants

BACKGROUND

Olfactory training (OT) represents a therapeutic option for multiple etiologies of olfactory dysfunction (OD) that also benefits normosmic subjects. In this retrospective study, we report the effectiveness of OT and factors associated with relevant changes in olfactory function (OF) in large groups of normosmic participants and patients with OD, including a control group that performed no training.

METHODS

This was a retrospective pooled analysis including 2 treatment cohorts of 8 previously published studies. Adult partici- pants that either presented with the major complaint of quantitative OD or normosmic volunteers were recruited at various ENT clinics and received OT or no training. The outcome was based on changes in objective olfactory test scores after OT.

RESULTS

A total of 601 patients with OD or normosmic subjects were included. OT was more effective compared to no training. No interaction was found between OT and OF. In multivariate analysis, higher baseline OF (adjusted odds ratio, aOR, 0.93) and posttraumatic (aOR, 0.29) or idiopathic OD (aOR, 0.18) compared to postinfectious causes were significantly associated with lower odds of relevant improvements in patients with OD receiving OT. Subgroup analysis of normosmic participants receiving OT further revealed a significant association of age and baseline olfactory function with improvements of overall OF.

CONCLUSIONS

This study demonstrated that OT was more effective than no training in patients with various causes of OD. Additi- onally, baseline olfactory performance and etiology of OD were identified as important factors associated with relevant improve- ments after OT.

Shotgun Lipidomics Discovered Diurnal Regulation of Lipid Metabolism Linked to Insulin Sensitivity in Nondiabetic Men

CONTEXT

Meal timing affects metabolic homeostasis and body weight, but how composition and timing of meals affect plasma lipidomics in humans is not well studied.

OBJECTIVE

We used high throughput shotgun plasma lipidomics to investigate effects of timing of carbohydrate and fat intake on lipid metabolism and its relation to glycemic control.

DESIGN

29 nondiabetic men consumed (1) a high-carb test meal (MTT-HC) at 09.00 and a high-fat meal (MTT-HF) at 15.40; or (2) MTT-HF at 09.00 and MTT-HC at 15.40. Blood was sampled before and 180 minutes after completion of each MTT. Subcutaneous adipose tissue (SAT) was collected after overnight fast and both MTTs. Prior to each investigation day, participants consumed a 4-week isocaloric diet of the same composition: (1) high-carb meals until 13.30 and high-fat meals between 16.30 and 22:00 or (2) the inverse order.

RESULTS

12 hour daily lipid patterns showed a complex regulation by both the time of day (67.8%) and meal composition (55.4%). A third of lipids showed a diurnal variation in postprandial responses to the same meal with mostly higher responses in the morning than in the afternoon. Triacylglycerols containing shorter and more saturated fatty acids were enriched in the morning. SAT transcripts involved in fatty acid synthesis and desaturation showed no diurnal variation. Diurnal changes of 7 lipid classes were negatively associated with insulin sensitivity, but not with glucose and insulin response or insulin secretion.

CONCLUSIONS

This study identified postprandial plasma lipid profiles as being strongly affected by meal timing and associated with insulin sensitivity.

Position paper on olfactory dysfunction

Background

Olfactory dysfunction is an increasingly recognised condition, associated with reduced quality of life and major health outcomes such as neurodegeneration and death. However, translational research in this field is limited by heterogeneity in methodological approach, including definitions of impairment, improvement and appropriate assessment techniques. Accordingly, effective treatments for smell loss are limited. In an effort to encourage high quality and comparable work in this field, among others, we propose the following ideas and recommendations. Whilst the full set of recommendations are outlined in the main document, points include the following: • Patients with suspected olfactory loss should undergo a full examination of the head and neck, including rigid nasal endoscopy with small diameter endoscopes. • Subjective olfactory assessment should not be undertaken in isolation, given its poor reliability. • Psychophysical assessment tools used in clinical and research settings should include reliable and validated tests of odour threshold, and/or one of odour identification or discrimination. • Comprehensive chemosensory assessment should include gustatory screening. • Smell training can be helpful in patients with olfactory loss of several aetiologies.

