Monthly Archives: May 2017

CO2 and the atmosphere ATTP

Thank you for this post.
The effect of adding extra CO2 to the atmosphere is fundamental to explaining the temperature of the atmosphere and the earth.
While I disagree on the level of the feedbacks and other interactions the temperature increase due to CO2 increase causes it has an obvious effect*.

One of the problems I have is defining the surface of the planet as an effective entity.
Because of the atmosphere, which in a sense is part of the surface when it reflects light [That light bounced of earth] we do not have a real surface like a meteorite or the moon but a layer of surfaces depending on what depth the light penetrates too.
This leads to your concept of a radiating layer [then the layer from which the energy is radiated directly to space will move to a slightly higher altitude.], also known as a TOA,  which is an artificial designation of the effective surface layer of the earth.

“Essentially, the presence of greenhouse gases prevents energy from being radiated directly from the surface to space; instead it’s radiated from within the atmosphere. you can think of there being a layer in the atmosphere where the energy can be radiated directly to space.” Yes.

“However, the temperature of the atmosphere decreases with increasing altitude, and so moving the radiating layer to a higher altitude will reduce the outgoing energy flux.”

Not happy with this comment as the outgoing energy flux total must be higher. The real temperature at the artificial TOA is not the same thing as the construct of  “what temperature  the TOA needs to be to radiate this amount of energy into space. Two problems.

The amount of energy going out to space from a square meter at that extra height means there are more meters for the energy to go out from. Which means there is an increased outgoing [total] energy flux. Which makes sense as the earth is hotter.

Technically if the earth is warmer then the temperature at the higher altitude now being used would be warmer than what it was before. Practically as it is an artificial construct the air is warmer at lower heights than it used to be and probably does not change in temperature at all. Being very thin and not much GHG or energy absorbent molecules at 100 km.

“If we were in energy balance before adding the extra CO2, then we’ll now have more energy coming in than going out, and we’ll warm until we’re back in energy balance.”

Conceptually the energy coming in balances the energy going out. The instance you put the CO2 extra in it increases the heat of the atmosphere it is in*  by delaying the return of that heat as energy to space. This is a momentary and continuous delay the end effect is as you say, energy in equals energy out or energy balance..

Introduction

Thank you to Allan and U3A for asking me to give a talk on science in medicine today.  I wished to draw attention to the progress that has been made.  Scientific medicine has moved beyond  the standard of faith that it enjoyed with alternative forms of medicine but it has failed in important areas to bring people along with it.  I hope to  correct or clean up some of the doubtful areas and at the same time mention some of the new advances being made.  I will touch on the place of alternative medicine, diet and vitamins. I will address vaccines then issues with population health where medicine has moved away from treating the individual to treating the population.

Medicine is the art of healing concerned with the health of individuals. It consists of diagnosis and treatment of medical conditions, both of the body and the mind. It helps  the body and mind repair as much as is possible.

Healing is an innate function. The body has developed both repair and defensive mechanisms. As has the mind. Without a will to survive, to repair and recover the body alone is like a rudderless ship.

I hope you will find it informative.

PSA Screening

Prostate cancer and screening

PSA tests. The jury was out. Top specialists like Tony Costello at RMH actively push for early detection for early treatment. Other  groups like the USANZ preferred that screening not be done as the rewards of detection and the downside of the treatment outweigh, they felt,  any active management. How times change. Now the guidelines are to

  1. Offer evidence-based decisional support to men considering whether or not to have a PSA test, including the opportunity to discuss the benefits and harms of PSA testing before making the decision.
  2. For men at average risk of prostate cancer who have been informed of the benefits and harms of testing and who decide to undergo regular testing for prostate cancer, offer PSA testing every 2 years from age 50 to age 69, and offer further investigation if total PSA is greater than 3.0 ng/mL.

Compare and contrast the attitude here to that for women. Several factors weigh in the men are older, The cancer is internal rather than external so harder to get at. The operation has functional rather than cosmetic consequences..

I am an interventionist, I believe that the test itself is easy to do, compared to a mammogram and the results are easier to interpret. The follow up for a positive result is just as traumatic with the biopsy and examination being more difficult. I find it hard to square the idea of watching known cancer if presumed low risk and would prefer the idea of some treatment earlier rather than later.  Of great interest are 3 concepts. One that with a low PSA < 1.0 at 40 and at 60 YO ones risk of cancer is almost negligible [less tests one good outcome. Secondly that if the blood test is going up but there is no lump felt an MRI of the prostate can be done to give complete visualization of it and guide management better.

Choice of procedure Robotic surgery or radiation or both. With apologies to the surgeon who has done all the work Radiation would be a preferred option, just. The upside is that any local spread should get knocked off. secondly the side effects are broadly similar. Prostate cancer is particularly prevalent in the Shepparton area and perhaps a study should be done by our local hospital on the actual incidence.

Vaccination

Vaccination mentioned only to be discarded. A very contentious subject.

Vaccination is good for most people. and for the population as a whole.
It should be encouraged. Without the help of vaccinations many of us would not be here today. Vaccination is exposing the body to a less harmful form of a disease to let the body develop its immune response to the more serious disease when it comes along. The vaccine is a temporary measure and the body does all the work.
There are side effects to vaccination just as there are to all medical and alternative medical treatments.

A new problem is that we have overcome the most serious past illnesses but new vaccines are constantly being developed. There are now 15 different childhood vaccines. We have reached a grey area between protecting everybody from everything at great cost or accepting that we cannot and should not do so.
Anyone wanting to see the effects of non vaccination should visit an older graveyard and look at the number of young people with diphtheria as the cause.

Influenza is an interesting vaccine, Two A and B variations. A is the most prevalent and most current infections are variations of the swine flu from 2009. The older Hong Kong Flu is still mildly active and included. The controversy here is whether all children of all ages should have the flu shot.  Current guidelines is only for children at extra risk. The death rate from meningococcal disease is the same as that for the flu. Which double standard would you like to choose?

A shingles vaccine for older people is out to reduce the risk of shingles. It has a 3 year effectiveness and a 50%  reduction in risk. I think the benefit is very low for this  injection and it smacks  of  salesmanship.

Hep A recommended for all and Hep B if going to Asia or needing blood transfusions.

