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Thursday, May 6, 2004

Be Wise


Dr. Lester CN Simon

Too much sunshine can be bad for your eyes. I was reminded of this recently when I read an article called The Tyranny of Choice by Barry Schwartz, in the April 2004 edition of Scientific American. Schwartz succeeds in disproving the apparent logic that if some choice is good then more choice is better. His research offers insight into why many people end up unhappy rather than pleased when the number of their options increases.

Are we in a dilemma of choice in Antigua and Barbuda? I am interested in the idea of tyranny of choice for at least three reasons. When I was a boy, I could never understand why my mother would go from shop to shop in search of the same item, end up buying the first one she looked at, and still seemed unhappy over her choice. Secondly, we face some serious choices in Antigua and Barbuda in general, and in medicine in particular. Thirdly, everyone just loves when a brilliant piece of research such as Schwartz’s work, makes practical sense. And yes, there is a fourth reason: I still want to understand the 16,544 members of my tribe who voted for the ALP.

Schwartz divided his research subjects into maximizers and satisficers. Maximizers are those who always aim to make the best possible choice. Satisficers simply aim for “good enough”, disregarding the search for possibly better selections.

The irony regarding maximizers (“choosy-choosy” people) is that the more choosy you are, the less happy you are with the fruits of your efforts. That is what Schwartz found. You worry about the alternatives you did not have time to investigate, even after you have made your selection from examining many of the choices. The satisficers (“make-do” or “mek-out” people as we might say) may not make a better choice but they are happier with their decisions.

Schwartz looked at a concept called “opportunity cost” to understand why too much choice can be a recipe for unhappiness. The basic idea here is that any one choice by definition is considered in relationship to another. So the effect or penalty or cost of choosing option one is that you lose the opportunity of option two. Can you imagine the abject turmoil persons would find themselves in, trying to decide on Monday morning, if they should drive the blue car or the red one, or maybe the small black one, or call the driver and ask him to drive them to work? How depressing? What unhappiness! The “mek-out” person will have no such worries.

Seriously, Schwartz noted that the consequences of unlimited choice may go far beyond mild disappointment, to suffering and depression. This is partly because the choosy persons blame themselves when the consequences of the choices do not live up to their expectations.

So what do we do to ward off a bout of national disappointment, suffering and depression? What with all the choices “shining” down on us? Schwartz suggests a number of (you guessed it) choices: We must choose when to choose. This means that we must restrict our options when the decision is not too crucial (the colour of the paper clip is certainly not that important, Ms Secretary; nor is the colour of the toilet paper, my dear heart, sweetie pie).

We must learn to accept “good enough”. This does not mean any wishy-washy old thing. It means that we settle for a choice that meets our core requirements rather than search for the elusive best. We must stop second-guessing the choice we made and stop worrying about what we might have gained from the options we rejected. Lastly, suggests Schwartz, we must control our expectations. If we do not expect too much, we won’t be disappointed. Again, this is not the same as harbouring the lowest possible expectations. It is not in conflict with saying to a child that the sky is the limit. That child must be given the opportunity to decide if he or she wants to be an astronaut and by so becoming, that child can reach the limits of the skies.

In regards to medicine, there are many choices facing us as we try to literally heal the nation. I have to remind that in Antigua and Barbuda we are well aware of the folklore of the John Bull. If we do not choose wisely, John may just have been a herald of the Bull to come!

Monday, March 29, 2004

The Spoils of Defeat


Dr. Lester CN Simon

I try hard to understand the 16,000 and odd people who voted for the ALP. I try to understand them because they say a lot about who we are. Unravelling this Birdie mystery is a prerequisite for rebuilding the nation. How do I reason with the fanatical ALP supporters who proclaim that they were born Labour and they would die Labour? I simply say to them that under Labour, the midwife and the mortician are equal. But then, they cannot even appreciate a good joke.

I listen to them. I engage them. I finally convince them that they are wrong and that the UPP is the right way forward. Then they hit me for six with the comment that, “All government tief”. In other words, they will stay with the thief they know rather than take a chance with another (unproven) thief. Somebody done tear out these people heart, dash it on the ground and watch big bus, tractor and flatbed truck run over it, in the presence of pompous policemen.

