My Science School

The cornea is the clear, front part of the eye that covers the iris (coloured part of the eye), pupil (black hole in the centre of the iris) and the eye chamber. The main job of the cornea is to refract light so that the image strikes the retina.

The cornea may be damaged in a number of ways, which may lead to loss of vision and blindness. In such cases sight may be restored if the damaged cornea is replaced with a functional one. This was only made possible in 1905, when a Moravian doctor, Eduard Zirm transplanted a deceased child donor’s cornea to the eye of a chemical burn victim.

Cornea transplants became more common with advances in operating microscopes and the establishment of eye banks for the donation of corneas.

Cancer is the uncontrolled growth of cells in the body. Such a growth is called a tumour. There are two kinds of tumours - benign and malignant. Benign tumours are not life-threatening. Malignant tumours are life-threatening if left untreated and can spread to other parts of a body.

Radiation therapy is a cancer treatment that uses high-energy, concentrated radiation to kill cancer cells. It is an important tool for treating cancer and is often used along with chemotherapy and surgery.

Radiation therapy was introduced in the beginning of the 20th century. In 1902 German surgeon, Georg Perthes, began using X-rays to shrink cancerous growths. However, in those days radium was used for radiation therapy and exposure to radium is dangerous. Today, a much safer form of radiation therapy uses Cobalt 60 as a source of gamma rays to kill the cancer cells and keep them from growing and multiplying.

Patients may first undergo surgery to remove cancerous tumours and then have radiation therapy or sometimes a dose of radiation is given during the surgery. Each patient’s treatment depends on the kind of cancer he or she has.

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In 1786, Luigi Galvani, an Italian physicist noted that an electrical current could be recorded from skeletal muscles. This set into motion a series of inventions and discoveries that finally ended with Willem Einthoven inventing the first Electrocardiograph machine in 1895.

Einthoven was a Dutch doctor and physiologist who was born in 1860 in Semarang, Indonesia. He published the first electrocardiogram (ECG) reading which was recorded on a string galvanometer, in 1902.

The idea behind the ECG is simple. Every time the heart beats, an electrical signal is generated. An electrocardiogram measures these electrical signals. To elaborate, electrocardiography is the method of graphic tracing of the electric current generated by the heart muscle during a heartbeat. It is a painless procedure that shows if the heart is beating at a normal rate and strength. It is used to check for different heart conditions and is one of the most commonly used tests in cardiac assessment today.

Electrocardiograms are made by applying electrodes to various parts of the body. The electrocardiogram shows upward and downward deflections that reflect the contraction of the atria and the ventricles of the heart. Any deviation is indicative of a possible heart disorder.

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Karl Landsteiner was an Austrian immunologist and physician born in 1868, in Baden bei Wien, Austria.

In 1900 Landsteiner found basic differences in human blood that made blood transfusions dangerous. In 1902 he showed that there were four basic types of human blood - A, B, O and AB - and developed the ABO system for blood typing based on these groups. This discovery made it possible to determine blood compatibility for safe blood transfusions.

He also discovered the Rhesus (Rh) blood factor which can result in miscarriage or illness in an unborn if undetected. Along with Erwin Popper, Landsteiner was the first to isolate the polio virus in 1909. He was awarded the Nobel Prize in 1930 for his achievements.

In 1936 he published a book called The Specificity of Serological Reactions, which laid the foundations for the science of immunochemistry.

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Ronald Ross was a British physician born in 1857 in Almora, India. He was awarded the Nobel Prize in Physiology or Medicine in 1902 for his discovery of the life cycle of the malarial parasite.

Deadly fevers were recorded as early as 2000 BC. These fevers, possibly due to malaria, caused a great number of deaths worldwide. Even today malaria causes around 3 million deaths every year and affects 40 per cent of the world’s population.

Till a little more than a century ago it was thought that these fevers were caused by something in the air, especially the air of swamps and in marshy areas. The word malaria itself means ‘bad air’ in Italian.

It was Sir Ronald Ross who discovered that malaria was not caused by bad air but by the bite of the female Anopheles mosquito. He traced the life history of the plasmodium parasite, and found that it began its life in the stomach of a mosquito. Here it bred rapidly and passed into the blood of a healthy person when the insect bit him.

Once mosquitoes were identified as the cause of malaria, worldwide efforts were made to destroy them and antimalarial drugs were developed. With this, the incidence of malaria dropped significantly all around the world.

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Aspirin is one of the most commonly used drugs in the world. It works as a pain reliever, heart attack preventer and cancer deterrent rolled into one. The key ingredient in Aspirin, Salicylic acid, has been used in traditional medicine since ancient times. It was harvested from the bark of the willow tree.

