Discover and publish cutting edge, open research.

Browse 18,018 multi-disciplinary research preprints

Most recent

Christina Moore

and 2 more

Background: Patients who undergo cardiac surgery are at increased risk of stroke, postoperative cognitive decline, and delirium. These neurocognitive complications have led to increased costs, intensive care unit stays, morbidity, and mortality. As a result, there is a significant push to mitigate any neurological complications in cardiac surgery patients. Near-infrared spectroscopy to measure regional cerebral oxygen saturations has gained consideration due to its non-invasive, user-friendly, and relatively inexpensive nature. Aim of Study: To provide a comprehensive summary of cerebral oximetry in cardiac surgery. The review interrogates multiple systematic reviews assessing different outcomes in cardiac surgery to assess if cerebral oximetry is effective. Further, the review analyzes all available interventions for an acute desaturation to determine the efficacy of individual interventions. Methods: A narrative review of randomized controlled trials, observational studies, and systematic reviews with metanalyses were performed through August 2021. Results: There is significant heterogeneity amongst studies regarding the definition of a clinically significant cerebral desaturation. In addition, the assessment of neurocognitive outcomes has large variability, making metanalysis challenging. To date, cerebral oximetry use during cardiac surgery has not been associated with improvements in neurocognitive outcomes, morbidity, or mortality. The evidence to support particular interventions for an acute desaturation is equivocal. Conclusions: Future research is needed to quantify a clinically significant cerebral desaturation and to determine which interventions for an acute desaturation effectively improve clinical outcomes.