How do you convert these people? How do you remove their unbearable ‘lightness of being’? I was taken up with the parallel between the religious aspects of the UPP campaign and the need to convert the Birdie, politically. I thought the UPP failed to exploit the link between the Bishop and the Serpent on the one hand, and the need to politically convert the ALP maniacs, on the other. I thought that promoting the reassuring, all-inclusive notion of “room under the tent” was not enough.

I felt that the key effect of the message from the Bishop was not just to believe in God. This belief or disbelief requires conversion. The principles of conversion used by the Bishop are universal. They too, can be used by Serpent to pull you into radio land via the snake pit. They can also be used by marketing experts. Indeed, they were used by the UPP. My concern was whether the UPP had done enough to market itself to the most vulnerable of the 16,000 maniacs?

The ALP tried marketing too. In many cases, they not only sold the ALP, they bought all the goods in the tray, the tray itself, and the poor old woman higgler too, including the stool she sits on and the ground there under. This is precisely what they mean when they say they were born Labour and they would die Labour. They are referring to slavery. Born in it, die in it, and proud of it! Marketing for the ALP means buying the entire market, lock stock and barrel. No wonder the dollar-barrel got to them so.

A wise friend (Dorbrene O’Mard) suggested that the UPP could not have run the risk of marketing itself to the 16,000 ALP maniacs. He said that in doing so the UPP would have alienated its own supporters. He is right. After all, you have to choose your customer. Even the ALP and prostitutes know this.

So what do we do with the 16,000 maniacs? I really thought it would be a good idea for the UPP government to feed the “dogs” first. Turn a “Rose” into a bouquet, for example. But like Little Bo-Peep, we must leave them alone, and they'll come home, wagging their tails behind them. You have to want to be converted, to be loved. You have to walk in freely and lay down your own, old burden under the big tent, the big national tent. Only then can we truly say, “Yes! Yes! Yes! We Have Them. We Have Them. The People Have Them.”

Monday, February 23, 2004

Air Head


Dr. Lester CN Simon

Why is it that some people do not join organizations or become diehard members of political parties? To answer this question, I turned to an excellent book by Loretta Napoleoni called Modern Jihad and subtitled, Tracing the Dollars Behind the Terror Networks.

I am not aware of any terrorist organization in Antigua and Barbuda. Nonetheless, all organizations, legal and illegal, have to abide by their own code. There is discipline among bands of thieves and even in the blazing depths of hell. Napoleoni said she wanted to know how her best friend had become a terrorist and why she had never tried to recruit her (Napoleoni). Her friend explained her motivations and revealed that Napoleoni was judged to be too independent and single-minded to join an armed organization.

Our concern here is not with armed struggle. Our concern is with the basic fact that some people are simply too independent and single-minded to join any organization. This is not to say that political organizations do not have independent thinkers. They do.

Nowadays, a rising level of expression of independent thought is staggering through this country. It can only be good for Antigua and Barbuda. Many of us are caught up in the rapture of the election campaign but we know that it is a time for critical thinking. Then this barefaced, mamaguy, samfie, Solomon O' Gundy, ginal pollster comes and tells us that all of us know, that all of us know (mark you) that general elections are won or lost in the 2 to 3 days before the election. Who is peeping the cards? Who is playing mas? Skylarking!

I have a big problem with anybody, politician or non-politician, trying with their entire academic might to pull wool over my eyes. However, it is quite another thing when a Brer Anancy pollster tries to shear a whole flock of sheep in front my face;
sans humanite, as they say in Trinidad and Tobago. Hear this brother man: Our carnival is in July and August, ah telling you!

So how is something as crucial as a general election won or lost just 2 to 3 days beforehand? Turn the whole Ides of March into one big fete, man. After all, it will still be a party, even though not a political party any more. Have we learnt our lessons so well from our erstwhile masters that we cannot resist the penchant to destroy ourselves? Or is our unmentioned, conniving, ancestral fungus then in West Africa, still infesting us?

Critical thinking should show us that blind obedience is not good for the eyes. Unquestioned obedience is always confined to a solitary answer. “Cannon to right of them, Cannon to left of them, Cannon behind them…Theirs not to reason why, Theirs but to do or die: Into the valley of death rode the six hundred”.

The staggering sense of independence is straightening out more and more people. What’s the use of getting drunk on cavalier nonsense when you can get plastered with a mount gaping with common sense? This means that the patriotic looser can now rest assured that the country will forever be in safe hands. These are not the grasping hands of any politician. They are the critical minds of independent thinkers. These are the ones that will shine the light towards the right part and party.

