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Enhanced Nutritional Aspects!
Since decades scientists have been putting prolonged efforts in developing healthier foods that can improve human health. Few such examples are as follows;
In the 1930s, immigrants to the United States living in big cities were unusually prone to rickets; a bone disease caused by the deficiency of vitamin D.
Poor dietary habits was one of the reasons and another reason was the tall, tightly packed in tenement buildings where many immigrants lived thereby blocking most of the exposure to direct sunlight which happens to be a key source’ of vitamin D. When food manufacturers began adding vitamin D to bread and milk, shortly thereafter rickets became very rare in the United States.
Field tests are underway for a decade by Purdue University and the U.S. Department of Agriculture’s Agricultural Research Service on a cancer-fighting tomato with three times more lycopene, an antioxidant, than conventional varieties.
Lycopene is known to trap harmful molecules that damage human body tissue and could lower the risk of breast and prostate cancers, as well as coronary heart disease. The development was discovered when attempting to lengthen the shelf life of tomatoes. This was chosen by American consumers as 2002’s top food biotechnology development.
Several research teams are also working to improve the quality of rice which is a staple food for half of the world’s population, by putting more nutrition into each grain.
The enhanced “golden rice” that is genetically enhanced to express carotenoids may help reduce childhood blindness, while new iron-rich rice could have a truly global impact and prevent malnutrition. In developing countries, where vitamin A deficiency prevails, grain from Golden Rice is expected to provide Pro- vitamin A.
In India, mustard seeds have been enhanced, so they contain more beta carotene by Monsanto Company, in cooperation with Michigan State University, USAID and the Tata Energy Research Institute in India, which could help alleviate vitamin A deficiencies.
Life Saving Vaccines:
The staple foods can be used to deliver inexpensive and effective vaccines for specific illnesses. They are known as edible vaccines. This strategy will make vaccines easily available and thereby save near about 15 million children who die each year from preventable diseases. For instance, researchers are experimenting with building a vaccine for hepatitis B that can be injected into bananas.
It attacks the liver. When eaten, the vaccine is absorbed through the intestine into the bloodstream, producing antibodies in the same way as an injected vaccine. Hence, biotechnology not only enhances the quality of nutrition and in curing of diseases through nutritious substances but also reduces food toxins and allergens.
Diagnostics:
It is in the area of diagnostics where biotechnology has arguably been most successful from the point of view of transforming practice.
The two major contributions of medical biotechnology to diagnostics presently are:
Pre-Diagnosis:
The ability to screen for and detect the predisposition for diseases in individuals.
Prognostication:
Better prediction of outcomes for particular diseases, or the effects of therapy on the patients. The majority of successful commercial diagnostic tests introduced as a consequence of medical biotechnology advances are nucleic acid tests and those tests based on monoclonal antibodies.
Considerable efforts are also being expended to harness the technologies used for proteomics and nanotechnology based researches for the purpose of advancing diagnostics.
Nucleic Acid Tests:
The fundamentals of genetic replication, first discovered in 1953 by Watson and Crick, laid the foundations of clinical molecular diagnostics. The invention of the polymerase chain reaction (PCR) in 1983 by Kary Mullis was a revolutionary discovery in molecular diagnostics.
The PCR is an in vitro technique for isolating and exponentially amplifying a fragment of DNA via enzymatic replication. It has the capability of amplifying even trace amounts of specific DNA to detectable levels.
The coupling of DNA amplification with fluorescence based detection results in what is known as “real-time PCR” wherein quantification of DNA occurs at the end of every amplification cycle to give highly sensitive and specific yet rapid results.
Nucleic acid tests for the human immunodeficiency virus (HIV) can quantify the amount of HIV in a patient’s blood sample (see also Blood: The Essence of Humanity). Although seldom used for the diagnosis of HIV in adults because of their relative cost, they can be used to test infants born to HIV-positive mothers.
Primarily it is used in the screening of donated blood in blood banks – to reduce the so-called “window period” where HIV may be undetectable in newly infected patients – and as a way to evaluate the success of anti-retroviral therapy by measuring the degree of reduction of the HIV viral load in treated patients.
Similar tests are also available for Hepatitis B and C viruses, cytomegalovirus, and Epstein-Barr virus to quantify the amount of virus in infected patients.
