Prion Diseases Research Paper

Creutzfeldt-Jakob Disease: It happens when a prion protein misfolds itself, thus causing a “domino effect” which unfolds itself causing a malfunction.

Proteinaceous Infectious Particles, commonly known as Prions, are extremely rare misfolds of the protein PrPc, which cause fatally neurodegenerative diseases, and are theorized to be infectious only by the protein itself (U.S National Library of Medicine, 1998). This “protein-only theory” is still heavily debated today, as some scientists deny the theory, and there isn’t a significant amount of evidence on each side to qualify the theory or disprove it (Soto, C. 2011). The base “Prion” protein is encoded in the gene PRNP, while being non-infectious. Prions are most commonly found in human prion diseases, but they can also be in other animals in the form of Mad Cow Disease and Chronic Wasting Disease, classified as Bovine Spongiform Encephalopathies

The meats that consumers eat are slabs of a cow’s muscle tissue and the infectious meat is only found in the nerve tissue. Of course there is the possibility of having some of the contaminated meat passed on to the meat that consumers eat when the cows are cut, but the chances are very slim. Since this disease is contracted through eating contaminated meat, the site of infection should be in the digestive tract, yet this disease eats away at the brain and nervous system.

     Mad Cow Disease, scientifically referred to as (BSE) Bovine Spongiform Encephalopathy, is a disease that affects those humans who eat the meat from infected cows. Mad Cow Disease is one of several fatal brain diseases called (TSE) Transmissible Spongiform Encephalopathy. (USDA) There was evidence of a new illness resembling the sheep disease scrapie. It was technically named BSE but quickly acquired the mad cow tag because of the way infected cattle behave. (CNN) In 1997, there was an award given to Stanley Prusiner, for concluding that a distorted protein called a prion was responsible for Mad Cow Disease, noted the long incubation period made it difficult to distinguish (Bryant).

BSE is a form of transmissible spongiform encephalopathy that is transmitted when cattle consume feed that contains other animal protein from infected animals such as scrapie in sheep (CDC,

Variant Creutzfeldt-Jakob disease (vCJD) is a rare and fatal human neurodegenerative condition falling under the category of Transmissible Spongiform Encephalopathy (TSE) because of having characteristic of spongy degeneration of the brain that it causes and its ability to be transmitted. First it was described in the United Kingdom in March 1996 and it has been connected with exposure to a TSE of cattle known as Bovine Spongiform Encephalopathy (BSE) sometimes called Classical BSE, having been reported first in 1986 in the United Kingdom.

Abnormal changes happen in the brain, and it appears as a sponge-like holes and gaps, causing deterioration in the areas of the brain. This can turn into spongiform degeneration that results in the progressive neurological and neuromuscular symptoms that are associated with CJD. This disorder is a result from a mutation in the gene that regulates the production of the human protein or direct transmission with abnormal protein in infected brain tissue. Scientist believe that there is a transmissible agent that is responsible for causing CJD. This is a slow virus, since it can take many years from exposure to the appearance of

The U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE. Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion. For reasons still unknown, this protein becomes altered and destroys nervous system tissue (brain and spinal cord). There exists strong epidemiologic and laboratory evidence for a causal association between a new human prion disease called variant Creutzfeldt-Jakob disease (vCJD) that was first reported from the United Kingdom in 1996 and the BSE outbreak in cattle (http://www.cdc.gov). According to The National Creutzfeldt-Jakob Disease Surveillance Unit, by June 2014 it had killed 177 people in the United Kingdom, and 52 elsewhere. This essay will focus on the possible causes, effects, and treatment for this

The aggregation of prion proteins and their transmissibility from one cell to another has been shown to be evident (Cushman et al.; Goedert et al. 2010), therefore strongly suggesting that these events may play a role in pathogenesis for many diseases, including both AD and PD. While none of these diseases is infectious in an identical way as

Another interesting finding was that CWD affects the lymph nodes first, the brain second, and shows clinical signs (drooling and weight loss) third. All those affected places no matter what lead to death. Based on their study there were four assumptions: deterministic transitions (between states), spatial homogeneity (210 sq. miles), homogenous transmission and mixing (age, sex, infection), and no migration. It is believed that CWD has been around since the late ‘60s-early ‘70s, and derived from scrapie or may be human induced. Janelle stated, “Given estimated parameters from data model is sensitive to adult survival- influenced by magnitude of transmission coefficients and harvest levels.” It was noted that in Wisconsin the DNR aren’t finding ways to manage CWD, they are letting it run its course. Also, there were no policy changes among hunting the

Prions (PrPsc) influence the PrPc proteins they come in contact with to misfold and begin to aggregate. The aggregation leads to development of fibers or plaques. The aggregation of PrPsc around the neurons triggers the cell to self destruct. It is also able to spread to nearby neurons resulting in areas of neuronal death which results in the brain tissue having spaces of void which appear like a sponge.

Mad Cow Disease Bovine spongiform encephalophathy ( BSE), which is mainly known as mad cow disease has infected the society and has put the lives of individuals at risk. This was very frightening to the people that ate meat during that time. The terrified people would not even want to eat hamburgers at MacDonald, steak at restaurant and much more. What also alarmed the people was the fact that there was a possibility of getting the human form of mad cow disease. This was called variant Creutzfeldt-Jakob disease (vCJD) which is through tainted blood, but this was only a theory which

This accounts for about 5% - 10% of cases in the United States. The last category of acquiring CJD is infectious CJD which occurs when an individual is exposed to an external source of prion protein. Common outside sources which may cause infectious CJD are medical procedures involving surgical instruments, growth hormone from human sources and certain transplanted human tissues. Another cause is ingestion of meat or other products from cattle infected with bovine spongiform encephalopathy (also known as mad cow disease). In the mid 1990’s scientists traced this type of CJD from cattle that were fed a diet comprised of processed brain tissue from other animals to individuals who consumed the beef. However, since its first description, less than 1% of cases were identified by acquiring the disease through exposure (Gozke et al. 2008). Below is a chart demonstrating the numbers of individuals diagnosed with CJD through the three categories described above in several different countries (“BSE Info”, 2007):

Transmissible spongiform encephalopathies (TSEs) are neurodegenerative diseases that are thought to be caused by the misfolding of prion proteins. Prions are able to replicate in the absence of nucleic acids. TSEs include: scrapie, bovine spongiform encephalopathy, Creutzfeldt-Jakob disease, kuru, Gerstmann-Straussler-Scheinker disease, and Fatal Familial Insomnia. They can affect many different animals, including humans. Currently, there are no ways to diagnose, treat, or cure TSEs, as much more research is needed before these diseases are completely understood.

The rabies virus travels through the peripheral nerves and transported to the central nervous systems and inflames the brain. Rabies invades the nervous system of animals.