There is a common practice of subjecting terrified little people to an expensive unneeded vaccination for whooping cough. Yes I am talking about grandparents who are about to have a grandchild. It is a rite of passage that we all have to endure even though the stuff does not work very well. In the remote chance of the grandchild developing whooping cough you will be exonerated. Plus it comes combined with tetanus toxoid and diphteria toxoid so at least you get your 50 year old booster of tetanus toxoid.

extra heart stuff

This is where Skepticism should come into play.
We start as a single cell and live on average 70 years after being born.
Our death rate after the first year is quite low and usually due to bad luck.
Say 2 deaths per thousand per year.  At that rate we should live on average 250 years.
But little things get in the way as we age. Fourteen and the mind starts working and some people decide to leave of their own volition. This stays steady at 1 per thousand increasing the rate to  3. Car accidents and activity related problems kick in by 20, Things increase slowly till 55  at a rate of 7 with the consequences of lifestyle choices due to alcohol tobacco, drugs, sex, diabetes, diet, Blood pressure , atheroma and cancer. From then to 70 the rate increases to 20 a year at the turning point. 500 people have gone. But now the rate kicks up steeply until the majority of people  die in the next 14 years. the rate going up to 40 people a  year at 80.

Cardiovascular disease is the most important  cause of death  in people over 70 accounting for 50 percent of all deaths, half due to heart attacks, slightly less to strokes then other vessels. Cancer accounts for 30 percent. Infection and Kidney and lung disease a large amount of the rest along with infections often secondary to these preexisting conditions.

Basically we start off with good arteries and we are genetically primed to wear out  after 70. The arteries build up atheroma which is a combination of calcification and plaque in the vessel walls. We can hasten the process. Bad dental hygiene causing infection in the blood vessels, smoking, Excessive alcohol, Lack of exercise and obesity. Illness like diabetes and blood pressure.

We can actually measure the development of the atheroma with a High quality CCTA (64-slice and higher) is not only able to provide reliable information on coronary luminal changes, but also has the potential to visualize morphological changes of the coronary artery wall, characterize atherosclerotic plaques and identify non-stenotic plaques which may not be detected by invasive coronary angiography. This showed a significant age related increase in calcification
Of these patients with abnormal changes to the coronary arteries, the number of significant coronary stenosis was directly related to the age group, as less than 15% of patients under 56 years had significant coronary stenosis, but this was increased to 29% and 38% in the age groups of 56–65 years and over 66 years,

Cardiac CT for calcium scoring It has been assumed that measurement of risk factors causal for CAD (e.g. dyslipidaemia or hypertension) would be predictive of coronary events, but the relative hazard ratios of these risk factors are inadequate to accurately predict outcome. Seventy-five per cent of previously asymptomatic patients (men < 55 years, women < 65 years) developing their first MI, would have been ineligible for lipid-lowering therapy prior to the event if assessed with a global risk score.
In four major studies, more than 75% of all hard coronary events occurred in persons classified as low or intermediate risk, and the majority of persons classed as high risk had no coronary events. Risk score assessment alone is inadequate in predicting individual coronary risk.

In contrast, a measure of flow limiting obstruction (with ischaemia testing or CT coronary angiography) is not likely to predict risk.
Sixty-eight per cent of MIs occur in vessels with less than 50% obstruction prior to plaque rupture and thrombosis; and 86% occur in vessels with a less than 70% obstructive lesion (the degree of obstruction required to provoke a positive ischaemia test).Similarly, recurrent MIs are usually caused by a second ‘angiographically minor lesion’ commonly found in patients with a large plaque burden.

44% of individuals had a coronary score of zero. This cohort has such a low long-term risk (99.4% 12-year survival), that any further coronary testing is not required, and interventions like lipidlowering therapy are not likely to alter outcome.

A study of asymptomatic persons with a CAC score of greater than 1000 demonstrated they had a 25% risk of death or MI at one year,

William Osler Quotes

The good physician treats the disease; the great physician treats the patient who has the disease.
Medicine is a science of uncertainty and an art of probability.
We are here to add what we can to life, not to get what we can from life.
The first duties of the physician is to educate the masses not to take medicine.
The greater the ignorance the greater the dogmatism.In seeking absolute truth we aim at the unattainable and must be content with broken portions.
The young physician starts life with 20 drugs for each disease, and the old physician ends life with one drug for 20 diseases.
The teacher’s life should have three periods, study until twenty-five, investigation until forty, profession until sixty, at which age I would have him retired on a double allowance.
It is much more important to know what sort of a patient has a disease than what sort of a disease a patient has.
The future is today.
Variability is the law of life, and as no two faces are the same, so no two bodies are alike, and no two individuals react alike and behave alike under the abnormal conditions which we know as disease.
The philosophies of one age have become the absurdities of the next, and the foolishness of yesterday has become the wisdom of tomorrow.
The desire to take medicine is perhaps the greatest feature which distinguishes man from animals.
Look wise, say nothing, and grunt. Speech was given to conceal thought.

Skeptical Medicine Living longer

Thanks to Allan and U3A for asking me to give a talk on scientific medicine today though I have termed it skeptical medicine. Apart from being a standout headline I wished to draw attention to the fact that scientific medicine has moved beyond  the standard of faith that it enjoyed with most other alternative forms of medicine but has failed in important areas to bring people along with it. Along with providing proof of effect scientific medicine also opens the door to doubt at the same time. I hope to open some of those doors today and correct or clean up the doubt where possible and leave open those doors where science needs to be more rigourous.
I was asked if skepticism was a good word to use in these politically correct times. In fact it is very appropriate because skepticism and  its counterpoint faith are the cornerstones of the progress in medicine.

Medicine is the science of healing concerned with the health of individuals first and then populations. It consists of diagnosis and treatment of medical conditions, originally of the body but also those of the psyche based on reproducible theory. Healing is an innate function of the human body and mind and the body has developed many repair mechanisms to go along with it defensive ones. Medicine is the art of helping the body and mind repair as much as is possible.Hi.

When these fail to work, breakdown or work to slowly As medicine has developed new ideas, treatments and medications replaced older  treatments. [ Osler 11]Feynman , an American scientist has said on science . “It only takes one experiment showing the opposite to disprove a theory”

What is really interesting from a medical perspective is how unskeptical of alternate medicine most people are. To illustrate I will ask hands up those people here who have taken vitamins in their lives? Almost everyone here.

Vitamins  are they good for us to take.

We have a great scientific knowledge of what they are and what they do.
Most people know and use the more common ones.
A through to K,  B 1-B 12  with some gaps there are 13 Vitamins. They are essential to life because they are not normally able to be made in our bodies [exception Vit D].
We have evolved in a world where we interact and depend on our food sources and if we have enough food we get more than enough vitamins.
They are all  available even through a restricted diet or junk food hence there is no need to supplement them as we always get more than we need.
As we get more than we need taking more does not make our bodies any better off.
In some cases e.g. Vitamin A, overdosing can lead to illness and death.
Would I recommend any vitamins to people.
Generally no.**** but some words later.
Perhaps B 12 injections  and vitamin D.
Folic acid in pregnancy as it can reduce Spina Bifida incidence.
There are a few people who do need vitamins due to problems with absorption in the gut, Coeliac disease, Pernicious anaemia, malabsorption syndromes. Surgery removing part of the bowel but they are extremely rare.
Lack of availability, B 12 in vegetarians, Vitamin C if not eating green foods, Vitamin D if not enough fish or sunlight.
Vitamin supplements are expensive and not helpful but still we take them.
The reasoning here appears to be  if a little is good for you, a lot should be better with a dose of I may be low so I will give it a try.

