Monthly Archives: May 2015

Does Osteopathy Work? Is it Scientific?

Victorian Skeptics

Osteopathy graphic 800W

By Mal Vickers

I was recently asked, “Does osteopathy work? Is it scientific?” The short answer is: osteopathy is unlikely to be effective for most health conditions. It’s a form of alternative medicine. I wouldn’t put it in the category of a sciencebased medicine. Read on if you’re interested in why I would think such a thing.

It’s difficult to definitively answer questions like this for three reasons.

One – Science is all about probability.

Two – it’s hard to prove a negative.

Three – it’s not a very clear question.

If the idea is to sort the wheat from the chaff in medical treatments, there are better/tougher questions to ask.

Let’s try to explore it.

Whole health disciplines might contain just a handful of useful treatments for some ailments,

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Charles Darwin – where he was right and wrong

by Tim Harding, B.Sc.

(An edited version of this essay was published in The Skeptic magazine, June 2015, Vol 35 No 2, under the title ‘Darwin’s Missing Link’.  The essay is based on a talk presented to the Mordi Skeptics on Tuesday 5 May 2015).

Charles Darwin (1809-1882) is best known for his major contributions to evolutionary theory. In 1859, Darwin published his theory of natural selection as the mechanism of evolution in his revolutionary book On the Origin of Species. This book provided compelling evidence overcoming the scientific rejection of earlier concepts of transmutation of species. The basic principles of his theory have been shown to be correct and are now widely accepted as the basis of mainstream zoology, botany and ecology.

On the other hand, in a later book Darwin got it wrong with the mechanisms of inheritance.  The empirical rules of genetics, based solely on observational results, were largely understood since Gregor Mendel’s ‘wrinkled pea’ experiments in the 1860s. The postulated units of inheritance were called genes, but in Charles Darwin’s time it was not understood where genes were located in the body or what they physically consisted of. Darwin knew that there must have been a physical mechanism for inheritance, but his speculations about it – called pangenesis – were incorrect. Fortunately for the credibility of his theory of evolution by natural selection, he published these speculations later in a separate 1868 book titled Variation of Animals and Plants Under Domestication.

Darwin’s early career

Charles Robert Darwin was born in Shrewsbury, England, on 12 February 1809 at his family home, The Mount. He was the fifth of six children of wealthy society doctor and financier Robert Darwin, and Susannah Darwin (née Wedgwood).

Darwin went to Edinburgh University in 1825 to study medicine. In his second year he neglected his medical studies for natural history and spent four months assisting Robert Grant’s research into marine invertebrates. Grant revealed his enthusiasm for the concept of transmutation of species (the altering of one species into another), but Darwin initially rejected this concept (probably for religious reasons).

Ideas about the transmutation of species were controversial as they conflicted with theological beliefs that species were unchanging parts of a designed hierarchy and that humans were unique, unrelated to other animals. The political and religious implications were intensely debated, but transmutation was not accepted by the scientific mainstream until Darwin’s theory.

In December 1831, Darwin had joined the Beagle ship voyage as a gentleman naturalist and geologist.  In South America, he discovered fossils resembling huge armadillos, and noted the geographical distribution of modern species in hope of finding their ‘centre of creation’.  As the Beagle neared England in 1836, he began to think that species might not be immutable after all.

In March 1837, ornithologist John Gould announced that mockingbirds collected on the Galápagos Islands represented three separate species each unique to a particular island, and that several distinct birds from those islands were all classified as finches. Darwin began speculating, in a series of notebooks, on the possibility that ‘one species does change into another’ to explain these findings, and around July of that year sketched a genealogical branching of a single evolutionary tree.  Unconventionally, Darwin asked questions of fancy pigeon and animal breeders as well as established scientists.

Charles Darwin

Charles Darwin in 1860, aged 51

In late September 1838, Darwin started reading Thomas Malthus’s An Essay on the Principle of Population with its statistical argument that human populations, if unrestrained, breed beyond their means and struggle to survive. Darwin related this to the struggle for existence among wildlife and plants, so that the survivors would pass on their form and abilities, and unfavourable variations would be destroyed.  By December 1838, he had noted a similarity between the act of breeders selecting traits and a Malthusian nature selecting among variants thrown up by chance.