But wait a minute! Following the independent thinker is not real independence. Everyone must follow one’s own lodestar, from incandescent fluorescent to iridescent flambeau. This disparate light brigade will atone for the desperate, idiotic Charge of the Light Brigade 150 years ago. Welcome to our second, true-fu-true Independence, where we will be strong and firm in peace or danger to safeguard our native land.

Saturday, February 14, 2004

Ones of a Kind


Dr. Lester CN Simon

It is a truth, universally accepted, that sickness and health are attended unequally by luck, money, common sense and good governance. Doctors struggle to square this trapezium. We try to keep up with dazzling advances in medicine and to fulfil the needs of our patients.

So what’s the fuss about the milestone news on cloning and stem cells? Let’s start with fertilization. This is the process in which genetic material in the sperm from the male unites with genetic material in the egg from the female.

Except for egg cells in the ovary in females and sperm cells in the testis in males, all other cells in humans have 46 genetic materials. Egg cells and sperm cells contain only 23 genetic materials. When the egg and the sperm combine during fertilization, the offspring will then have the full complement of 46 genetic materials.

Cloning is an attempt to create cells that are genetically identical to an original cell. This is a radical departure from natural fertilization in which the offspring is not genetically identical to the mother or the father but rather it is a genetic composite of both parents.

In cloning, the egg is manipulated outside the body before the sperm is introduced. The sperm is not used at all. The 23 genetic materials in the egg are removed. These are then replaced by 46 genetic materials from other cells which already have the ready-made 46 genetic materials. The egg does not realize that the new 46 genetic materials did not come from the natural combination of 23 from the egg and 23 from the sperm.

After this false fertilization by manually inserting into the empty egg, the ready-made 46 genetic materials, special chemicals called growth factors and others are added. The egg is fooled into growing and developing as if a normal egg had been fertilized by the sperm.

With nuff respect to the women of POWA in particular and to all women in general, the indispensable role of the egg should be underscored. After removing the 23 genetic materials from the egg, the egg is still essential for the implantation of the ready-made 46 genetic materials from another cell. In effect, a female’s empty egg can be falsely fertilized by the 46 genetic materials in cells from herself, another female or a male. The male’s sperm cannot perform this receptive, nurturing function.

In the landmark study just published, the ready-made 46 genetic materials were provided by the same female that provided the egg. The researchers also tried to clone male cells by using cells from the ear lobe. They were unsuccessful. With all respect to the eminent scientists, a woman would have told them that since men just don’t listen, they should have taken the 46 genetic materials from some other part of the male’s anatomy! Any suggestions?

Stem cells refer to cells that give rise to other cells. They do this after fertilization, throughout pregnancy and for our entire life. All types of cells in the body are derived from stem cells. These include blood forming cells, heart cells, nerve cells, etc. Stems cells that are made soon after fertilization are more potent than those made as we grow older.

In many diseases, the underlying problem is a fault with the stem cell and this fault is passed on to the regular cells, which become dysfunctional. Such diseases include sickle cell disease, diabetes, heart disease, cancer and brain diseases, among others.

The value of manufacturing stem cells is that it is hoped that stem cells may one day be injected into patients to replace the deranged stem cell that caused the disease. This is referred to as therapeutic cloning since the idea is to clone cells only to harvest the potent stem cells early for the treatment of diseases. Alternatively, reproductive cloning refers to cloning an animal or a human being by allowing the cloning process to go all the way after implanting the falsely fertilized egg in a woman’s uterus.

There are many ethical and legal issues about cloning. Regarding reproductive cloning, take a look in the mirror. You should like what you see but do you really think we can tolerate another one exactly like you in this world? When in a fit of rage you tell your “what-ever” daughter that you wish she will have children just like her, do you really want your wish granted?

Concerning therapeutic cloning, it is a truth, locally accepted, that we are struggling to walk like moko jumbie to see a new hospital on the hill while we are crawling like ground lizard to barely see to Holberton hospital on the plain.

Tuesday, February 10, 2004

Call and Response


Dr. Lester CN Simon

Sometimes in our lives, we get lucky. It is said that good luck is when preparation meets opportunity. So being lucky does not necessarily mean winning large sums of money. It can come from hearing a few bars of wonderful music, seeing a beautiful painting, or catching an overwhelming feeling in church. These moments seem to be in perfect harmony with nature. They represent a flash flood of ethos that causes the mind to become awash with respect for the limitless potential of the human spirit.

