The Uses of Biotechnology in the Field of Medicine - Essay Example

?INTRODUCTION Important in the development of biotechnological applications is the ease of use, safety, sensitivity, and reproducibility of the protocols being developed. Development of one protocol demands discovery of new concepts and proposal of new methods. For example, polymerase chain reaction (PCR) is a biotechnological process that basically replicates many copies of certain sequences in vitro. By itself, it is a very reliable diagnostic tool in identifying infectious biological agents or vectors and infected host cells (World Organisation for Animal Health, 2009). On the other hand, amplified sequences can be inserted into other, more easy-to-manipulate species, such as microorganisms, thereby leading to the assessment of characteristics possessed by the resulting gene products of these sequences, such as structure, pH and function. In medicine, such findings are important because diseases that previously remain to be an enigma has been found to be caused by a depletion or over-expression of proteins whose functions have only recently been identified. So far, there are multiple procedures that have been developed, each catering to the specific needs of various research groups. This is a testament to the ever-growing field of biotechnology. This paper summarizes the different functions of various biotechnological procedures that are applicable to the prevention, diagnosis and treatment of diseases. PREVENTION THROUGH VACCINES Vaccines are one of the most common and effective means of providing protection against infectious diseases. Because of its extensive use, continuous vaccine development is going underway since its initial use. One of the targets of advancement is the means of production. Basically, vaccines are just deactivated viruses, units or components, or antigens which induce immune reactions from the receiving individual. The effectiveness of vaccination lies on its induction of memory immune cells that act against multiple attacks of the corresponding natural infective exposure. Vaccine production Initially embryonated eggs were used for the propagation of virus units for vaccine production. In this process, an aliquot of virus solution is injected into the allantoic cavity of a 10- to 11-day old embryonated egg. The infected eggs are then incubated in temperatures suitable for growth of the virus (Szretter et al., 2006). However, since egg-based vaccine production imply that individuals with egg allergies cannot be vaccinated, a different host was searched for. With the parallel development of cancer cell research, hyperproliferative cancer cells were seen as a better means of vaccine production. Firstly, individuals allergic to egg-based products can now avail of vaccinations. Secondly, cell culture-based production is more cost-efficient than egg-based production because cancer cells are much easier to culture than embryonated eggs. Similar to egg-based production, infective virus units are inoculated into a culture of a particular cancer cell line, usually Madin Darby canine kidney (MDCK) (Szretter et al., 2006). One of the novel protocols to produce vaccinations, especially the subunit vaccines, which are described later in this paper, is through recombinant protein expression. Briefly, developed expression systems, or microorganisms processed to receive genes and express proteins of other organisms, are inserted through a vector. Not only is this cost-efficient, but is much safer to handle than the culturing clinically-derived viruses. In addition, through recombinant protein expression certain mutations can be introduced to the antigen to make it more immunogenic (Zhang et al., 2007). Post harvest, the viruses undergo further processing. The virus units are weakened or deactivated either chemically, by formaldehyde or ?-propiolactone, through heat, or radiation. This deactivation prevents the vaccine from causing illness to the handlers and to the recipients. If to be used in another time, these harvested viruses are also stored in liquid nitrogen (Szretter et al., 2006). In addition, virus units may be administered as a whole, may be disrupted chemically (split), or may undergo isolation of certain biomolecules, which serve as antigens for antibody recognition and memory (Cox et al., 2003). In the third option, which is commonly called subunit vaccines, the choice of biomolecules isolated is based on their immunogenicity. Usually, subunit vaccines contain 1-20 antigens that are the best in inducing immune response (National Institute of Allergy and Infectious Diseases, 2011).. Because it contains more viral components, whole vaccines are more immunogenic, and result to more frequent side reactions (Cox et al., 2003). There are several considerations in vaccine production. Growth rates also vary among different strains. For example, in flu vaccine production, Influenza B units are incubated longer than Influenza A to obtain similar amounts of the virus strains (Szretter et al., 2006). Next, the strain that is contained in the vaccine should be similar to those that will be circulating in the community. For vaccines that prepare against highly mutating viruses, such as Influenza vaccine, this may be problematic, because first, as of this moment, there is no way for the prediction of the characteristic of the