Darwin now had the framework of his theory of natural selection, but he was fully occupied with his career as a geologist and held off writing a sketch of his theory until his book on The Structure and Distribution of Coral Reefs was completed in May 1842.

Evolution by natural selection

Darwin continued to research and extensively revise his theory of natural selection while focusing on his main work of publishing the scientific results of the Beagle voyage.  He tentatively wrote of his ideas to the famous Scottish geologist Charles Lyell in January 1842; then in June he roughed out a 35-page pencil sketch of his theory. Darwin began correspondence about his theorising with the botanist Joseph Dalton Hooker in January 1844, and by July had rounded out his sketch into a 230-page essay, to be expanded with his research results and published if he died prematurely.

His famous 1859 book On the Origin of Species was written for non-specialist readers and attracted widespread interest upon its publication. As Darwin was already an eminent scientist, his findings were taken seriously.  The evidence he presented generated scientific, philosophical, and religious discussion. The debate over the book contributed to the campaign by Thomas Huxley and his fellow members of the X Club to secularise science by promoting scientific naturalism. Within two decades there was widespread scientific agreement that evolution, with a branching pattern of common descent, had occurred, but scientists were slow to give the mechanism of natural selection the significance that it deserved.

species divergence

Diagram representing the divergence of species, from Darwin’s Origin of Species

Darwin’s theory of evolution is based on some key facts (based on wild populations without human interference), which biologist Ernst Mayr has summarised as follows:

  • Every species is fertile enough that if all offspring survived to reproduce the population would grow.
  • Despite periodic fluctuations, populations remain roughly the same size.
  • Resources such as food are limited and are relatively stable over time.
  • Individuals in a population vary significantly from one another.
  • Much of this variation is heritable.

From these key facts, the following important inferences may be made, once again summarised by Ernst May:

  • A struggle for survival ensues.
  • Individuals less suited to the environment are less likely to survive and less likely to reproduce.
  • Individuals more suited to the environment are more likely to survive and more likely to reproduce and leave their heritable traits to future generations, which produces the process of natural selection.
  • This slow process gradually results in populations changing to adapt to their environments, and ultimately, these variations accumulate over time to form new species.

Natural selection provided a mechanism for variation and eventual speciation, but it did not explain the inheritance of variation.  Without some way to explain the inheritance of characteristics acted on by natural selection, his theory would be incomplete.

Mechanisms of inheritance

Before the advent of genetics, Hippokratic theories attempted to explain inheritance in terms of a blending of fluids extracted from all parts of both male and female bodies during intercourse.  It was thought that the characteristics of the offspring are determined by the relative amounts and strength of fluids from each part of the body of each parent.

On the other hand, ‘preformationist’ theories held that the new mammalian offspring is already preformed in miniature, either within the egg of its mother or in the semen of its father.  Both of these types of theories incorporated ‘encasement’, which was the thesis that God created all future organisms in miniature, and that reproduction was just the growth and development of these miniatures.

Hippokratic theories were very good at explaining inheritance but very bad at explaining growth and development; whilst preformationist theories were the opposite – very good at explaining growth and development but very bad at explaining inheritance.  To give some examples, Hippokratic theories were unable to adequately explain phenomena such as the regeneration of freshwater polyps; while preformationist theories were unable to adequately explain how the mating of a mare with a donkey produces a mule.

Darwin came to his hypothesis of pangenesis, from a different direction – to fill a gap left in his theory of evolution.  Darwin’s breeding experiments on domestic animals (mainly pigeons) in the 1850s and 60s were part of his attempts to complete his evolution theory.  He was attempting in these experiments to show just how quickly varying characteristics can be amplified by domestic breeding, and therefore how natural selection can operate.