. Vitamins were a discovery of modern science but they are now the best example of alternative medicine. Alternative medicine is the last bastion of faith based medicine, working on faith in a belief even when the belief lacks a logical basis. It also emphasises the triumph of faith over logic. Both a fear of modern medicine and a lack of trust in it.

Junk food is bad for you.    No
Food is food whether it is processed, roasted or pasteurised. It has its own set of protein , fat and carbohydrate usually, with lashings of vitamins and minerals. The two things wrong are that they are very tasty  and eating them fills one up with too many calories.  Secondly they re too easy to get and lead to a lack of discipline in eating sensibly.
It is the overeating that is the problem.
Vary the fast foods and eat in moderation and the dietitians should go away. [Kebabs?]. Personally I feel that cooking is one of the skills that should be taught at school to all children. Domestic science  It used to be called.

In short Vitamins, while a scientific discovery, are mainly just another alternative medicine

Any questions?

Alternative medicine has been around a long time. Alternative medicines are called that to draw a distinction between scientific and non scientific medicine. The distinction is meant to sound harsh. One of the two major factors in healing is the mind. Positive thinking is an essential component of survival. Going forwards against the odds is necessary to survive. And a body with hope or faith doe much better than one. The placebo effect.

Early medical practice worked  on faith and herbs. Witch doctors became herbalists, herbalists became doctors and witches and a little science crept into the mix.
Chiropracty, Acupuncture, Herbalism, Cupping , Faith healing, Homeopathy,  Diet pills, Anti aging pills and creams developed. Some forms like Acupuncture and Herbalism predate Western Medicine, Others like Chiropracty grew up together with it and  modern inventions. A few I would not touch with a barge pole, think Colonic irrigation. They are all treatments intended to improve health. They generally lack scientific [provable] links between the treatment and the disease but have had many years of use and experience. Quote 4

Does it work? Yes but not in most cases. People who are prepared to try have a higher success rate.
There are two golden rules to enjoying life which also apply to Alternative and normal Medicine use.
-Try it and see.            Give it a few weeks and if it helps you, go for it.
–   Never be first .

Is there Quackery involved? Yes. Selling snake oil in the old days is the modern day anti wrinkle cream. An easy way to spot a scam is to look for these traits in the marketing. New, Improved, Expensive, Rare, Unusual and impossible.  Like rhinoceros horn, or the latest juice from an unknown, exotic sounding South American plant to lose 10 kilos in 2 weeks.

In summary Alternative Medicine is the last bastion of faith based medicine which is one of the two major was that we heal. Particularly when we have become skeptical of modern medicine

 

You have a choice.  Let someone else try it first. This works extremely well in conventional medicine as well [Vioxx, Lipobay etc]
Quotes 12, 10, 2,

Myth A placebo effect  exists   Yes

The placebo effect is one of the major reasons why any therapy works. Believing that something is having an effect seems to encourage the patient to feel better and in some case for problems to actually resolve. Mind over matter? It seems that health and illness can be matters of perception in many cases. It seems to have a higher strike rate with symptoms that are non physical and hence not testable as in depression.  his in turn makes it much harder medically to assign values to drugs used in these conditions.
The effect is patient variable and effected by belief. If one knows a placebo is being used there may still be some effect but it is nowhere near as strong. Hence the ability or ease with which people can be hypnotised, or not. In strictly assessable conditions, like infection or trauma, placebos have little value.
What is it. I like to think of it as the antithesis or opposite of skepticism, belief or faith, and yes in some cases it does move mountains

Anecdotes, if needed. I had a patient who had had Talipes and club feet as a child. At 60 I had occasion to check his feet and balance. To my surprise the whirled arthritic stumps of tissue he moved on gave him no pain or problems. He had adapted perfectly to what he had been gifted with and did not seem be aware that he had any limitations or pain. Another patient had a severe carpal tunnel syndrome in both wrists proven on USS.  He also had a morbid fear of surgery. He went to see a Chiropractor in a neighbouring town and pronounced himself cured, which he was. Did the disease go or spontaneously remit or was he believing he was not in pain.

Vaccination mentioned only to be discarded.

Vaccination is good for most people, and for the population as a whole.
It needs to be encouraged.
There are side effects to vaccination just as there are to all medical and alternative medical treatments.
Some people have too much faith in the few bad effects to see the large number of good effects.
People who experience bad effects will always look for a cause and proximity appears to be proof.
Demonizing people for their fears is wrong and does not help. It makes them stubborn and suspicious.
Remember if our immunisation is up to date there is very little risk for us.

Flu vaccines are for the H1N1  Influenza A , formerly known as the swine flu. It is the same variety that caused the Spanish Flu in 1920

Screening tests and treatment

Cholesterol testing and treatment
This is where Skepticism should come into play.

We can all have a cholesterol test but what should we do with it?
There are Government guidelines giving some advice.
There are two competing views out there.
One is that the statins are so good we should all be on them as soon as we are old enough  and stay on them forever. There are studies to show that even in people with normal cholesterol lowering it will increase your life expectancy.
So, we all take vitamins that are useless and expensive, in handfuls,why not take something which is useful and expensive and works?

This is the nub of the distrust in medicine we have talked about.
Sometimes the selling of the product gets a little bit too close to snake oil.

A statement again. Statins do have a place and a target. Cholesterol should be dropped.
But not on the basis of cholesterol levels.

Cardiovascular disease is the most important  cause of death  in people over 70 accounting for 50 percent of all deaths, half due to heart attacks, slightly less to strokes then other vessels.  Basically we start off with good arteries but half of us are genetically primed to wear out  after 70. The arteries build up atheroma which is a combination of calcification and plaque in the vessel walls. We can hasten the process. Bad dental hygiene causing infection in the blood vessels, smoking, Excessive alcohol, Lack of exercise and obesity. Illnesses like diabetes and blood pressure.

Cardiac CT for calcium scoring  shows this progression with age nicely, less than 15% of patients under 56 years had significant coronary stenosis, but this was increased to 29% and 38% in the age groups of 56–65 years and over 66 years. In one study, 44% of individuals had a coronary score of zero. This cohort has  a low long-term risk (99.4% 12-year survival).  In contrast cholesterol levels are ineffective at predicting heart attacks.

