Addressing STEM Concepts through a Food Safety Activity

The activity described in this article engages students in learning about proper meat storage procedures by using the Internet. They apply their knowledge practically through creation of a pamphlet to be displayed in their kitchen at home and a follow-up report on their parents’ kitchen procedures; they may also participate in a classic food storage experiment. This activity is well suited for elementary school children in the second through fourth grades and promotes all basic STEM (science, technology, engineering, and math) concepts. Kitchen activities require all these concepts for successful and safe outcomes. The examination of food storage devices references engineering, and technology is used for the research and pamphlet creation. The section on bacteria introduces life sciences, and physical sciences come into play through the discussion of heat inducing change in the meats. Math skills are integral to the reference table containing temperatures and times.     

Interferon regulatory factor-1 as a positive regulator for high glucose-induced proliferation of vascular smooth muscle cells

High glucose-induced proliferation of vascular smooth muscle cells (VSMCs) plays an important role in the development of diabetic vascular diseases. However, molecular mediators responding for the proliferation of VSMCs remain to be determined. In this study, VSMCs were isolated from the rat thoracic aorta, and two cell models with Irf-1 knockdown and overexpression were established by transfecting cells with pGCsi-FU-Irf-1 and pGC-FU-Irf-1, respectively. Subsequently, high glucose was added to cells to induce proliferation. Proliferation assays were performed to see whether Irf-1 was involved in high glucose-induced proliferation of VSMCs. In addition, the expression of Irf-1 was detected in VSMCs stimulated with high glucose and the thoracic aorta of diabetic rats to confirm the relationship between Irf-1 expression and the proliferation of hyperglycemia-dependent VSMCs. The results showed that Irf-1 expression was significantly higher in the thoracic aorta of diabetic rats and VSMCs stimulated with high glucose than that in nondiabetic rats and untreated cells. Overexpression of Irf-1 accelerated the proliferation of VSMCs, and down-regulation of Irf-1 expression significantly depressed the proliferative ability of VSMCs under high-glucose conditions, indicating that Irf-1 was a positive regulator for high glucose-induced proliferation of VSMCs. It could be presumed that Irf-1 is associated with the accelerated proliferation of VSMCs in diabetic vascular diseases and may prove to be a potential target gene for disease treatment.     

Could a dysfunction of ferritin be a determinant factor in the aetiology of some neurodegenerative diseases?

Background

The concentration of iron in the brain increases with aging. Furthermore, it has also been observed that patients suffering from neurological diseases (e.g. Parkinson, Alzheimer…) accumulate iron in the brain regions affected by the disease. Nevertheless, it is still not clear whether this accumulation is the initial cause or a secondary consequence of the disease. Free iron excess may be an oxidative stress source causing cell damage if it is not correctly stored in ferritin cores as a ferric iron oxide redox-inert form.

Scope

Both, the composition of ferritin cores and their location at subcellular level have been studied using analytical transmission electron microscopy in brain tissues from progressive supranuclear palsy (PSP) and Alzheimer disease (AD) patients.

Major conclusions

Ferritin has been mainly found in oligodendrocytes and in dystrophic myelinated axons from the neuropili in AD. In relation to the biomineralization of iron inside the ferritin shell, several different crystalline structures have been observed in the study of physiological and pathological ferritin. Two cubic mixed ferric–ferrous iron oxides are the major components of pathological ferritins whereas ferrihydrite, a hexagonal ferric iron oxide, is the major component of physiological ferritin. We hypothesize a dysfunction of ferritin in its ferroxidase activity.

General significance

The different mineralization of iron inside ferritin may be related to oxidative stress in olygodendrocites, which could affect myelination processes with the consequent perturbation of information transference.