Darwin called his explanation of inheritance ‘the hypothesis of Pangenesis’, which he published in 1868.  However, he provides a more succinct description of this hypothesis in an earlier unpublished manuscript on pangenesis sent to Thomas Huxley in 1865:

“Furthermore, I am led to believe from analogies immediately to be given that protoplasm or formative matter which is throughout the whole organisation, is generated by each different tissue and cell or aggregate of similar cells; – that as each tissue or cell becomes developed, a superabundant atom or gemmule as may be called of the formative matter is thrown off; – that these almost infinitely numerous and infinitely minute gemmules unite together in due proportion to form the true germ; – that they have the power of self-increase or propagation; and that they here run through the same course of development, as that which the true germ, of which they are to constitute elements, has to run through, before they can be developed into their parent tissues or cells. This may be called the hypothesis of Pangenesis”.

pangenesis

The Laws of Inheritance & Pangenesis

Darwin further proposed that his hypothesis would not only account for inheritance, but also for development:

“The development of each being, including all the forms of metamorphosis and metagenesis, as well as the so-called growth of the higher animals, in which structure changes, though not in a striking manner, depends on the presence of gemmules thrown off at each period of life, and on their development, at a corresponding period, in union with the preceding cells”.

Through these mechanisms, Darwin proposed that inheritance and development were tied together – not only in the generation of offspring and early stages of embryonic life, but throughout the life of the organism.  By giving ‘gemmules’ the power to be modified throughout the life of an organism and then be transferred to the next generation, he argued that inheritance should be viewed as a form of growth.

By means of this single hypothesis, Darwin attempted to not only fill a gap in his theory of evolution, but whether he meant to or not, he created an apparent synthesis between the then competing paradigms relating to inheritance and development.

After reading Variation Under Domestication, Francis Galton (a cousin of Darwin’s) arranged for a series of experiments to be conducted on rabbits initially housed in the Zoological Gardens of London and later at his Kensington home.  His intention was to demonstrate the transmission of ‘gemmules’ to succeeding generations via blood injected from one rabbit to another, using coat colour as a marker.  Galton ultimately found that not a single instance of induced variation of coat colour occurred in a total of 88 offspring from blood transfused parents, and in 1871 published his results in Nature.

In later editions of Variation Under Domestication, Darwin admitted in a footnote that he would have expected to find ‘gemmules’ in the blood, although their presence was not absolutely necessary to his hypothesis.  Darwin’s response is unconvincing, as he provides no alternative explanation as to how the ‘gemmules’ are transmitted from the parents’ somatic cells to the germ cells.  He made no real attempt to modify his hypothesis in response to Galton’s falsification of it, indicating a possible abandonment of commitment to his hypothesis.

After the rediscovery of Mendel’s work in the 1890s, scientists tried to determine which molecules in the cell were responsible for inheritance.  In 1910, Thomas Hunt Morgan argued that genes are on chromosomes, based on observations of a sex-linked white eye mutation in fruit flies.  In 1913, his student Alfred Sturtevant used the phenomenon of genetic linkage to show that genes are arranged linearly on the chromosome.  It was soon discovered that chromosomes consisted of DNA and proteins, but DNA was not identified as the gene carrier until 1944. Watson and Crick’s breakthrough discovery of the chemical structure of DNA in 1953 finally revealed how genetic instructions are stored inside organisms and passed from generation to generation.

In view of the fact that it took another 85 years after Darwin’s book Variation Under Domestication before the molecular mechanisms of inheritance to be discovered, Darwin can hardly be blamed for getting it wrong way back in 1868.  This was before even chromosomes had been discovered, let alone DNA.

On the plus side, Darwin’s theory of evolution by natural selection, with its tree-like model of branching common descent, has become the unifying theory of the life sciences. The theory explains the diversity of living organisms and their adaptation to the environment. It makes sense of the geologic record, biogeography, parallels in embryonic development, biological homologies, vestigiality, cladistics, phylogenetics and other fields, with unrivalled explanatory power; it has also become essential to applied sciences such as medicine, agriculture, conservation and environmental sciences.

References

Darwin, Charles (1859) The Origin Of Species. 6th ed. 1873. London: John Murray.

Darwin, Charles (1875) The Variation of Animals and Plants Under Domestication, Vol II London: John Murray.

Mayr, Ernst (1982) The Growth of Biological Thought: Diversity, Evolution, and Inheritance Harvard University Press.

Copyright notice: © All rights reserved. Except for personal use or as permitted under the Australian Copyright Act, no part of this website may be reproduced, stored in a retrieval system, communicated or transmitted in any form or by any means without prior written permission. All inquiries should be made to the copyright owner, Tim Harding at tim.harding@yandoo.com, or as attributed on individual blog posts.