In 1763, a clergyman named Reverend Edward Stone, outlined the uses of the willow bark in treating fevers and other disorders. His writings on the subject are believed to have inspired the use of this bark to treat fevers by many physicians of the time.

Scientists began to study this ingredient and in 1829, a French pharmacist Pierre-Joseph Leroux managed to isolate salicin. Raffaele Piria was the first to synthesize salicylic acid from salicin. Aspirin as we know it came into being in the late 1890s in the form of acetylsalicylic acid when chemist Felix Hoffmann at Bayer Laboratories in Germany produced it from dry meadowsweet leaves. The drug became an instant hit and is commonly used today to relieve aches, pains and fevers.

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Sigmund Freud was born in 1856 in Freiberg, now in the Czech Republic. Trained as a neurologist, he invented psychoanalysis as a method of treating mental disorders.

He proposed that mental disorders may not have their source in the brain but in the mind. In other words, some mental disorders may not occur in the nerves of the brain but in the mind of the person.

Freud made use of hypnosis as a tool to enable his patients to recount past incidents that they may not otherwise have remembered. He found that patients improved after these sessions and laid the foundations of the branch of psychology known as ‘psychoanalysis’. He also developed such therapeutic techniques as ‘free association’ and ‘transference’. He was also interested in dream analysis. However, his theories are controversial and tend to cast women in an unfavorable light.

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In the late 1800’s, scientists were experimenting with cathode-ray tubes, which are electron emitting devices now used in TV’s and computers. In 1895, during one of these experiments, a German physicist named Wilhelm Rontgen discovered that a strange radiation was originating from the cathode tube he was working on. He called this unknown radiation ‘x-rays’.

Rontgen investigated these rays and found that they produced an image on a photographic plate and could penetrate materials such as paper, wood and living tissue. It was also found that x-rays could not pass through dense objects like bone and metal. This meant that dense materials left an imprint on photographic film. This led Rontgen to take the first x-ray image on December 22, 1895 of his wife’s hand showing her bones and a ring that she was wearing.

This discovery was a medical breakthrough since doctors could now look into the body without surgery. Soon physicians were using x-rays to find out what was not possible to diagnose by just a physical examination of the patient.

Rontgen received the first ever Nobel Prize in Physics in 1901 for his remarkable discovery and is known as the ‘Father of Diagnostic Radiology’. Today, X-ray technology is used in medicine, material analysis and devices such as airport security scanners.

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Elie Metchnikoff was born in 1845 in Kharkiv, Ukraine. He was a Russian-born zoologist and microbiologist who received the Nobel Prize for Physiology or Medicine in 1908.

He proposed the theory of cellular immunity which describes the protective immune process of an organism, where individual cells of the immune system recognize and react to invading germs by engulfing and destroying them. These immune cells are called white blood cells or leukocytes and work as the first line of defence against foreign bodies (antigens).

Leukocytes are made up of phagocytes and lymphocytes. Whilst phagocytes swallow foreign particles, lymphocytes keep a memory of previous invaders so that the body can act against them if they attack again. Metchnikoff was the first to discover the white blood cells called phagocytes and suggest that these cells had an immune function in our bodies. This process is called phagocytosis and laid the foundation of the theory of cellular immunity. Metchnikoff is therefore called the “Father of Innate Immunity”.

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One of the most significant practices in hospitals after the introduction of surgical asepsis was the use of surgical gloves. This practice is now part of surgical protocol in every corner of the world.

The story of surgical gloves is a truly heart-warming one! It began in 1890 when William Halsted, the chief surgeon at the prestigious John Hopkins Hospital in Baltimore, USA, faced a staff issue. The head nurse, Caroline Hampton, threatened to resign saying that the newly introduced disinfectants were burning her hands.

Halsted, who was fond of the nurse, approached the Goodyear Rubber Company to create rubber gloves which would protect her hands. It was soon found that the gloves were very effective in protecting both the staff and the patients as well. Before long other hospital staff began wearing them and the practice spread.

In an interesting development, Halsted and Caroline Hampton were married after this. Thus, the story of surgical gloves began as a gesture of love!

In the modern era, it is inconceivable for hospital staff to work without gloves. They are used for a variety of purposes, the latest being the Coronavirus outbreak. Today along with hospital staff, even the general public is wearing gloves as part of the fight against Covid-19.

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Emil von Behring was born in 1854 in Hansdorf, now in Poland. He was one of the founders of immunology. He received the first Nobel Prize in Medicine for his work on serum therapy and its use in the treatment of diphtheria.

