Smallpox, Syphilis and Salvation

by Sheryl Persson

  The science becomes more complex and the technology more breathtaking. By 1977 a research team had spliced a rat insulin gene into a bacterium that then produced insulin. By the 1980s due to the development of recombinant DNA techniques it became possible to make human insulin.[49] In simple terms (one hopes) the human gene which codes for the insulin protein was cloned and then put inside common bacteria. A number of tricks were performed on the gene to make the bacteria want to use it to constantly make insulin. In 1982 the Eli Lilly Corporation produced human insulin, the first approved genetically engineered pharmaceutical product.

  Pharmaceutical companies no longer needed animals and could produce genetically engineered insulin in unlimited supplies. Big vats of bacteria now make tons of human insulin. Escherichia coli is the most widely used type of bacterium, but yeast is also used. Using human insulin has eliminated concerns about the potential for transferring animal diseases. While companies still sell a small amount of insulin produced from animals, mostly porcine, from the 1980s onwards diabetics have increasingly moved to human insulin created through recombinant DNA technology. In 2001 it was estimated that around 95 per cent of insulin users in most parts of the world took some form of human insulin. In keeping with these developments, in the 1980s researchers began providing alternate drug delivery systems to the syringe, which had been used since the 1920s. Insulin pens, jet injectors and pumps are now available.

  In the mid 1990s researchers began to improve the way human insulin works in the body by changing its amino acid sequence and creating an analogue, a chemical substance that mimics another substance so well that it fools the cell. Analogue insulin disperses more readily into the blood, allowing the insulin to start working in the body minutes after an injection. The work to produce better insulin goes on. Researchers have taken up the challenge to produce edible insulin, experimenting with a plastic coating that is only the width of a few human hairs that would protect the drug from stomach acid. Since 2000 there have been promising tests on inhaled insulin devices.[50]

  ***

  Of course much of the research that is conducted today is focused on seeking a cure for diabetes so that in the future there would be no need for synthesised insulin and state-of the-art, easy-to-use delivery methods. In 2005 a national genetic study was launched by Professor Grant Morahan, head of the Western Australian Institute of Medical Research’s Diabetes Research Centre and discoverer of the gene IL12B which is implicated in Type I diabetes. DNA from 3000 Australian families with diabetic children will be collected and studied. The aim of the project is to determine the precise genetic causes of both Type I and Type II diabetes, both of which are on the increase.[51]

  The World Health Organization estimates that more than 180 million people worldwide have diabetes and it is predicted that this number will more than double by 2030. In 2005, an estimated 1.1 million people died from diabetes. Almost 80 per cent of diabetes deaths currently occur in low- and middle-income countries but there is an alarming trend: diabetes deaths are projected to increase by over 80 per cent in upper-middle income countries between 2006 and 2015.[52]

  Frederick Banting in his eureka moment solved the insulin puzzle. Today because of his legacy researchers are working on creating the cells that produce insulin in the laboratory in the hope that, one day, non-working pancreas cells can be replaced with insulin-producing cells. Another hope for diabetics is gene therapy. Scientists are focusing research on correcting the insulin gene’s mutation so that diabetics would be able to produce insulin on their own. In a worldwide breakthrough, reported in the May 2005 issue of the science journal Nature, researchers at the John Curtin School of Medical Research at the Australian National University in Canberra discovered a gene that if mutated in a person might be responsible for the development of juvenile diabetes.

  One technique that has been pioneered in an attempt to restore normal blood glucose levels in people with Type I diabetes is islet transplantation. Transplantation as a treatment has become possible because of the development of the science of immunology, which began with Paul Ehrlich. Since the 1970s, transplantation of islets has been investigated as an alternative to whole-pancreas transplants, the first of which was carried out in 1966. Islet transplantation involves transplanting only the islet cells that contain the critical insulin-producing beta cells.[53] Compared to whole-pancreas transplantation it is a simpler and less invasive procedure. Following the transplant, patients must take immunosuppressive drugs to keep their bodies from rejecting the new islets. Islet transplantation is limited, however, because very few donor pancreases are available each year.

