Incorporating Medical Museum Specimens Into the Training of Environmental Health Students.

Xenobiotics, radiation, and other environmental health risk factors leave their mark on human organs. This can be demonstrated through the use of pathology museum specimens. Upon completing two semesters of postgraduate studies in environmental health, a tour of the Museum of Pathology is offered to postgraduate students at Athens Medical School who are being trained in environmental health. A structured questionnaire is employed to assess the specimens' impact on several aspects: improving students' observational skills, reinforcing the taught material, acquiring new relevant knowledge, and cultivate the social-cognitive ability of empathy. Additionally, students are asked to evaluate the necessity of preserving metadata associated mainly with the social context of the specimens. This research-educational initiative, a component of an ongoing larger project, underscores the significant educational and research value of museum specimens pertaining to environmental health. Furthermore, effectively utilizing such exhibits can enrich the museum experience for visitors and increase public awareness of environmental health issues.

Mathematical modeling for Delta and Omicron variant of SARS-CoV-2 transmission dynamics in Greece.

A compartmental, epidemiological, mathematical model was developed in order to analyze the transmission dynamics of Delta and Omicron variant, of SARS-CoV-2, in Greece. The model was parameterized twice during the 4th and 5th wave of the pandemic. The 4th wave refers to the period during which the Delta variant was dominant (approximately July to December of 2021) and the 5th wave to the period during which the Omicron variant was dominant (approximately January to May of 2022), in accordance with the official data from the National Public Health Organization (NPHO). Fitting methods were applied to evaluate important parameters in connection with the transmission of the variants, as well as the social behavior of population during these periods of interest. Mathematical models revealed higher numbers of contagiousness and cases of asymptomatic disease during the Omicron variant period, but a decreased rate of hospitalization compared to the Delta period. Also, parameters related to the behavior of the population in Greece were also assessed. More specifically, the use of protective masks and the abidance of social distancing measures. Simulations revealed that over 5,000 deaths could have been avoided, if mask usage and social distancing were 20% more efficient, during the short period of the Delta and Omicron outbreak. Furthermore, the spread of the variants was assessed using viral load data. The data were recorded from PCR tests at 417 Army Equity Fund Hospital (NIMTS), in Athens and the Ct values from 746 patients with COVID-19 were processed, to explain transmission phenomena and disease severity in patients. The period when the Delta variant prevailed in the country, the average Ct value was calculated as 25.19 (range: 12.32-39.29), whereas during the period when the Omicron variant prevailed, the average Ct value was calculated as 28 (range: 14.41-39.36). In conclusion, our experimental study showed that the higher viral load, which is related to the Delta variant, may interpret the severity of the disease. However, no correlation was confirmed regarding contagiousness phenomena. The results of the model, Ct analysis and official data from NPHO are consistent.

Assessment of singlet oxygen dosimetry concepts in photodynamic therapy through computational modeling.

BACKGROUND: In photodynamic therapy (PDT) oxygen plays a vital role in killing tumor cells. Therefore oxygen dosimetry is being thoroughly studied. METHODS: Light distribution into tissue is modelled for radiation-induced fibrosarcoma (RIF) and nodular basal cell carcinoma (nBCC), in order to study the influence of blood flow on singlet oxygen concentration effectively leading to cell death ([1O2]rx) from PDT, within this light distribution. This is achieved through initial oxygen supply rate (g0) and initial molecular oxygen concentration ([3O2]0) calculations. Monte Carlo simulations and mathematical models are used for spatial and temporal distributions of [1O2]rx. Hypoxia conditions are simulated by minimizing [3O2]0 and g0. Furthermore, an optimization algorithm is developed to calculate minimum initial molecular oxygen concentration needed ([3O2]0,min) for constant [1O2]rx, when blood flow changes. RESULTS: Our results validate that in initially well-oxygenated scenarios with normal blood flow maximum [1O2]rx values are significantly higher than corresponding values of hypoxic scenarios both for RIF and nBCC models, with maximum oxygen supply rate percentage variations being independent from g0. Moreover, [1O2]rx appears to be more affected by an increase of g0 than of [3O2]0 values. For low blood flow there is a linear relationship between [3O2]0,min and g0, while for better oxygenated areas high blood flow reduces [3O2]0,min needed in exponential manner. CONCLUSIONS: Blood flow appears to be able to compensate for oxygen consumption. The developed optimization protocol on oxygen dosimetry offers a suitable combination of [3O2]0,min and g0 to achieve constant [1O2]rx, despite possible blood flow variations.