Conclusions

We hope the current manuscript will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency and generalisability of work in this field.

Early prediction of tumour response to PRRT

[177Lu-DOTA0, Tyr3]-octreotate (177Lu-octreotate) in peptide receptor radionuclide therapy (PRRT) offers direct intra-therapeutic dosimetry. The aim of this study was to compare tumour and non-tumour parameters and assess intra-individual variations. Patients, methods: Retrospective analysis of 53 consecutive PRRT treatment cycles (mean activity of 7.53 ± 0.46 GBq 177Lu-octreotate, intended four cycles at intervals of 10–14 weeks, standard nephroprotection) in 27 GEP NET patients. Extended planar dosimetry with serial wholebody imaging on selected, non-superimposed tumour and non-tumour regions; liver (LM), bone (BM), and other (OM) metastases. The per-cycle variation was compared with posttreatment response (CT/MRI three months post-treatment, modified SWOG criteria). Results: Residence time in tumor lesions (133–147 h) exceeded that in kidneys (93 h). Tumour-to-kidney absorbed dose ratios ranged from 14 to 28 (LM, BM, OM). Intra-individual per-cycle dose variation was insignificant for kidneys, but significant for metastases (LM, BM, and OM; p < 0.05). The mean per-cycle decrease of tumour absorbed dose (_D/A0[%]) was linked to morphologic response after PRRT. A mean decrease of >20% was predictive of a partial or minor remission in all 11 evaluable patients, while absent significant dose reduction indicated stable or progressive disease in 4/5 patients. The dose decrease was unrelated to volume effects and also observed for BM. Conclusion: Besides confirmation of a favourable tumour-to-kidney parameter relation for 177Lu-octreotate, stepwise intra-lesional comparison seems to imply a prognostic impact of tumor dosimetry: The early per-cycle change _D/A0 between treatment cycles may predict the outcome after PRRT. Larger studies are needed to confirm this finding.

Position paper on olfactory dysfunction

BACKGROUND

Olfactory dysfunction is an increasingly recognised condition, associated with reduced quality of life and major health outcomes such as neurodegeneration and death. However, translational research in this field is limited by heterogeneity in methodological approach, including definitions of impairment, improvement and appropriate assessment techniques. Accordingly, effective treatments for smell loss are limited. In an effort to encourage high quality and comparable work in this field, among others, we propose the following ideas and recommendations. Whilst the full set of recommendations are outlined in the main document, points include the following: - Patients with suspected olfactory loss should undergo a full examination of the head and neck, including rigid nasal endoscopy with small diameter endoscopes. - Subjective olfactory assessment should not be undertaken in isolation, given its poor reliability. - Psychophysical assessment tools used in clinical and research settings should include reliable and validated tests of odour threshold, and/or one of odour identification or discrimination. - Comprehensive chemosensory assessment should include gustatory screening. - Smell training can be helpful in patients with olfactory loss of several aetiologies.

CONCLUSIONS

We hope the current manuscript will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency and generalisability of work in this field.

Carbonate Based Ionic Liquid Synthesis (CBILS®): development of the continuous flow method for preparation of ultra-pure ionic liquids

Development of a new continuous flow method for preparation of ultra-pure ionic liquids; analytical verification includes highly sensitive combustion and solution calorimetry.

IgM-enriched solution BT086 improves host defense capacity and energy store preservation in a rabbit model of endotoxemia

Introduction

The therapeutic value of intravenous immunoglobulin (IVIG) as an adjuvant therapy in sepsis remains debatable. We hypothesized that intravenous administration of BT086, a predominantly IgM IVIG solution, would improve host defense in an established rabbit model of endotoxemia and systemic sepsis.

Methods

New Zealand white rabbits were randomized into the following four groups: (1) the negative control group without lipopolysaccharide (LPS, control), (2) the positive control group with LPS infusion (LPS group), (3) the albumin‐treated LPS group (ALB+LPS group), and (4) the BT086‐treated LPS group (BT086 + LPS group). A standardized amount of E. coli was intravenously injected into all of the animals. The vital parameters, the concentration of E. coli in the blood and other organs, the residual granulocyte phagocytosis activity, and the levels of the inflammatory mediators were measured. Histological changes in the lung and liver tissue were examined following autopsy.