What this means is that  up to 44% of people are at little to no risk of heart attack whatever their cholesterol level. But over half of us are.
Early studies showed a relationship of cholesterol levels with heart disease but some more recent studies dispute this, What is indisputable is that if you have proven blood vessel disease a statin has some chance of helping reduce your risk.
Cholesterol levels not being  a help one needs to be guided by family history, diabetes, hypertension and smoking  and by your risk averse nature.
If at high risk a CT scan being clear could suggest medication is not needed.
There are drawbacks with the risk of radiation exposure the younger one is  and medication might be a safer option.
For an older person the CT risk is less and the benefits of a clear study need to be weighed up against the possibility of a score causing needless anxiety or the need to go further and do an angiogram.

 

Infection and Kidney and lung disease a large amount of the rest along with infections often secondary to these preexisting conditions.
A cholesterol test and treatment with statins is often advised by doctors.This brings up the second problem of screening  for cancer.
The problem with screening is when to start, who to start with and how often
Cancer is a disease of aging and most cancer occurs over 50. Cancer cells can start from one cell or sometimes as a field change in susceptible cells. Cells can double at different rates, every 12 hours or every week Cancers appear to be growing rapidly when in fact they are slowing down and are mostly undetectable in the early most rapid divisive phase which can be as little as 6 months or as long as 8 years to get to a detectable size.
The problem is if the cells are capable of metastasizing by blood or lymph spread. The more vascular the organ or the more aggressive the tumour the higher the chances that it will have already spread before being found.

Treatment consists of two modalities. Removal or destruction once identified. Waiting to assess for recurrence when hopefully a chemotherapy regime or the newer MIB ad MAB treatments may be possible.

Breast Cancer screening

Breast cancer is the most common female cancer over 50. It comes on earlier than the male equivalent, prostate cancer by 10 years. Younger patients are in middle age with families just grown up, a husband to look after and still active in a career, perhaps paying off a house. Enjoying life in other words. The outcome was distressing on every level, a high risk of death, usually  disfigurement and scarring with a mastectomy and radiotherapy and emotional distress. Genetics showed a small group of at risk people with a history  of breast cancer in the family, about 10% so no other good guideline for investigation. Diagnosis was by mammography if available or operation with a biopsy and re operation.

Breast cancer screening as a project started 25 years ago with mammogram guidelines.
People at risk with a family history are strongly recommended to have them , usually from 40 onwards or earlier if the family history includes a relative who developed it at an early age. Routine screening is recommended and free  for women from 50-74  in Australia.

Facts.
More than 75% of breast cancers occur in women over 50.
90% of women who get breast cancer have no family history.
An estimated 3,046 Australian women died from breast cancer in 2016.
In 2012, 14 680 people (14 560 women and 120 men) were diagnosed.

Positive reports and statistics. A bit of mathematics. Not all positive reports from screening programs mean you are at high risk. When a condition is relatively rare, like cancer, and increases with age, it is good to be at the shallow end [younger].

Breast cancer is uncommon in younger women so a woman of 40 with a positive result has a much higher result of a false positive. The news should not be treated with doom and gloom but a positive attitude of hope  and investigation started. On the other hand a positive result at 75 should set the alarm bells ringing. This is much more likely to be the real deal. The outlook must still be positive but firm.

Issues  Anxiety that may last for years even when  biopsies  have been done .
Cumulative radiation exposure. at a 2 yearly rate. which may lead to an increase in 30 years time of thyroid and other cancers.
Missing  a tumour that may be there but missed and present in the next 2 years, advise to keep doing BSE .  >50% of tumours are found by the patient or doctor, not screening.
Over diagnosis. In the older age group the chance of dying before a cancer grows enough to cause death means one should not have done the scan in that person [which person?].

While screening has been pushed strongly in Australia and the death rate has dropped it is not clear cut that screening is needed or cost effective. BSE is widely practiced in China and Canada and result outcomes are not that much different. One recent analysis interpreted breast cancer mortality trends by age to indicate that these reductions were mostly a result of treatment rather than screening.44

The problem as always is that the patients who do not screen but develop breast cancer  will always have someone saying you should have had a mammogram. Women seem to have addressed this issue themselves breaking into 56% having mammograms and 44% not. It is voluntary, If one is risk averse it is a wise move. It is always a wise move if you get cancer and never a wise move if you don’t. By refusing to call up women over 74, the highest risk group , the Breast screening  self acknowledge that there are age and cost constraints and actually helping diagnose everyone is not their goal.  The same with not calling up 40 year olds shows the perceived risk for this group is low.

If one does regular checking and finds a lump then one can at least say that a mammogram done more than 4 months previously would have missed it. and since it has already been there in excess of 2 years in most cases the 4 months does not make much difference to the question of spread and outcome. Especially as the reduction in mortality is heavily weighted towards the newer drugs available for some of the responsive cancers.

Prostate cancer and screening

PSA tests. The jury was out. Top specialists like Tony Costello at RMH actively push for early detection for early treatment. Other  groups like the USANZ preferred that screening not be done as the rewards of detection and the downside of the treatment outweigh, they felt,  any active management. How times change. Now the guidelines are to

  1. Offer evidence-based decisional support to men considering whether or not to have a PSA test, including the opportunity to discuss the benefits and harms of PSA testing before making the decision.
  2. For men at average risk of prostate cancer who have been informed of the benefits and harms of testing and who decide to undergo regular testing for prostate cancer, offer PSA testing every 2 years from age 50 to age 69, and offer further investigation if total PSA is greater than 3.0 ng/mL.

 

Compare and contrast the attitude here to that for women. Several factors weigh in the men are older, The cancer is internal rather than external so harder to get at. The operation has functional rather than cosmetic consequences..

I am an interventionist, I believe that the test itself is easy to do, compared to a mammogram and the results are easier to interpret. The follow up for a positive result is just as traumatic with the biopsy and examination being more difficult. I find it hard to square the idea of watching known cancer if presumed low risk and would prefer the idea of some treatment earlier rather than later.  Of great interest are 3 concepts. One that with a low PSA < 1.0 at 40 and at 60 YO ones risk of cancer is almost negligible [less tests one good outcome. Secondly that if the blood test is going up but there is no lump felt an MRI of the prostate can be done to give complete visualization of it and guide management better.

Choice of procedure Robotic surgery or radiation or both. With apologies to the surgeon who has done all the work Radiation would be a preferred option, just. The upside is that any local spread should get knocked off. secondly the side effects are broadly similar. Prostate cancer is particularly prevalent in the Shepparton area and perhaps a study should be done by our local hospital on the actual incidence.

Screening for skin cancer. Absolutely essential in fair skinned people in Shepparton. Most of us have a good knowledge of our own skin through touch if not through sight. Any skin lesion that does not heal after 6 weeks is skin cancer, get it checked. Any lump that should not be there and is growing might be skin cancer, get lumps checked. Any black or brown discoloured spot is probably a seborrhoeic keratosis, but you cannot exclude  melanoma. vital to get any flat lesions like freckles that appear or are growing checked.

