Publications by authors named "Amir Masoud Afsahi"

4 Publications

  • Page 1 of 1

Late Complications of COVID-19; a Systematic Review of Current Evidence.

Arch Acad Emerg Med 2021 20;9(1):e14. Epub 2021 Jan 20.

Department of Global Health and Socioepidemiology, Graduate School of Medicine, Kyoto University, Kyoto. Japan.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7927752PMC
January 2021

Reinfection risk of novel coronavirus (COVID-19): A systematic ‎review of current evidence.

World J Virol 2020 Dec;9(5):79-90

Université Aix-Marseille, Institutde Neuro-physiopathologie (INP), UMR 7051, Faculté de ‎Pharmacie, 27 Bd Jean Moulin, Marseille 546789235, France.

Background: There is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients.

Aim: To summarize the recent findings and reports of CoVID-19 reinfection in patients previously reCoVered from the disease.

Methods: This study was a systematic review of current evidence conducted in August 2020. The authors studied the probable reinfection risk of novel coronavirus (CoVID-19). We performed a systematic search using the keywords in online databases. The investigation adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the reliability and validity of this study and results.

Results: We reviewed 31 studies. Eight studies described reCoVered patients with reinfection. Only one study reported reinfected patients who died. In 26 studies, there was no information about the status of the patients. Several studies indicated that reinfection is not probable and that post-infection immunity is at least temporary and short.

Conclusion: Based on our review, we concluded that a positive polymerase chain reaction retest could be due to several reasons and should not always be considered as reinfection or reactivation of the disease. Most relevant studies in positive retest patients have shown relative and probably temporary immunity after the reCoVery of the disease.
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http://dx.doi.org/10.5501/wjv.v9.i5.79DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7747024PMC
December 2020

Assessment of mechanical properties of articular cartilage with quantitative three-dimensional ultrashort echo time (UTE) cones magnetic resonance imaging.

J Biomech 2020 12 24;113:110085. Epub 2020 Oct 24.

Department of Radiology, University of California San Diego, San Diego, CA 92093, USA. Electronic address:

Conventional magnetic resonance imaging (MRI) is not capable of detecting signal from the deep cartilage due to its short transverse relaxation time (T2). Moreover, several quantitative MRI techniques are significantly influenced by the magic angle effect. The combinations of ultrashort echo time (UTE) MRI with magnetization transfer (UTE-MT) and Adiabatic T (UTE-AdiabT) imaging allow magic angle-insensitive assessments of all regions of articular cartilage. The purpose of this study was to investigate the correlations between quantitative three-dimensional UTE MRI biomarkers and mechanical properties of human tibiofemoral cartilage specimens. In total, 40 human tibiofemoral cartilage specimens were harvested from three male and four female donors (64 ± 18 years old). Cartilage samples were scanned using a series of quantitative 3D UTE Cones T* (UTE-T*), T (UTE-T), UTE-AdiabT, and UTE-MT sequences in a standard knee coil on a clinical 3T scanner. UTE-MT data were acquired with a series of MT powers and frequency offsets to calculate magnetization transfer ratio (MTR), as well as macromolecular fraction (MMF) and macromolecular T (Tmm) through modeling. Cartilage stiffness and Hayes elastic modulus were measured using indentation tests. Correlations of 3D UTE Cones MRI measurements in the superficial layer, deep layer, and global regions of interest (ROIs) with mechanical properties were investigated. Cartilage mechanical properties demonstrated highest correlations with UTE measures of the superficial layer of cartilage. AdiabT, MTR, and MMF in superficial layer ROIs showed significant correlations with Hayes elastic modulus (p < 0.05, R = -0.54, 0.49, and 0.66, respectively). These UTE measures in global ROIs showed significant, though slightly lower, correlations with Hayes elastic modulus (p < 0.05, R = -0.37, 0.52, and 0.60, respectively). Correlations between other UTE MRI measurements (T*, T, and Tmm) and mechanical properties were non-significant. The 3D UTE-AdiabT and UTE-MT sequences were highlighted as promising surrogates for non-invasive assessment of cartilage mechanical properties. MMF from UTE-MT modeling showed the highest correlations with cartilage mechanics.
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http://dx.doi.org/10.1016/j.jbiomech.2020.110085DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7890416PMC
December 2020

Predictors of mortality in patients with COVID-19-a systematic review.

Eur J Integr Med 2020 Dec 17;40:101226. Epub 2020 Oct 17.

School of Public Health, Central Michigan University, Mount Pleasant, MI, 48859, United States.

Introduction: In the current COVID-19 pandemic, disease diagnosis is essential for optimal management and timely isolation of infected cases in order to prevent further spread. The aim of this study was to systematically review the assessment of risk and model the predictors of mortality in COVID-19 patients.

Methods: A systematic search was conducted of PubMed, Scopus, Embase, Google Scholar, and Web of Science databases. Variables associated with hospital mortality using bivariate analysis were included as potential independent predictors associated with mortality at the  < 0.05 levels.

Results: We included 114 studies accounting for 310,494 patients from various parts of the world. For the purpose of this analysis, we set a cutoff point of 10% for the mortality percentages. High mortality rates were defined as higher than 10% of confirmed positive cases and were given a score of two, while low mortality (<10%) was assigned the score of one. We then analyzed the associations between 72 variables and the observed mortality rates. These variables included a large range of related variables such as demographics, signs and symptoms and related morbidities, vital signs, laboratory findings, imaging studies, underlying diseases, and the status of countries' income, based on the United Nation's classifications.

Conclusion: Findings suggest that older age, hypertension, and diabetes mellitus conferred a significant increased risk of mortality among patients with COVID-19. In the multivariate analysis, only diabetes mellitus demonstrated an independent relationship with increased mortality. Further studies are needed to ascertain the relationship between possible risk factors with COVID-19 mortality.
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http://dx.doi.org/10.1016/j.eujim.2020.101226DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568488PMC
December 2020