2. The unique properties of stem cells and the ways of reception. 3. The application of stem cells in curing the worldwide diseases. i. The effectiveness of using stem cells in diabetes treatment and possible risks of this therapy. ii. What are the benefits and risks of using stem cells in curing cardiac disorders, such as ischemic disease and stroke? iii. How neural disorders, such as Parkinson’s, Alzheimer’s and spinal cord injuries can be treated by stem cells and what are the fears about application of this therapy on human? 4. The issues connected with stem cells research.
6. Reference list
The world of science is developing very rapidly. This can be explained by the desire of people to know everything, e.g. the origins of life, the structure of human’s organism, the secrets of universe etc. The one of a set of branches in science is regenerative medicine, which includes stem cells research. Generally, stem cells are unique cells in the human’s body, which have an ability to renew themselves and become specialized into liver cells, kidney cells or spinal cord cells from unspecialized type of cells. There are several advantages and disadvantages of using stem cells in treatment the most common diseases of the world. The subject of this research project is to evaluate the benefits and risks of using stem cells in curing global diseases. It merits study, because stem cells are the constituent part of human organism and their abilities must be explored, in order to use them in therapies for diseases such as Alzheimer’s, Parkinson’s, diabetes mellitus, spinal cord injuries and cardiac disorders. It is significant to know possible risks of using stem cells, as well as their benefits. 2. The unique properties of stem cells and the ways of reception. Basically, stem cells are unspecialized cells in the human organism, which have a significant ability to renew themselves and become specialized with new functions.
They have distinguishing properties to develop into different types of cells, such as brain cells, nerve or liver cells etc. The stem cells repair dead cells; moreover they can divide without any limitations. Generally, there are four sources of stem cells: stem cells from embryo; stem cells from fetus; stem cells from adult human; stem cells from umbilical cord. Saxena (2009) emphasizes, the stem cells are divided in two categories of their origination: adult and embryo. Embryonic stem cells derived from 5-7 days old fertilized eggs, which are called blastocyst. Specifically, the stem cells are taken from the balstocyst’s cavity, inner cell mass. The most important feature of embryonic stem cells, they are totipotent. This means they can differentiate into every type of cells, whereas human adult stem cells can be differentiated only into the cells, from where they were originated. Another category is human adult stem cells. These stem cells are undifferentiated cells, which can be found among differentiated cells in different organs or tissues.
They have the similar properties as embryonic stem cells, but with limitations. Adult stem cells repair the organs and tissues, where they were found (Polak &ump; Bishop 2006). However, the conducting research on embryonic stem cells has controversial debate in the whole world. There are a lot of ethical issues connected with embryonic stem cells. There are most common diseases, which are the main causes of death in the whole world, such as diabetes mellitus; cardiac disorders (ischemic disease); neural diseases (Parkinson’s, Alzheimer’s, spinal cord injuries) . The next paragraphs would describe and evaluate the risks and the benefits of using stem cells in curing these disorders. 3. The application of stem cells in curing the worldwide diseases. i. The effectiveness of using stem cells in diabetes treatment and possible risks of this therapy.
The diabetes is the Sixth Leading Cause of Death in the U.S. (Goldthwaite 2006). According to the Goldthwaite (2006), it is about 7% of the world’s population is with diabetes and this number is expected to increase by 2025. The diabetes is characterized by disability of organism to regulate the concentration of glucose in the blood. The level is under control of insulin, a hormone which secreted by β-cells of Islets of Langerhans in the pancreas. There is another hormone, which is secreted by α-cells of this Islets, it is a glucagon. These two hormones are maintains the homeostasis (stability in the body). So the β-cells failure causes the deficiency of released insulin into the blood and glucose concentration increases, this may lead to the stroke, kidney failure etc. Generally, there are two types of this disease, type 1 and type 2. The type 1 diabetes is caused by destruction of β-cells by human’s immune system. The type 2 diabetes is the condition, when the organism cannot use insulin correctly; this is a result of genetic inheritance or environmental factors (Goldthwaite 2006).
