Introduction: Acute pulmonary embolism (aPE) is frequently associated with coronavirus infectious disease-2019 (COVID-19) with an incidence of more than 16%. Among the new promising biomarkers of aPE, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) showed correlations with aPE prognosis. The aim of this study was to conduct an exploratory analysis to check the possible role of cell blood count (CBC) parameters as diagnostic and prognostic biomarkers of aPE in COVID-19 patients. Materials and Methods: A case control study was conducted. Two populations were compared: (i) patients hospitalised from 31 January 2020 to 30 June 2021 with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection and aPE confirmed at angio computed tomography (aCT) or pulmonary scintigraphy (COVID-19 aPE group); (ii) patients hospitalised from 31 January 2017 to 30 June 2021 without SARS-CoV-2 infection whose suspicion of aPE was excluded by aCT or pulmonary scintigraphy (no-aPE group). Results: Overall, 184 patients were included in the study, 83 in COVID-19 aPE group and 101 in no-aPE group. At the univariate analysis, COVID-19 patients with aPE had higher NLR, PLR, neutrophil and lymphocyte counts than patients without aPE (p < 0.05). No significant difference was found in mean platelet volume and platelet counts. No difference in mortality rate was detected. At the multivariate analysis, neutrophil and lymphocyte counts were both associated with diagnostic of aPE while no CBC parameters were associated with mortality at day#7. Conclusions: Neutrophiland lymphocyte counts could be predictors of the early detection of aPE in COVID-19 patients. The value of CBC indices as biomarkers of aPE in daily clinical practice needs to be investigated in further studies.

UNASSIGNED: Coronavirus disease 2019 is abbreviated as \"COVID-19\" caused by the severe acute respiratory syndrome-corona virus 2 first emerged in Wuhan, China, on December 2019. On 15th of March, this disease has been classified by the World Health Organization as a pandemic and a global public health emergency.
UNASSIGNED: The study\'s aim was to evaluate the knowledge and behavior toward the virus among professional students of Riyadh, Saudi Arabia.
UNASSIGNED: A cross-sectional study done on 753 students which were invited to complete a Google document using a 20-item electronic questionnaire that was design to gauge knowledge and attitude toward COVID-19. The study was conducted from February 20 to March 18, 2020 in Alkharj and Riyadh region.
UNASSIGNED: The predominant sex is male (73%), the common age is <25 years old, more medical students were involved in the study than any other specialty and the predominant educational degree of the participants was bachelors. The awareness of mode of transmission of novel coronavirus infection is less in business administration participants compare to others and is highly significant (P ˂ 0.001). Most of the participants (588 [98%]) were aware of coronavirus but only 302 (50%) of respondents are aware of COVID-19 which is highly significant (P ˂ 0.001).
UNASSIGNED: The results are mostly uniform among different professional students with the exception of some knowledge-related questions. The Internet was the main source of information, so there is a need to create more awareness about COVID-19 through social media.

BACKGROUND: Aim of this study is to analyse the characteristics of ventilator-associated pneumonia (VAP) inpatients infected by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2).
METHODS: A retrospective study was conducted, including coronavirus infectious disease 2019 (COVID-19) patients who developed VAP from March to May 2020 (VAP COVID-19). They were compared to non-COVID-19 patients who developed VAP from January 2011 to December 2019 (VAP NO COVID-19) and COVID-19 patients who did not develop VAP (NO VAP COVID-19).
RESULTS: Overall, 42 patients were included in the VAP COVID-19group, 37 in the NO VAP COVID-19 group, and 188 in the VAP NO COVID-19 group. VAP COVID-19 had significantly higher rates of shock (71% vs. 48%, p = 0.009), death in ICU (52% vs. 30%, p = 0.011), VAP recurrence (28% vs. 4%, p < 0.0001), positive blood culture (26% vs. 13%, p = 0.038), and polymicrobial culture (28% vs. 13%, p = 0.011) than VAP NO COVID-19. At the multivariate analysis, death in patients with VAP was associated with shock (p = 0.032) and SARS-CoV-2 (p = 0.008) infection.
CONCLUSIONS: VAP in COVID-19 patients is associated with shock, bloodstream, and polymicrobial infections.