Non Melanomas are either basal cell or squamous cell cancers. SCC are flat ulcers, BCC’s have raised edges. A BCC can be excised, curetted  or sometimes if small treated with a cream that reverses it’s growth. The earlier one gets to it the easie to treat. Field of change means you can get new lesions near he old lesion de novo, not as a recurrence so keep an extra watch on that area and the corresponding area on the other side of th body.

Finally for Alan who so kindly issued an invitation to talk. I want to thank him for the opportunity and all those of you who have come along today and asked such interesting questions.

  • Estimates of over diagnosis vary widely. Based on UK and European reviews, it is estimated that for every 1000 women in Australia who are screened every two years from age 40 onwards , notified 50 to age 74, around 8 (between 2 and 21) breast cancers may be found and treated that would not have been found in a woman’s lifetime.
  • There has been international debate and differing conclusions about the contributions of screening and improvements in treatment to reductions over time in breast cancer mortality. One recent analysis interpreted breast cancer mortality trends by age to indicate that these reductions were mostly a result of treatment rather than screening.44 However, statistical modelling analyses of national US data, using seven independent statistical models, gave a combined estimate that around half the mortality reduction was attributable to screening and half to treatment.4
  • In Australia, even with a fully implemented mammographic screening program, more than half of breast cancers are diagnosed after investigation of a breast change found by the woman or by her doctor.7

We start as a single cell and live on average 70 years after being born.
Our death rate after the first year is quite low and usually due to bad luck.
Say 2 deaths per thousand per year.  At that rate we should live on average 250 years.
But little things get in the way as we age. Fourteen and the mind starts working and some people decide to leave of their own volition. This stays steady at 1 per thousand increasing the rate to  3. Car accidents and activity related problems kick in by 20, Things increase slowly till 55  at a rate of 7 with the consequences of lifestyle choices due to alcohol tobacco, drugs, sex, diabetes, diet, Blood pressure , atheroma and cancer. From then to 70 the rate increases to 20 a year at the turning point. 500 people have gone. But now the rate kicks up steeply until the majority of people  die in the next 14 years. the rate going up to 40 people a  year at 80.

Cardiovascular disease is the most important  cause of death  in people over 70 accounting for 50 percent of all deaths, half due to heart attacks, slightly less to strokes then other vessels. Cancer accounts for 30 percent. Infection and Kidney and lung disease a large amount of the rest along with infections often secondary to these preexisting conditions.

Basically we start off with good arteries and we are genetically primed to wear out  after 70. The arteries build up atheroma which is a combination of calcification and plaque in the vessel walls. We can hasten the process. Bad dental hygiene causing infection in the blood vessels, smoking, Excessive alcohol, Lack of exercise and obesity. Illness like diabetes and blood pressure.

We can actually measure the development of the atheroma with a High quality CCTA (64-slice and higher) is not only able to provide reliable information on coronary luminal changes, but also has the potential to visualize morphological changes of the coronary artery wall, characterize atherosclerotic plaques and identify non-stenotic plaques which may not be detected by invasive coronary angiography. This showed a significant age related increase in calcification
Of these patients with abnormal changes to the coronary arteries, the number of significant coronary stenosis was directly related to the age group, as less than 15% of patients under 56 years had significant coronary stenosis, but this was increased to 29% and 38% in the age groups of 56–65 years and over 66 years,

Cardiac CT for calcium scoring It has been assumed that measurement of risk factors causal for CAD (e.g. dyslipidaemia or hypertension) would be predictive of coronary events, but the relative hazard ratios of these risk factors are inadequate to accurately predict outcome. Seventy-five per cent of previously asymptomatic patients (men < 55 years, women < 65 years) developing their first MI, would have been ineligible for lipid-lowering therapy prior to the event if assessed with a global risk score.
In four major studies, more than 75% of all hard coronary events occurred in persons classified as low or intermediate risk, and the majority of persons classed as high risk had no coronary events. Risk score assessment alone is inadequate in predicting individual coronary risk.

In contrast, a measure of flow limiting obstruction (with ischaemia testing or CT coronary angiography) is not likely to predict risk.
Sixty-eight per cent of MIs occur in vessels with less than 50% obstruction prior to plaque rupture and thrombosis; and 86% occur in vessels with a less than 70% obstructive lesion (the degree of obstruction required to provoke a positive ischaemia test).Similarly, recurrent MIs are usually caused by a second ‘angiographically minor lesion’ commonly found in patients with a large plaque burden.

44% of individuals had a coronary score of zero. This cohort has such a low long-term risk (99.4% 12-year survival), that any further coronary testing is not required, and interventions like lipidlowering therapy are not likely to alter outcome.

 

A study of asymptomatic persons with a CAC score of greater than 1000 demonstrated they had a 25% risk of death or MI at one year,

I did not ask who had tried these other modalities as some of us who did might feel ashamed at being skeptical.  It is funny how the skepticism that produced medicine is sometimes turned back on it.

[So what is it that drives us to seek health treatments and to take treatments  in the manner that we do. One is our vanity, one is our mortality, one is health, one part is our wives. Fear of our looks and performance, fear of death, fear of illness and fear of our spouse. What tempts us to try the paths less trodden? The ones without  trials and proof. The ones that demand experiment and belief at the same time? The truth is that people wish to feel in control and not have other people tell them what to do.  [To be an individual, just like everybody else. Yet at the same time they want to follow the crowd and conform. It is the nature of human beings to be contradictory in their choices  and decisions.]

Why do we get sick and how do we restore  or keep better health?Life brings trauma There is a saying he who is his own doctor has a fool for a patient.
Usually said by doctors when a patient goes against their own sage advice.
Health is an individual responsibility but one can always seek external advice.
Health is having a sound  mind and body. An old Latin proverb, Mens sana in corpore sano.
So onto understandingMedicine deals with healing, [Doctors are teachers] but one does not have to be a doctor to understand the concept of healing

ABC Catalyst statins program ‘could contribute to deaths’www.theaustralian.com.au/…statins…deaths/…/6da032cef8cc643075c46713f8c95272

 Jun 15, 2015 – The ABC may have contributed to the death of thousands of … “If patients continue to avoid statins over the next five years, this could result in …

British government figures released last week show that 92 deaths have been linked to the statin drugs developed to lower cholesterol. It is believed that the …In July 1999, Bayer ’ s clinical trial of Baycol 1.6 mg revealed a ‘ high incidence (about 12 per cent) of severe CK elevation …partly connected with symptoms ’ , leading to a decision to discontinue the project without publishing the results of the trial. 13 . The safety margin for our compound from the noeffect level to non-tolerable dose is less than three-fold, whereas for (Mevacor) it is at least 12-fold ’ .

Vitamins  are they good for us to take.

