The afterlife of Henrietta Lacks

In February 1951, Henrietta Lacks, a thirty-year-old mother of five, went for an examination at the John Hopkins hospital after noticing blood stains on her underwear. Doctors were quick to conclude that she had most likely contracted cervical cancer. To confirm their diagnosis they took a sample of her tissue and had it analyzed. The news was anything but encouraging: the tumor contaminating the cervix turned out to be malignant. In October, the same year, and only after a few months’ struggle with the disease Henrietta Lacks died.

Immortal cells of a dying patient

Even though Henrietta and her family could not have realized this fifty years ago, her body did not finish its life just yet. Some of the cells are alive even to this very day, more than half a century after their owner’s death. They are being carefully grown in numerous laboratories across the world and have even reached outer space after being sent into the orbit on a satellite, enabling researchers to observe the effect of zero gravity on cell growth. In fact, if we were to weigh all Henrietta’s surviving cells together, they would probably largely exceed the weight of her entire body fifty years ago.

The fascinating journey of Henrietta’s cells began in 1951 when a part of her tumor’s tissue was sent to the laboratory of Otto Gey, a researcher at John Hopkins University who had been striving for decades to find a solution to growing human cells in a laboratory in order to facilitate cancer research. He struggled to find the solution for a long time, but the cells simply refused to grow and divide in an artificially created environment. That was until he came across the cells from Henrietta’s tumor and decided to give them a go.

Miraculous HeLa cells

Even after spending several days in an artificial culture medium, Henrietta’s tumor cells continued to divide successfully and there was no indication of them growing old and dying as was common for all the previous experiments. Gey named them after his patient: HeLa cells. He concealed the identity of his patient with great care and it was only revealed after his death.

However, as rapidly as HeLa cells multiplied in Gey’s laboratory in 1951, they multiplied inside Henrietta’s body. Even though the patient died because of uncontrollable multiplication of tumor cells in her body only half a year after her first visit to the hospital, the very cells that did her so much harm were soon helping to save many other lives.

In the 50s the vaccine for polio was already developed with the help of HeLa cells which have to this day enabled an abundance of researches that have led to the discovery of many important facts about life and the workings of the human body.

Immortal cell lines

Henrietta’s cells were the first to be successfully grown in artificial, laboratory conditions and later used to create an immortal cell lines which is a term used for describing cells that can – in an appropriate feeding environment – continue to divide outside the body without aging. In normal circumstances, cells can only divide for a limited number of times (ten or more) before losing this ability and slowly dying.

Programmed cell death after a certain number of divisions was in fact what stopped Gey from creating an immortal cell line from normal cells in the human body. It was only Henrietta’s cells that had the ability to divide indefinitely. That was because they lacked the mechanism responsible for stopping an uncontrolled multiplication. Its inactivity failed to trigger cell death after a certain amount of duplication.

Cell aggression beats the competition

As HeLa cells turned to be very useful in numerous researches, Gey simply mailed them to his colleagues all across the world so they could grow and use them in their work. Soon, other scientists started reporting having created their own immortal lines of human cells. However, it soon turned out that these so-called new lines were really just a form of Henrietta’s cells. These were found to be very aggressive, as they were capable of infecting other cell cultures and eventually eliminating the competition even when applied in extremely small doses.

In 1972, for example, Russian scientists sent their American colleagues six different lines grown in various parts of the former Soviet Union, but it was discovered that all of them were actually HeLa cells. Americans did not prove to be any more successful either: in 1968 they tested 34 lines and proved that 24 of those were actually derived from Henrietta’s cells.

Growing patient cells

As scientists perfected the methods of growing human cells and cells of other mammals in laboratories, they quickly began to wonder whether it was possible to create immortal lines for specific individuals as well. Organ transplantation always entails a risk that the immune system will reject a transplanted heart or liver. Doctors try to overcome this with special medications that the patient with a transplanted organ has to take regularly for the rest of his or her life as well as by observing the similarities between the organ donor and the organ recipient. The transplant is done only if the donor organ and the recipient are a close enough match to assure a good chance to battle rejection with drugs.