In accordance with Chaudhari (2001), there were a lot of attempts to find the best cure for diabetes treatment. The start of this research was transplantation of pancreas and the first successful transplantation was in the middle of 1960s. However, there were problems too, such as reaction of immune system on the foreign objectives in the body and also limited supplies of pancreas. The next therapy was islet transplantation. In contrast with pancreas transplantation, this method has such benefits as enough of local anesthesia, instead of general; these islets can be treated with immunosuppressive agents, in order to decrease the immune rejection. Moreover, this therapy has problems; they are deficiency of viable mass of islets; hard post-transplant period and also immune reaction (Chaudhari et al 2001).
All these methods are not effective, they do not cure the diabetes and there are a lot of problems associated with therapies, they just stop or slow the progression of the disease. Currently, the science is interested in using stem cells “in vitro” to derive the implants. The term “in vitro” means “grown in the tube”, artificially. As Chaudhari (2001) claim, the convenience and benefit of this method, is that the various factors can be added in vitro, e.g. grown factor etc. The benefits of using stem cells are the independence of insulin injections for three and more years; deceleration of progress the β-cells destruction, whereas the risks are formation of tumors; the migration of stem cells in different regions and formation of cancer cells. ii. What are the benefits and risks of using stem cells in curing cardiac disorders, such as ischemic disease and stroke?
Cardiovascular diseases are the leading causes of death in the whole world. According to Joggerst (2009), about 35 million of people die from strokes, cardiac diseases. The heart is the most important organ in the human’s body, it works as a pump, which circulates the blood around the organism. It divided into two parts: left and right. Each of these sides has two chambers: atrium and ventricle. The left ventricle is the departure of the blood into the aorta, so it is very significant and failure of it will break the blood circulation. (Kent 2000). The most common cardiac disease, causing the failure of left ventricle is ischemic heart failure, which is results from deficiency of oxygen in the cardiac tissues. So, the consequence of this is a destruction of great amount of cardiomyocytes (cardiac muscle cells), which the cause a cascade of events, such as formation of scars, the wall of left ventricle become thin and the circulation of blood is disturbed, all these may lead to the death (Goldthwaite …). The scientist are looking forward to using stem cells in regeneration the cardiomyocytes. In 2001, Jackson carried the experiment on mice, injecting the adult mouse stem cells derived from bone-marrow and this demonstrated the regeneration of these cells into cardiomyocytes and endothelial cells.
The several experiments were made with the same successful results, such as Orlic (2001), which also used the bone-marrow derived stem cells and the formation of cardiomyocytes and smooth muscle cells was achieved. According to these investigations, researches consider that human adult bone-marrow stem cells have a great potential in repairing the cardiac cells. Basically, there are two types of bone-marrow derived cells: mesenchymal (differentiate to bones, muscles, tendons etc.) and hematopoietic (differentiate to the blood cells) stem cells. As Goldthwaite (2007) points out the most effective are mesenchymal stem cells, because of the relatively low immunogenicity and easy culturing them under special conditions. So, the researches on rats, pigs and mice showed the decrease of infarct’s size, low immune rejection and increase of myocardial functions. iii. How neural disorders, such as Parkinson’s, Alzheimer’s and spinal cord injuries can be treated by stem cells and what are the fears about application of this therapy on human?
The scientists are suggested that stem cells have a great potential in treatment the neurodegenerative disorders, such as Parkinson’s, Alzheimer’s and spinal cord injuries, but at the same time these therapies have several risks, which can be explained by not enough investigations in this field and requires more time to do it. The Parkinson’s disorder is a type of neurodegenerative diseases, which is characterized by death of special аcells, which produce a chemical, called dopamine. Dopamine is responsible for human’s movement, because it carries the signals to the brain. The loss of these cells can cause symptoms, such as tremors, rigidity and disability to move (Wu 2010).