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What if Sydney University’s complementary medicine research shows it’s useless?

The Conversation

Simon Chapman, University of Sydney

The Faculty of Medicine at the University of Sydney has just announced A$1.3 of funding from Blackmores, the complementary medicine manufacturer, for a Chair in Integrative Medicine (a blending of evidence-based conventional and complementary medicine). It will be named after the company’s owner, Maurice Blackmore.

The Dean of the Faculty, Bruce Robinson, has given a coherent and persuasive account of why research in this area is of importance to modern medical practice. Nearly a quarter of Australians with chronic health problems use complementary and alternative medicine (CAM) and the bewildering range and often changing nature of these products are often of unknown efficacy, and may have important adverse or beneficial interactions with prescribed medicines. Still, more of the “worried well” regularly use unnecessary vitamins and other dietary supplements, often achieving little other than the generation of expensive urine in consumers and handsome profits in manufacturers.

Robinson is correct in arguing that medical practitioners and students know little about what a significant proportion of their patients are using and about whether these preparations help, harm, generate only placebo effects or simply waste patients’ money. And he is absolutely correct in making it clear from the beginning that the relationship will be at “arm’s length”, with Blackmores having no say in the research projects selected, in vetting the results produced, or in any post-publication researcher communications about those results. But there is already a great deal of evidence about a large number of complementary and alternative medicine preparations being useless, and about how faith in their magical properties can too often cause people with serious health problems to stay away from “conventional” evidence-based treatments of known effectiveness.

Complementary and alternative medicine manufacturers continue to produce and promote many of these substances, paying no heed to the evidence for their uselessness. Conventional medicines (so-called “ethical pharmaceuticals”) have to pass through onerous regulatory hurdles to prove both safety and efficacy. With the exception of the United States and New Zealand, prescribed medicines cannot be advertised directly to consumers. While the complementary and alternative medicine industry has to satisfy concerns about safety and toxicity, it does not have to satisfy standards of efficacy and can promote useless products in often quasi-mystical and vague language.

The University of Sydney needs to be extremely careful that its association with Blackmores does not turn into a “CAM-wash” exercise, where any adverse research findings on efficacy or interactions are ignored by the company, with the products not being withdrawn or the promotional language unchanged. There are social and financial costs in the mass consumption of unnecessary and ineffective “medicines”. The pages of medical journals routinely expose such drugs in the conventional medicines area. Many are highly sceptical that far too many players in the complementary and alternative medicine industry are the historical siblings of snake-oil medicine. For the Blackmores-University of Sydney association to repudiate that concern, it will be important to see evidence that the evidence-based and ethical principles at the heart of medical research are both shared and acted upon by the company.

In view of the sensitivities involved over potential reputational damage, the Faculty would do well to appoint an external audit committee to periodically review the relationship and to provide the Faculty with a report on the impact of the research program on the way Blackmores responds to the research it will have supported.

Editor’s note: please ensure your comments are courteous and on-topic. The Conversation

Simon Chapman is Professor of Public Health at University of Sydney.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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Amanda Vanstone on ‘We need a new hero’

“Islamic State has had tremendous success in wooing young, disenchanted people from the West to embark on the adventure of a lifetime and head off to fight in support of the caliphate. Is there anyone stupid enough to think that the photos of these kids just accidentally end up in the Western media? These kids are lambs to the slaughter. IS don’t need their numbers; they need the message to the West: “Your young people think we’re great.”…In this way, they not only promote themselves but they cause us to ask ourselves where we have gone wrong.

IS has something else in its favour, too. As outdated and sickening as we find their ideology, they are at least out there selling it. The West hasn’t had a leader in my lifetime who has taken on the task of selling Western democratic philosophy. It starts with the unbeatable premise that all men are created equal, that everyone gets a say in who will govern us, that everyone is equal before the law, that presidents and prime ministers are subject to the same laws as tradies and teachers. I can’t think of a better message.