  For decades, success rates for this procedure remained under 10 per cent. However, in 2000 the introduction of the Edmonton Protocol—a new set of procedures for conducting islet transplants—raised success rates to 80 per cent.[54] Research is underway to answer questions about safety and effectiveness, such as how long the transplanted islets will survive and whether the success rate can be sustained and thus be considered a ‘cure’. In October 2006 the Mayo Clinic reported on a study of 36 islet cell transplant recipients. More than 40 per cent were off insulin therapy completely within one year of the transplant. By two years, however, less than 14 per cent of transplant recipients remained free of insulin therapy.[55]

  Today, things have almost come full circle with what is called xenotransplantation, the transfer of living cells or tissues from one species to another.[56] For 60 years, before synthetic insulin was available, people with Type I diabetes injected pig insulin, and now researchers are investigating whether islets from pigs can be successfully transplanted into humans. Another exciting possibility is stimulating stem cells to become beta cells that could then be transplanted. This approach would overcome the risks of immune reaction to foreign tissues and problems associated with the transfer of tissue from donor to patient.

  With such a shortage of islet cells available for transplantation, news of the world’s first successful transplant of living human donor islet cells in 2005 raised exciting possibilities for the treatment of diabetes. A medical team that included Japanese doctors and the US surgeon Dr James Shapiro, who developed the Edmonton Protocol, removed part of a 56-year-old woman’s pancreas and transplanted the insulin-producing cells into the woman’s 27-year-old diabetic daughter.[57] The transplanted islets began producing insulin within minutes. The recipient was able to stop using insulin after 22 days; she had been on daily injections for twelve years. Both women were well three months after the operation and doctors predicted that the transplant could last up to five years.

  Research scientists associated with the Juvenile Diabetes Research Foundation Islet Transplantation Centres in North America and Europe are investigating new therapies that can achieve ‘selective immune tolerance’ by targeting the cells that destroy islets while leaving the beneficial, disease-fighting immune responses untouched.[58] Another approach is to reengineer islet cells so that they escape recognition by the immune system, or encapsulate islets in protective membranes to protect them from immune attack. The scope of this type of research is truly breathtaking.

  In April 2007 it was widely reported that researchers had come closer than ever before to finding a cure for diabetes. A pilot study of fifteen people newly diagnosed with Type I diabetes found that stem cell therapy eliminated the need for insulin therapy for varying periods of time. Patients were treated with a high dose of immune-suppression drugs followed by an intravenous injection of their own blood stem cells, in a procedure called autologous nonmyeloablative hematopoietic stem cell transplantation (AHST). The new study was conducted by scientists in São Paulo in Brazil and in Chicago under the direction of Julio C. Voltarelli from the University of São Paulo. It was the first trial to look at stem cell therapy in humans with Type I diabetes. Richard Burt, the senior author of the study, said that he believed that the treatment helped the body regenerate its immune system.[59]

  During a three-year follow-up it was found that
patients had become insulin free for varying periods, the longest of which was 35 months, and there were few adverse side-effects. Experts stressed, however, that the research is preliminary and urged caution when interpreting the results, which were published in the 11 April issue of the Journal of the American Medical Association. The gene therapy intervention took place within six weeks of the onset of Type 1 diabetes and the question remains as to whether intervention later would be as successful. Further biological studies are now necessary to confirm the role of the treatment in changing the natural history of Type I diabetes and to evaluate the contribution of adult stem cells to this change.

  Time will tell. Perhaps when the cause of diabetes is finally understood, then not long after a cure will at last be found. That will be another medical breakthrough, and like Frederick Banting’s and Charles Best’s discovery of insulin, it will change the world. Until then, there are many great minds on the job.

