ABSTRACT
Background: COVID-19 is a respiratory infection brought about by SARS-COV-2. Most of the patients contaminated by this pathogen are afflicted by respiratory syndrome with multiple stages ranging from mild upper respiratory involvement to severe dyspnea and acute respiratory distress syndrome cases. Keeping in mind the high sensitivity of computed tomography (CT) scan in detecting abnormalities, it became the number one modality in COVID-19 diagnosis. A wide diversity of CT features can be found in COVID-19 cases, which can be observed before the onset of clinical signs. The review article is aimed to highlight recent discrepancies in CT-scan and chest X-ray (CXR) characteristics between COVID-19 and Middle East Respiratory Syndrome (MERS). Method: This review study was performed in the literature from the beginning of COVID-19 until the middle of April 2021. For this reason, all relevant works through scientific citation websites such as Google Scholar, PubMed, and Web of Science have been investigated in the mentioned period. Results: COVID-19 was more reproductive than MERS, while MERS was significantly higher in terms of mortality rate (COVID-19: 2.3% and MERS: 34.4%). Signs of ground-glass opacity (GGO), peripheral consolidation, and GGO accompanying with consolidation are the same signs CXR in both MERS and COVID-19. Indeed, fever, cough, headache, and sore throat are the most symptoms in all studied patients. Conclusion: Both COVID-19 and MERS have the same imaging signs. The most similar chest CT findings are GGO, peripheral consolidation, and GGO superimposed by consolidation in both studied diseases, and no statistical differences were seen among the mean number of chest CT-scans in MERS and COVID-19 cases.
ABSTRACT
OBJECTIVE: Polydopamine coated iron oxide nanoparticles (Fe3O4@PDA NPs) were synthesized, characterized, and their MR imaging contrast agents and photothermal potency were evaluated on melanoma (B16-F10 and A-375) cells and normal skin cells. To this end, MTT assay, Fe concentration, and MR imaging of both coated and uncoated NPs were assessed in C57BL/6 mice. METHODS: Fe3O4 nanoparticles were synthesized using co-precipitation, and coated with polydopamine. The cytotoxicity of Fe3O4 and Fe3O4@PDA NPs on melanoma cells, with different concentrations, were obtained using MTT assay. MR images and Fe concentrations of nanoprobe and nanoparticles were evaluated under in vivo conditions. RESULTS: Findings indicated that uncoated Fe3O4 showed the highest toxicity in animal (B16-F10) cells at 450µg/ml after 72h, while the highest toxicity in human (A-375) cells were observed at 350µg/ml. These nanoparticles did not reveal any cytotoxicity to normal skin cells, despite having some toxicity features in A-375 cells. MR image signals in the tumor were low compared with other tissues. The iron concentration in the tumor was higher than that of other organs. CONCLUSION: It is concluded that the cytotoxicity of Fe3O4@PDA was found to be significantly lower than uncoated nanoparticles (p <0.001), which allows some positive effects on reducing toxicity. The prepared nanoprobe may be used as a contrast agent in MR imaging.
