Brain Death in Medical Ethics

Researchers are continually discovering new medicinal therapies. Technology is advancing at an unprecedented rate, and modern medicine has turned into an expansive multi-trillion dollar enterprise. New tools such as ventilators and feeding tubes give doctors the ability to extend a person’s life beyond its natural limits. Conditions which used to kill 100% of victims no longer cause as many deaths per year. While these medical technologies bring about the benefit of longer human lives, they have created a new realm of ethical dilemmas. As the old adage goes, “With great power comes great responsibility.” If we have so much power, we must know how and when we can apply it. Two recent medical cases highlight the need to establish ethical rules by which we may govern medical practice. In the first case, 14-weeks-pregnant Marlise Muñoz was declared brain dead and placed on life support. State laws mandated that the physicians keep her on life support to protect the fetus despite its nonviable status and despite the Muñoz family’s protests. Physicians eventually removed Muñoz from life support, allowing both her and her baby to die completely. In the second case, 22-weeks-pregnant Robyn Benson was also declared brain dead and placed on life support. Benson’s child was delivered successfully at 34 weeks, and physicians removed Benson from life support the following day, allowing her to die completely. These two cases present us with a difficult question: is it ever morally permissible to keep an irreversibly-damaged corpse on life support? I will argue that it is morally permissible to perfuse a corpse when doing so would give life to another human being. I will develop this idea by defining death, by evaluating our responsibilities to the dead, and by appealing to medical principlism to critique these two cases. My findings give physicians an ethical standard for clinical situations involving brain dead patients

Comparing Common Techniques for Calculating Parasite Prevalence

Raccoons (Procyon lotor) are the final host for raccoon roundworms (Baylisascaris procyonis). Raccoon roundworm is the leading cause of a dangerous neurological disease, known as larva migrans encephalopathy. Diagnostic tools for detecting the presence of B. procyonis within a raccoon population include necropsy, fecal flotation, and latrine analysis. Necropsies yield the highest measure of prevalence, with fecal flotation and latrine analysis often underestimating infection rates. We necropsied 225 raccoons gathered from 10 townships of Clark and Greene Counties in Ohio. We collected fecal samples from 95 raccoons negative for B. procyonis at necropsy. We suspended the feces in Sheather’s solution to float any eggs, and prepared slides from this solution. Nearly 14% of raccoons negative at necropsy for B. procyonis possessed eggs in their feces. We used a chi squared test for equality of distributions to determine the likelihood that a positive fecal analysis is related to B. procyonis prevalence or to the area in which the raccoon was trapped. These data will help us determine how well fecal analyses estimate parasite prevalence

Does Baylisascaris procyonis Phylogeny Correlate with That of the Raccoon (Procyon lotor)

Baylisacaris procyonis, commonly known as the raccoon roundworm, is a parasite that inhabits the small intestine of the North American raccoon (Procyon lotor). Although humans do not typically become the definitive host, humans can become infected through handling soil containing eggs. B. procyonis can induce serious health complications in cases of human infection, including degenerative retinal and behavioral changes, coma, and even death. High prevalence of B. procyonis in a raccoon population increases the probability of transference to human hosts. In our study, we analyzed the genetic structure of B. procyonis harvested from raccoons of southwestern Ohio, and compared this to the genetic structure of the raccoons they inhabited. It is our hypothesis that the genetic structuring of the roundworms is the same as the genetic structuring of the raccoons. We isolated DNA from the roundworms using the method outlined in the DNA Minikit (Qiagen). Our research team isolated DNA from each roundworm sample and sent it to the Plant-Microbe Genomics Facility at The Ohio State University for gene amplification and sequencing. We built phylogenetic trees using these sequences, and compared these trees to some constructed for the raccoons. The correlations drawn between the raccoon and B. procyonis phylogenetic trees will help us better understand the relationship between the two species

Baylisascaris procyonis Impacts Raccoon (Procyon lotor) Diets

Raccoons (Procyon lotor) are the definitive host for raccoon roundworms (Baylisascaris procyonis). Raccoon roundworm is responsible for a dangerous neurological disease known as larva migrans encephalopathy. Raccoons are omnivorous animals and rely on various food items. Dietary analyses help determine how a raccoon changes its diet in response to environmental features. Raccoons eat whatever food resource is most convenient and abundant. Parasite infections can potentially affect host eating habits in order to keep the host alive and active longer. In this study, we analyzed the diets of necropsied raccoons from ten townships of Clark and Greene Counties by examining their stomach contents. We categorized stomach contents by separating out plant material, vertebrate tissue, and invertebrate tissue. We measured the total stomach mass and the mass of plant material alone in order to compare and obtain a percentage of plant material in the raccoons’ diet. We conducted two chi-squared tests for equality of distributions. We tested the null hypotheses that raccoons from townships with high prevalence (\u3e60%) have the same vertebrate tissue and plant tissue prevalence as raccoons from townships with low roundworm prevalence

Does Baylisascaris procyonis Impact Raccoon (Procyon lotor) Genetics?

Raccoons (Procyon lotor) are the final host for raccoon roundworms (Baylisascaris procyonis). Raccoon roundworm is the leading cause of a dangerous neurological disease, known as larva migrans encephalopathy. Phylogenetic trees illustrate co-evolutionary events between species living in a symbiotic relationship with each other. Throughout the coevolution of host and parasite, many aspects of a population affect the way the members interact with one another and with symbiotic species. In order to evaluate the relationship between host and parasite in regards to diet, we isolated DNA from intestinal wall tissue, amplified a portion of exon 2 from MHC II, and sent our samples to Ohio State University for sequencing. We calculated heterozygosities for the nine townships we surveyed. We used a chi-squared test for equality of distributions to test whether raccoons from townships with above 60% prevalence have different heterozygosity for this locus than other raccoons. These data will help us to understand the relationship between raccoons and raccoon roundworm

Baylisascaris procyonis prevalence in raccoons (Procyon lotor) and its relation to landscape features

Raccoons (Procyon lotor) are the final host for raccoon roundworm (Baylisascaris procyonis). Raccoon roundworm is the leading cause of a dangerous neurological disease known as larva migrans encephalopathy. Land fragmentation occurs when natural environments are broken up by urban or agricultural landscapes. Raccoons thrive in urban environments, while raccoons in agricultural settings forage over larger areas than raccoons in urban settings do. Land fragmentation affects concentrations of B. procyonis parasites in intermediate hosts. We calculated the prevalence of raccoon roundworm in 9 townships of Greene and Clark Counties by necropsying 226 raccoon intestines. Prevalence is defined as the number of raccoons infected with roundworm divided by the total number of raccoons sampled. We determined that the prevalence of B. procyonis from Beavercreek township is significantly lower than the other townships (χ2 = 25.19, p-value = 0.0007). Prevalence of raccoon roundworm in this region is lower than many areas in the Midwestern United States, suggesting the need for further research to determine reasons for the lower prevalence in the Ohio region

Predicting Baylisascaris procyonis Roundworm Prevalence, Presence and Abundance in Raccoons (Procyon lotor) of Southwestern Ohio Using Landscape Features

Raccoon roundworm is a leading cause of a neurological disease known as larva migrans encephalopathy in vertebrates. We determined that roundworm prevalence is significantly lower in Beavercreek Township than other townships surveyed, and that mean patch size and proportion of landscape modified by urbanization or by agriculture are good predictors of roundworm prevalence and abundance in raccoons. The proportion of landscape modified by urbanization was the best predictor of roundworm presence. These data will facilitate predictions regarding roundworm prevalence in areas that have not been previously sampled, and contribute to devising management strategies against the spread of raccoon roundworm