, more than 3 million cases of coronavirus disease 2019 (COVID-19) and about 200,000 deaths have been reported worldwide. The outbreak of this novel disease has become a global health emergency and continues to rapidly spread around the world. Based on the clinical data, approved cases are divided into four classes including mild, moderate, severe, and critical. About 5% of cases were considered critically ill and 14% were considered to have the severe classification of the disease. In China, the fatality rate of this infection was about 4%. This review focuses on currently available information on the etiology, clinical symptoms, diagnosis, and mechanism of action of COVID-19. Furthermore, we present an overview of diagnostic approaches and treatment of this disease according to available findings. This review paper will help the physician to diagnose and successfully treat COVID-19.

In contrast to most vertebrates, invertebrate deuterostome echinoderms, such as the sea star Asterias rubens, undergo regeneration of lost body parts. The current hypothesis suggests that differentiated cells are the main source for regenerating arm in sea stars, but there is little information regarding the origin and identity of these cells. Here, we show that several organs distant to the regenerating arm responded by proliferation, most significantly in the coelomic epithelium and larger cells of the pyloric caeca. Analyzing markers for proliferating cells and parameters indicating cell ageing, such as levels of DNA damage, pigment, and lipofuscin contents as well as telomere length and telomerase activity, we suggest that cells contributing to the new arm likely originate from progenitors rather than differentiated cells. This is the first study showing that cells of mixed origin may be recruited from more distant sources of stem/progenitor cells in a sea star, and the first described indication of a role for pyloric caeca in arm regeneration. Data on growth rate during arm regeneration further indicate that regeneration is at the expense of whole animal growth. We propose a new working hypothesis for arm regeneration in sea stars involving four phases: wound healing by coelomocytes, migration of distant progenitor cells of mixed origin including from pyloric caeca, proliferation in these organs to compensate for cell loss, and finally, local proliferation in the regenerating arm.

BackgroundThe effect of tranexamic acid (TXA) on bleeding and improvement of surgical field during functional endoscopic sinus surgery (FESS) is not clear yet. This study was conducted to answer this question.MethodsThis trial was conducted on 60 patients with chronic sinusitis at Beasat Hospital, Hamadan, Iran, from April to November 2013. Thirty patients in the intervention group received three pledgets soaked with TXA 5% and phenylephrine 0.5% for 10 minutes in each nasal cavity before surgery. Thirty patients in the control group received phenylephrine 0.5% with the same way. The amount of bleeding and the quality of surgical field were evaluated at 15, 30, and 45 minutes after the start of surgery using Boezaart grading.ResultsThe quality of the surgical field in the intervention group compared to the control group was significantly better in the first quarter (P = 0.002) and the second quarter (P = 0.003) but not in the third quarter (P = 0.163). Furthermore, the amount of bleeding was much less during all periods in the intervention group than in the control group (P = 0.001).ConclusionTopical TXA can efficiently reduce bleeding and improve the surgical field in FESS in patients with rhinosinusitis. Based on these findings, topical TXA may be a useful method for providing a suitable surgical field during the first 30 minutes after use.Trial RegistrationIranian Registry of Clinical Trials IRCT201212139014N15

The average values of GIN differed significantly between children with a history of OME and normal controls (p < 0.001). The mean values of the DDT score were significantly different between the two groups (p = 0.002).

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