Formally described in 1972, apoptosis is one of the key mechanisms responsible for programmed cell death. It is characterized by several distinct features including cell shrinkage, chromatin condensation and formation of apoptotic bodies which are ultimately consumed by phagocytic cells. Under normal conditions, apoptosis is utilized as a tool for elimination of damaged cells and maintaining homeostasis. However, apoptosis may also be initiated as an immune response to disease or toxic agents and is, therefore, a popular target for drug development. Unfortunately, many disease states (such as cancer, encephalomyelitis, and type I diabetes) show a downregulation of apoptosis such that the diseased cells are not effectively eliminated, allowing …show more content…
This central responsibility of apoptosis initiation and execution is given to a family of cysteine-dependent aspartate proteases commonly referred to as caspases.
There are two different types of caspases; initiators and executors. Initiator caspases are accountable for initiating apoptosis via activation of executer caspases, while executors conduct cell demolition. Due to the immense importance of their function, caspases are actively regulated via binding of small chemical groups or proteins to amino acid residues, a process formally known as post-translational modifications (PTMs). Such protein modifications are known to induce conformational and functional changes and therefore represent a powerful code by which caspases and hence apoptosis is regulated. Common examples of PTMs of caspases which are actively being investigated include, phosphorylation, ubiquitination, N-acetylation, Sumoylation, and S-nitrosylation. Interestingly, several of these PTMs are known to target the same residue. For example, both Sumoylation (binding of a Sumo protein) and
Montaner, B. and Perez-Tomas, R. 2001. Prodigiosin-induced apoptosis in human colon cancer cells. Life sciences, 68 (17), p. 2025-2036.
Euthanasia is one of the most complicated issues in the medical field due to the debate of whether or not it is morally right. Today, the lives of many patients can be saved with the latest discoveries in medicine and technology. But we are still unable to find cures to all illnesses, and patients have to go through extremely painful treatments only to live a little bit longer. These patients struggle with physical and psychological pain. Dr. Martin Luther King Jr. discusses the topic of just and unjust laws in his “Letter from Birmingham Jail” which brings into question whether it is just to kill a patient who is suffering or unjust to take that person’s life even if that person is suffering. In my opinion people should have the right, with certain restrictions, to end their lives in the way they see fit if they are suffering from endless pain.
4. Phillips B, Trucco M. Immunotherapy-based strategies for the treatment of autoimmune diabetes: searching for the cure. Current Pharmaceutical Design [serial online]. 2011;17(29):3217-3223. Available from: MEDLINE with Full Text, Ipswich, MA. Accessed November 19, 2013.
The pancreas can be divided into two sections when studying the histology. The pancreas has exocrine and endocrine functions, each with unique cell types. The exocrine pancreas serves to secrete digestive enzymes into the duodenum. Some of the specific enzymes and secreted substances are Proteases, lipase, amylase, bicarbonate, and water (Bowen, “Exocrine Secretions”). These enzymes are used to break down protein, fat, and carbohydrates respectively. The bicarbonate simply act as an acid buffer to prevent damage of the small intestine as the stomach acid must be neutralized. The enzymes are created in acinar cells and the bicarbonate is synthesized in epithelial cells surrounding pancreatic ducts (Bowen “Exocrine
Stem cells help us to maintain and heal our bodies, as they are undifferentiated cells, their roles are not yet determined. They have the ability to become anything during early life and growth. Stem cells come from two sources, namely: embryonic stem cells (embryo’s formed during the blastocyst phase of embryological development) and adult stem cells (see figure 3).
... secrete enzymes pepsinogen and renin, which break down the unfolded proteins. (Nam et al, 2010).
10) Weizmann Institute of Science: Death of a Cell, a discussion of one series of studies of cellular apoptosis
Thought to be an oncogene, a gene that has potential in transforming normal cells into tumor cells, p53 was regarded as the most prominent tumor suppressor gene [1]. P53 is a gene which signals apoptosis (programmed cell death) if a cell cannot be repaired due to an extensive amount of damage. As stated in the textbook, p53 regulation occurs by an E3 ubiquitin-protein ligase known as MDM2 [1]. "Controlling the controller" is a statement that describes the molecular interaction where the presence of MDM2 targets the p53 for proteosome via degradation. With three main checkpoints in cell cycle, the literature states p53 functioning from G1 into S phase in a chaotic cell [2]. The normal state of cells is to keep p53 levels low in order to prevent uncontrolled apoptosis and random cell cycle arrest from occurring. In a further note, although p53 promotes apoptosis and cell cycle arrest, cancer may result from p53 unable to recognize the problematic site. In turn, a mutation in p53 may result engaging in new activities. These activities include cellular transformation, tumor metastasis,...
“The word 'leukemia' is a very frightening word. In many instances, it's a killer and it's something that you have to deal with in a very serious and determined way if you're going to beat it” - Kareem Abdul-Jabbar. Many people, including tons of children, fight leukemia every day trying to beat this vicious cancer. Without knowing how leukemia is exactly caused, it puts a damper on how to avoid it.
The Phase I trial will be discussed here as it pertains to the topic at hand. The typical treatment for cervical cancer if surgery is not a viable option – like if the cancer has spread, then called locally advanced cervical cancer – is chemotherapy and radiation treatment at the same time. This phase I clinical trial is simply looking to add ipilimumab to this regimen, but once the chemo/radiation has been completed (LACC article). Chemo and radiation destroy tumor cells, which causes tumor-associated antigens to be released. Once released, these antigens are exogenous (outside the cell) and will be presented to helper T cells to initiate an immune response.
The term Euthanasia is derived from Greek, meaning good death. Taken in its common usage however, euthanasia refers to the termination of a person’s life, to end their suffering, usually from an incurable or terminal condition. It is for this reason that euthanasia was also coined the name “mercy killing”. Another type of euthanasia is Active Euthanasia refers to the deliberate act, usually through the intentional administration of lethal drugs, to end an incurably or terminally ill patient’s life. ("The Ethics of Euthanasia.") The earliest recorded date of euthanasia is dated back to 5th century B.C.-1st Century B.C. In ancient Greece and Rome, before the coming of Christianity, attitudes towards active euthanasia and suicide tended to be
“This knowledge will help us design drugs that mimic the viral effects on these proteins to either activate a host’s immune response or shut it down,” said Dr. Michael Gale, associate ...
The immune system defends the body against foreign invaders through a sequence of steps known as the immune response. A network of organs, cells and tissues must work together in order to protect the body. The immune response can be divided into innate immunity and adaptive immunity, though these divisions are artificial and the system functions as a single unit.
nuclei was then inactivated and substituted with dead nuclei from the extinct frog. Some eggs started to grow and divide to early embryo stage (a tiny ball of m...
Death occurs when living stops. From the event of death, we have created religious and cultural traditions. It has become the core of literature and entertainment. As a society we are somewhat fascinated by it. Healthcare practitioners fight everyday to prevent it from happening. Can this event, which is absolute, change its meaning over time?