A few nights ago, preparation and opportunity collided when I heard the broadcast of an ALP political meeting in which a member of the audience urged the speaker to, “Talk as you like!” Most listeners have been concentrating on the words of the speaker and his superhuman feat of building a tamarind tree. My concentration was on the response of the audience. Taken together, the broadcast was a case of call-and-response that sits right up there with any fine piece of music that I would call simply classical.

In the opening pages of Calypso & Society, the author, Gordon Rohlehr referred to the work of the ethnomusicologist, Dena Epstein who wrote about the characteristic West African nature of the call-and–response musical form. Rohlehr noted that this musical element exists in Calypso and in folksong throughout the Caribbean. Indeed it has influenced Blues, Jazz, and other forms and styles of black music in the United States and the Caribbean. Some regard it as a defining feature of all black music.

Call-and –response is a musical style in which a leader sings a line (call) and a
chorus sings a line (response) alternately. At political and other meetings and in some churches, the response takes on the artful task of punctuating the speaker. The speaker has to be very mindful of the fact that he or she is the one in charge. If the speaker loses sight of this basic fact, the responding audience can become the caller, and the caller can be thrown out of rhythm, rhyme and reason.

The call-and-response interplay of the Tamarind Tree speech resonated because it was a classical involvement of the audience. This nexus between the audience and performer is the soul of our music. The music becomes participatory. You cannot watch this music from a distant, double-decker pavilion. Almost like little children clamouring for attention, fine music must be seen, not just heard.

When I listened to the political broadcast, I thought, here was a politician on the government side, organically involved with his audience in the very participatory way that the opposition party claims as its battle cry. Talk as you like! You have more words than he!

Some writers suggest that the interplay of call and response has been around for a long time. They claim that it might have been the first form of human dialogue and the derivation of language. Other writers see the concept of call-and-response as part of the drama of life. By this they mean: What life asks of us, and how we respond.

We are all currently engaged in the fervour of a very crucial call-and-response build-up to a general election in Antigua and Barbuda. Please be careful. Bob Barley said, “One good thing about music, when it hits you, you feel no pain”. In the heat of the political battle, you may feel you are on a Sauline road to conversion. What with all the dazzling, bright lights!

When you think you are doing the calling, you may in fact be responding to the real call from Jah, Rastafari. Do you really think that you have more words than He? Alternatively, your call may be a response to being led down the garden path of the forbidden fruit by the real serpent, Beelzebub. And please do not blame Eve simply because it is evening time.

If you talk as you like, you may not like what you talk. But if your heart is right, your mind is pure and you really and truly love this beautiful country, all you have to do without fear is open your mouth and : Talk as you like!

Saturday, January 24, 2004

A Bird In The Hand


Dr. Lester CN Simon

This is not a political article. The title came to mind because of the outbreak of avian influenza (bird flu), which has spread from birds to humans. It also represents a comical look at some of our sayings and nursery rhymes. For example, I never expected to see the day (or night) when the cow jumped over the moon. But cows have made the lunar leap. They have become stark raving, non-grazing lunatics, as Mad Cow Disease shows us.

The basic science of influenza tells us that there are three types of influenza viruses. Type A, type B, and type C. Wild birds are the natural habitat of influenza A virus. From wild birds it can spread to chicken, pigs, whales, horses, and seals. On the surface of the influenza A virus, there are two proteins called protein H (hemagglutinin) and protein N (neuraminidase). There are 15 types of protein H (H1, H2 ….H15) and 9 types of protein N (N1, N2…..N9). Hence there are 135 (15 x 9 = 135) subtypes of influenza A viruses. Two subtypes of influenza A found in humans are A (H1N1) and A (H3N2). Influenza B and influenza C viruses are found only in humans.

Pigs can be infected with two different subtypes of influenza A virus. In the pig, the genes responsible for making protein H and protein N can become assorted and then they can re-assort. This can result in the formation of a new virus. For example, subtypes H3N4 and H5N6 viruses in a pig can swap genes to produce a third virus subtype, H3N6.

The pigs are crucial because pigs are susceptible to infection from both avian and mammalian viruses, including human influenza subtypes. Pigs act as “mixing vessels” for the creation of new subtypes. Recent research suggests that humans can serve as “mixing vessels” just like pigs. The danger with new subtypes is that most people may have little or no protection since they were never exposed to the new subtype, either by natural infection or by vaccination. This may allow for an epidemic or a pandemic.

