Mechanistic transmission modeling of COVID-19 on the Diamond Princess cruise ship demonstrates the importance of aerosol transmission.

Several lines of existing evidence support the possibility of airborne transmission of coronavirus disease 2019 (COVID-19). However, quantitative information on the relative importance of transmission pathways of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains limited. To evaluate the relative importance of multiple transmission routes for SARS-CoV-2, we developed a modeling framework and leveraged detailed information available from the Diamond Princess cruise ship outbreak that occurred in early 2020. We modeled 21,600 scenarios to generate a matrix of solutions across a full range of assumptions for eight unknown or uncertain epidemic and mechanistic transmission factors. A total of 132 model iterations met acceptability criteria (R2 > 0.95 for modeled vs. reported cumulative daily cases and R2 > 0 for daily cases). Analyzing only these successful model iterations quantifies the likely contributions of each defined mode of transmission. Mean estimates of the contributions of short-range, long-range, and fomite transmission modes to infected cases across the entire simulation period were 35%, 35%, and 30%, respectively. Mean estimates of the contributions of larger respiratory droplets and smaller respiratory aerosols were 41% and 59%, respectively. Our results demonstrate that aerosol inhalation was likely the dominant contributor to COVID-19 transmission among the passengers, even considering a conservative assumption of high ventilation rates and no air recirculation conditions for the cruise ship. Moreover, close-range and long-range transmission likely contributed similarly to disease progression aboard the ship, with fomite transmission playing a smaller role. The passenger quarantine also affected the importance of each mode, demonstrating the impacts of the interventions.

The effects of carvedilol, metoprolol and propranolol on cisplatin-induced kidney injury.

The ß-adrenoceptor blockers may have anti-oxidant properties or induce ß-arrestin recruitment beyond classical desensitization of receptor/G protein coupling, offering potential therapeutic benefits. Here, we investigated the effects of carvedilol, metoprolol and propranolol in an animal model of cisplatin-induced nephrotoxicity. Rats received the ß-blockers (3 or 12 mg/kg/day) with or without cisplatin, and kidney function was investigated using renal scintigraphy, histopathology, and serum variables. Metoprolol and propranolol as well as low-dose carvedilol did not alter kidney function, per se. Meanwhile, high-dose carvedilol reduced renal accumulation of Technetium-99m (99mTc)-labeled dimercaptosuccinic acid (99mTc-DMSA) without significant effect on other variables. Furthermore, low-dose carvedilol prevented cisplatin-induced reduction of tracer uptake, but high-dose of this drug aggravated the situation. In this regard, both low and high -doses of carvedilol significantly inhibited cisplatin effects on kidney histology, BUN and creatinine levels. Also, high-dose propranolol inhibited cisplatin adverse effects on radiotracer uptake, histological manifestations, BUN and creatinine levels, while metoprolol failed to cause a notable effect. Taken together, carvedilol and high-dose propranolol may offer potential benefits in cisplatin nephrotoxicity.

Estimating the nationwide transmission risk of measles in US schools and impacts of vaccination and supplemental infection control strategies.

BACKGROUND: The spread of airborne infectious diseases such as measles is a critical public health concern. The U.S. was certified measles-free in 2000, but the number of measles cases has increased in recent years breaking the record of the nationwide annual number of cases since 1992. Although the characteristics of schools have made them one of the most vulnerable environments during infection outbreaks, the transmission risk of measles among students is not completely understood. We aimed to evaluate how three factors influence measles transmission in schools: personal (vaccination), social (compartmentalizing), and building systems (ventilation, purification, and filtration). METHODS: We used a combination of a newly developed multi-zone transient Wells-Riley approach, a nationwide representative School Building Archetype (SBA) model, and a Monte-Carlo simulation to estimate measles risk among U.S. students. We compared our risk results with the range of reported transmission rates of measles in school outbreaks to validate the risk model. We also investigated the effectiveness of vaccination and ten supplemental infection control scenarios for reducing the risk of measles transmission among students. RESULTS: Our best nationwide estimate of measles transmission risk in U.S. schools were 3.5 and 32% among all (both unvaccinated and immunized) and unvaccinated students, respectively. The results showed the transmission risk of measles among unvaccinated students is > 70 times higher than properly immunized ones. We also demonstrated that the transmission risk of measles in primary schools (assuming teacher self-contained classrooms) is less than secondary schools (assuming departmentalized systems). For building-level interventions, schools with ductless-with-air-filter and ductless-without-air-filter systems have the lowest and highest transmission risks of measles, respectively. Finally, our simulation showed that infection control strategies could cut the average number of infected cases among all students in half when a combination of advanced air filtration, ventilation, and purification was adopted in the modeled schools. CONCLUSIONS: Our results highlight the primary importance of vaccination for reducing the risk of measles transmission among students. Yet, additional and significant risk reduction can be achieved through compartmentalizing students and enhancing building ventilation and filtration systems.