We have a great scientific knowledge of what they are and what they do.
Most people know and use the more common ones.
A through to K,  B 1-B 12  with some gaps there are 13 Vitamins. They are essential to life because they are not normally able to be made in our bodies [exception Vit D].
We have evolved in a world where we interact and depend on our food sources and if we have enough food we get more than enough vitamins.
They are all  available even through a restricted diet or junk food hence there is no need to supplement them as we always get more than we need.
As we get more than we need taking more does not make our bodies any better off.
In some cases e.g. Vitamin A, overdosing can lead to illness and death.
Would I recommend any vitamins to people.
Generally no.**** but some words later.
Perhaps B 12 injections  and vitamin D.
Folic acid in pregnancy as it can reduce Spina Bifida incidence.
There are a few people who do need vitamins due to problems with absorption in the gut, Coeliac disease, Pernicious anaemia, malabsorption syndromes. Surgery removing part of the bowel but they are extremely rare.
Lack of availability, B 12 in vegetarians, Vitamin C if not eating green foods, Vitamin D if not enough fish or sunlight.
Vitamin supplements are expensive and not helpful but still we take them.
The reasoning here appears to be  if a little is good for you, a lot should be better with a dose of I may be low so I will give it a try.

Myth 2 Junk food is bad for you.    No
Food is food whether it is processed, roasted or pasteurised. It has its own set of protein , fat and carbohydrate usually, with lashings of vitamins and minerals. The two things wrong are that they are very tasty  and eating them fills one up with too many calories.  Secondly they re too easy to get and lead to a lack of discipline in eating sensibly.
It is the overeating that is the problem.
Vary the fast foods and eat in moderation and the dietitians should go away. [Kebabs?]. Personally I feel that cooking is one of the skills that should be taught at school to all children. Domestic science  It used to be called.

In short Vitamins, while a scientific discovery, are mainly just another alternative medicine

Any questions?

Cholesterol Myth

Medicine an anglo french word for a thousand years  from the Latin  The science or practice of the diagnosis, treatment, and prevention of disease  Latin Medicus healer ? from mead?  so did we give alcohol drinks to make people better.

I would like to add my own take to the Cholesterol Myth that swirls around the internet and occasionally breaks the surface, such as on the controversial Australian saturated fat and cholesterol Documentary by Mary Ann Demasi in 2013 on Catalyst. One of the problems is that everyone who promotes the myth also seems to promote their own version of alternate facts.  The argument made, with a little dash of snake oil, is that cholesterol is a natural substance that aids in repair of the body and has not been shown to cause an increase in the rate of heart attacks. Indeed in some studies the opposite. The medicines used to lower cholesterol also may have harmful side effects on the muscles and have a link to dementia.

The problem? A lot of this is true but irrelevant, it is how the facts are put together that should count.  What is cholesterol?  A few facts.

Cholesterol  is an organic molecule.  We make it so it is not a vitamin although it is essential for life. It is a type of lipid molecule, and is made by all animal cells and functions as a  component of all animal cell membranes; essential to maintain both membrane structural integrity and fluidity. Cholesterol is the difference between plants and animals as it enables animal cells to dispense with a cell wall (to protect membrane integrity and cell viability), thereby allowing animal cells to change shape rapidly and animals to move (unlike bacteria and plant cells, which are restricted by their cell walls). Cholesterol is made in much smaller amounts by plants  [100 times less] Human breast milk also contains significant quantities of cholesterol. Cholesterol is oxidized by the liver into a variety of bile acids. Equally important  is the range of other substances derived from cholesterol  that are absolutely important to life and function.it is the precursor molecule for the synthesis of vitamin D and all steroid hormones, including the adrenal gland hormones cortisol and aldosterone, as well as the sex hormones progesterone, estrogens, and testosterone, and their derivatives.    Every cell is capable of synthesizing it.

Most ingested cholesterol is esterified and poorly absorbed. The body also compensates for any absorption of additional cholesterol by reducing cholesterol synthesis. For these reasons, cholesterol in food has little, if any effect on concentrations of cholesterol in the blood. Cholesterol is recycled in the body. The liver excretes it into the digestive track. Only 20% of total daily cholesterol production occurs in the liver; other sites include the intestines, adrenal glands, and reproductive organs.  The main regulatory mechanism is the sensing of intracellular cholesterol. A human weighing 70 kgms  normally synthesizes about 1 gram (1,000 mg) per day, and his body contains about 35 g, mostly contained within the cell membranes. Typical daily cholesterol dietary intake for an adult is 300mg.  Every day, up to 1 g of cholesterol enters the colon and is excreted. It forms between  1 to 2 in a thousand parts  of our bodies by weight.

The take home message is that cholesterol is important to life and health, That the levels we have are well regulated and in balance  and that the body has mechanisms adapted over millions of years to regulate the amount of cholesterol that each person has and needs. The amount of cholesterol in the bloodstream reflects the amount of cholesterol in the cells and not the other way around.

Cholesterol and heart disease. Arteries develop plaques at sites of inflammation and the plaques build up cholesterol in modified inflammatory [foam] cells. The plaques rupture with age and size and can temporarily or permanently block an artery. If this is a coronary or brain artery the consequences are a heart attack or stroke. Yet the facts are also that only certain people develop atheroma and only certain blood vessels. So two people with the same diet, age and cholesterol levels can have widespread disease or no disease at all.  Veins  do not develop atheroma. This indicates the body is selective in where it has it’s problems. People are born with the capacity to develop bad arteries. Arteries can  respond to inflammation in the the body  and outside [smoking].

*[Proof? Consider the GIT. Stomach and large bowel cancer galore but hardly ever the 4 meters of small bowel. Similarly muscle cells and brain cells, nothing relatively speaking.]

Cholesterol levels vary widely , a common range in Australia is 3.0 to 7.0. but levels can go over 10. Unlike Blood pressure, where actuarial studies show that there is a causal relationship  between high BP and early death no such studies exist for cholesterol. It is the state of the arteries, not the cholesterol level that is important.

There is a wealth of evidence showing where treatment can be beneficial and this is when a diagnosis of arterial disease has been made.Post heart attack statins show a reduction in heart attacks in the months afterward. Hence people are commenced on statins commensurate with heart attack procedures even with low cholesterol. The jury is out on why,  a cholesterol lowering effect or an associated anti inflammatory effect.When one has cardiovascular disease there is some evidence that cholesterol lowering may slow or reverse the atheroma. Since  we have nothing else to offer people with proven disease, people with high risk of disease, diabetics, smokers, family history of disease or atheroma conditions such as past stroke are all strongly advised to take such treatment.

 

One suggestion I can make is for people who have a high risk averse nature and a family history but who are also concerned about side effects. Especially as they may have to take the medications for 40 plus years. There is a wonderful test known as a cardiac MRI.  This shows the amount of calcification in arterial vessels importantly those of the heart. This is extremely well correlated with the presence and degree of atheroma. and increases in age with all of us. Someone at risk whose MRI  shows disease worse than expected for their age group would be strongly advised to go on medication.