Donor organ transplantations can always entail some problems and risks, so researchers started to think about ways to grow healthy cells of a failing organ in a laboratory and reinsert them into the patient later on. This would prevent the risk of a rejection of foreign tissue, as the artificially grown cells would not differ in any way from those of the patient, already within his body.

Today, skin and bone marrow growing therapies are already available. A sample of cells is taken from the patient and multiplied in sufficient amounts in a laboratory only to be transferred back into the patient later on. Skin growing can prove to be particularly difficult, taking several weeks to produce enough for transplantation, which might already be too late for the heavily injured.

Cells adapt to specific tasks

Another problem with growing ordinary cells present in different tissues of the adult human body is that cells can only perform a limited number of divisions. Sooner or later the process comes to an end or the cells produced do not respond to our needs.

Even though the genetic code of every cell contains all the information it requires for development, most of the cells that make up an adult body have already lost the ability to use the entire code. In the environment of a specific organ, cells adapt to perform a specific task and this adaptation is usually irreversible.

When a cell takes on a function within a blood vessel, the heart, the skin or the nervous system of an individual it can not "change its mind" and take on a different role. Scientists have not yet figured out what exactly happens within a cell when it is adapting to a specific task, but the fact remains: a part of its genetic code shuts off for good.

The mother of all cells

However, not all the cells within the human body have this one-way limitation in terms of their function. Those that have the ability to develop into other types are called stem cells. Their main characteristic is the option to develop into more specialized cells. The bone marrow, for example, contains special stem cells, capable of producing red blood cells that transport oxygen throughout our bodies. Similar stem cells that can produce other specific cells have also been found in various organs.

The capability to develop into every single one of several hundred cell types within the human body is possessed only by very young stem cells that can be found in the first days following fertilization in a group of some ten cells that constitute an embryo. These are called embryonic stem cells and are the only ones with the rare capability of developing into any cell type in different environments.

Immortal stem cell lines

Another important feature of embryonic stem cells is that they can be used to create a cell line. If grown correctly, they can multiply indefinitely without growing old and dying after some ten divisions, as is usually the case with already differentiated cells, such as skin or bone marrow cells. The first line of human embryonic stem cells was created in 1998 in the US.

Today, several hundred exist in the world. In the US, however, following the president George W. Bush’s decree, public research funds can only be used on the 22 lines created before the beginning of his mandate in 2001. This issue is once again gaining importance as the president vetoed the act that would approve the continuation of federal funding of this important/vital field of science.

A mathematical intrigue at the Swedish court

Monetary prizes for solving complex scientific and technical problems are not awarded as often as they used to be. Today, tenders where a committee of experts offers prizes for the best creations that are sent to its address by a certain date are a common way of finding solutions in the fields of architecture and other artistic/technical disciplines, but not so much in science. Every once in a while an organization or an individual still announces that a prize will be given to anyone who can solve some seemingly insoluble problem, but these awards are not really significant in terms of more extensive financing of scientific work. In the past, however, this used to be quite different.

A little more than a hundred years ago, the Swedish mathematician Gösta Mittag-Leffler persuaded King Oscar the 2^nd of Sweden to organize a mathematics competition in honor of his 60^th birthday. As the king was a student of mathematics himself, he took to the idea quickly, especially because Mittag-Leffler had succeeded in convincing two highly distinguished European mathematicians to take part in the jury that would set the tasks and evaluate the solutions. The invitation was accepted by Karl Weierstrass of Berlin and Charles Hermite of Paris.

Is the solar system stable?

Four tasks were given, all relating to the essential problems that were also principal subjects of mathematical research of the time. Even though the king’s birthday was not until 1889, the preparations already started in 1884, so that scholars from across Europe would have enough time to examine the problems thoroughly and come up with their solutions. In the middle of 1885 Nature magazine printed an announcement inviting scientists to participate in a mathematical competition in honor of King Oscar the 2^nd’s 60^th birthday. The deadline for submitting the solutions to the Swedish court and the president of the jury Gösta Mittag-Leffler was June 1^st 1888. Naturally, the essay in which its author would describe his solution was not allowed to be signed in order to enable unbiased evaluation of the work. That is why everyone was required to enclose his solution with a sealed envelope containing his name.