Correction to: Estimating the nationwide transmission risk of measles in US schools and impacts of vaccination and supplemental infection control strategies.

An amendment to this paper has been published and can be accessed via the original article.

Vascular endothelial growth factor expression and vascular density in oral squamous cell carcinoma (OSCC): A study on clinical and histopathologic significance.

BACKGROUND: New blood vessels formation is a critical step in tumor progression. Vascular density affects the clinical outcome and prognosis of malignant tumors. The aim of this study was to investigate the relation between the Vascular Endothelial Growth Factor (VEGF) expression and vascular density with the clinical and histopathologic features in oral squamous cell carcinoma (OSCC). METHODS: In this retrospective study, 22 paraffin embedded block of well-differentiated OSCC were examined immunohistochemically for VEGF expression. Vascular density was determined by counting the blood vessels in 6 fields with 100 (HPF) on hematoxylin-eosin stained slides. The relation between the VEGF expression and vascular density with clinical and histopathologic features were analyzed by t-test, ANOVA, and Chi-square tests. RESULTS: A significant relation between gender (P=0.06) and tumor size (p=0.05) with vascular density was obtained. The relation between VEGF expression and gender (p=0.41), age (p=0.35), lymph node involvement (p=0.38), tumor size (p=0.15) and tumor differentiation (p=0.34) was not significant. The relation between vascular density and age (p=0.55), lymph node involvement (p=0.20), and tumor differentiation (p=0.80) was not significant. CONCLUSION: Blood vessels formation relates to tumor size. Controlling the tumor size by manipulating the blood vessels formation may contribute to the inhibition of tumor progression in malignant tumors.

Non-alcoholic fatty liver disease and dairy products consumption: Results from FASA Persian cohort study.

Background/objectives: There are limited data on the association between dairy products consumption and nonalcoholic fatty liver disease (NAFLD). This study was conducted to evaluate the association between total intake of different dairy products and fatty liver index (FLI), a marker of subclinical fatty liver. Methods: A total of 7,540 adults were included in this population-based cohort study. Dairy products consumption was evaluated by a validated interview questionnaire for food intake frequency. The FLI was calculated using the standard formula. Liver enzyme levels, lipid profiles, glycemic profiles and demographic characteristics were recorded for all participants. Univariate and multiple logistic regression models were used to respectively assess the mean percentage difference of mean FLI and odds ratios (ORs) for subclinical NAFLD across quantiles of dairy consumption. Results: The mean age of all participants was 48.81 ± 9.631 years. FLI measurements for men and women were 26.71 ± 23.39 and 39.99 ± 26.64 respectively, which was significantly higher in women (P < 0.05). Multiple logistic regression analysis demonstrated that the amount of milk consumption was an independent preventive predictor of FLI (OR = 0.96; 95% CI: 0.94-0.99), conversely, it did not predict higher levels of liver enzymes. In term of cheese intake, participants in the third tertile of cheese intake had significantly lower FLI than lower tertiles (P = 0.01). However, there wasn't any significant association between cheese intake and the odds of FLI in the multivariate model (P > 0.05). We didn't find any significant association between yogurt consumption and NAFLD indicators (P > 0.05). Conclusion: Higher milk consumption was inversely associated with FLI. However, there wasn't any significant association between other types of dairy products and NAFLD indicators.

TLR2 and TLR4 mRNA expression levels in liver transplant patients with acute rejection.