Dementia is associated with advancing age and atheroma and appears genetic in origin, Alzheimer’s in particular not seemingly due to atheroma but another sort of plaque formation should not be caused by drugs that lower cholsterol. After all it is not more prevalent in people with low cholesterol. Muscle and liver upsets occur as a side effect but like all medications if something upsets you stop and find another treatment. LDL and HDL cholesterol are protein/fat  complexes that carry the protein around. Small changes in outcomes are shown in studies of little value in my opinion as Cholesterol is made in the cells, not in the bloodstream.  If you do not want to take the treatment offered best check with the MRI.

 

This leads to a digression to one of the other topics. How to live longer.  What is the normal human lifespan. How can we prolong it.  Telomeres for the scientists here. The sad news is that in general nothing much is going to work. We are programmed for obsolescence. To get out of the way and let the younger ones through. There is so much to say on this topic. Humans , 70 years

Accidents and cancer,  disease and malnutrition are unavoidable. Muscle ageing, Immune system weakening, Bone thinning, loss of height, worn joints, heart disease and strokes are systemic. Atheroma in the blood vessels will get all of us given enough time. But only in the arteries , not the veins. Why not? because we are programmed to  develop atheroma in arteries. So no matter what diet or exercise you choose it will make no difference. Cancer diets, Blood type diets, Atheroma diets, Antioxidants, all useless. That little bit of cell that started you off writes finis. As in Gattica. You only have so many heartbeats. Mind you if you exercise or come toU3A lectures you may not live longer but it will certainly feel as if you have .

One diet works but it is a stretch to call it a diet. Fasting, starvation. It has been shown that people who are starved for long periods of time do live longer.  It may have to do with slowing down, slower heart rate, lower BP, less inflammation in the body, all things that happen naturally with starvation.

Inflammation reduction may help as disease and aging processes are accelerated by inflammation. One theory with heart attacks is that they may be caused by infections in some people. Hence antibiotics may help.

People with inflammatory diseases such as rheumatoid  and auto immune disease are much more prone to atheroma. Here a simple native medicine from the bark of a tree has shown promise in many areas but is usually overlooked. It’s name, aspirin.

In atheroma and prostate cancer it has proven to help more than harm with just small doses. Just look out for the stomach and some other side effects.

Metformin is an unusual drug which has an effect on insulin activity. It produces a wide range of other useful health outcomes. It is useful in polycystic ovary , fertility and obesity syndromes. and it reduces some cancer risk. Again some people cannot tolerate it with occasional difficult side effects.

The new MIB and MAB drugs for autoimmune and cancer problems work in part by inflammation reduction. They can however knock the immune system around seriously with infective side effects.  Could they be the elixir of life? It is now possible.

Thousands of Britons are dying from heart attacks and strokes after being scared away from cholesterol-lowering drugs by warnings of non-existent side effects, the lead author of a major study claims.

An investigation into statins has demonstrated aching muscles and other reported symptoms could not be blamed on the drugs.

The study, which involved about 10,000 patients at risk of heart and artery disease, highlighted a “nocebo effect” – the opposite of the placebo effect.

Warnings of common side effects listed on statin information leaflets were giving rise to nocebo symptoms despite having no provable connection with the drugs, researchers found.

Professor at Imperial College London and co-author of the study, Peter Sever, said reports of side effects had led to a fall in the number of patients taking statins and a reluctance among some doctors to prescribe them.

“There are people out there who are dying because they’re not taking statins, and the numbers are large, the numbers are tens of thousands, if not hundreds of thousands,” he said.

“And they are dying because of a nocebo effect, in my opinion.”

The study, published in The Lancet medical journal, was conducted in two phases, the first of which included 10,180 patients aged 40 to 79 from the UK, the Irish Republic and Scandinavia.

Patients in the first trial were “blinded” so neither they nor doctors knew who was receiving the active drug.

The study found rates of muscle-related symptoms were similar whether or not patients received the statin or placebo.

Subsequently when patients knew they were taking statins, reports of muscle-related side effects were 41 per cent more common among those being treated.

Prof Sever was highly critical of the Medicines and Healthcare products Regulatory Agency (MHRA) for “jumping the gun” by insisting on the side effect warnings in 2009.

“Many of us would say that the MHRA … did not make a profound value judgment based on the evidence,” Prof Sever said, adding the agency had acted on observational reports not based on robust science.

“These warnings should not be on the label … I would love to see these side effects removed.”

The study was funded by drug company Pfizer, which makes statins, but the authors stressed all data collection, analysis and interpretation of the results was carried out independently.

 

The superbug myth

We have been going to have superbugs resistant to all antibiotics spreading throughout the world due to overuse of antibiotics by GP’s and Hospitals.

While it is true that there are resistant bugs out there it is not a fact that widespread resistance is developing or that it will ever become a serious problem.

 

There are two reasons for this. One is that bacteria that carry and express extra genes have a hard time competing with their mates who do not carry the extra baggage  So over time the ones with the extra baggage miss out and die out.

TRhe second is that we do have some heavy antibiotic exposure in the food industry with livestock. Cattle sheep pigs and chickens to name a few Prawns and fish  in fish farms was a surprise. The reason farmers keep feeding the animals antibiotics is because they do not get as sick and hence put on more weight and size and are more valuable to the farmers.

Yet superbugs have not destroyed the farming industry even though the exposure is up to 100 times that of human exposure on a regular basis. Surely it is obvious that if they werr to develop they would have done so and taken over by now.

One other factor is the remarkable speed at which bacteria grow and exist. Alifetime for a bacteria is about 1 hour compared to our 70 years. Resistance develops quickly but is also bred out just as quickly.

As an aside this reduction in infection leads to a reduction in inflammation and could be one of the measures one could actually take to improve one’s lifespanb. In fact there is a myth out there that bacteria are a cause of heart attacks and some trials have been done on taking antibiotics to help reduce this risk.

 

 

Hello to everyone.

My name is Harry Lee and am am a partly retired GP wishing to share a bit of advice on Medicine gathered during my working years. The subject today is Skeptical Medicine which covers the myths in medicine and a look at some of the practices we do and the reality behind them.

To start with I am making some statements to show where I am not coming from.

Firstly, Vaccination is good, everyone should vaccinate their children and themselves appropriately. Fluoridation of the water supply is good, it protects teeth and at 66 years of  age and numerous dental visits later I can only reiterate how important dental health is.

Secondly I would like to comment on a comment by Dr John Tickle, a medical guru, whose advice was moderation in all things, except fish and laughter. and a sage friend of mine who says “Listen to your body”. My own version of this for good health would be “Listen to your wife”

Subjects I will discuss today include the Cholesterol myth. Diet, exercise and vitamins in the search for  living longer, An advance in the treatment of prostate cancer and the screening controversy,

Superbugs, The value and interpretation of screening and medical tests in general ending with what one should and should not do medically in life.