Results

The elimination of E. coli from the bloodstream was expedited in the BT086‐treated group compared with the LPS‐ and albumin‐treated groups. The BT086 + LPS group exhibited higher phagocytic activity of polymorphonuclear neutrophils (PMNs) than the control and ALB+LPS groups. The liver energy stores were higher in the BT086 + LPS group than in the other groups.

Conclusion

Our data suggest that the IgM‐enriched IVIG has the potential to improve host defense in a rabbit model of endotoxemia. Studies using different animal models and dosages are necessary to further explore the potential benefits of IgM‐enriched IVIG solutions.

[Position paper "Chemosensory testing for expert opinion in smell disorders"]

Providing expert opinion in the context of smell disorders is often challenging, not only with regard to general aspects of providing an expert opinion but particularly with regard to chemosensory testing. Currently there is no consensus which chemosensory test should be selected and how they should be executed. This positions paper from Committee on Olfaction and Gustation of the German Society of Otorhinolaryngology, Head and Neck Surgery aims to give concrete recommendations for chemosensory testing for providing expert opinion for smell disorders with regard to the selection and execution of these test.

Continuous-flow synthesis of adipic acid from cyclohexene using hydrogen peroxide in high-temperature explosive regimes

Safe only in a microreactor! The synthesis of adipic acid from cyclohexene by tungstic acid-catalyzed oxidation using hydrogen peroxide following the classical Noyori protocol can be accomplished in good yields with residence times as short as 20 min at 140 °C using a safe and scalable microreactor environment. Under these intensified conditions the use of a phase-transfer catalyst is not required.

Can electromagnetic fields influence the structure and enzymatic digest of proteins? A critical evaluation of microwave-assisted proteomics protocols

This study reevaluates the putative advantages of microwave-assisted tryptic digests compared to conventionally heated protocols performed at the same temperature. An initial investigation of enzyme stability in a temperature range of 37-80 °C demonstrated that trypsin activity declines sharply at temperatures above 60 °C, regardless if microwave dielectric heating or conventional heating is employed. Tryptic digests of three proteins of different size (bovine serum albumin, cytochrome c and β-casein) were thus performed at 37 °C and 50 °C using both microwave and conventional heating applying accurate internal fiber-optic probe reaction temperature measurements. The impact of the heating method on protein degradation and peptide fragment generation was analyzed by SDS-PAGE and MALDI-TOF-MS. Time-dependent tryptic digestion of the three proteins and subsequent analysis of the corresponding cleavage products by MALDI-TOF provided virtually identical results for both microwave and conventional heating. In addition, the impact of electromagnetic field strength on the tertiary structure of trypsin and BSA was evaluated by molecular mechanics calculations. These simulations revealed that the applied field in a typical laboratory microwave reactor is 3-4 orders of magnitude too low to induce conformational changes in proteins or enzymes.

[Cardioprotection]

The demographic change is associated with an increasing number of elderly patients with serious comorbidities. The prevalence of coronary heart disease in particular increases with age and raises the risk of perioperative myocardial ischemia. In the last few years various interventions have been evaluated to lower the perioperative risk for serious cardiovascular events. This includes cardioprotective medical interventions, for example with β-receptor blockers and statins. Current guidelines recommend that patients who are on β-receptor blockers or statins for chronic treatment of cardiovascular diseases should continue this medication throughout the perioperative period. Myocardial conditioning has been assessed to be effective under numerous experimental conditions and clinical trials have also provided evidence for myocardial protection by conditioning. Besides ischemic and anesthetic-induced preconditioning the noninvasive technique of remote preconditioning offers interesting possibilities, especially for patients with serious comorbidities; however, large scale randomized clinical multicentre trials are still needed. Regarding cardioprotective effectiveness, the clinical data for regional anesthesia are very heterogeneous; nevertheless regional anesthesia is very effective in postoperative pain therapy. Therefore regional anesthesia should be used as a part of multimodal therapy concepts to lower the risk of perioperative cardiovascular events.