Over the past 100 years, there have been 3 flu pandemics. In 1918-1919 the Spanish flu was caused by influenza A (H1N1). About 20 million people died worldwide.
In 1957-1958 the Asian flu by influenza A (H2N2) caused 98,000 deaths. In 1968-1969 about 46,000 people died from the Hong Kong Influenza A (H3N2) pandemic.

The flu (influenza) and the common cold affect the respiratory system. They are caused by different viruses. The flu is worse than the common cold. People with the cold have a runny or stuffy nose. It may be difficult to tell the difference, but the flu is usually more intense, with fever, body aches, extreme tiredness and dry cough. The flu may be complicated by pneumonia and can result in hospitalization, especially in high risk groups such as the elderly and the chronically ill.

Bird flu (avian influenza) is caused by influenza type A. Bird flu runs a spectrum from mild illness to rapidly fatal disease in birds. Fifteen subtypes of influenza A infect birds. Subtypes H5 and H7 are highly contagious among birds, and are rapidly fatal.

Bird flu in wild birds can spread to domestic poultry such as chickens and turkeys. Live birds markets in Asia play an important role in spreading epidemics of bird flu.

The control of an outbreak of influenza A (H5N2) among the poultry population in USA during a 1983-1984 epidemic cost US$65 million. More than 17 millions birds had to be destroyed. More than 13 million birds died or were destroyed in Italy during the 1999-2001 bird flu epidemic caused by influenza A ( H7N1) epidemic.

Can humans get bird flu? Yes. The bird flu viruses more often infect other birds and pigs. But in 1997, bird flu caused by avian influenza A (H5N1) infected humans. This was the first documented case of transmission of avian influenza from birds to humans. It took place in Hong Kong where 6 of 18 humans infected, died.

This first case of direct transmission of influenza from avian to humans was alarming to health authorities worldwide. In Hong Kong, destruction, in 3 days, of some 1.5 million birds, the entire poultry population, averted a pandemic.

The alarm bells went off again in 2003 with an outbreak of avian influenza A (H5N1) in Hong Kong. It caused 2 human cases with 1 death. Then there was avian influenza A (H7N7) in the Netherlands in 2003 with the death of a veterinarian. Mild cases of avian influenza A (H9N2) occurred in 2 children in Hong Kong in 1999 and in 1 child in 2003.

The most recent alarm bells rang out loudly this month. First, there was an outbreak of avian influenza A (H5N1)in the poultry population in Vietnam in December 2003. Then laboratory tests confirmed the presence of avian influenza A (H4N1) in humans in Viet Nam. Children died. It is thought that they became infected by playing in yards where chickens were kept. They probably made contact with infected avian faeces, a good source of influenza A. Two birds in the bush may be better than one bird in the hand.

There is no evidence yet of direct human to human spread of the recent avian influenza A (H5N1). Nonetheless, H5N1 is of particular concern because it can mutate into subtypes rapidly. Its genes can re-assort with others easily to form new subtypes. WHO notes that H5N1 has the unique capacity to cause severe disease, with high mortality, in humans.

The relationship between humans and animals is in the spotlight as new diseases emerge. The vegetarians should not laugh. Do we know what is going into plants and vegetables for human consumption?

If we worry about meat and other cattle-derived products, pigs, chicken, turkey and other avian products, what will be left to eat? The little dog laughed to see such fun, and the dish ran away with the spoon.

Tuesday, January 6, 2004

The Cow Jumps Over


Dr. Lester CN Simon

In a previous article, we looked at the basic science of a group of degenerative, spongiform brain diseases in which the brain in reduced to a sponge. In this article, we look at the full spectrum of these diseases with emphasis on the more important ones.

There are at least 6 transmissible spongiform brain diseases that affect animals. For over 200 years, shepherds have recognized a spongiform brain disease called scrapie, in sheep and goats. It is called scrapie because the animals degenerate and itch to the extent that they rub against any object and scrape off their wool.

Chronic wasting disease of mule deer and Rocky Mountain elk is a spongiform disease seen in Colorado and Wyoming, USA. Scrapie and chronic wasting disease are the only 2 spongiform brain diseases that appear to be spread directly from animal to animal.