  POSTSCRIPT

  Leonard Thompson, the fourteen-year-old boy who was the first diabetic to be treated with insulin, lived for thirteen years after receiving the pancreatic extracts prepared by Frederick Banting and Charles Best, and James Collip. But Leonard did not die from diabetes. In a cruel twist of fate he died tragically, as too many young people do, in a motorcycle accident. At the time of his death Leonard Thompson’s pancreas was preserved and it is displayed as item 3030 in the anatomical museum at the Banting Institute.

  CHAPTER 8

  MAKING A MIRACLE OUT OF A MOULD

  THE DISCOVERY OF PENICILLIN

  I became interested—immediately—in Fleming’s paper, not because I hoped to discover a miraculous drug for the treatment of bacterial infection which for some reason had been overlooked, but because I thought it had great scientific interest. In fact, if I had been working at that time in aim-directed scientific surroundings, say in the laboratory of a pharmaceutical firm, it is my belief that I would never have obtained the agreement of my bosses to proceed with my project to work with penicillin.[1] Ernst Chain

  Before the second half of the twentieth century infections engendered the same kind of fear that cancer creates today. Even a thorn or needle prick could lead to infection. Glands would swell, ulcers would form and require lancing to release pus, amputations were common, and very often a gruesome and painful death would result. The infectious wards in hospitals were crammed with people suffering from puerperal fever, scarlet fever, meningitis, osteomyelitis, heart disease and pneumonia, and one in three cases ended in death. This was the nightmare of wound infections and many infectious diseases before penicillin.

  The discovery of penicillin dramatically changed the world and has been interpreted as the pinnacle of medical achievement, but the story of penicillin is set against a backdrop of rivalry, hardship and disappointment. It begins in 1928 with a stroke of luck, when Alexander Fleming, a Scottish bacteriologist, noticed mould had prevented the growth of bacteria on a Petri dish in his laboratory. But the main plot of the story is the rediscovery of penicillin ten years later by an Australian pharmacologist, Howard Florey, and his dedicated team at Oxford University. Their systematic work transformed the antibiotic ingredient in the mould, Penicillium notatum, into penicillin, a drug that has since saved millions of lives. The story is even more dramatic and astonishing because these history-changing events took place in Britain during the dark days of World War II.

  A decade after Alexander Fleming abandoned penicillin and went back to working on lysozyme, an enzyme in bodily secretions, he became an international cause célèbre. So widespread was his fame that it extended beyond Earth. After the Americans landed on the moon in 1969, a crater was named after Fleming, the discoverer of penicillin.[2] But had it not been for Howard Florey; Ernst Chain, a German-born biochemist; and Norman Heatley, a biochemist whose background was in the natural sciences; and their colleagues at the Dunn School at Oxford University, the world might not have had penicillin.

  Fleming—a small, neat man with a mild Scottish accent, who sported a bow tie—discovered penicillin, and Florey—his opposite, tall, testy and a chain smoker—developed it. However, the controversy and confusion about who did what continues. In 1998, Professor Sir Henry Harris, who succeeded Florey as Professor of Pathology at Oxford, succinctly summed up the situation: ‘Without Fleming, no Chain or Florey; without Chain, no Florey; without Florey, no Heatley; without Heatley, no penicillin.’[3]

  FLEMING’S ACCIDENTAL DISCOVERY

  Alexander Fleming was born into a Scottish sheep-farming family in 1881, the seventh of eight children. His family worked an 800-acre farm in a remote part of Scotland and their nearest neighbours were a mile away. The Fleming children spent much of their time roaming the streams, valleys and moors of the surrounding countryside, and this, Fleming said, was where he learnt a great deal from nature.[4]

  After their father’s death, Alexander’s eldest brother inherited the farm and another brother who had studied medicine opened a practice in London. At fourteen Alexander followed his siblings to London and attended the Polytechnic School in Regent Street after which he found employment in a shipping firm, but the job provided little satisfaction. In 1900, when the Boer War broke out between the United Kingdom and its colonies in southern Africa, Fleming and two of his brothers joined a Scottish regiment. Their training was not onerous, consisting mostly of shooting practice and swimming. All three remained in England and did not see active service. After leaving the army Alexander was encouraged by his brothers to study medicine, something he could afford to do after inheriting money from an uncle. Alexander topped the qualifying examinations and had his choice of medical schools. It is said that his decision to go to St Mary’s in London was influenced by the fact that he had played water polo against their team. Perhaps this was an indication that Fleming was not imbued with lofty ideals.