Toll-like receptors (TLRs) have important role in transplant outcomes by activating the innate immune system and production of pro-inflammatory cytokines, leading to graft rejection. We assessed the expression level of TL2 and TLR4 in acute rejection (AR) on the 1st and 7th-day post-transplantation. TLR2 and TLR4 expressions were evaluated by real-time PCR in both the AR group (n = 50) and non-AR (n = 50), compared with the control group. Also, the correlation of the expression levels of TLRs between both the 1st and 7th day was analyzed. ROC curve analysis was used to determine the cut-off value for TLRs expression. TLR4 mRNA expression was significantly up-regulated in AR patients vs. the controls on the 1st day (p ≤ 0.05) and it was down-regulated in non-AR vs. controls on the 1st day (p ≤ 0.05). Also, TLR4 expression had decreased in both AR and non-AR groups vs. control on the 7th day (p ≤ 0.05). Both TLR2 and TLR4 expression in comparison to non-AR had increased in the AR group on the 7th day (p ≤ 0.05). TLR2 expression positively correlated between 1st and 7th day in AR (r = 0.3, (p ≤ 0.05) and non-AR group (r = 0.2, p ≤ 0.05). ROC curve analysis showed a cut-off value of TLR2 up to 0.98 with sensitivity 71.05 (95%CI = 54.1-84.6) and specificity 63.27 (95%CI = 48.3-76.6) that could distinguish between AR and non-AR group (p ≤ 0.05). The data support that both TLR2 and TLR4 expression have an effective role in AR after liver transplantation and could be used as possible biomarkers for AR to choose better therapeutic strategies based on immunological aspects.

An Unrecognized Hazard in E-Cigarette Vapor: Preliminary Quantification of Methylglyoxal Formation from Propylene Glycol in E-Cigarettes.

Up to 95% of the liquid volume in an e-cigarette consists of propylene glycol. Previous research has shown that propylene glycol can generate diacetyl and formaldehyde when heated. New research shows that propylene glycol can also generate methylglyoxal, an alpha di-carbonyl compound recently shown to cause epithelial necrosis at even lower concentrations than diacetyl, the flavoring chemical associated with bronchiolitis obliterans ("Popcorn Lung"). We analyzed chemical emissions from 13 JUUL pod flavors. Diacetyl and methylglyoxal was detected in 100% of samples with median concentration (range) of 20 µg/m3 (less than limit of quantification: 54 µg/m3) and 4219 µg/m3 (677-15,342 µg/m3), respectively. We also detected acetaldehyde (median concentration: 341 µg/m3) and propionaldehyde (median concentration: 87 µg/m3) in all samples. The recent evidence that methylglyoxal is more cytotoxic to airway epithelial cells than diacetyl makes this an urgent public health concern. Current smokers considering e-cigarettes as a smoking cessation tool, and never users, who may be under the impression that e-cigarettes are harmless, need information on emissions and potential risks to make informed decisions.

Obstructive Sleep Apnea: A Prediction Model Using Supervised Machine Learning Method.

Obstructive Sleep Apnea (OSA) is the most common breathing-related sleep disorder, leading to increased risk of health problems. In this study, we investigated and evaluated the supervised machine learning methods to predict OSA. We used popular machine learning algorithms to develop the prediction models, using a dataset with non-invasive features containing 231 records. Based on the methodology, the CRISP-DM, the dataset was checked and the blanked data were replaced with average/most frequented items. Then, the popular machine learning algorithms were applied for modeling and the 10-fold cross-validation method was used for performance comparison purposes. The dataset has 231 records, of which 152 (65.8%) were diagnosed with OSA. The majority was male (143, 61.9%). The results showed that the best prediction model with an overall AUC reached the Naïve Bayes and Logistic Regression classifier with 0.768 and 0.761, respectively. The SVM with 93.42% sensitivity and the Naïve Bayes of 59.49% specificity can be suitable for screening high-risk people with OSA. The machine learning methods with easily available features had adequate power of discrimination, and physicians can screen high-risk OSA as a supplementary tool.

Vascular endothelial growth factor and ki-67 antigen expression in relation to age and gender in oral squamous cell carcinoma.

BACKGROUND AND AIMS: Vascular endothelial growth factor (VEGF) and Ki-67 antigen are contributing factors in this process cell proliferation and new blood vessels formation in tumor progression. This study was conducted to examine the relationship between the expression of VEGF and Ki-67 and gender and age of patients with oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Twenty-three archival samples of well-differentiated OSCC were examined immunohisto-chemically and assessed by obtaining Total Score (TS = proportion score × staining index). For statistical analysis, t-test and Pearson's correlation were employed. P≤0.05 was considered statistically significant. RESULTS: The differences in VEGF expression between males and females (P = 0.43) and different ages (P = 0.88) were not significant. The differences in Ki-67 expression was between males and females (P = 0.67) and different ages (P = 0.88) were also not significant. A positive correlation of VEGF and Ki-67 expression was observed in males and females in addi-tion to ≤ 60 years age group (r = 0.22, r = 0.008, and r = 0.58, respectively; P < 0.05). The expression of VEGF had a nega-tive relation to Ki-67 in > 60 years group (r = -0.48, P < 0.05). CONCLUSION: The expression of VEGF and Ki-67 between males and females and different ages were not significant among oral squamous cell carcinoma cases evaluated.