The first of the four questions which were given in formal mathematical language pertained to the problem of the movement of three bodies. In other words, the jury was interested in the question of the stability of our solar system. Today, more than a hundred years after the event took place, what happened a couple of months after the announcement of the winner is more interesting than the initial question and its answers. When the winning solution was already being prepared to be published the editor of the magazine noticed that the jury had rewarded a work which was not completely flawless. One of the mistakes actually turned out to be of key importance.

The winner was no surprise

The winner of the competition was none other than the eminent French mathematician Henri Poincaré who, despite his young age at the time, already enjoyed a very high reputation. In the period between the announcement of the competition and the deadline for submissions he was even elected a member of the French Academy of Sciences which was a great honor for a man of only 32.

The competition was not about winning the money. The awarded sum came nowhere close to that of today’s Nobel Prize. The winner received 2500 Swedish kronor which was approximately one third of a professor’s yearly salary. The award improved the young mathematician’s scientific career significantly and enabled him to secure a good position at one of the renowned universities, but it certainly did not make him rich. As we are about to find out, the prizewinning Poincaré actually lost more than he gained on account of the award.

With his 158 pages long solution to the first problem Poincaré enclosed a short accompanying letter which he signed, even though all of the submitted essays were supposed to be anonymous. It was during the evaluation process that the jury already knew exactly who the author of the solution, which was later unanimously voted to be the best, was. The winner was announced during the celebration of the king’s birthday on January 21^st 1889. A part of the prize was also the publication of the solution in the prominent mathematical journal Acta Mathematica.

It was at this moment that the problem occurred. In July of 1889 when the editor of the journal was preparing Poincaré’s article for publication he noticed a few minor mistakes in the manuscript. He notified Mittag-Leffler who, in turn, wrote a letter to Poincaré on 16^th July to inform him that all of the mistakes but one could be fixed immediately. The one mistake was neither a typing error nor a minor mathematical error. It turned out to be of a much greater importance. As it soon turned out, Poincaré overlooked something essential in his proof which was only discovered after the prize had already been awarded and the article was almost put into print.

How to avoid a scandal?

What to do? If it were to become known that the wrong solution had been rewarded, the reputation of both the king and all of the highly esteemed mathematicians that took part in the evaluation process would be destroyed. The disgrace would be especially devastating to Poincaré who had just begun to shine as the new star on the European scientific scene.

Poincaré went back to work in order to correct the mistake, but the more he examined the problem the more it seemed it was not merely a minor error that could be fixed easily. At first, he sent extensive comments to the text which were meant to clarify the issue, but it became increasingly obvious that explanations alone would not be enough to deal with the difficulty.

So what kind of an error was it? In his original solution Poincaré used a completely new method that made his work much easier and caused a minor revolution in the solving of similar mathematical problems. Instead of calculating the entire orbits of individual bodies or planets, Poincaré chose to focus only on specific moments when a planet or asteroid intersects with a chosen plane. In other words, this method would be best compared to taking an image of the solar system at the exact moment when the observed body circles the sun. In the case of Earth, this would happen once a year.

Poincaré only wanted to determine if a planet or an asteroid, after circling the sun, returns to the same spot, or to find out how the yearly positions change with time. In simpler words: if a chosen plane is always intersected at the same point, the orbit of the motion is obviously stable, but if the plane is crossed at a slightly different point each time, this change has to be described and examined to determine whether these deviations occur within a stable system.

The chaotic mechanics of the stars

Poincaré’s discovery which he had also argued for in his original essay was that the solar system was stable, at least in a simple model of the sun with one bigger planet and one small asteroid orbiting in the same plane. His first finding was that, in this case, the orbits of motion were stable. When he examined the problem again, it became evident that he had forgotten to take into account an entire range of solutions which were not stable, but would lead to chaos.

