lecture 14: stem cells: what is all the fuss? Flashcards Preview

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Flashcards in lecture 14: stem cells: what is all the fuss? Deck (18)
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1
Q

What do people hear about stem cells?

A
  • concern about use of human embryos
  • very catchy, emotive captions
  • “you, me, everybody”
2
Q

How acceptable do the australian public think using stem cells to conduct medical research and treat disease is?

A
  • don’t know - 6%
  • no - 5%
  • yes - 88%
  • DIISR - community attitudes to biotechnology (2010)
3
Q

Does the australian public think of using human embryonic stem cells to conduct medical research and treat disease is acceptable?

A
  • don’t know - 6%
  • no - 17%
  • yes - 70%
  • DIISR - community attitudes to biotechnology (2010)
4
Q

What are issues associated with use of human embryonic stem cells in research?

A
  • isolate cells from inner cell mass of blastocyst
  • day 6
  • this is how you get the stem cells
  • the embryo is destroyed in the derivation process
  • this is what is so offensive to that minority of the population
  • preimplantation embryos are vastly different from foetal tissue
  • originally created for infertility treatment that are no longer required
  • very very small
  • however a human embryo is probably different from simply a culture of cells
  • has a potential to be a life
  • only can be realised if put in a uterus, and even then only 30% of those will go on to full pregnancy etc
  • concern about the sanctity of life and reproductive technology
    • isn’t an embryo a life?
    • why do scientists have to kill IVF embryos to get stem cells?
    • why do we have excess IVF embryos? why do IVF clinics deliverately make more embryos than are required? do they do this to make more $?
    • are IVF couples forced to donate their embryos? if they don’t will their treatment be compromised?
    • concern that IVF embryos are “farmed” for spare parts
5
Q

What are issues associated with use of human embryonic stem cells in research (SCNT) ?

A
  • great concern about the abuse of this technology
  • rate limiting factor could be considered to be where are the eggs going to come from
  • scientists use SCNT to create life to destroy a life (embryo = life)
  • can’t SCNT be used to clone humans?
  • concerned that women will be exploited by SCNT - forced/able to sell eggs
  • SCNT will be used to create monsters (half human/half animal) if animal eggs are used
6
Q

Are iPS cells really the ‘ethical’ alternative?

A
  • Yamanaka
  • by passes use of human embryo
  • not without its ethical issues
  • Yamanak told Nature: “we are presenting new ethical issues, maybe worse ones, because many people can do this – and without telling anybody”
  • establishment of induced pluripotent stem cells from centenarians for neurodegenerative disease research
  • iPS can also be used to create clones e.g. Tiny the mouse
    • very inefficient generation
      • tetraploid blastocyst generated by fusion of two-cell embryo
      • iPS cells are injected into the tetraploid blastocyst which then steer development
      • developing embryo is implanted in surrogate mother
      • 22 births/624 injections (3.5%)
      • 2 births/187 injections (1.1%)
      • nature paper demonstrated germline transmission
7
Q

How is the use of stem cells highly regulated?

A
  • project by project consideration of:
    • how consent will be obtained
    • likelihood of significant advance in knowledge or improvement in technologies for infertility treatment
    • number of embryos necessary to achieve project goals
  • ethics approval and NHMRC licence; research involving use of human embryos act 2002, prohibition of human cloning act 2002
  • embryo
  • stem cells
  • research
  • national statement on ethical conduct in human research
  • SCNT for stem cells allowed following 2006 amendment
    • prohibit the transfer of an embryo generated by SCNT to the uterus of a woman or animal
  • iPS cells:
    • need national statement on ethical conduct in human research
    • ethics approval to get tissue sample
    • OGTR (office of gene transfer technology ) if the genetic modification is required
    • stringency isn’t quite as great for the generation of iPS cells
8
Q

What is the perception of stem cells in the media?