Gail Gauvreau

and 11 more

Eosinophilic airway inflammation in patients with atopic dermatitisTo the Editor,Atopic dermatitis (AD) is a chronic inflammatory skin disorder described as the first clinical manifestation of the atopic march leading to allergic asthma (AA) then allergic rhinitis (AR). AD, however, is not limited to childhood onset1, with some patients developing asthma first2. Most AD patients are reported to have airway hyperresponsiveness (AHR)3,4 airway eosinophilia5, and concurrent asthma. The Hamilton Integrated Research Ethics Board approved this study. In cohort 1 we evaluated AHR and sputum eosinophils in AD patients (6 mild, 6 moderate-severe) but with no history of asthma, to determine if undiagnosed asthma was present in this population. AD patients were characterized using skin prick test (SPT) Eczema Area and Severity Index (EADI), Asthma Control (ACQ-5) and Leicester Cough (LSQ) questionnaires, spirometry, AHR, and sputum eosinophils, and compared to mild AA (n=14) with no history of AD. Refer to supplement for eligibility and methods. Neither group had used parenteral or oral anti-inflammatory therapy for >1 month. Twenty-one of the 26 patients had a history of AR with 9/21 (43%) reporting AR first in a ‘reverse atopic march’ sequence. AD had a significantly higher EASI score and methacholine PC20, and lower ACQ-5 score compared to AA (all p<0.01) (Table 1). Despite having no history or clinical diagnosis of asthma, 3/12 (25%) AD demonstrated AHR defined by methacholine PC20 <16mg/ml, with data from all AD patients showing negative correlations between methacholine PC20 versus blood eosinophils (r = -0.81, p = <0.01), EASI score (r = -0.74, p = <0.01), and a trend versus IgE (r = -0.53, p = 0.07). When AD patients were grouped by AHR present/absent, those with AHR had significantly higher EASI score (p = 0.02) and blood eosinophils (p<0.001) (Table 1). Furthermore, when AD patients were grouped as mild (n=6) or moderate-severe (n=6) by EASI score, those with AHR were all classified as moderate-severe. The difference in AHR was not explained by allergen sensitivity because the number of positive SPT for animal, mould, house dust mite, or pollen was similar between AD subgroups when divided by AHR present/absent, or by AD severity. Nine of 12 (75%) AD patients demonstrated sputum eosinophilia, as defined by ≥3%6, with levels similar to AA. In AD there was no relationship between sputum eosinophils versus methacholine PC20 or EASI score. We measured cough by LCQ to determine if sputum eosinophils in AD could be explained by eosinophilic bronchitis, however we found no relationship between LCQ score versus sputum eosinophils or blood eosinophils, and additionally there was no relationship between LCQ versus methacholine PC20 or EASI score. To further interrogate the concept of reverse atopic march, in cohort 2 we obtained biopsies of unaffected skin from the lower back of patients with moderate to severe AD (n=17), AA with no history of AD (n=14) and healthy controls (HC, n=15) to measure histological features common to AD. Internal controls showed lesional skin of AD had greater lymphocytic infiltration, epidermal thickening (both p<0.01) and spongiosis compared to their unaffected skin (p=0.04). (Table 2). In unaffected skin, lymphocytic infiltrate was significantly higher in AD versus AA (p=0.03) and HC (p = <0.01), with no difference between any groups for spongiosis, neutrophilic infiltration, vacuole numbers, or epidermal thickening. Eosinophils in unaffected skin were too infrequent for analysis. Notably, skin from AA was histologically similar to HC. Taken together, our observations from this small study suggest that allergic disorders can occur independently or in reverse order to that described by the atopic march. Furthermore, a significant proportion of patients with AD have AHR and eosinophilic airway inflammation indicating potential development of airways inflammatory disease including asthma.References1. Burgess JA, Dharmage SC, Byrnes GB, Matheson MC, Gurrin LC, Wharton CL, et al. Childhood eczema and asthma incidence and persistence: a cohort study from childhood to middle age. J Allergy Clin Immunol . 2008;122(2):280-5.2. Barberio G, Pajno G, Vita D, Caminiti L, Canonica G, Passalacqua G. Does a ‘reverse’atopic march exist? Allergy . 2008;63(12):1630-2.3. Corbo G, Ferrante E, Macciocchi B, Foresi A, De Angelis V, Fabrizi G, et al. Bronchial hyperresponsiveness in atopic dermatitis.Allergy . 1989;44(8):595-8.4. Barker AF, Hirshman CA, D’Silva R, Hanifin JM. Airway responsiveness in atopic dermatitis. J Allergy Clin Immunol . 1991;87(4):780-3.5. Kyllönen H, Malmberg P, Remitz A, Rytilä P, Metso T, Helenius I, et al. Respiratory symptoms, bronchial hyper‐responsiveness, and eosinophilic airway inflammation in patients with moderate‐to‐severe atopic dermatitis. Clinical & Experimental Allergy . 2006;36(2):192-7.6. Belda J, Leigh R, Parameswaran K, O’Byrne PM, Sears MR, Hargreave FE. Induced sputum cell counts in healthy adults. Am J Resp Crit Care Med . 2000;161(2):475-8.Cusack RP,Whetstone CE,Alsaji N,Howie KJ,Stevens C,Wattie J,Wiltshire L,Howran J,O’Byrne PM,Sehmi R,Lima H,Gauvreau GMDepartment of Medicine, McMaster University, Hamilton, Ontario, CanadaConflict of InterestThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.No funding to report* Correspondence: Gail M GauvreauAddress: McMaster University, 1200 Main St W., HSC 3U31E, Hamilton, Ontario Canada L8N 3Z5Phone: 1-905-525-9140 ext 22791Email: gauvreau@mcmaster.caKeywords: asthma, atopic dermatitis, airway hyperresponsiveness, eosinophils, skin, inflammation

Mun Leng Lee

and 2 more

Objectives: Rhinitis affects up to 40% of the population worldwide and can significantly reduce quality of life. Some patients remain symptomatic despite maximal medical therapy. In refractory cases, posterior nasal neurectomy (PNN - the division of the intranasal nerve branches containing postganglionic parasympathetic fibres) is postulated to reduce symptom burden. The objectives of this paper were to review the literature to establish whether the procedure is effective and safe in the management of allergic and non-allergic rhinitis. Design: A systematic review of Pubmed, EMBASE and MEDLINE was undertaken. Studies were excluded if not available in English or undertaken in non-human subjects. Participants: Seventeen articles satisfied the inclusion criteria studying in total 2029 patients. Sample size ranged from 8-1056. Main Outcome Measures: Patient-reported objective and subjective outcomes and post-operative complications were reviewed Results: There were two randomised controlled trials, two case control studies, and the remaining thirteen were case series using both objective and subjective outcome measures. All but one study found improved patient reported outcomes following PNN. Complications were reported in 10 studies - haemorrhage was the most common complication and was observed in 28 patients (1.6% of subjects). Conclusions: Endoscopic posterior nasal neurectomy is safe and appears to be effective in the treatment of intractable rhinitis but the level of the available evidence was generally poor. Larger, well designed studies are needed to clarify its role in the management of difficult-to-treat rhinitis.