A miniaturized microtiter plate protocol for the determination of in selenized yeast via enzymatic hydrolysis of protein-bound

This paper describes a simple/low volume enzymatic extraction method for selenomethionine (SeMet) determination in selenized yeast samples. In contrast to traditional methods which generally utilize large sample volumes consuming significant amounts of costly enzymes, the modified protocol employs a microtiter plate format allowing a reduction of the required sample volumes to 1 mL per extract. The extraction is performed in a parallel (5 × 4 = 20 position microtiter plate) reaction platform made out of sintered silicon carbide, fitted with standard disposable glass HPLC/GC vials. Due to the high thermal conductivity of silicon carbide, this set-up can be placed on a standard hotplate to accurately maintain the desired extraction conditions (37 °C, 20 h) for all positions of the microtiter plate. Hydrolysis of selenium-enriched yeast with a combination of protease XIV and lipase VII (ratio 2 : 1, w/w) using these low-volume conditions provided identical results to the more traditional high-volume method. The amount of SeMet was determined by HPLC/ICPMS and confirmed a high recovery rate for SeMet (93 ± 2%, n = 3) for the certified reference material SELM-1.

Microwave-assisted high-throughput acid hydrolysis in silicon carbide microtiter platforms--a rapid and low volume sample preparation technique for total amino acid analysis in proteins and peptides

An efficient microwave-assisted high-throughput protein hydrolysis protocol was developed utilizing strongly microwave absorbing silicon carbide-based microtiter platforms. The plates are equipped with 20 bore holes having the proper dimensions for holding standard screw-capped HPLC/GC vials. Due to the possibility of heating up to four heating platforms simultaneously (80 vials), parallel microwave-assisted acid hydrolyses can be performed under carefully controlled conditions significantly reducing the overall time required for protein hydrolysis and the subsequent evaporation step required for larger volumes of acid. An extensive optimization of the hydrolysis conditions has demonstrated that 5min irradiation at 160°C with 6N HCl leads to comparable results in terms of total and individual amino acid recovery as the traditional method requiring 24h heating at 110°C. Complete hydrolysis of several proteins and synthetic peptides was performed using 25μg of sample material and 100μL of 6N HCl in a dedicated low-volume HPLC/GC vial. Since the hydrolysis and subsequent analysis can be performed from the same vial, errors caused by sample transfer can be minimized. Control experiments have demonstrated that the observed rate enhancements are the result of a purely thermal/kinetic effect as a consequence of the considerable higher reaction temperatures.

Microwave-assisted derivatization procedures for gas chromatography/mass spectrometry analysis

In this review, published applications of microwave-assisted derivatization procedures for gas chromatography/mass spectrometry (GC/MS) are summarized. Among the broad range of analytical techniques available, GC/MS is still the method of choice for most high-throughput screening procedures in forensic/clinical toxicology, doping control and food and environmental analysis. Despite the many advantages of the GC/MS method, time-consuming derivatization steps are often required in order to obtain desirable chromatographic characteristics or to improve the stability and detectability of the target analytes. These derivatization processes typically require reaction times from 30 min up to several hours at elevated temperature. In contrast, microwave protocols have demonstrated to be able to reduce the time required for derivatization to a few minutes, and can thus very effectively shorten the overall analysis time, in particular when carried out in a high-throughput format. Herein, the literature in this field is summarized and recent experimental techniques for performing parallel GC/MS derivatization protocols are discussed.

[Two- and three-dimensional, morphologic and functional MR-imaging in smelling disorders]

Olfactory dysfunction is a frequent diagnosis. This overview describes recent standards in structural imaging related to olfactory dysfunction, with magnetic resonance imaging being the most significant imaging tool both quantitatively and qualitatively. Relevant MRI-techniques to be applied in patients during routine clinical workup and the consecutive imaging evaluation are presented and discussed.

