Modern Medical Techniques: Making Medical Process Easier

The term Genes was coined by the Danish biologist William Johannes. However Gregory Johann Mandel was the first to show hereditary factors in all the biological species. These genes were responsible not only for transmitting hereditary traits, but also for influencing the entire process of life. For long these genes remained an enigma, but with the discovery of the DNA (Deoxy Ribonucleic Acid) by Watson and Crick in 1953, some of these mysteries were solved. The structure of the DNA was like a twisted rope ladder. If ladder is to be straightened, we would see that the two sides of the ladder consisted of long chains of sugar and phosphate molecules in repeated sequence. This structure is never varied.

The two sides of the ladder were connected by rungs which were further divided into two halves each linked to one side of the ladder. These half rungs can be formed with different kinds of glucose. These half rungs with the attached part of the ladder are known as nucleotides. These molecules are formed in a fixed arrangement which forms the genetic code. The genes control the operations like multiplication and synthesis of proteins. Before the division of the cell the DNA ladder splits from the middle. The separated nucleotides now pick up their partners from the free floating nucleotides, forming another ladder. This replication is followed by differentiation, whereby specialized cells form different parts of the body.

The genes are found in the thread like bodies called chromosomes which lie in the nucleus of the cell. Mice have 20 pairs and human beings have 23 pairs. The nucleus is filled with RNA. The difference between RNA and DNA is that while the former is of single strand, the latter is of double strand. The RNA has uracil instead of Thiamine of DNA. The RNA consists messenger which transfer RNA.

DNA Finger Printing-it is a technique; also called genetic finger printing for identifying the component of DNA that is unique to a particular individual. Just as one person finger prints are different from everyone else and can be used for identification so a small section of the DNA of an organism uniquely distinguishes particular organism from all others. The difference in genetic makeup between two individuals of the same type is very small. However they do exist. This technique was first developed by Alec Jeffrey in 1985 in U.K.

DNA finger printing is becoming an established forensic technique and has been used successfully as evidence in court cases of rape. It is also being used to investigate family relationship in animal populations and to measure the extent of breeding by looking at the degree of variability in DNA profiles comparing the DNA patterns of parent and offspring may in future be useful in preventing trade in endangered species or in proving paternity suits. It can also be used in forensic medicine for identifying criminals in murder cases etc.

Genetic Engineering-it is a technique in which manipulation of genes in the form of fusions, deletions, inversions and transpiration takes place. Gene splicing and Recombinant DNA technology are also forms of genetic engineering. In the Recombinant DNA technology, DNA of one organism is grafted into DNA of another.

During the process of recombination an E-Coli bacterium is broken up by a detergent. The plasmid is submerged in a restriction enzyme called restriction endow nuclease which creates various cleavages in the plasmid. The restriction enzyme is again used to separate a DNA from a virus. This gene is inserted into the DNA of the bacteria. DNA lipase now helps to join the two segments by acting like glue. Now the hybrid plasmid is introduced into the bacterium which now fiercely divides and multiplies.

By this process, many engineered substances have been produced e.g. (human insulin, INTERCRON) (anti-virus and anti-cancer) somatrem (growth hormone) vaccine for Hepatitis plasminogen activator (blood clotting) etc.

Hormones-It is a chemical secretion from the body which regulates various process in human body. It is secreted from endocrine gland, which travels through blood and reaches various parts of body where it regulates various functions. Thus unlike enzyme its site of production and site of action is not same. Some important glands secreting hormones cells are Pituitary gland, thyroid, Pineal gland, Para thyroid gland, thymus gland and Adrenal gland etc.

Tissue Culture Technology-it is the technology of artificially growing micro-organisms or cells or tissues to the desired genetic purity with properties, such as high yields and disease resistance. In fact it is sophisticated method for growing living tissues in vitro (i.e. in glass) or in vivo.

For in vitro culture tissue from a plant or animal is placed in a medium, usually liquid, in which an assortment of substances has been dissolved. Contamination by bacteria, a major obstacle in the early days of tissue culture, is controlled by antibiotics added to the mediun.

In vivo tissue culture is carried out by implanting tissue into a living plant or animal. Both these methods have been refined to a point where a single cell isolated from a tissue can be cultured successfully. This type of technique is known as cell culture.

Applications:

(i) Vaccine against viral disease such as polio. The virus must be cultivated on living tissue in vitro, (ii) Recognition under the microscope of chromosomes that cause various kinds of disorders, such as down's syndrome, (iii) Growing skin for grafting onto extensive bums, (iv) Cancer and immunology research, (v) Propagation of desirable varieties of asparagus, orchids and many other plants, identical clones were produced in this way.

Source: Medical Society of London annual magazine