Diana Baetscher

and 5 more

DNA metabarcoding is used to enumerate and identify taxa in both environmental samples and tissue mixtures. The composition and resolution of metabarcoding data depend on the primer(s) used. Markers that amplify different genes can mitigate biases in primer affinity, amplification efficiency, and reference database resolution, but few empirical studies have evaluated markers for complementary performance. Here, we assess the individual and joint performance of 22 markers for detecting species in a DNA pool of >100 species of primarily marine and freshwater fishes, but also including representatives of elasmobranchs, cephalopods, and crustaceans. Marker performance includes the integrated effect of primer specificity and reference availability. We find that a portfolio of four markers targeting 12S, 16S, and multiple regions of COI identifies 100% of reference taxa to family and nearly 60% to species. We then use the four markers in this portfolio to evaluate metabarcoding of heterogeneous tissue mixtures, using experimental fishmeal to test: 1) the tissue input threshold to ensure detection; 2) how read depth scales with tissue abundance; and 3) the effect of non-target material in the mixture on recovery of target taxa. We consistently detect taxa that make up >1% of fishmeal mixtures and can detect taxa at the lowest input level of 0.01%, but rare taxa (<1%) were detected inconsistently across markers and replicates. Read counts showed weak correlation with tissue input, suggesting they are not a valid proxy for relative abundance. Despite this limitation, our results demonstrate the value of a primer portfolio approach—tailored to the taxa of interest—for detecting and identifying both rare and abundant species in heterogeneous tissue mixtures.
Background: Patients with persistent atrial fibrillation(PsAF) still have a higher risk of recurrence after catheter radiofrequency ablation. Nevertheless, effective recurrence forecast tools have not been established for these patients. Thus, this research aimed to develop and validate an easy-to-use linear prediction model for predicting postoperative recurrence in patients with PsAF. Methods: We conducted a single-center, retrospective, observational study of patients with PsAF admitted to our hospital from June 2013 to June 2021. Univariate analysis was used to screen risk factors, then we used multivariate regression analysis to evaluate the independence of each risk factor and construct a combined prediction model which incorporated into a nomogram, finally, we took the receiver operating characteristic (ROC) curve to predict the value of nomogram model. Additionally, the calibration curves and decision curve analysis (DCA) were also performed to assess the clinical utility of the nomogram. Results: A total of 209 subjects were included in the study and 42 (20.10%) were followed up to September 2021 for recurrent AF.  Duration of AF, Left atrial diameter(LAD), BMI, CKMB, and alcohol consumption were independent risk factors (P < 0.05),  these variables were integrated into the nomogram model, and the area under the curve (AUC) was 0.895, the sensitivity was 93.3%, and the specificity was 71.4%, indicating that the model had an excellent predictive performance.  The C-index of the predictive nomogram model was 0.906. The calibration curves and DCA results manifested that the Model had a splendid predictive correction and discrimination ability. Conclusion: This simple and innovative clinical nomogram (that any clinician can use in the daily clinic) can help evaluate the risk of recurrence after catheter ablation in PsAF, facilitate preoperative evaluation as well as the postoperative follow-up, and may also help generate personalized therapeutic strategies.

Browse more recent preprints

Recently published in scholarly journals

Browse more published preprints

How it works

Upload or create your research work
You can upload Word, PDF, LaTeX as well as data, code, Jupyter Notebooks, videos, and figures. Or start a document from scratch.
Disseminate your research rapidly
Post your work as a preprint. A Digital Object Identifier (DOI) makes your research citeable and discoverable immediately.
Get published in a refereed journal
Track the status of your paper as it goes through peer review. When published, it automatically links to the publisher version.
Learn More
Featured communities
Explore More Communities

Other benefits of Authorea

Multidisciplinary

A repository for any field of research, from Anthropology to Zoology

Comments

Discuss your preprints with your collaborators and the scientific community

Interactive Figures

Not just PDFs. You can publish d3.js and Plot.ly graphs, data, code, Jupyter notebooks

Featured templates
Featured and interactive
Journals with direct submission
Explore All Templates