Exhaled breath samples had the highest positive rate (26.9%, n=52), followed by surface swabs (5.4%, n=242), and air samples (3.8%, n=26). COVID-19 patients recruited in Beijing exhaled millions of SARS-CoV-2 RNA copies into the air per hour. Exhaled breath emission may play an important role in the COVID-19 transmission.

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Despite notable efforts in airborne SARS-CoV-2 detection, no clear evidence has emerged to show how SARS-CoV-2 is emitted into the environments. Here, 35 COVID-19 subjects were recruited; exhaled breath condensate (EBC), air samples and surface swabs were collected and analyzed for SARS-CoV-2 using reverse transcription-polymerase chain reaction (RT-PCR). EBC samples had the highest positive rate (16.7%, n=30), followed by surface swabs (5.4%, n=242), and air samples (3.8%, n=26). COVID-19 patients were shown to exhale SARS-CoV-2 into the air at an estimated rate of 103-105 RNA copies/min; while toilet and floor surfaces represented two important SARS-CoV-2 reservoirs. Our results imply that airborne transmission of SARS-CoV-2 plays a major role in COVID-19 spread, especially during the early stages of the disease.

BackgroundCyclin-dependent kinase inhibitor 2A/2B (CDKN2A/2B) near chromosome 9p21 have been associated with both atherosclerosis and artery calcification, but the underlying mechanisms remained largely unknown. Considering that CDKN2A/2B is a frequently reported site for DNA methylation, this study aimed to evaluate whether carotid artery calcification (CarAC) is related to methylation levels of CDKN2A/2B in patients with ischemic stroke.MethodsDNA methylation levels of CDKN2A/2B were measured in 322 ischemic stroke patients using peripheral blood leukocytes. Methylation levels of 36 CpG sites around promoter regions of CDKN2A/2B were examined with BiSulfite Amplicon Sequencing. CarAC was quantified with Agatston score based on results of computed tomography angiography. Generalized liner model was performed to explore the association between methylation levels and CarAC.ResultsOf the 322 analyzed patients, 187 (58.1%) were classified as with and 135 (41.9%) without evident CarAC. The average methylation levels of CDKN2B were higher in patents with CarAC than those without (5.7 vs 5.4, p = 0.001). After adjustment for potential confounders, methylation levels of CDKN2B were positively correlated with cube root transformed calcification scores (β = 0.591 ± 0.172, p = 0.001) in generalized liner model. A positive correlation was also detected between average methylation levels of CDKN2B and cube root transformed calcium volumes (β = 0.533 ± 0.160, p = 0.001).ConclusionsDNA methylation of CDKN2B may play a potential role in artery calcification.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-1093-4) contains supplementary material, which is available to authorized users.

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Our findings indicate that dietary fiber intake is inversely associated with risk of Barrett's esophagus and esophageal cancer. Further large prospective studies are warranted.

Aim: CDKN2A/2B near chromosome 9p21 has been proposed as a potential genetic etiology for both atherosclerosis and arterial calcification. DNA methylation, which can change the expression of CDKN2A/2B, may be an underlying mechanism for this association. This study aimed to evaluate whether CDKN2A/2B methylation is related to aortic arch calcification (AAC) in patients with ischemic stroke.Methods: DNA methylation levels of CDKN2A/2B was measured using venous blood samples in 322 patients with ischemic stroke. A total of 36 CpG sites around promoter regions of CDKN2A/2B were examined. AAC was quantified with Agatston score based on results of computed tomography angiography.Results: There were 248 (77.0%) patients with and 74 (23.0%) patients without evident AAC. Compared with patients without AAC, patients with AAC had higher methylation levels of CDKN2B (5.72 vs 4.94, P < 0.001). Using a generalized linear model, positive correlation between methylation levels and log-transformed calcification scores was detected at CDKN2B (β = 0.275 ± 0.116, P = 0.018).Conclusion: Patients with higher levels of DNA methylation of CDKN2B may bear increased risk for AAC. Further studies to reveal the underlying mechanisms of this association are warranted for establishing a cause–effect relationship.

BackgroundThe COVID-19 pandemic and physical distancing guidelines have compelled stroke practices worldwide to reshape their delivery of care significantly. We aimed to illustrate how the stroke services were interrupted during the pandemic in China.MethodsA 61-item questionnaire designed on Wenjuanxing Form was completed by doctors or nurses who were involved in treating patients with stroke from 1 February to 31 March 2020.ResultsA total of 415 respondents completed the online survey after informed consent was obtained. Of the respondents, 37.8%, 35.2% and 27.0% were from mild, moderate and severe epidemic areas, respectively. Overall, the proportion of severe impact (reduction >50%) on the admission of transient ischaemic stroke, acute ischaemic stroke (AIS) and intracerebral haemorrhage (ICH) was 45.0%, 32.0% and 27.5%, respectively. Those numbers were 36.9%, 27.9% and 22.3%; 36.5%, 22.1% and 22.6%; and 66.4%, 47.5% and 41.1% in mild, moderate and severe epidemic areas, respectively (all p<0.0001). For AIS, thrombolysis was moderate (20%–50% reduction) or severely impacted (>50%), as reported by 54.4% of the respondents, while thrombectomy was 39.3%. These were 44.4%, 26.3%; 44.2%, 39.4%; and 78.2%, 56.5%, in mild, moderate and severe epidemic areas, respectively (all p<0.0001). For patients with acute ICH, 39.8% reported the impact was severe or moderate for those eligible for surgery who had surgery. Those numbers were 27.4%, 39.0% and 58.1% in mild, moderate and severe epidemic areas, respectively. For staff resources, about 20% (overall) to 55% (severe epidemic) of the respondents reported moderate or severe impact on the on-duty doctors and nurses.ConclusionWe found a significant reduction of admission for all types of patients with stroke during the pandemic. Patients were less likely to receive appropriate care, for example, thrombolysis/thrombectomy, after being admitted to the hospital. Stroke service in severe COVID-19 epidemic areas, for example, Wuhan, was much more severely impacted compared with other regions in China.