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.
Humans have to deal with many different diseases and the ones most disliked are the ones with no cures. Like cancer, transmissible spongiform encephalopathies have no cure, but they are more rare. These diseases are prion diseases which cause the brain to deteriorate. Prions are proteins that sometimes behave like viruses, which mean that they should have some form of nucleic acid, but since they don’t, they cause abnormalities. The nervous system contains many normal prions, but when an abnormal prion comes along, it transforms all the normal prions into abnormal ones. Bovine spongiform encephalopathy is found in cattle, but it can be transmitted to humans.
In bovine spongiform encephalopathy (BSE), the disease is caused by the misfolding of proteins that cause proteins and peptides to develop a fibrillary structure. The PrPc is a correctly folded prion and the misfolded form is called PrPSc. BSE occurs when the normal PrPc come into contact with the toxic PrPSc and the normal prion takes on the shape of the PrPSc. The normal chaperones are unable to convert the PrPSc back to the normal form. The PrPSc now takes on the role of chaperone and the conversion of PrPc prions continue over and over. PrPSc, now being hydrophobic avoids the water of the inner cell and begin to accumulate and form plaques along the neuronal cell membranes. The aggregation of the prions on the cell membrane eventually lead to cell death which produces the sponge-like appearance in the brain of cattle infected with BSE (Thompson, 2014).
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
This disease gets its name from the German neurologist Hans Gerhard Creutzfeldt and Alfons Maria Jakob that first identified this disease. (Victor, 2015) VCJD is primarily found in the brain of the cattle. Abnormal proteins called prions have thought to be the cause of this disease in both cattle and in humans. These prions cause tiny holes that look like a sponge under a microscope. (Melissa Conrad Stöppler, 2015) Unlike most viruses and bacteria these prions unfortunately do not die when exposed to heat, ultraviolet light, and radiation. Disinfectants that are usually used to kill viruses and bacteria also do not work to kill prions. Even cooking the meat very well will not lower the risk of prions in the
This week may be the last week I write to you. In my last letter to you, you may have noticed that I seemed depressed and not like myself. I wasn’t completely truthful in that letter. I’m not just having a bad day, I’m diseased with an incurable, fatal disease.
It is a rare, degenerative but fatal brain disorder affecting very a small fraction of persons. The symptoms usually arise at the age of 60 and the person dies within a year. Many researchers believe that this disorder is the result of an abnormal protein known as prion. About 5-10% cases reported in the United States share a genetic basis where this form of dementia is caused by a mutation in the gene for the prion protein. Patients with Creutzfeldt-Jakob disease suffer from the problems associated with muscle coordination, personality changes, impaired memory, judgment making, thinking disability and impaired vision. Other possible symptoms include insomnia and depression. In later stages the persons
Creutzfeldt Jakob Disease (CJD) is a rapidly progressive form of Dementia. Early diagnosis is important because the underlying cause of Dementia may be treatable. It appears randomly with no apparent reason, about 10% of those who are infected receive the disease through heredity. The use of a computerized axial tomography scan (CT) can help rule out other problems like stroke or brain tumor. The most effective is a Magnetic resonance imaging (MRI), because it can reveal patterns of abnormal brain signals and characteristics of CJD. In rare cases a brain biopsy may need to be performed. A small piece of tissue is removed and it is examined by a Neuropathologist, usually an MRI is sufficient. When a symptom on set happens, individuals may develop confusion, depression, behavioral changes, impaired vision and impaired coordination. As the disease processes there may be a loss of memory, also infected individuals may develop neuromuscular abnormalities. In later stages of the disease, individuals may have further loss of physical, intellectual functions, a coma, and repeated infections of the respiratory tract. Some people have life threatening and life ending complications, that develop less than a year after being
Brain disorders are categorized as major health conditions based on the fact that the brain is the control center of the body. Brain disorders come in many forms and at times are difficult to diagnose based on their complexity. A very rare degenerately unchangeable brain disorder of the central nervous system is Creutzfeldt-Jakob disease (CJD). Creutzfeldt-Jakob disease affects one person in a million within a population that is worldwide (Llorens et al., 2015). The USA is known to have two hundred cases of patients diagnosed with Creutzfeldt-Jakob disease each year (Llorens et al., 2015). Although the disease is very rare, it is very deadly because after onset of symptoms of the disease the patient usually passes after a year of diagnosis. Most patients develop the disease around their sixties and typically only have one year left to live (Head et al., 2009). CJD can be categorized etiologically as sporadic, infectious, and inherited neurodegenerative disorder due to the misfolded proteins making it very unique. Symptoms in clinical trials of CJD have consisted of rapid onset of progressive dementia, involuntary muscle contractions, inability to balance, cognitive impairment and visual deterioration (Gozke et al., 2008).
Due to the inability of the brain to replace nerve cells, some brain function is lost. The key question in Alzheimer’s disease is, what causes the neuron degeneration (Johnson, 1989)? The focus for finding the cause is on abnormal structures found in the brain of people with Alzheimer’s. Unfortunately, the abnormal structures the brain undergoes still has researchers uncertain as to how they are involved in Alzheimer’s and exactly how the disease occurs.
Diseases that are neurodegenerative, such as Alzheimer's, have a similar mechanism to prion diseases that infect the brain and slowly destroy it (Frost and Diamond, 2010). The mechanism of neurodegenerative disease, including prion diseases, begins with a normal human protein
In addition to the cervid species in which chronic waste disease can occur in wide variety of other animals. These other animals include monkeys, sheep, cattle, prairie voles, mice, and ferrets. Environmental transmission has been linked to contact with infected bodily fluids and tissues. Once the prions are in the environment chronic waste disease prions may remain infectious for many years. Thus, Decomposition of the disease carcasses, infected gut piles left by hunter, as well as urine, saliva, feces, and antler velvet of infected individuals that are deposited in the environment.
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