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CT Scan and MRI Introduced

The use of X-rays in medicine was a huge breakthrough at the turn of the century. British engineer Godfrey Hounsfield came up with an improvement on the 70-year-old technology. It combined X-ray images with a computer.

Hounsfield called this technology a CT (computerized tomography) scan, also called CAT scan (computerized axial tomography). It was especially useful for looking at head injuries and brain problems, because it showed about 100 times greater detail in soft tissues than traditional X-rays. Hounsfield was knighted and won the 1979 Nobel Prize.

In the 1980s another imaging technique was added to the tools of medicine. Nuclear magnetic resonance is a technology that, using a gigantic magnet, can line up the protons- or nuclei of hydrogen atoms – in an object (or organism) to align with the north-south polarity of the magnet. A computer “reads” this to create an image in a process known as MRI, magnetic resonance imaging. MRI can give an image of any plane through the body, while the patient’s experience consists of lying still in a body-sized tube, and hearing the click of the machinery.

Atom Medicine

In the last 20 years the use of atom medicine has become so widespread that every big medical centre uses some form of it in diagnosis and treatment. Thousands of hospitals all over the world have had very successful results with radioactive iodine for thyroid cases.

The chief medical use of radioisotopes is against cancer. Every year thousands of cancer patients are being treated with radio-cobalt, which in many ways is better than X-ray treatment.

The radioisotopes can be given in smaller doses, and can be concentrated more accurately on the cancerous cells. In addition, they cannot cause burns and have no harmful radiation effect.

Radioisotopes for Diagnosis

In some cases it is important for the surgeon to know whether an injured bone has “dead” from loss of blood supply.

Few years ago it was necessary to wait several months, and sometimes even a year, for the accurate diagnosis that made treatment possible. Now surgeons have discovered how to find in a few minutes whether the bone has ‘died”. It is done by using a radioscope – Sodium 24. When this isotope is pumped into the injured bone, it keeps its radio-activity if the bone is “dead”. But if the bone is still living, the blood carries away the radioisotope within ten minutes.

By measuring the amount of radio-activity left in the bone, the surgeon gets the information about the condition of the injured bone.

Diagnosing Heart Ailments

Scientists have discovered that the beginning of coronary thrombosis can be detected and located by the use of radioactive iodine. The isotope of iodine is attracted to inflamed tissues and thus shows the exact place of thrombosis.

Electrocardiograms do not always show the beginning of a heart attack. The use of the radio-active iodine is better than electrocardiogram in this respect; it shows exactly the location of the thrombosis and it is helpful in treatment.



Proton Beams for Brain Operation

In some cases it is necessary to make a brain operation, cutting several nerve tracts. In 1958 surgeons made this operation for the first time with an “atomic knife” – a proton beam that required no cutting into the brain. Usually such operation required weeks of preparation and many weeks of recovery. The atomic operation took about two hours; as soon as it was over, the patient walked off a meal. He did not feel any pain and only said that he was tired from sitting in the same position for two hours. During the operation the patient was rotated from time to time so that the beam from synchrocyclotron could strike the brain at different angels. The surgeons directed the beam from another room, giving the patient instructions from time to time by telephone.

The proton beam was 10mm wide and 2 mm thick.

1938. Nylon is Invented

In 1928 a team of researchers, led by organic chemist Wallace H. Carothers of the United States and sponsored by the chemical firm, set out to discover what sorts of materials they could produce from varying combinations of long-chain molecules. In a pioneering process called polymerization they combined atoms into long molecules that varied in the types of atoms used and the ways they were joined, producing an assortment of unique materials. Then one day in 1930 they discovered an unusual property of one of their molten substances: it would stick to a glass rod and form a fine strand. As soon as the strand met the cold air, it solidified and formed a long continuous fiber that was both flexible and strong. If the fiber was then stretched to four or five times its original length, its properties changed further: it strengthened still more and at the same time became lustrous. Its structure was such that it could be spun into a fiber resembling silk, but it had high strength and elasticity and exceptional resistance to abrasion, rot, mildew and chemicals. For eight years chemists, physicists, engineers, and textile experts labored to develop this oddity into a usable fiber that could be manufactured on a large scale. In 1938 the announced their success. This synthetic textile fiber was to be called nylon.

1973. Biotechnology

Two American biochemists, Stanley H. Cohen and Herbert W. Boyer, inaugurated the science of genetic engineering – and its associated field of biotechnology – in 1973. They showed that it was possible to break down DNA into fragments and combine them into new genes, which could in turn be placed in living cells. There they would reproduce each time a cell divided into two parts.

1996. Cloning of an Adult Mammal

When Dr. Ian Wilmut introduced the world to the first successful clone of an adult mammal – a seven-month old Finn-Dorset lamb named Dolly – a new frontier in science opened wide.

When Dr. Ian Wilmut and his team from the Roslin Institute created a lamb named Dolly they accomplished what many experts thought was a scientific impossibility. Unlike off-spring produced in the usual fashion, Dolly does not merely take after her biological mother. She is a carbon copy, a laboratory counterfeit so exact that she is in essence her mother’s identical twin.

In 1996 Dolly became the first large animal to be cloned from genetic material extracted from an adult cell.

Scientists inserted a cell from ewe’s udder into an egg from the same animal after removing the egg’s DNA. The bioengineered embryo was implanted in the ewe’s womb and Dolly developed as a clone. Her birth at the Roslin Institute in Scotland was announced in 1997 and caused an international sensation.

What advances in modern medical science interest or impress you most?


Date: 2015-01-12; view: 714


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