Yes, part of the battle is on the ground, for territory, fought with troops and equipment. However, the bigger battle is for hearts and minds, and that has to be fought in mainstream and social media. Ask yourself this: is there is a wordsmith out there to lift our hearts and minds and help us win this battle? There was Churchill in the Second World War, Kennedy in the Cold War; now, we need a new hero.” – Amanda Vanstone


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The Tesla battery heralds the beginning of the end for fossil fuels

The Conversation

John Mathews

Wind and solar power have made great strides in recent years, accounting for 56% of net additions to global power capacity in 2013.* What holds them back is their transience and intermittent character. The sun doesn’t shine at night and the wind doesn’t blow year-round – these are the mantras of all those opposed to the progress of renewables.

Now the renewable power billionaire Elon Musk has just blown away that final defence. Last Thursday in California he introduced to the world his sleek new Powerwall – a wall-mounted energy storage unit that can hold 10 kilowatt hours of electric energy, and deliver it at an average of 2 kilowatts, all for US$3,500.

That translates into an electricity price (taking into account installation costs and inverters) of around US$500 per kWh – less than half current costs, as estimated by Deutsche Bank.

That translates into delivered energy at around 6 cents per kWh for the householder, meaning that a domestic system plus storage would still come out ahead of coal-fired power delivered through the conventional grid.

What’s more, Musk is going to manufacture the batteries in the United States, at the “gigafactory” he is building just over the border from California in Nevada. He is not waiting for some totally new technology, but is scaling up the tried and tested lithium-ion battery that he is already using for his electric vehicles.

Not just for homes

Now the fossil fuel companies – from fuel suppliers such as coal miners to coal-burning electric power utilities – will be on the defensive, fighting the new normal of cheaper renewable supplies and storage. Instead of asking “can we have our own energy system?” communities will be asking “why can’t we have it?”

The Tesla Energy system launched last week is comprehensive, with global ramifications. The Powerwall system offering 10 kWh is targeted at domestic users. It is complemented by a commercial system termed the Powerpack offering 100 kWh storage, and a stack of 100 such units to form a 10 megawatt hour storage unit that can be used at the scale of small electricity grids.

Whole communities could build micro-grid power supply systems around such a 10 MWh energy storage system, fed by renewable energy generation (wind power or rooftop solar power), at costs that just became super-competitive.

At his launch last week, Musk maintained that the entire electric power grid of the US could be replicated with just 160 million of these utility-scale energy storage units. And two billion of the utility-scale units could provide storage of 20 trillion kWh – electric power for the world.

The revolution begins

It is instructive to put these numbers in context. There are already around 2 billion cars and commercial vehicles on the world’s roads, and nearly 100 million new vehicles are being added every year.

If it’s feasible to build these exhaust-pumping complex machines, it’s certainly feasible to build the storage units that will help to make them unnecessary. What’s more, Elon Musk has just announced that he intends to do so.

Musk is a Henry Ford-style figure who takes others’ innovations and scales them up, taking the breathtaking entrepreneurial leaps that others can only dream about. Suddenly the world of renewable energy just moved to become the new normal – because when combined with cost-effective storage it becomes unbeatable.

Musk will not be alone. Already China is gearing up to be the world’s renewable energy superpower, with the largest installed base of wind power and probably by this year the world’s largest installed base of solar photovoltaic (PV) power, as well as by far the world’s largest manufacturing system for wind turbines and solar photovoltaic cells.

There are already Chinese companies such as BYD producing their own energy storage units based on lithium ion technology for both domestic and commercial usage – although not as sleek nor as cheap as the new Tesla offering.

But give them time and they will be producing at comparable scale and cost, or bettering it. This is capitalist competition – and its propagation is what makes Tesla’s announcement the start of the real renewables revolution.

No going back

What about Australia and the sorry state of affairs in which the Abbott government can see nothing beyond coal exports and does everything it can to halt the transition to renewables? Tesla’s announcement has just shifted the ground beneath their feet.

No longer can anyone in Australia claim that renewables would be “nice” if only they came with storage. Now they do.

A smart government in Australia would be looking to ride this wave and promote Australian renewable technology as a source of wealth for the country in a post-fossil fuel era.

Finally we would be able to move beyond the fruitless debates in Australia over whether to have a carbon tax or not, and move to the more immediate and practical issue of promoting renewable industry and technology.