A
  • they’ve had a lot more success than actually true
  • “grow new breasts”
  • stem cell cancer cure hope
  • dental and medical news: stem cells grow replacement
  • stem cell method offers new hope
  • breakthrough in diabetes research
  • grow your own heart
  • no men or women needed: scientsits create sperm and eggs froms tem cells
  • artificial sperm takes men out of equation
  • stem cells turned into glow-in-the-dark blood cells
  • stem-cell-coated contact lenses are curing the blind
  • alzheimer’s hope
  • lipo fat turns to stem cells
  • stem cell crystal ball
  • grow your own organs
  • only proven use of stem cells is using HSCs for blood diseases
  • not for broad application
  • long way from being able to deliver on the promise of stem cells in regenerative medicine
9
Q

What is the growth in ‘novel’ applications of stem cells?

A
  • huge community demand
  • gradual increase in the number of clinical trials
  • not meeting demand
10
Q

What are clinical trials to evaluate possible treatments?

A
  • mesoblast (ASX) bone marrow → cartilage, bone, heart
  • advanced cell technology
    • precursors from embryonic stem cell → rare type of blindness – stargardt’s macular degeneration and macular degeneration
11
Q

How can stem cell science be translated?

A
  • demonstrated efficacy and risk assessment in preclinical models
    • peer review
    • clinical trials
    • proven therapy
    • !
  • rationale and preclinical evidence of efficacy and safety
    • peer review
    • medical innovation, involving few seriously ill patients
    • clinical trials when possible
    • proven therapy
    • !
  • no rationale or preclinical evidence of efficacy
    • no peer review
    • stop
    • X
  • we are now seeing lots of illegitimate companies advertising use of stem cells
12
Q

What are hazards of unproven stem cell treatments?

A
  • outside clinical trials by non-experts
  • lack of proven benefits
  • endorsed by patient testimony
  • risk of physical harm
  • financial exploitation
  • diversion from existing proven therapies
  • disqualification from future clinical trials
  • based on selling hope
13
Q

What are experiences of Australians in regards to medical tourism?

A
  • findings:
    • considered pro-active and well informed
      • did not seek advice from local doctor
    • no choice but to travel abroad
      • australia ‘fallen behind’
      • condition deteriorating quickly
    • aware possible risks and benefits
      • risks defined as financial
    • high costs
      • financial and emotional
    • all reported benefits – ‘it works’
  • “it can down to the worst that could happen was nothing really…. we could spend our money have gotten no result…” - lisa
  • “i have not regretted it for a day. it certainly made a difference and as I said, it’s given me hope…” - natalie
14
Q

At what cost (medical tourism)?

A
  • more at risk than “doing your money”
  • unexpected growths
    • scientific american: in the flesh: the embedded dangers of untested stem cell cosmetics
    • new scientist: stem cell treatment causes nasal growth in woman’s back
    • stem cell ‘cure’ boy gets tumour
  • death
    • forestdale man died after operation to help him walk again
    • europe’s largest stem cell clinic shut down after death of baby
    • both died from the incredibly invasive techniques used to deliver the stem cells
15
Q

What unproven SCTs are being offered in Australia?

A
  • increasing number of doctors offering autologous “stem cell” or SVF treatment
    • usually liposuction derived but also peripheral blood
    • $9k+ per treatment (multiple encouraged)
    • offered for many conditions including osteoarthritis, autism, retinal neuropathy, MS, MND, and SCI
    • intra-articular and IV delivery
  • marketed as ‘medical practice’
  • if there is a catastrophe the whole industry will get shut down
16
Q

How are stem cells a regulatory challenge?

A
  • only regulated if donor cells used
  • if using patient’s own cells doctor can do almost whatever they want
17
Q

What is the expectations gap?

A
  • most support, lowest perceived risk
  • demand from patients is not going to go away
  • si per Stamina, si alla vita
    • we are here for the freedom of cure with stem cells because in italy our politicians want to destroy our hopes
    • stamina was a clinic offering help to sick and dying children that otherwise were not getting much help
    • brought to the attention of the government and shut down
    • these people were outraged
  • right to try
  • minimal standards
    *
18
Q

How do we manage community expectation?

A
  • Stem Cell Treatments - A quick guide for medical practitioners, frequently asked questions - NHMRC
  • The australian stem cell handbook
  • beware of dr google
  • www.stemcellsaustralia.edu.au

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