A third disease, transmissible mink encephalopathy, was discovered in Wisconsin, USA in 1947. Encephalopathy simply means brain disease. Ingestion of contaminated food stuffs is thought to be the mode of infection.

The remaining three spongiform brain diseases in animals include exotic ungulate encephalopathy, identified in British zoos in the mid-1980s. Ungulates are hoofed mammals including antelopes, cheetahs and others. Feline spongiform encephalopathy in domestic cats was discovered in 1990. These two spongiform diseases in ungulates and cats are thought to be due to the same infectious agent that causes Mad Cow Disease, the sixth and most notorious of animal spongiform brain diseases.

Mad Cow Disease or Bovine Spongiform Encephalopathy (BSE) was first discovered in Britain in November 1986. The cows’ mental state ranged from initial apprehension to frank madness. Since the 1940s, cattle feed was enriched with meat and bone meal from other animals including sheep and other cows. Ordinary grass was insufficient for cattle.

Offal refers to the entrails and internal organs of an animal that are used as food. The enriched meal for cattle includes offal from slaughterhouses. It goes through a process called rendering. Here, the melted fat is removed as tallow. Tallow is the hard fatty substance from animals. It can be used to make some candles and soap.

After the tallow is removed, the solids comprise meat and bone meal for cattle. How did the first cows with Mad Cow Disease get infected? They got infected from the enriched meal during the winter of 1981-1982. The rendering process had been altered. The use of chemicals called organic solvents and the high temperatures used in the rendering process were stopped. The lack of these chemicals and the absence of high temperatures meant that any infectious agents in the animals used in rendering, survived and were inadvertently passed on. The infectious agents came from scrapie-infected sheep.

The next time you hear someone say they do not eat meat, just smile. Some rendering processes use spoiled meats scraps and animal carcasses. In addition to preparing meat and bone meal to enrich cattle feed, many by-products are derived from the rendering process. Some of these rendered products include high-protein base used in soaps, medicine and candy. Render unto cattle and render unto Caesar.

According to the Wall Street Journal, processed cow fats are used to make cookies and salty snacks taste rich, and lipstick to glide on smoothly. Cow proteins end up in shampoo. Gelatin from cattle hide and bones is found in ice cream, candy, marshmallows and in capsules encasing drugs. Cow lips are used in taco filling and other offal parts are found in pet food.

The manufactures claim that none of the organs that are known to transmit Mad Cow Disease are used in their preparation. If we accept this as truth, we have to also accept that the science of Mad Cow Disease is evolving. The brain and the spinal cord are known to be the areas that harbour the infectious agents called prions.

Dr. Prusiner, the discoverer of prions, noted that there are discoveries that widen the spectrum of prion diseases in mice. These discoveries are prompting a search for human prion diseases that affect the peripheral nervous system and muscles.

The spongiform brain diseases in humans include Kuru, Creutzfeldt-Jakob Disease (CJD), Gerstmann-Straussler-Scheinker Disease and Fatal Insomnia.

CJD is the most common human spongiform disease. Yet it is very rare. The estimated incidence is about 1 case per million, per year, worldwide. Before 1995, it existed in 3 forms. Sporadic or random CJD (about 85%), familial CJD, and CJD from use of infected medical organs or products. Familial CJD means that bad genes are passed on to an offspring.

Sporadic CJD is rare in people under 30 years of age. There is progressive mental deterioration and death occurs in less than a year. In late 1995, a new form of CJD was observed in Britain. It was called new variant CJD. In retrospect, the first case was probably in 1994, some eight years after Mad Cow Disease was discovered. It was called new variant CJD because the patients were teenagers or younger than classic, random or spontaneous CJD patients. New variant CJD (nvCJD) patients survived longer.

Kuru is due to cannibalism among the Fore people of New Guinea. Industrial cannibalism in scrapie-enriched cattle feed is the cause of Mad Cow Disease and nvCJD is due to humans eating infected beef products.

Canine, ovine, bovine, asinine? Respectively: tooth, sheep, cow, stupid or foolish?

Monday, January 5, 2004

Mad Food

Eat This. But Not In Remembrance of Me!

Dr. Lester CN Simon

The title of this article is aimed at linking two crucial aspects of the basic science of Mad Cow Disease. Mad Cow Disease is the lay person’s term for Bovine Spongiform Encephalopathy (BSE). BSE is only one of a list of spongiform brain disorders in animals and humans in which the brain is literally reduced to a sponge.