Diphtheria is a highly contagious disease which is spread by contact or through the air. It was once considered to be fatal, especially among children.

In 1889, Behring became associated with the Institute of Hygiene in Berlin, where he carried out research in the field of immunization. Behring, along with Japanese bacteriologist Kitasato Shibasaburo, showed that it was possible to immunize an animal against tetanus by injecting it with the blood of another animal already Infected with the disease. Building further upon this research, Behring and Jewish physician Paul Ehrlich developed a serum that produced immunity against diphtheria. The diphtheria antitoxin became a routine treatment of this disease and Behring is widely known as “a saviour of children” for this contribution.

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Wilhelm Waldeyer-Hartz was born in 1836 in Brunswick, Germany. He was a professor of anatomy and pathology. He is best known for his research on the nervous system and for coining the words ‘neuron’ and ‘chromosome’.

Waldeyer pointed out in 1867 that cancer is formed when cell division becomes uncontrolled. He also explained that cancer begins as a single cell and spreads by multiplying rapidly and initiating new growths. He said that cancer could be cured if it was diagnosed and treated in the early stages.

For many years the surgical removal of cancerous tumours was seen as the only remedy, till the discovery of radiation at the end of the 19th century. Radiation and chemotherapy made non-surgical treatment of cancer possible.

Now cancer, which was believed to be incurable not so long ago, is viewed as a disease that can be cured, just as Waldeyer had suggested.

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Jean-Martin Charcot was born in 1825 in Paris, France. He was a neurologist and professor of anatomical pathology. Charcot is one of the pioneers in neurology and various diseases and conditions are named after him, such as Charcot’s disease, Charcot’s joint, Charcot’s artery and Charcot’s fever.

He has an interesting epithet to his name- “The Napoleon of neurosis”. Neurosis is defined as a class of mental disorders which are functional in nature.

In the 19th century not much was known about the causes of mental illness and treatments were often barbaric and ill-judged. Charcot attempted to explain certain abnormal behaviours by categorizing them as ‘hysteria’ and his treatment involved the use of ‘hypnosis’.

Hypnosis is a condition involving reduced awareness, selective attention and a tendency to respond to suggestion. Hysteria was the term applied to patients who showed uncontrolled emotional distress.

Hysteria is no longer accepted as a medical diagnosis by doctors, but hypnotism is still considered an important tool in medicine.

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Gregor Johann Mendel was born in 1822 in Heinzendorf, Austria. He was an Augustinian monk, mathematician and botanist. Mendel is known for laying the foundation for the science of genetics.

Mendel discovered how traits were passed on from one generation to the next. Before his time, it was believed that the traits from both parents were ‘blended’ and passed down in a child. Mendel discovered that traits were not blended but passed on intact, in discrete units, from one generation to the next. Mendel conducted experiments on the life cycles of around 29,000 pea plants over eight years. He studied seven different features or traits found in pea plants, such as pod shape and colour, flower position and colour, seed shape and colour and plant height.

He noted that when a yellow pea plant and a green pea plant were cross-bred, their offspring always produced yellow seeds. However in the next generation, the green colour appeared in the ratio 1 green to 3 yellow. Mendel explained this phenomenon by saying that the green pea plant had ‘recessive’ traits and the yellow pea plant had ‘dominant’ traits. He outlined two laws called the Law of Segregation and the Law of Independent Selection, also called ‘Mendel’s laws of inheritance’, to explain his findings.

He published his findings in 1866 saying that ‘invisible factors’ were responsible for the traits of an organism. We now know that these invisible factors are called genes. Mendel established many of the rules of heredity and is known as the ‘Father of Genetics’.

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The ubiquitous thermometer is a familiar object in every home. Used to measure body temperature, it is used universally as one of the primary indicators of sickness. Before the thermometer was invented, the physician would check the temperature of a patient by hand.

The first instrument for measuring temperature was invented by Galileo Galilei in 1593. He filled a glass bulb with air and connected it to a long tube of water to show variations in temperature. This instrument was called a thermoscope since a calibration was not present for measuring the temperature.

In 1612, Venetian physician Santorio Santori transformed the thermoscope into a thermometer by adding a numerical scale for measurement. In 1654, an enclosed thermometer was invented by the Grand Duke of Tuscany, Ferdinand II. He used alcohol as the liquid inside.

In 1714, Daniel Gabriel Fahrenheit invented the first precision thermometer. He used mercury instead of alcohol or water. In 1724 he introduced the standard temperature scale ‘Fahrenheit scale’ which was used to record temperature changes accurately. This thermometer was the most accurate till date and was the first to be mass produced. It is still in use today.

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