Scientific Literacy Writing Assignment 1
Cardiac Arrest is a major health concern in the US. The American Heart Association releases a yearly report on cardiac arrest statistics from previous years that is a very good resource for information on the subject. The report also includes a list of the top contributing factors and health factors related to cardiac arrest, such as smoking, physical inactivity, nutrition, obesity, cholesterol, sleep troubles, diabetes, and high blood pressure (American Heart Association, 2025). The report for 2025 is titled “2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association.” According to the 2025 report, sudden cardiac arrest was the cause of 19,171 deaths in 2022 (American Heart Association, 2025). The report also states that strokes accounted for one of every twenty deaths in the US in 2022 (American Heart Association, 2025). Ischemia could also be a cause of cardiac arrest (Cleveland Clinic, 2024).
Ischemia is a condition in which there is less than average blood flow in an area of your body, such as in your heart, brain, digestive system, or arms or legs (Cleveland Clinic, 2024). There are different types of ischemia determined by which part of your body is affected. Ischemia has a variety of symptoms, like shortness of breath, dizziness, and paleness in the affected area (Cleveland Clinic, 2024). There are also a variety of causes of ischemia, such as blood clots, low blood pressure, and vasculitis, among other causes (Cleveland Clinic, 2024). Ischemia can be treated in many different ways, such as medications like blood pressure-lowering medication, blood thinners, and antiplatelets (Cleveland Clinic, 2024), surgeries, or a change to the patient’s lifestyle. Ischemia is a very serious condition, as it can lead to heart attacks, stroke, or critical limb ischemia, which can lead to tissue damage. Reperfusion is related to ischemia, as it is when there is tissue damage caused by the lack of blood flow to the area of the body after ischemia (Wikipedia, 2025). Treatments for reperfusion include therapeutic hypothermia, which helps to minimize the damaging effects of ischemia and reperfusion by reducing inflammation (Wikipedia, 2025). Cleveland Clinic made some interesting discoveries about treating ischemia related injuries by studying effects on rats with kidney cancer related to ischemia using mesenchymal stem cells, or MSC secretions (Cleveland Clinic, 2019). There has been research on whether or not intercellular mitochondrial transfer could be used to treat ischemia and reperfusion.
Intercellular mitochondrial transfer, simply put, refers to the movement of mitochondrial information that is vital to cell functions (Lu, et al., 2022). Theis very important process can help to repair damaged cells in different parts of the body, and there has been study on how to use this process in a therapeutic way to repair cells damaged by different diseases, such as cancer (Lu, et al., 2022). Artificial mitochondrial transfer or transplantation, also referred to as AMT/T, was first used in 1982 when it was part of a mixture of mitochondrial cells and antibiotic-sensitive cells (Le, et al., 2022). This process has since been studied in other various ways, including a study in which these mitochondrial cells were injected into a living organism, mice, to be specific (Lu, et al., 2022). This process continues to be a promising advance in medical science.

References
Ischemia. (2024, February 29). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/ischemia
Liu, Z., Sun, Y., Qi, Z., Cao, L., Ding, S. (2022, May 19). Mitochondrial transfer/transplantation: an emerging therapeutic approach for multiple diseases. Cells and Bioscience, 12(66). https://doi.org/https://doi.org/10.1186/s13578-022-00805-7. BioMedCentral.
Martin, Seth S, MD. et al. (2025, January 27). 2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association. , 151(8). https://doi.org/https://doi.org/10.1161/CIR.0000000000001303. PubMed.
New Research Demonstrates the Regenerative Power of Mesenchymal Stem Cells for Ischemic Kidney Injury in Rats (2019, May 3). Cleveland Clinic. https://consultqd.clevelandclinic.org/new-research-demonstrates-the-regenerative-power-of-mesenchymal-stem-cells-for-ischemic-kidney-injury-in-rats
Reperfusion Injury (2025, February 21). Wikipedia. https://en.wikipedia.org/wiki/Reperfusion_injury
2025 Heart Disease and Stroke Statistics (2025, January 27). American Heart Association. https://professional.heart.org/en/science-news/2025-heart-disease-and-stroke-statistics

Scientific Literacy Writing Assignment 2

Mitochondria can, in fact, successfully be transplanted into neutral cells, as shown by the experiment described by Hayashida. The mitochondria were observed to not only be functional, but effective in neurological recovery in rats that had suffered cardias arrest (Hayashida, 2023). Three types of mitochondria were used in this experiment, frozen-thawed mitochondria, freshly isolated mitochondria, and a control group of vehicle mitochondria (Hayashida, 2023). Though both types of mitochondria proved to be functional, the freshly isolated mitochondria were observed to be more effective in recovery in the treated rats, leading to a 90.0% survival rate, as opposed to the 54.5% survival rate of the rats treated with the frozen-thawed and the vehicle mitochondria (Hayashida, 2023). The body weights of the rats were also observed to be higher in the group treated with the freshly isolated mitochondria (Hayashida, 2023).
The transplanted mitochondria were observed to increase survival in the rats used in the experiment and were also shown to increase body weight in the rats (Hayashida, 2023), however, these were not the only things that were improved. The blood lactate levels of the arteries of the rats were seen to significantly reduce in the rats after resuscitation, in the freshly isolated group more than the frozen-thawed and vehicle groups (Hayashida, 2023). The pulmonary lung edema levels were shown to be much lower in the freshly isolated group than in the vehicle and the frozen-thawed groups (Hayashida, 2023). The glucose levels of the rats were observed to be lower in the freshly isolated group than the vehicle and frozen-thawed groups, however the glucose levels of all three groups returned to normal after about 120 minutes of observation (Hayashida, 2023). The cerebral fusion rates of the rats were seen to be higher by a significant amount in the freshly isolated group, observed to be around 107.7% (Hayashida, 2023). All three types of mitochondria were observed to be very successful in this experiment.
With the use of MitoTracker Deep Red, the mitochondria were able to be observed under a microscope (Hayashida, 2023). Using this method, the mitochondria were observed to be persistent in the brain, kidney, and spleen 24 hours after injection (Hayashida, 2023). However, the same persistence of the injected mitochondria was not observed in the heart, liver, or lungs after 24 hours (Hayashida, 2023). This presents the question of why the mitochondria were able to persist in the brain, kidney, or spleen, and not the heart, liver, or lungs.
Both types of mitochondria, freshly isolated and frozen-thawed, were used in the experiment, and both were observed to be functional. However, as previously stated, the freshly isolated mitochondria seemed to be more effective in the treatment of the rats that had suffered from cardiac arrest. The rats treated with the freshly isolated mitochondria had a higher percentage of survival rate after 72 hours, and a higher body weight after treatment (Hayashida, 2023). They freshly isolated group was also seen to have lower blood lactate, pulmonary lung edema, and the cerebral fusion as well (Hayashida, 2023). So, even though both types of mitochondria were seen to be effective, along with the vehicle control group as well, the freshly isolated mitochondria proved to be the most successful for treatment after cardiac arrest.

References:
Hayashida et al. Exogenous mitochondrial transplantation improves survival and neurological outcomes after resuscitation from cardiac arrest. BMC Medicine (2023). 21:56. https://doi.org/10.1186/s12916-023-02759-0.