| 1. |
- Gerkin, Richard C., et al.
(författare)
-
Recent Smell Loss Is the Best Predictor of COVID-19 Among Individuals With Recent Respiratory Symptoms
- 2021
-
Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 46
-
Tidskriftsartikel (refereegranskat)abstract
- In a preregistered, cross-sectional study, we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0–100 visual analog scales (VAS) for participants reporting a positive (C19+; n = 4148) or negative (C19−; n = 546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19− groups exhibited smell loss, but it was significantly larger in C19+ participants (mean ± SD, C19+: −82.5 ± 27.2 points; C19−: −59.8 ± 37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC = 0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0–10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4 < OR < 10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable.
|
|
| 2. |
- Parma, Valentina, et al.
(författare)
-
More Than Smell—COVID-19 Is Associated With Severe Impairment of Smell, Taste, and Chemesthesis
- 2020
-
Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 45:7, s. 609-622
-
Tidskriftsartikel (refereegranskat)abstract
- Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19–79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (−79.7 ± 28.7, mean ± standard deviation), taste (−69.0 ± 32.6), and chemesthetic (−37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms.
|
|
| 3. |
- Sullivan, Mitchell A., et al.
(författare)
-
Improving size-exclusion chromatography separation for glycogen
- 2014
-
Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1332, s. 21-29
-
Tidskriftsartikel (refereegranskat)abstract
- Glycogen is a hyperbranched glucose polymer comprised of glycogen beta particles, which can also form much larger composite alpha particles. The recent discovery using size-exclusion chromatography (SEC) that fewer, smaller, alpha particles are found in diabetic-mouse liver compared to healthy mice highlights the need to achieve greater accuracy in the size separation methods used to analyze alpha and beta particles. While past studies have used dimethyl sulfoxide as the SEC eluent to analyze the molecular size and structure of native glycogen, an aqueous eluent has not been rigorously tested and compared with dimethyl sulfoxide. The conditions for SEC of pig-liver glycogen, phytoglycogen and oyster glycogen were optimized by comparing two different eluents, aqueous 50 mM NH4NO3/0.02% NaN3 and dimethyl sulfoxide/0.5% LiBr, run through different column materials and pore sizes at various flow rates. The aqueous system gave distinct size separation of alpha- and beta-particle peaks, allowing for a more detailed and quantitative analysis and comparison between liver glycogen samples. This greater resolution has also revealed key differences between the structure of liver glycogen and phytoglycogen.
|
|
| 4. |
- Wan, Yujun, et al.
(författare)
-
Comparing different techniques for obtaining molecular size distributions of glycogen
- 2023
-
Ingår i: European Polymer Journal. - 0014-3057. ; 201
-
Tidskriftsartikel (refereegranskat)abstract
- Glycogen is a hyperbranched glucose polymer, serving as a major energy reservoir in animals. Characterization of the size distributions of complex branched polysaccharides helps in the understanding of their structural and functional properties. This study compared the effectiveness of various techniques in analyzing glycogen size distributions, namely size-separation-based techniques (size exclusion chromatography (SEC) and asymmetric-flow field-flow fractionation (AF4)) and imaging-based methods (transmission electron microscopy (TEM) and atomic force microscopy (AFM)). SEC and AF4 gave similar glycogen size distributions. TEM was suboptimal for obtaining size distributions due to the difficulty of preventing aggregation artifacts during sample preparation. AFM appeared to avoid the problem, but the size distributions so obtained had substantially lower resolution and were much more laborious to acquire. The microscopy-based techniques, especially TEM, do however provide richer morphological information on individual particles than do SEC and AF4. These results suggest that combining size-separation and microscopy (imaging) techniques could provide a holistic view of glycogen size distribution and morphology, which may also be applicable to the characterization of other complex branched polymers.
|
|