China has given the world a huge lesson in the business-like way it has gone about building and promoting its renewable energy industries, importing technology from around the world and now improving on it as well, and scaling up production so as to drive down costs.

Now Musk and his Tesla Energy have just taken that process one decisive further step, to encompass storage as well as renewable power generation. From here there is no going back.

*This article was updated on May 19 to more accurately reflect the uptake of renewable energy.

The ConversationJohn Mathews is Professor of Strategic Management, Macquarie Graduate School of Management at Macquarie University.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.


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Louis Armstrong playing ‘Shine’

Louis Armstrong is widely regarded as the first great jazz soloist; although Sidney Bechet was arguably the first notable musician to play a jazz solo on a recording (Wild Cat Blues in July 1923). Armstrong was born in 1901 in the poorest section of New Orleans.  He learned to play the cornet in the Coloured Waif’s Home where he later became leader of the children’s band there. After he left the Waif’s Home, by day he was delivering coal from a mule-drawn cart and later on by night he was playing cornet in honky-tonk bars.  In time, he graduated to become a full-time musician, playing in the bands of Kid Ory, Fate Marable and the Tuxedo Brass Band.

Armstrong’s main cornet mentor during his early life had been Joe ‘King’ Oliver, who had left New Orleans for Chicago in 1918 after the closing down of the Storyville red light district.  In mid-1922, Oliver invited Armstrong to play second cornet in his Creole Jazz Band at the Lincoln Gardens dance hall on the south side of Chicago.

In September 1924, the successful African-American dance band leader Fletcher Henderson hired Armstrong specifically to be his featured soloist in New York.  Henderson had previously heard Armstrong in 1922 whilst on tour in New Orleans and offered him a job in his small touring band, but Armstrong had turned the offer down.  As Henderson’s 1924 offer now provided Armstrong an ideal opportunity to develop his own musical identity, he readily accepted it and travelled by train to New York from Chicago.  Musician and jazz critic Ted Gioia has described this transition as a major watershed in jazz history: ‘The New Orleans pioneers exit stage left; Armstrong on trumpet enters stage right heralding the new Age of the Soloist’.  Similarly, the jazz writer Gary Giddens credits Armstrong with changing jazz from a collective idiom to a soloists art.

Here is the young Louis Armstrong in his prime, aged 31. This is an excerpt from the short film ‘A Rhapsody In Black In Blue’ (1932).

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Turning the tables: using genetic mutations to fix nature’s problems

The Conversation

Merlin Crossley, UNSW Australia

Everyone is different. That’s a simple truism, but it’s is also true when it comes to how people respond to diseases; some people are laid low and others shrug off the same ailment.

And it’s true of genetic diseases. Even when two individuals carry the same mutation, the severity of the disease may vary between them.

Sometimes this is due to environmental variation, but in other cases it reflects additional genetic changes that also influence how the disease affects that person. Some people will have other harmful mutations that combine with the main disease gene to make the condition worse, while more fortunate people may have inherited other variations, actual beneficial mutations, that reduce or even eliminate symptoms.

One of the best known illustrations of this phenomenon centres around the inherited blood disorder sickle cell anaemia. This lifelong condition is due to mutations in the adult globin gene – a point mutation in that gene renders it defective and patients suffer from anaemia throughout their lives. The symptoms can be severe. Damaged blood cells can block blood vessels leading to intense pain and even loss of life.

In the blood

But, as mentioned above, symptoms vary between individuals. Environmental variability also influences symptoms, so affected individuals may be advised to avoid high altitude and oxygen stress, for example. But genetic variations also exist. Some individuals carry a second mutation in the regulatory region of another globin gene that alleviates symptoms of sickle cell anaemia.

These individuals have a benign condition called Hereditary Persistence of Foetal Haemoglobin (HPFH). They have an “up-mutation” in the control region of a separate globin, the foetal globin gene, which boosts expression of that gene. The extra foetal globin can replace the defective beta globin.

I realise that is fairly complicated. But, put simply: humans have several globin genes. The foetal globins are turned on before birth and have a high affinity for oxygen; they enable the baby to snatch oxygen from its mother’s blood. After we are born the adult, or beta globin, gene comes on and the foetal globin gene is shut off.