new strain to be accurate, and second, vaccination should be more frequent, as the vaccine taken previously may not confer resistance to the new strain (Cox et al., 2003). Types of vaccines Toxoid vaccines. This type of vaccine may be used against bacteria that naturally produce toxins that cause diseases. Toxoid, from which the name of the vaccine is derived, is actually the formalin-deactivated form of its corresponding bacterial toxin. Diphtheria and tetanus are two diseases prevented by the use of toxoid vaccines (National Institute of Allergy and Infectious Diseases, 2011).. Conjugate vaccines. Conjugate vaccines are special subunit vaccines that are specific for polysaccharide coating of bacteria. Because younger children have immature immune responses, their antibodies are unable to respond to the antigens of bacteria because these antigens are covered with polysaccharide. With conjugate vaccines, antibodies specific for the polysaccharides can detect the presence of the corresponding bacteria even if its antigens are hidden (National Institute of Allergy and Infectious Diseases, 2011).. Live, attenuated vaccines. From the name itself, the virus or bacterial units used for this vaccine are viable, although their replication ability is decreased. This type of vaccines induces an immune response that is similar to that in reaction to natural infection. This response includes a localized, mucosal and a systemic response. The immune response localized to mucosa serves as the first line of defense against infection. It comprises of increased mucus and fluid secretion that contains the lymphocytes (Cox et al., 2003). Inactivated vaccines. The name suggests that these contain nonviable viral units either whole, split, or subunit. They were chemically disrupted so the virus units in the vaccine cannot replicate inside the body. Their non-viability also prevents them from mutating into a possibly more potent form of the disease to which it is supposed to prevent the body from acquiring. Compared to live, attenuated vaccines, inactivated vaccines are more stable. They usually do not need cold storage, and they can be transportable to areas that do not have refrigerators. However, because they induce relatively weaker immune response than live, attenuated vaccines do, several dosages are needed before ample amounts are given (National Institute of Allergy and Infectious Diseases, 2011).. In choosing the type of vaccine to be used, several considerations should be made. One of the most important considerations is safety. In giving Influenza vaccines, for example, one can choose between a live, attenuated vaccine and inactivated vaccine. However, there are hypothetical health issues raised against live, attenuated vaccines of Influenza. First is the possibility of DNA mutations that these viruses can undergo. These mutations, in turn, may allow them to propagate at an alarming level. Second, the viruses in the vaccines may undergo a reassortment with other viruses that have infected the vaccinated individual. If this happens, a more potent virus, which no vaccine is prepared against, may arise to inflict illness to the patient. However, such incidence has yet to be reported (Cox et al., 2003). Future Vaccines DNA Vaccines. Still in experimental stages, DNA vaccines are one of the most promising advancements in the field of medicine. As the name implies, the vaccine contains the pathogen’s genetic material, which are taken up by the recipient’s cells. Inside the cell, the pathogen DNA is read and expressed into the antigens that they code for. These are then presented by the recipient cells for the immune cells to develop memory against. Because it only contains the genetic material, it is impossible for the vaccine to cause side effects to the recipient. Because of the advancements in this field of research, some are already at its clinical testing stages (National Institute of Allergy and Infectious Diseases, 2011). HIV vaccines. Because of the continuous rise of the number of individuals with HIV, there is a more extensive effort on developing HIV vaccines. One of the funded studies on HIV vaccine uses a two-pronged approach. First, the HIV vaccine should decrease the immune response of T cells against HIV so that less immune cells will be infected. Second, the vaccine should increase the activity of antibody-producing B cells against HIV to compensate for T cells’ decrease in activity (National Institute of Allergy and Infectious Diseases, 2010). Things to consider Aside from the abovementioned considerations, the age group to which the vaccine shot will be administered to should be determined. The immune naivety of children and decreased immune functionality of adults should be kept in mind. Logically, a greater amount of virus components should be provided for these age groups. However, their safety from the possible side effects of increased dosage is a primary priority. As such, lesser doses of the vaccines should be given to these age groups (Cox et al., 2003). DIAGNOSTICS Diagnostics is a vital part of medical practice as it is the primary determinant of the effectiveness of treatment. In simple terms, biotechnology aids in diagnostics as it makes it easy to visualize the presence or absence of a certain disease. It shows the difference of an inflicted to a normal individual at a molecular level. It