It turned out that Poincaré had forgotten to take into consideration a geometrical configuration which leads to completely different solutions than the ones he had described in his original essay. Today, we would describe these new solutions, which he overlooked at first, as chaotic. Even though they are precisely determined by clear equations and the paths of the bodies in question are such that their future motion is possible to predict, this kind of a prediction depends on the knowledge of the initial conditions. If there is only a slight difference in the position of the bodies at the beginning, they are bound to move in a completely different way. On the basis of this finding Poincaré could only conclude that not all forms of movement in a simplified system of three bodies were stable, which also meant that the solar system or any other similar system were not necessarily or absolutely stable.

In the couple of months when Poincaré was striving to correct the mistake he had made in his original article, he set the foundations for a new branch of mathematics which later developed to become the chaos theory. The 158 pages of the original essays were expanded to 270 pages. The problem, however, was that the original article had already been printed in Sweden. Fortunately for all those involved it was not yet distributed to the subscribers. To avoid a scandal Poincaré paid 3585 kronor for the reprint of the issue which was much more than the sum of the prize money he had received. They also made sure that most of the first prints of the journal were destroyed, but a couple of the original issues remained. In 1985, during his research visit to Sweden, the American mathematician Richard McGehee was looking through some archives and came upon a couple of copies of the 13^th issue of Acta Mathematica in an unlabeled box containing Mittag-Leffler’s letters. When he was scanning through it he discovered that Poincaré’s article was different than the one he was familiar with from other copies of the same journal.

Even though Poincaré won the prize for the first, flawed version of the article, the edited article, with which he made a giant leap towards the science of chaos, is much more important from today’s point of view. It might seem contradictory, but the award was definitely given to the right person, although for the wrong solution and the wrong essay.

The priest who came up with the Big Bang

The Big Bang theory is believed to be one of the most popular scientific theories today. According to this theory, the universe began as an extremely hot and dense substance which expanded and cooled down with time until, 14 billion years later, it acquired the form that we can observe today whenever we look towards the sky on a clear night. The theory is well supported by experiments and represents a good example of the almost incredible capacity of modern science for taking a small number of data gathered on our small planet and reconstructing the history of the entire universe from the first moments on.

Despite the popularity of the Big Bang theory only a few people today are aware that the first to describe it was a Belgian priest called Georges Lemaître who, in addition to preaching, dedicated his time to science and was among other things a friend of Albert Einstein himself. Einstein accepted the primeval atom theory, as Lemaître called his idea about the development of the universe which was later given its much more resounding name, the Big Bang, with great interest which was not followed by the larger scientific community until the 1960s. That was when two American scientists accidentally discovered that microwave radiation, which can only be explained by the notion that the universe was once much hotter than today, was reaching us from all the directions of the universe.

The universe as a radioactive atom

Of course, Georges Lemaître was not merely an amateur scientist. Even though he was ordained a Catholic priest in the fall of 1923, he always remained true to science. After earning his doctoral thesis in mathematics the same year he was ordained, he started his postdoctoral studies at Cambridge where he furthered his knowledge under the tutelage of Arthur Eddington who was believed to be one of the most eminent astronomers of the time. It was with him that Lemaître became acquainted with the latest discoveries and the newest research methods in astronomy as well as cosmology which was already gradually becoming a branch of science within which experimentally verifiable theories could be formed.

After a year spent in England, he left for Harvard in the USA where he collaborated with Harlow Shapley, another great name of contemporary astronomy. In Boston, which is believed to be one of the most important academic centers of the world due to its elite universities, he also perfected his knowledge at the prestigious MIT, where he became even more drawn to cosmology and started to study models of the universe implied by Einstein’s completely new general theory of relativity. He obtained his doctoral degree at MIT before returning to Belgium and becoming a professor at the Catholic University of Leuven.

Soon after his return, he published the first drafts of his theory of the origin of the universe. Even though one might have expected that, as a Catholic priest, he would look to the biblical story of creation when forming his idea about the Big Bang, this was far from so. His inspiration came from neither astronomy nor the theory of relativity, but from at the time completely new quantum physics. More specifically, he became inspired to form his idea about the primeval atom when studying the phenomenon of radioactivity.

Is the creation of the universe a mere coincidence?