This laboratory study was done to evaluate the efficacy of personal protective equipment (PPE) and high-volume evacuation (HVE) against the spread of human coronavirus type 229E (HCoV-229E) during a standard dental procedure.
Patient and operator manikins were used to recreate a dental setting inside a custom-built class III cabinet-like chamber. The mouth of the patient manikin was inoculated with an HCoV-229E suspension, the viral load of which was similar to that of asymptomatic people infected with severe acute respiratory syndrome coronavirus 2. The dental procedure was performed with an air turbine handpiece and HVE for 10 seconds. The efficacy of surgical masks, N95 (filtering facepiece class 2) and filtering facepiece class 3 respirators, and face shields was tested via quantitative real-time polymerase chain reaction.
The wide surface on which the inoculum was spread caused low contamination. Over the external surfaces of masks and respirators, when a face shield was not worn, viral loads ranged from 1.2 through 1.4 log10 mean gene copies per cm2. When the shield was worn, viral loads dropped below the detection limit (< 0.317 log10 gene copies/cm2) for all PPE. On the operator\'s forehead, viral loads were 0.6 through 0.8 log10 gene copies/cm2. Inside the operator manikin\'s mouth, viral loads were under the detection limit when using any PPE, with or without the shield. HVE did not significantly change viral loads.
All PPE combinations significantly reduced viral loads in the operator manikin\'s mouth to below the detection limit, but HVE did not decrease viral contamination.
Although caution is suggested when removing and disposing of PPE to avoid self-contamination, the combination of PPE and face shields drastically decreases the risk of transmitting human coronavirus during aerosol-generating dental procedures.

Severe acute respiratory syndrome-coronavirus 2, a novel betacoronavirus, has caused the global outbreak of a contagious infection named coronavirus disease-2019. Severely ill subjects have shown higher levels of pro-inflammatory cytokines. Cytokine storm is the term that can be used for a systemic inflammation leading to the production of inflammatory cytokines and activation of immune cells. In coronavirus disease-2019 infection, a cytokine storm contributes to the mortality rate of the disease and can lead to multiple-organ dysfunction syndrome through auto-destructive responses of systemic inflammation. Direct effects of the severe acute respiratory syndrome associated with infection as well as hyperinflammatory reactions are in association with disease complications. Besides acute respiratory distress syndrome, functional impairments of the cardiovascular system, central nervous system, kidneys, liver, and several others can be mentioned as the possible consequences. In addition to the current therapeutic approaches for coronavirus disease-2019, which are mostly supportive, stem cell-based therapies have shown the capacity for controlling the inflammation and attenuating the cytokine storm. Therefore, after a brief review of novel coronavirus characteristics, this review aims to explain the effects of coronavirus disease-2019 cytokine storm on different organs of the human body. The roles of stem cell-based therapies on attenuating cytokine release syndrome are also stated.

Ventilatory support is vital for the management of severe forms of COVID-19. Non-invasive ventilation is often used in patients who do not meet criteria for intubation or when invasive ventilation is not available, especially in a pandemic when resources are limited. Despite non-invasive ventilation providing effective respiratory support for some forms of acute respiratory failure, data about its effectiveness in patients with viral-related pneumonia are inconclusive. Acute respiratory distress syndrome caused by severe acute respiratory syndrome-coronavirus 2 infection causes life-threatening respiratory failure, weakening the lung parenchyma and increasing the risk of barotrauma. Pulmonary barotrauma results from positive pressure ventilation leading to elevated transalveolar pressure, and in turn to alveolar rupture and leakage of air into the extra-alveolar tissue. This article reviews the literature regarding the use of non-invasive ventilation in patients with acute respiratory failure associated with COVID-19 and other epidemic or pandemic viral infections and the related risk of barotrauma.