also shows a difference between a pathogen that causes a disease and one that does not. Despite biotechnology‘s vast importance in the aspect of diagnostics, it important to note that it entails the correct assessment of molecular differences found among samples, because, as already established, not all differences lead to the inability of certain pathogens not to inflict diseases. Differences in the importance of which diseases should a population be screened of is dependent on its socioeconomic status. Usually, poorer areas tend to suffer more from infectious diseases than richer countries do. The latter, on its part, suffer more from lifestyle illnesses such as cancer than infectious diseases. Knowing this fact, one can assume that screening of infectious diseases in a poor town such as those in Africa is much more appropriate than screening for cancer. PCR, which was mentioned in the introduction, is a biotechnological tool that can be used in various ways in the field of medicine. In diagnostics, it is used by using a primer that has a complementary sequence to that of a gene specific to the organism in question. Primers have already been developed for the detection of Mycobacterium tuberculosis, which causes the respiratory ailment that goes by the same name, Chlamydia trachomatis and Neisseria gonorrhea that are transmitted sexually, Helicobacter pylori, and Malaria parasite (Genetech Biotechnology, 2005). Aside from PCR, other techniques can be used in medicine. In this section of the paper, techniques other than mere replication of DNA sequences are will be discussed and related to the field of diagnostics. Despite the identical make-up of the set of genes which two organisms of the species may contain, its strains have a different genotype, mainly because not all DNA are protein-coding or even signals for transcription or replication. These differences in DNA are most usually nucleotide insertions or deletions, which are detected by processes such as the tandem of PCR, restriction fragment polymorphisms (RFLP) and pulse field gel electrophoresis (PFGE) (World Organisation for Animal Health, 2009). In simple terms, this group of procedures, replicate DNA sequences, cut those sequences at distinct points, and determine the differences in the length of the spliced material. PFGE is an important component of this group of biotechnological tools because it determines differences in molecular weights, which reflect the differences in the number of nucleotide bases present in the sequence. Identifying strains are necessary in diagnostics because genotypic differences might confer one strain resistant to the antibiotics applied against the other variant. Such phenomenon is a usual occurrence in microorganisms, whose corrective mechanisms on its genetic processes such as replication are not as fine-tuned as those possessed by higher forms of life such as animals. One example of these microorganisms is the methicilin-resistant Straphylococcus aureus (MRSA), a variant of the skin disease causing-S. aureus type strain. As the name suggests, MRSA growth is not inhibited by the application of the usual antibiotics used against the type strain. As such, an infection outbreak is much more difficult to stop and treat. Determination of MRSA through RFLP is important so that effort and resources are not wasted on treating this highly resistant strain with penicillins. In addition to diagnosis of an infection with a much more potent strain, PCR-RFLP and electrophoresis is important in describing the epidemiology of a certain outbreak. For such purposes a database is an important component of analysis as it entails comparison within a species (among variants). Detected genetic differences are probably caused by mutations that are brought about by differences in habitat. In turn, these differences in habitat are caused by differences in geographical location. Moreover, RFLP-PFGE is one of the ways by which the presence of, or the DNA sequences associated with genetic diseases may be identified. Findings of such procedures are important in better understanding of the disease and better assessment of the risk of inheriting such conditions. It also leads to early detection, early intervention, and possibly even the discovery of new and more effective therapy procedures. Aside from genetic diseases, biotechnology is also useful in detecting cancer, which is one of the top leading causes of mortality. However, cancer is easy to treat with early detection, thus the need to improve the cost- and time-efficiency of the cancer-specific diagnostic tool. It has already been established that molecular changes caused the cells to be hyper-proliferative. For example, the mutations in APC and K-RAS genes causes colorectal cancer, but a wild-type APC gene and a mutated K-RAS gene causes apoptosis. In addition, active p53 is very common among human cancer. These facts are used in diagnostics such that in choosing molecular markers for cancer, one opts to look for traces of APC mutations rather than K-RAS mutations (Wagener). THERAPY Several health conditions are already alleviated by biotechnological techniques. Cystic fibrosis, a genetic disease that affects breathing, is improved by the intake of a recombinant-produced protein that degrades the mucus build up in the lungs. Another treatment approach involves viral colonization of