It is known that radioactive elements are not stable, but decay with time, releasing energy. Even though one can not predict exactly when a particular radioactive atom would disintegrate completely it is possible to predict with great precision when, for instance, one half of the radioactive atoms in a multitude of identical atoms would disintegrate. When getting acquainted with the principles of quantum physics, Lemaître asked himself whether it might be more than a mere coincidence that the half-life of some radioactive elements comes very close to the estimations of the age of the universe, based on the measurements of the expansion rate of the universe. Could it be that we are living in some worn out version of a radioactive universe?

According to Lemaître’s original idea the universe began as a kind of a “large radioactive atom” which is why we can determine its exact age. The analogy between the universe and radioactivity was also of key importance in terms of overcoming the famous problem of explaining the very beginning of the universe. If we wanted to give a causal explanation of the first moment, we would have to refer to an even older event, but we can not do so for the very reason that we want to explain the very first event. Many different thinkers throughout history have dealt with this problem at length, but its most well-known formulation probably came from Immanuel Kant who described it as the first antinomy of pure reason.

The essential thing that one should keep in mind when dealing with radioactive atoms is that their disintegration is completely coincidental. It is impossible to predict when exactly a particular atom would disintegrate which is also why there no exact cause for its decay can be determined. It is completely unpredictable, only the probability that the decay will take place within a certain period of time can be predicted. Lemaître expanded his idea about the coincidental decay of the radioactive atom to his idea about the universe as the primeval atom to which all the laws of quantum physics must apply as well. Even though it does not describe exactly the same type of event, the analogy that Lemaître tried to establish is quite obvious. Just as a particular decay has no cause, even though it is dictated by exact laws of quantum physics, the universe as a whole might lack a cause, which still does not mean that exact physical laws do not apply to it.

The universe began shortly before the beginning of time

In 1931 he described his idea in an article published in Nature magazine in which he wrote, among other things: “If the world began with a single quantum particle, the concepts of time and space had no particular meaning in the beginning; they only acquired meaning when the original quantum particle multiplied to a substantial number of quanta. If this idea is correct, the beginning of the world took place just before the beginning of space and time.”

At first glance, this way of thinking might be something that one would never expect from a Catholic priest, but anyone who is familiar at least some of the history of the Christian theological thought will quickly realize that the similarity with the famous doctrine of creation is evident. Just as God, according to the doctrine of creation, is absolutely free in his creation of the world and is not subjected to any kind of limitations, thoughts or higher purposes, Lemaître’s primeval atom is completely free in terms of the moment it “chooses” to disintegrate.

Although the analogy with the coincidental radioactive disintegration was of key importance at the beginning, it became less and less relevant while the theory was being perfected. Lemaître himself developed his theory in the years to follow, founding it on the general theory of relativity, but it was considered to be much too unusual at the time to be accepted within the wider scientific community as a serious description of the actual universe and not merely as one of many hypotheses. In science, a rule exists that the more a theory is unusual, the stronger arguments and experimental proofs it needs in order to be accepted by the scientific community. As we have already mentioned, cosmic microwave background radiation, which meant a great contribution to the acceptance of the Big Bang theory, was only discovered a couple of decades after the Second World War, and the idea about the primeval atom was long regarded as an exotic hypothesis rather than a description of the actual history of the universe. Lemaître died soon after he had received the news about the discovery of cosmic microwave radiation which confirmed his visionary idea about the origins of the universe.

In 1936 he was elected member of the Pontifical Academy of Sciences which advises the Pope on matters relating to science. In 1960 he even became its president and kept the post until his death in 1966. He always defended the belief that there is no ideological conflict between science and religion. He claimed this to be true as a high dignitary of the Church as well as one of the most esteemed scientists of his age.