  In 1905 circumstances led Fleming to specialise as a surgeon, but to take up a position in the specialty would require leaving St Mary’s. The story goes that the captain of the rifle club did all he could to keep Fleming at St Mary’s because Fleming was an expert marksman. He also convinced Fleming to work in his department, the Inoculation Service. Fleming made a surprising switch to bacteriology, joined the rifle club and remained at St Mary’s for what was a lengthy career.

  In 1909 after developing Salvarsan, his chemical treatment for syphilis, Paul Ehrlich went to London to discuss his findings. Fleming, in addition to his hospital commitments, had established a successful private practice treating syphilis patients, many from the artistic fringe. An expert in this field, he was one of very few physicians in London to administer the ‘magic bullet’ and he also adopted Ehrlich’s pioneering intravenous injection method. Because of the success of Salvarsan, Fleming’s practice boomed and he was given the nickname ‘Private 606’, an allusion to both the disease and to Salvarsan, called 606 because it was the 606th arsenical compound that Ehrlich had tested.[5]

  When World War I broke out in 1914, many of the staff of the St Mary’s bacteriology department went to France to set up a battlefield hospital laboratory. Soldiers suffered horrendous infections even from insignificant wounds. Fleming, inspired by Ehrlich, believed that there must be a chemical like Salvarsan that could help fight microbial infection even in wounds caused by shrapnel. During the course of the war, Fleming made many innovations in treatment of the wounded, and because of his battlefront experience he was determined to find a substance that could stop bacterial infection. Ironically, without knowing it had happened, he did find one.

  Back in his St Mary’s laboratory in the 1920s, Fleming had searched for an effective antiseptic. He was conducting an experiment with bacteria when a tear fell from his eye into a culture plate. Later he noticed that a substance in his tear killed the bacteria but was harmless to the body’s white blood cells. Fleming had discovered an enzyme that occurs in many human body fluids, and in animals and plants. He named the enzyme lysozyme and although it had a natural antibacterial effec
t it did not work against strongly infectious agents so Fleming continued his search.[6]

  There are various stories about how Fleming actually discovered penicillin, but whether any are entirely correct is perhaps debatable. In 1928, Fleming was doing research into influenza and one detail that does not seem to vary is that Fleming was away from his laboratory on a holiday for two weeks. During his absence a fungus spore entered the laboratory by some means and ended up on a Petri dish on which bacteria had been growing. Some accounts say that the spore drifted into Fleming’s laboratory through a window he left open when he went away. The more accepted version now is that the spore had drifted up the stairs from a mycology laboratory one floor below.[7] What the spore did when it got into Fleming’s laboratory is also up for debate: the spore landed on a Petri dish of staphylococcus Fleming had cultured as part of the research he was doing for the chapter in a book on bacteriology; Fleming hadn’t properly disinfected the Petri dish; it was on top of a pile of others in a tray of disinfectant, ready to be cleaned; the Petri dishes were in a messy pile that Fleming was straightening and the telltale mould escaped being washed away to oblivion by a matter of centimetres. Take your pick.

  What is important is what Alexander Fleming saw. When he came back from his holiday he noticed a clear patch, a halo surrounding a yellow-green mould that was growing on the Petri dish of staphylococci bacteria and supposedly said, ‘That’s funny.’ The halo indicated that the bacteria around the mould had been killed. Or according to another account he didn’t notice it at all. When he came back from his holiday the mould on the Petri dish was about the size of a 20-cent coin and, around it, the bacteria had died, but as it wasn’t very noticeable he threw it in a bucket. His friend and colleague Professor Hare came in to talk about some subject, noticed it, pulled it out and said, ‘That’s interesting.’[8] Again, take your pick.