But in a few people with HPFH the foetal globin gene stays on throughout life. Interestingly, this doesn’t seem to cause any health problems. Individuals with HPFH can even have normal pregnancies. They just have extra foetal globin in their blood.

The crux of the matter is this: if an individual inherits the sickle cell mutation and an HPFH mutation, they have few if any symptoms, because the extra foetal globin does the work of the defective adult globin gene.

So could one effectively “cure” sickle cell anaemia by introducing the HPFH mutation into blood cells affected by the defective adult globin gene?

Switching on the backup

Well, this is precisely the approach we have taken. Using the new technique of “genome editing”, we have introduced one of the best characterised HPFH mutations, and we find that we can successfully turn on the sleeping foetal globin gene.

At this stage we have only done this in cell lines in the laboratory. To turn this into a therapy, one would have to do it in haematopoietic stem cells – i.e. blood-forming stem cells – from the patient. It would be necessary to achieve a high frequency of editing in enough stem cells to enable repopulation of the patient’s blood with genetically enhanced cells.

Gene repair

But if it is so easy to edit the genome now, why don’t we just correct the sickle cell mutation rather than introducing a new mutation, albeit a beneficial and benign mutation?

Well, that is certainly a good strategy in the case of sickle cell anaemia, and many people are working on just that. But it may be a less ideal strategy for other blood diseases and various genetic diseases where large genes or regions of the genome are deleted.

In the case of the thalassaemias, for example, many different gene deletions occur. It may not be practical to edit in large gene replacement cassettes, and one would have to design a different insert for each mutation. In contrast, building in the foetal globin activating mutation should provide additional globin and work to compensate in many of these conditions.

Towards gene therapy using genome editing

A new age of genetic engineering is beginning, due to the ability to edit the genome using new DNA-cutting tools, with the technical names: CRISPRs, TALENs and ZFNs.

Gene correction or the introduction of beneficial mutations may be important in treatments in the future.

In agriculture they may also be important. Many genome wide association studies have identified beneficial mutations associated with particular prised qualities. Genome editing can also be used to introduce beneficial mutations in this context and may give rise to a new generation of crops and livestock.

The techniques are also interesting because no new or artificial material need be introduced. All one is doing is mimicking a naturally occurring beneficial mutation. The introduction of artificial transgenes has alarmed some parts of society.

Additionally, transgenes are recognised as foreign by some organisms and are shut down by epigenetic silencing, just as computer viruses are recognised and shut down by anti-virus software.

Beneficial mutations are unlikely to be subject to the same limitations. They are already known to work in nature and introducing them to improve human health or in agriculture may have many advantages.

The ConversationMerlin Crossley is Dean of Science and Professor of Molecular Biology at UNSW Australia.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.


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Jean Sibelius on critics

Jean Sibelius (8 December 1865 – 20 September 1957) was a Finnish composer of the late Romantic period. His music played an important role in the formation of the Finnish national identity.

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Four card solution

Obviously we need to turn over the D to check that there is a 3 on the back (everybody gets this one right). And equally obviously, there’s no need to turn over the K (and again, everybody realises this). The 3 card is a tricky one. Most people think that you need to turn this card over to see whether there is a D on the other side. This would be necessary had the claim been that “Every card that has a D on one side has a 3 on the other, and vice versa”. But it wasn’t. The 7 is the other tricky one. It doesn’t occur to most people that we need to turn this card over to check that the letter on the back is not D. If it is D, then the claim is false.

This trick illustrates the phenomenon of confirmation bias. Most people, being fairly charitable sorts, want to turn over the 3, find a D on the back and confirm the claim (“Well done, you’re right!”). And so it is with homeopathy (or conspiracy theories). People who want to believe that the treatment works actively search for opportunities to confirm this belief, focusing on homeopathy patients who seem to have got better (“3 cards”) and reject opportunities to disconfirm it, by ignoring research studies (“7 cards”).

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Senator Richard Di Natale on The Australian Vaccination Network

Dr. Richard Di Natale (born 6 June 1970) is an Australian Senator and leader of the parliamentary caucus of the Australian Greens party. Di Natale is a former medical practitioner, and was elected to the Australian Senate in the 2010 Australian federal election.

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