To get a clear grasp of the basic science so that we can apply it to public health, we have to understand a peculiar set of diseases caused by agents called prions.

When we think of the causes of infections, parasites, fungi, bacteria and viruses readily come to mind. The first three agents contain many sophisticated, genetic chemicals including DNA and RNA. These three infectious agents grow, reproduce, make and use proteins once nutrients are available. Viruses, on the other hand, are not as sophisticated. A virus possesses either DNA or RNA, not both. Viruses cannot grow, reproduce and make or use proteins unless they inhabit living cells.

As important as proteins are, it was not considered possible that a protein could cause infection by itself. Infection means that the causative agent sets up shop in the host and multiples therein. Proteins should not be able to do this since they do not have the chemical genetic machinery in the form of DNA or RNA.

Enter the prion. In 1980, Dr. Stanley Prusiner evoked a good deal of scepticism when he proposed that the infectious agents causing spongiform brain diseases in animals and, more rarely, in humans might consist of protein and nothing else. At the time, Dr. Prusiner was considered a heretic. His work was revolutionary. He realised that dogma held that the conveyers of transmissible diseases required genetic material, DNA or RNA, in order to establish an infection in a host. Fifteen year later, Dr. Stanley Prusiner was awarded the Nobel Prize in Medicine for his work on prions.

The name prion (pronounced "pree-ons" by Dr. Prusiner), is an acronym. Actually you may say it is a prionic acronym, as you will see later. It comes from the words: proteinaceous infectious particle, using the first three letters of proteinaceous (pro) and the first two letters of infectious (in). Obviously, this would lead to the name, proin but it was decided to call it prion instead of proin, because prion has a better sound.

But even if prions cause diseases, they are proteins; and all proteins are made by genes (DNA and RNA). So how do the prions reproduce when they cause infections? Do they have a piece of genetic material attached to them? No. The genes that make prions are where all genes are: inside the cell. They make prion proteins (PrP) all the time without necessarily causing any sickness. This suggests that prion proteins exist in two states, a normal, innocent state and an abnormal, corrupted, sinister state.

Good prions are easily degraded by the usual protein-degrading enzymes in all cells. Unfortunately, bad prions resist this degradation. Hence, bad prions will always win and the good ones will lose. The concept of good prions is relatively new. When prions were first discovered, they were thought to be intrinsically bad. Just recently, in December 2003, it was considered that one sort of prion has a vital role to play in how memory can be stored in the brain. Hence the name of this article.

Shape or conformation is very important to proteins. Change the shape and the function can change. The bad prion acts as an infectious agent by somehow causing a change in the shape of the good prion, which then becomes a rebel prion and damages the body. The derivation of the name prion is itself prionic in that the name was changed from proin to prion.

The shape of a protein is only one aspect of its structure. There is a more basic building block comprising a sequence of amino acids. The closer 2 prions are in their basic structures, the easier it is for a bad, rebel prion to corrupt a normal prion by forcing it to alter its shape and become a rebel too. Birds of a feather do all sorts of things together.

This raises the concept of species barrier. Species barrier refers to the difficulty of prions made by one species causing disease in another species. The cause of this difficulty is unknown but it is important in light of Mad Cow Disease in which bad prions from other animals such as sheep and cows were part of the feed for cows.

The close genetic link between sheep and cows allows for the transformation of “Mad Sheep Disease’ to Mad Cow Disease. “Mad Sheep Disease”, known for over 200 years is called scrapie because the sheep have a terrible itch and scratch against a fence until they scrape off their wool.

Kuru is a prion disease that was found in 1957 among the Fore tribal population of Papua New Guinea. Transmission was due to the practice of ritualistic cannibalism. With the cessation of this social custom, Kuru has essentially disappeared. Kuru is the Fore word for shivering, trembling or “laughing death”.

Sheep and cow prions differ at 7 positions. Alternatively, cow and human prions differ at more than 30 positions. Because of this greater variance, Dr. Prusiner thinks that the likelihood of transmission of prions from cows to people is low. But low does not mean impossible because it does occur. Maybe only a small area of similarity is required for corruption of the human prions by the bovine prions. Additionally, other types of proteins called chaperone proteins may assist in the alteration and corruption of the good prions.

In genetic and other terms, are we humans far from the madding cow?