The mutation pattern of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has changed constantly during worldwide community transmission of this virus. However, the reasons for the changes in mutation patterns are still unclear. Accordingly, in this study, we present a comprehensive analysis of over 300 million peptides derived from 13,432 SARS-CoV-2 strains harboring 4,420 amino acid mutations to analyze the potential selective pressure of the host immune system and reveal the driver of mutations in circulating SARS-CoV-2 isolates. The results showed that the nonstructural protein ORF1ab and the structural protein Spike were most susceptible to mutations. Furthermore, mutations in cross-reactive T-cell epitopes between SARS-CoV-2 and seasonal human coronavirus may help SARS-CoV-2 to escape cellular immunity under long-term and large-scale community transmission. Additionally, through homology modeling and protein docking, mutations in Spike protein may enhance the ability of SARS-CoV-2 to invade host cells and escape antibody-mediated B-cell immunity. Our research provided insights into the potential mutation patterns of SARS-CoV-2 under natural selection, improved our understanding of the evolution of the virus, and established important guidance for potential vaccine design.

BACKGROUND: The severe acute respiratory syndrome-like disease coronavirus disease 2019 (COVID-19) is a disastrous global pandemic with 16,288,490 infected cases and 649,884 deaths. Until now, no effective treatments are found.
METHODS: The virus uses the 3-chymotrypsin-like protease for inducing the activity of the viral polyproteins and the spike (S) glycoprotein for human cell entry through the human angiotensin-converting enzyme 2 receptor. Blocking the active binding sites of these molecules might be beneficial for decreasing the activity of the virus and suppressing the viral entry to the human cells. Here, docking methods were used to identify a group of ligands may perform the blocking operations.
RESULTS: The results revealed the strongest binding affinities, sorted high to low, for tadalafil (Cialis) (phosphodiesterase type 5 inhibitor, tirofiban (antiplatelet), paraxanthine (central nervous system stimulant), dexamethasone, gentian violet cation (triphenylmethane), salbutamol, and amlodipine (calcium channel blocker).
CONCLUSIONS: These substances may provide vital help for further clinical investigation in fighting against the current global pandemic of the COVID-19.

Coronavirus 19 (COVID-19) is an extremely transmittable microbial infection that has emerged in Wuhan (China) in late 2019, leading to severe acute respiratory syndrome coronavirus 2 syndrome, and caused a pandemic all over the globe. This study is a systematic review of all 927 clinical trial studies performed worldwide from the beginning of the COVID-19 mysterious pandemic in China. These researches have registered in different databases. According to the best of our knowledge, China (74.82%), the United States (4.49%), and France (2.72%) have the most significant number of clinical trials, respectively. Clinical trials can be randomized or nonrandomized. Due to our results, 32.58% of studies were randomized, and 7.12% were not randomized. Most of the studies were open-labeled studies (22.44%), and double-blinded (4.42%) and quadruple blinded (2.48%) studies stand in second and third place regarding the number of trials, respectively. The direction and quantity of clinical trials attempted to identify a possible cure for COVID-19 demonstrates the depth of this crisis. As we are writing this article, a significant international endeavor will find a cure or vaccine for containing this devastating and mysterious disease.

The coronavirus disease 2019 (COVID 19) pandemic has presented major challenges to ophthalmologists. Reports have shown that ocular manifestations can be the first presenting symptoms of COVID 19 infection and conjunctiva may be a portal of entry for the severe acute respiratory syndrome (SARS) associated coronavirus 2 (SARS CoV 2). The purpose of this article is to provide general guidance for ophthalmologists to understand the prevalence of ocular presentation in COVID 19 patients and to reduce the risk of transmission during practice. Relevant studies published in the period of November 1, 2019, and July 15, 2020, regarding ocular manifestations of COVID 19 and detection of SARS CoV 2 in the eye were included in this systematic review and meta analysis. The pooled prevalence of the ocular manifestations has been estimated at 7% (95% confidence interval [CI]: 0.03-0.10) among COVID 19 patients. The pooled detection rate of SARS CoV 2 from conjunctiva was low (1%, 95% CI: 0.00-0.03). Conjunctival symptoms were the most common ocular manifestations in COVID 19, but the positive detection rate of the SARS CoV 2 virus by reverse transcription-polymerase chain reaction of conjunctival tears or secretions remained low. No study has shown a definite transmission of COVID 19 through ocular mucosa or secretions. In summary, ocular manifestations in COVID 19 patients commonly comprise ocular surface symptoms. Although a low prevalence of ocular symptoms was encountered among patients infected by SARS CoV 2, it is imperative for all ophthalmologists to understand the full spectrum of COVID 19 symptoms or signs including those of the eyes as well as to adopt appropriate protective measures during clinical practice.