He was not pleased when Pope Pius XII referred to science, including the cosmology of the Big Bang which had been his area of expertise all along, to try and prove that scientific and divine truths were actually one and the same. Even today, high Church dignitaries often declare that science has been coming to similar conclusions as those described in Church doctrines. According to them, The Big Bang theory is supposed to describe the development of the universe all the way back to the beginning of time with the exception of the first moment which is of course said to be the work of God

Lemaître strongly disagreed with such interpretations which have also been defended by later Popes: “In my opinion, the theory (of the primeval atom) remains beyond all metaphysical or religious questions. It allows the materialist to deny the existence of any transcendent Being. (…) At the same time it corresponds to the words of the prophet Isaiah who spoke of the ‘hidden’ God who was not even seen at the beginning of the universe …”

Cannibals, Insomnia and Mad Cows Disease

Not long after the Second World War, Australian colonial officials assigned to the remote planes of Papua New Guinea noticed an unusual disease among the members of a small tribe called Fore. The locals called it kuru which, in their language, means “to tremble”. That is because those affected by the disease were gradually unable to control their muscles so they started to shake and sometimes even laugh or cry uncontrollably. Once the first symptoms of the disease appeared the sufferer’s death would follow in a matter of months.

The unusual diet of the natives

In 1957 when Carleton Gajdusek, at the time a 33-year-old doctor, arrived to New Guinea, the stories about the mysterious disease, told by the colonial officers, immediately caught his attention. He set out to visit the tribe and began conducting a thorough analysis to discover the true cause of the illness. In order to research the disease Gajdusek had to gather samples of the tissue belonging to the diseased natives. Most of the times he achieved this by somehow buying a dead body and doing an autopsy, sometimes right on the kitchen table in his hut, saving the tissue samples in a shared refrigerator.

When, after carrying out different tests, he eliminated the possibility that the disease was being caused by viral or bacterial infections, he started examining all the environmental factors that could have contributed to the outbreak of the disease. He analyzed the food that the members of the tribe ate as well as the surroundings of their dwellings, but he was unable to discover the cause of the disease. Even worse: he failed to classify the disease into any of the main medical categories into which diseases are usually sorted. By all appearances, kuru was neither a genetic disease nor an infection or a psychosomatic disorder and was not caused by the environment.

After long years of research, which he continued in the USA, he succeeded in proving that the disease was transmitted through brain tissue. He used a sample of a patient’s brain tissue to infect the brains of a healthy monkey and it fell ill. In 1976 he received the Nobel Prize for Medicine for his research on this “completely new form of infection”.

It soon became clear why the disease was spreading even more rapidly among the women and children of the tribe. It turned out that the kuru disease epidemic was caused by ritual cannibalism adopted by the tribe from their neighbors. It was typical of the tribe not to cook and eat their enemies, but their own people who had passed away. This culinary ritual represented a part of their custom of bidding farewell to the dead. Symbolically, the funeral was compared to digestion and they shared different parts of the cooked corpse according to the hierarchical structure of their society; only feeding on the members of the inner family circle was forbidden. If a woman died, for example, her daughters-in-law would get her arms and legs while her sisters-in-law would get her buttocks and her intestines. If a man died, his testicles were given to their uncles’ wives.

Cannibalism has disappeared from New Guinea four decades ago after being successfully eradicated by the missionaries soon after their arrival. However, a few of the older female members of the Fore tribe still die of the disease each year which means that that the incubation period can last very long. According to evaluations, the disease has caused the death of almost 3000 natives.

Has the central dogma of molecular biology been violated?

However, Gajdusek was not the only one to have received the Nobel Prize for research in this interesting field of medicine. In 1997 the prestigious scientific award was also given to Stanley Prusiner who succeeded in substantially developing Gajdusek’s findings and discovering the mechanism that explains how this disease and similar diseases actually work on a molecular level. (Gajdusek also became known for being one of the few Nobel laureates to have been sentenced to prison at an old age. In 1997, while living in the USA, he was sentenced to 18 months of prison for child molestation. He found out about Prusiner’s Nobel Prize while serving his sentence.)

In 1972 Prusiner, then a young neurologist based in San Francisco, lost a patient to the Creutzfeldt-Jakob disease, which is well known today on account of the mad cows disease. As he did not know much about the disease at the time, he buried himself into literature and found out that it had been proved on animals that the Creutzfeldt-Jakob disease, scrapie in the case of sheep and the exotic kuru disease from Papua New Guinea were all transmitted by the infection of healthy brain tissue with a sample taken from a diseased organ.