For hereditary cancers, genetic screening using PCR-based methods combined with bioinformatics databases and disease registries offers the possibility of earlier diagnosis or even pre-emptive therapy. Genetic testing has also allowed for the identification of particular genetic mutations in cancer with prognostic significance. It also allows for the identification of family members who possess the gene, and who are thus at extremely high risk of developing cancer.
Prenatal genetic screening is offered in most developed countries, with the rationale of detecting chromosomally abnormal conceptions and the presence of genetic disorders, and thereby offering the option of terminating conceptions early.
Pre-implantation genetic diagnosis (PGD) are the genetic diagnostic tests performed on embryos prior to implantation and is an alternative to prenatal diagnosis where PCR was used for sex determination in the embryos of patients with X-linked diseases.
Monoclonal Antibodies:
Georges Kohler, Cesar Milstein, and NielsKaj Jerne won the Nobel Prize in Physiology or Medicine for their discovery of the process of producing monoclonal antibodies in 1975. The use of monoclonal antibodies is being effective in diagnostic purposes. In the field of pathology, they are now routinely used as part of immunohistochemistry to detect antigen in fixed tissue sections, thus facilitating diagnosis.
Tagged with radio-isotopes and injected into patients, monoclonal antibodies can improve the precision of surgery by pinpointing the location of target cells. George Stark’s western blot technique for detecting proteins, perhaps best known for its use in HIV confirmatory testing, is also dependent on monoclonal antibodies directed against the target proteins.
Proteomics for Diagnostics:
The earliest attempts at using proteomics for clinical diagnostics involved using high throughput investigations to identify novel disease biomarkers via surveying the clinical samples of healthy and diseased individuals. Proteins found to be differentially distributed between these samples were then selected with a view to identifying them as potential biomarkers.
However, this strategy has not been successful to date because of problems related to inter-individual variability, i.e., protein level differences related to age and gender; and issues related to the disease, i.e., most diseases may not have one single unique biomarker.
However, although potentially revolutionary, this technology suffers from numerous issues such as high operational costs and operator expertise requirements.
Nano Diagnostics:
The application of nanotechnology in clinical diagnostics is relatively new, even compared to proteomics. Rather than searching for new biomarkers, as is the case for much of biotechnology research in diagnostics, research in Nano diagnostics is mainly centred on extending the limits of current diagnostic techniques.
A prime example of this is research in microfluidic or “lab on a chip” systems, with the idea of combining the numerous processes of DNA analysis onto a single glass and silicon chip. Within a chip the size of a conventional microscope slide are fluidic channels, heaters, and all the devices present within considerably larger PCR machines.
Another example is the “pill camera” used to detect gastrointestinal bleeding, powered by micro-electromechanical systems (MEMS). Within a capsule the size of a regular tablet are a video camera, optics, a light-emitting diode, and a transistor. Images taken by the camera are transmitted to an external computer for analysis.
This obviates the need for more risky gastrointestinal endoscopy. Although nanotechnology opens up a wide array of possibilities in the future of clinical diagnostics, there are no mass-market products available at this point in time. It remains to be seen if its great promise can be fulfilled in the near future.
Organ Transplantation:
The most gripping advances of the century in the fields of biochemistry, cell and molecular biology, genetics, biomedical engineering and materials science have given rise to the field of tissue engineering that is a remarkable new multidisciplinary approach to a critical problem in modern medicine.
The goal of tissue engineering is to develop methods to construct organs in the laboratory that can subsequently be used in medical applications and simultaneously to produce organs or tissues that can be used for research purposes.
Such research might include testing new drugs, simulating diseases in order to develop better treatments and reducing the use of animal tissues and organs in biological research in general. Tissue engineering uses synthetic or naturally derived engineered biomaterials to replace damaged or defective tissues, such as bone, skin, and even organs.
In addition to alleviating the shortage of organs available for transplant, tissue engineering holds the promise of producing better organs for transplant because then it may be possible to construct such organs using cells harvested from the patients themself. This would eliminate the problem of organ rejection and the necessity for the patient to remain on lifelong medication as a result.
Even more exciting from a clinician or researcher’s point of view is the idea of using tissue engineering in combination with stem cell technology. Stem cells are immature cells which, when appropriately stimulated, can mature and become many different adult cell types.
Using stem cells and tissue engineering it may one day be possible to order ‘off- the-shelf tissues and organs to alleviate any number of medical conditions.