Diagnostik von Riechstörungen - Standards und Forschung

Olfactory dysfunction has been reported to affect about 79,000 patients who were treated annually in German ORL-hospitals. The incidence of olfactory dysfunctions emphasizes the need for diagnostic strategies. This article features on the dysfunction of human olfaction including neurodegenerative diseases. Standard procedures for the psychophysical and objective assessment of olfactory function are presented. Current diagnostic imaging techniques for routine use and scientific approaches are discussed.

Long-term results of the combined modality therapy for advanced cervical metastatic head and neck squamous cell carcinoma

AIM

A consensus treatment strategy for advanced cervical metastatic head and neck squamous cell carcinoma has not been established. The aim of this retrospective study was to investigate the outcome of these patients uniformely using a strategy which consists of surgery for the primary tumor and the neck metastases followed by postoperative radio(chemo)therapy.

METHODS

We included a selected series of 518 patients with previously untreated head and neck squamous cell carcinoma. The overall survival (OS), the disease specific survival (DSS), the disease free survival (DFS), the local control (LC) and regional control (RC) estimates were calculated. The statistical relationship of various clinical and histopathological variables on the above mentioned estimates were analyzed.

RESULTS

The overall survival probability was 73.2% for pN0 stage, 43% for pN>1 stages and 31% for pN2c/pN3 stages. The pN stage significantly influenced the survival probabilities in oropharyngeal (p=0.0001) and laryngeal tumors (p<0.0001) in univariate analyses. In multivariate analysis, age, pT stage, pN stage, M stage, and extranodal spreading were independent risk factors for decreased disease-specific survival.

CONCLUSIONS

We could show that pN stage is an important independent prognostic factor in head and neck cancer. The presented multimodal treatment protocol provides excellent oncological outcomes and should therefore be standard of care for patients with operable advanced cervical metastatic head and neck squamous cell carcinoma.

[Vallecular cyst as a rare cause of progressive inspiratory stridor]

BACKGROUND

Vallecular cysts are frequently observed, benign masses of the upper aerodigestiv tract. Usually they appear as harmless and asymptomatic and go unnoticed by the patient. In rare cases, obstructions of the upper airway due to monstrous vallecular cysts may become life threatening.

CASE

We report on a 69-year-old otherwise healthy woman with a rapidly progressive history of dyspnea caused by a pedicled vallecular cyst. Increasing stridor prompted emergency surgical resection.

CONCLUSION

Vallecular cysts that increase in size can cause dyspnea due to obstruction of the aditus of the larynx. This case demonstrates the need for surgical treatment at an early stage of pedicled vallecular cysts.

Post-infectious olfactory dysfunction exhibits a seasonal pattern

HYPOTHESIS

We investigated whether olfactory dysfunction following infections of the upper respiratory tract (post-URTI) has an incidence matching the seasonality of URTIs.

STUDY DESIGN

Retrospective study.

METHODS

In total, 457 patients (126 male, 331 female) with post-URTI olfactory loss were examined during a 6-year-period (1999-2004). Their records were assessed for age, sex, and time of onset of the disease. The severity of olfactory dysfunction was assessed using the "Sniffin' Sticks" (odour threshold, odour discrimination, and odour identification).

RESULTS

Incidence of post-URTI olfactory dysfunction exhibited seasonal fluctuations with deviations from the winter seasonality of URTIs. The overall incidence of the disease differed significantly between months. March (12.7%) and May (12.6%) were the months with the highest incidence of the disease throughout the year. The lowest incidence was observed in September (5.6%). Significant differences were found between these months and months with a high incidence of URTIs.

DISCUSSION

The peak incidence of post-URTI olfactory loss in March may be explained by the high incidence of influenza at this time. However, it is unclear why the incidence of the disease presents a second peak in May, when the incidence of respiratory viruses is relatively low. Climate conditions at this time might play a role in the susceptibility of the nasal epithelia towards certain viral infections, e.g. parainfluenza type III.

CONCLUSION

Post-URTI olfactory dysfunction exhibits spring seasonality with peaks in March and May and possible causative factors being influenza and parainfluenza viruses (type III), respectively.