As the only research material he could get in sufficient amounts were infected sheep, he decided to try and isolate the agent that causes scrapie, a disease of the central nervous system which affects small cattle (sheep, goats and pigs). The method required for an isolation of this sort was complicated because different types of molecules had to be extracted from the infected tissue. These molecules then had to be tested in order to determine whether they caused the disease or not. This would be a more detailed description of the process: a part of the brain tissue was taken from the diseased animal and put into a centrifuge in order to separate individual molecules. The separated samples were then injected one by one into a mouse to determine which part was still infected. The process was then split into further phases to observe and determine which parts were still causing the disease.

The first hypotheses suggested the existence of the so-called slow viruses, but it turned out that the extract obtained from diseased brains could still cause an infection, even if all its nucleic acids which contain the viruses’ genetic material were destroyed with radiation. It was also found out that by adding enzymes that deform proteins the sample was made less contagious, which meant that proteins were most probably the main cause of the disease.

Proteins are very important molecules in our bodies, often called nature’s robots. Proteins perform all kinds of different tasks in our cells. They are built from long chains of amino acids which do not crawl around cells like long snakes, but form complex structures as soon as they come into existence. It is only in this form that they become active and capable of performing different tasks. The protein called hemoglobin, for example, carries oxygen through blood.

Nobody was able to understand, though, how proteins multiplied in the absence of DNA or RNA which contain the instructions for their production. According to the classical theory, the foundation of all modern biology, genetic material is stored in DNA molecules which provide the basic information cells need to produce proteins which then perform different tasks in our bodies. According to this theory, also called the central dogma of molecular biology, the transfer of information is only possible from DNA to proteins and in no way in the opposite direction. A protein can not create instructions for its own production and write them into the cell genome. It is most certainly not capable of doing anything like that. It is the cell that can produce proteins, keeping their blueprints stored inside its genetic code.

Bad molecules

Quite a few hypotheses attempting to solve the riddle of the mysterious infectious proteins were made, but in the end the most accurate one also turned out to be the probably most unusual hypothesis which won Pruisner his Nobel Prize. As he was aware of the fact that promotion was an important part of science, he needed an attractive name to suit his innovative idea. He wanted something simple, easy to remember, that would sound like the already established scientific terms like quark, proton, neutron, electron … And so, the prion was born.

Usually, only one form of a protein is stable. Prions are special among proteins because they have two stable forms. The common, natural form can be found in healthy organisms while the other one causes the disease. The most extraordinary thing is that the “bad” prion has a great ability to recruit. If it meets a “good” prion it will most probably turn him into a “bad one” when they come into contact. The consequence of this conversion is that in the presence of merely a few “bad” prions the majority of the “good” prions gradually turn “bad”. And this is exactly what happens in the case of prion diseases. Prions are, in fact, proteins that can multiply without the participation of genes.

In the case of a spontaneous Creutzfeldt-Jakob disease, the first “bad” prions appear by coincidence and they immediately start their mission of conversion. In about a year after the first symptoms occur, the patient succumbs to the disease. Some families, fortunately there are no more than a hundred in the world, are genetically prone to suffer from this disease due to their slightly different genetic code. Nevertheless, we can be infected by “bad” prions as well. In most cases, people were infected while having their brains examined because doctors repeatedly used the same electrodes, transferring the diseased patient’s “bad” prions to a healthy patient’s brain where they set out on their deadly mission.

A mutation in the part of the genetic code responsible for the production of prion proteins can also cause an unusual disease, named fatal family insomnia. It was first noted in the 80s within a respectable Italian family whose ancestors, upon reaching a middle age in their adult lives, have died for centuries of unusual symptoms which were always accompanied by insomnia. Sometime between their 35^th and 60^th year of life some of the family’s members found themselves suddenly unable to fall asleep normally. The problems could not even be remedied with potent sleeping pills and they continued to grow worse with every month that went by until the patient, terminally exhausted fell into a coma which was followed by death not even a year after the first symptoms occurred.

A cure for treating prion diseases has yet to be found. This is due to the fact that it is extremely difficult to prevent “bad” prions from leading other prions astray once they have entered a body. The usual drugs, successful in fighting viruses and bacteria are powerless. A prion inside a living body practically can not be “killed”.