COVID-19 diagnostic approaches with an extensive focus on computed tomography in accurate diagnosis, prognosis, staging, and follow-up.

Although a long time has passed since its outbreak, there is currently no specific treatment for COVID-19, and it seems that the most appropriate strategy to combat this pandemic is to identify and isolate infected individuals. Various clinical diagnosis methods such as molecular techniques, serologic assays, and imaging techniques have been developed to identify suspected patients. Although reverse transcription-quantitative PCR (RT-qPCR) has emerged as a reference standard method for diagnosis of SARS-CoV-2, the high rate of false-negative results and limited supplies to meet current demand are the main shortcoming of this technique. Based on a comprehensive literature review, imaging techniques, particularly computed tomography (CT), show an acceptable level of sensitivity in the diagnosis and follow-up of COVID-19. Indeed, because lung infection or pneumonia is a common complication of COVID-19, the chest CT scan can be an alternative testing method in the early diagnosis and treatment assessment of the disease. In this review, we summarize all the currently available frontline diagnostic tools for the detection of SARS-CoV-2-infected individuals and highlight the value of chest CT scan in the diagnosis, prognosis, staging, management, and follow-up of infected patients.

Effects of MRI on stemness properties of Wharton's jelly-derived mesenchymal stem cells.

Mesenchymal stem cells (MSCs), derived from various tissues, are served as a promising source of cells in clinic and regenerative medicine. Umbilical cord-Wharton's jelly (WJ-MSCs)-derived MSCs exhibit advantages over those from adult tissues, such as no ethical concerns, shorter population doubling time, broad differentiation potential, readily available non-invasive source, prolonged maintenance of stemness properties. The aim of this study was to evaluate the effect of MRI (1.5 T, 10 min) on stemness gene expression patterns (OCT-4, SOX-2, NANOG) of WJ-MSCs. Additionally, we assessed cell viability, growth kinetics and apoptosis of WJ-MSCs after MRI treatment. The quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) data showed that transcript levels of SOX-2, NANOG in MRI-treated WJ-MSCs were increased 32- and 213-fold, respectively. MTT assay was performed at 24, 48, and 72 h post-treatment and the viability was not significantly different between the two groups. The doubling time of the MRI group was markedly higher than the control group. In addition, the colony formation ability of WJ-MSCs after MRI treatment significantly increased. Furthermore, no change in apoptosis was seen before or after MRI treatment. Our results suggest that the use of MRI can improve the quality of MSCs and enhance the efficacy of mesenchymal stem cell-based therapies.

The effect of iodine-131 beta-particles in combination with A-966492 and Topotecan on radio-sensitization of glioblastoma: An in-vitro study.

Glioblastoma tumors are resistant to radiotherapy, and the need for drugs to induce radio-sensitization in tumor cells has always been a challenge. Besides, radiotherapy using targeted radionuclide would be effective even for resistant tumors. It has been shown topoisomerase I and poly (ADP-ribose) polymerase (PARP) enzymes have critical roles in the repair process of DNA injury in cells. Therefore, the inhibition of the activity of these enzymes can halt this process and result in the accumulation of damaged DNA in cells and the induction of cell death in tumors. In the present research, the impact of beta-particles of iodine-131 in combination with Topotecan (TPT), as the inhibitor of topoisomerase I, and A-966492, as the inhibitor of the PARP enzyme on the possible increase of radio-sensitivity of glioblastoma cells was assessed. For this purpose, a human glioblastoma cell line, U87MG, was cultured in flasks coated with Poly-Hema to achieve 300 µm-diameter spheroids. Then, nontoxic concentrations of A-966492 and TPT were applied in the cell culture media. The viability of the cells treated with iodine131 in combination with A-966492 and TPT was determined by the clonogenic assay. The expression rate of gamma-H2AX, as a biomarker of DNA double-strand breaks, was analyzed using immunofluorescence microscopy to unravel the effect of TPT, A-966492 (1 µM), and radiation on the cell death induction. The combination of each TPT or A-966492 with radiation resulted in the increased rate of cell death, and the ratios of sensitizer enhancement at 50% survival (SER50) were elevated by 1.45 and 1.25, respectively. Chemo- and radio-sensitization were promoted when iodine-131 was combined with A-966492 and TPT, with the SER50 of 1.68. Also, the expression of γ-H2AX was significantly increased in cells treated with A-966492 and TPT combined with radiation. The results demonstrated that iodine-131, in combination with A-966492 and TPT, had marked effects on radio-sensitizing and can be used as a targeted radionuclide for targeting radiotherapy in combination with topoisomerase I and PARP inhibitors to enhance radiotherapy in clinics.