lung cells. This provides the gene that is initially defective in the patient with cystic fibrosis (Anonymous, 2008). Biotechnological advancements in the field of therapy have always been present. In 2003, Ahmed et al. were able to develop a protocol by which a virus can be programmed to specifically colonize and cause the lysis of cancer cells. The programmed virus contains a gene that causes another viral gene essential for its replication to be degraded only by normal cells. On the other hand, Hess et al. published the same year their findings of pancreatic regeneration among diabetic mice through adult bone marrow stem cell transplantation. This improvement in the function of pancreas is evident in increased levels of insulin and reduction of hyperglycemia. Bacteriophages are now being developed as a transport mechanism for the protein and DNA vaccines and as a more effective alternative to antibiotics (Clark and March, 2006). Transgenic plants provide an avenue for giving molecules that confer resistance against certain diseases. Tobacco was initially exploited for the successful expression of Streptococcus mutans surface protein A to provide possible resistance against dental caries. An antigen of hepatitis B virus was also inserted into the plant for possible development of a novel way to produce a hepatitis B vaccine. This provides vaccines that have better storage because plant tissues can be dried to minimal moisture content, thus preventing degradation. Vaccines through plants circumvents cold-storage issues, thus making the more available and more durable. Because of its potential, the principle has been tried out successfully on rice (Oryza sativa), which is a staple in several countries around the world (Pascual, 2007). In the treatment of cancer, biotechnological processes have been developed as treatment options for cancer. For example, inactivating p53 is one of the options. Many other activated pathways have been used as a target of therapeutics. Fusion proteins derived from promyelocytic leukemia (PML) and retinoic acid receptor have been found on PML cells. In turn, treatment with all-trans retinoic acid degrades these fusion proteins. Among breast cancer cells, the activity of the protein of oncogene ERBB2 is inhibited by the action of trastuzumab (Herceptin). Such treatment options pave the way for a therapy that is more directed towards cancer cell masses, unlike the traditional methods in which also the normal cells are affected (Wagener). Cytokine therapy is particularly effective against malignant tumor. It allows the most effective immune responses to target against the hyperproliferative cells.  Interleukin-2 and Interleukin-12 are just some of the cytokines used in this mode of treatment. These cytokines increase the rate of development of T- and B-cells, increasing the cell-mediated and antibody immune responses of the body. However, side effects such as nausea, vomiting, fatigue, and headache are associated with cytokine therapy (Livernois et al., 1997). Because it has been established that estrogen induces the growth of breast cancer cells, endocrine hormone therapy alleviates the growth of breast cancer by decreasing estrogen production or preventing it to reach the estrogen-receptor positive breast cancer cells. Selective estrogen receptor modulators may be taken in orally to inhibit the estrogen receptors in the breast tissue. In addition, aromatase inhibitors may be used to prevent estrogen production (Casey, 2010). Monoclonal antibodies are immune proteins that deactivate the pathogen by attaching to its specific parts. Because of its specificity, it is especially effective against cancer cells, which has a lot in common with the normal cells because they arise from normal cells. Primarily, monoclonal antibodies make the other immune cells recognize the cancer cells as foreign bodies. However, it can also act as a preventive measure in the proliferation of cancer cells by attaching to growth factor receptors, thus inhibiting them from detecting signals from growth factors. They may also attach to growth factors released by cancer cells to promote vascularization. By attaching to the growth factors, the receptors will not recognize the signal from the cancer cells. Finally, by attaching a radioactive particle on the antibodies, radiation can be directed specifically toward cancer cells (Mayo Clinic, 2010). CONCLUSION The uses of biotechnology in the field of medicine are vast and constantly changing. It is quite possible that more techniques will be developed in the future as many questions come about with every answer discovered. What is important is the acknowledgement that biotechnology is a vital part of prevention, diagnostics and therapeutics. With this techniques will certainly be improved and changed in the future. References Ahmed, A., Thompson, J., Emiliusen, L., Murphy, S., Beauchamp, R.D., Suzuki, K., Alemany, R., Harrington, K. & Vile, R.G., 2003. A conditionally replicating adenovirus targeted to tumor cells through activated RAS/P-MAPK-selective mRNA stabilization. Nature Biotechnology, 21, pp. 771-777. Anonymous, 2008. What is gene therapy? Available at: http://www.biotech.wisc.edu/outreach/poster/genetherapy.html. Date accessed: May 14, 2011. Casey, J., 2010. Endocrine therapies for breast cancer. 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