 

So in summary To live longer or to live happier, that is the question. Should we strive to prolong life or accept the blessing of what we have been given. Should we stay with our peer group or outlive them. Does it bring more happiness or just crowd the rowboat needlessly? Do we reach an emotional end point as well as a physical one.

Vitamins. Do we need them and when.

On solid ground here. Most people know that vitamin supplements are not helpful but still we take them. Why?

A through to K, are proteins essential to life but not normally able to be made in our bodies [exception Vit D]. They are all normally available through a normal diet hence there is no need to supplement them as we always get more than we need under normal circumstances. Is more better? No, as we get more than we need taking more does not make our bodies any better off. In some cases e.g. Vitamin A, overdosing can lead to illness and death.

Retinols are found in foods that come from animals (meat, milk, eggs). The form of vitamin A found in plants is called beta-carotene (which is converted to vitamin A in the body)

 

The mystery of the human condition

I am going to define life for a human being. 70 year average.

inflexion at 70. All gone by 84. Death rate from 1 year on 0.2 % a year slow rise to 0.3 at age 14. To 1.0%

Joshua

angech says:

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Joshua says: April 30, 2017 at 1:39 pm
=={ The odds of it happening once are 100%.}==
What? The odds of a 1,000 year rain happening one in the last few years in the UK is 100%?”
The odds of it happening per year in the preceding 1000 years are 0.1% per year.
Once it happens, in any year, the odds of it happening in that year are 100%.
?? Had to happen? Why did a 1,000 year rain have to happen [a second time] over any given period of 1,000 years?
Again the odds of a second event in the next 1000 years were 0.1% per year, and yes it did happen again so 100%.
A little read of the Hitchhikers Guide Infinity drive explains this paradox.
While the chances are remote they will happen at some stage given enough time. The point is the circumstances actually did happen thus that particular probability is now 1 [100%].

“Bear in mind, you are dealing with to someone whose knowledge of statistics is extremely limited, but I’m hoping you could provide a simple explanation your thinking.”
I doubt that your knowledge of statistics is limited given your interest in the topic of CC over this number of years. Statistics is funny stuff and is often misused by both sides when it should not be.

See Willard’s excellent summation April 30, 2017 at 2:42 pm
“”Doc’s point is that there’s a reading whereby attribution is trivial. Split the Earth in an infinity of regions and ask: what are the odds that a unique future event happens in one of its regions by luck. The probability that the unique event eventually happens converges toward 100%.The chances it happens at a specific spot and not elsewhere is almost 0%.”
However he called it a trick, when the trick is the reverse, ascribing random rare events to causation, see Taleb “Fooled by Randomness”

CO2 in Seawater: Equilibrium, Kinetics, Isotopes, 1st Edition Zeebe   &    Wolf-Gladrow   have some wonderful stuff on our topic though hard to copy and paste.
It backs up ATTP and his presentation of equations.
The money line is page 41  1.2.4  total alkalinity and charge balance
“Sillen [1961] argued that considering the origin of the ocean, we might say that the ocean is the result of a gigantic acid base titration in which acids that have leached out from the interior of the earth are titrated with bases that have formed from the weathering of primary rock ”

That is the essence of what I have been saying.
In an authoritative text book.

Side tracking  on permeability of sediments [undefined] and stating that the seafloor is covered with impermeable clay flies in the face of Broecker  “The high-CaCO3 sediments that drape the oceans’ ridges and plateaus typically have ?90% CaCO3 and a water-free density of 1 g cm?3.”
The  amount of CaCO3 available for dissolution in such a sediment is 72 g cm?2.
This amount could neutralize 6.3×1017 mol of fossil fuel CO2. This amount exceeds the combined oceanic inventory of dissolved CO2? (1.6×1017 mol) and of dissolved VHBO3? (0.8×1017 mol). It is comparable to the amount of recoverable fossil fuel carbon.”
In other words the first 8cm or so of the available usable sediment
is not covered by impermeable clay, it is usable now.
It has the capacity to soak up 4 times the amount of CO2 already present in the ocean as DIC without blinking.
Only then would it be used up under an impermeable blanket as Dikran puts it.
It would be available to soak up all the fossil fuel that can theoretically be discovered.
And we still would not have an acid sea of consequence for the carbonic acid itself in equilibrium with the available CaCO3 is the buffer of the sea.”We may be on the same page at times.
Dikran Marsupial says:    November 8, 2016 at 10:23 am
” Now I am not claiming that there is no transfer of CaCO3 from the ocean floor to the deep ocean,” but my understanding is that there isn’t very much. BTW note that sedimentary rocks such as limestone tend not to form in the deep ocean because of the dissolution process that Marco mentions, so it isn’t clear that there is an abundence of CaCO3 in the rocks forming the ocean floor to begin with (I suspect the Atlantic ocean floor is mostly baslt, i.e. silicate rock).

So what is your evidence for an unlimited supply of CaCO3 from the ocean floor?
Oh, BTW, thanks for putting up the second and third pictures. Your computer skills are way above mine. The second one shows the calcareous ooze right on top of the mid ocean ridges and further out under the red clay.

Confirming my point “There are bucket loads of carbonate in the earth’s crust, every subsurface volcanic eruption exposes more to the ocean” despite your assertion to the contrary.
Dikran Marsupial says:    November 9, 2016 at 9:56 am    “. I don’t think this is necessarily correct.”

You also said, incorrectly.
“the reason that land based volcanoes give off a lot of CO2 is because they are largely erupting magma formed from subducted crust from shallower oceans that has carbonate sediments.”

The magma is the same, molten basalt under the sea and on land.
Any component of “subducted crust from shallower oceans that has carbonate sediments” can only be present in the ocean ridge volcanoes under the sea. That is where the subduction takes place.Subducted crust is melted,gone, not crust no more.
Land based volcanoes give off extra CO2 because  the magma passes through ordinary crust with layers of chalk limestone marble etc, carbonate sediments from 2 billion years of non subducted crust formation of sediments from shallower oceans.

Finally, you state
“this one states that calcereous oozes are scarce below 5000m (i.e. below the CCD),”
the statement should read but doesn’t “recent calcareous oozes” as in the next sentence
[wonder why Dikran didn’t mention that one]  it says ancient calcareous oozes at greater depths if moved by sea floor spreading.
By the picture accompanying these calcereous oozes are abundant not scarce you would agree.
The term scarce applies to CaCO3 deposits on the red clay surface below the CCD
.””That said: I think the hard part isn’t learning d(x^2)/dx = 2x which kids can memorize just as easily as A=?r2. It’s understanding “slope” = “rate” and understanding what to do with rates etc.””   Lucia Maths and need to get a book written

Plot trinity James one of 3 in the 5 series plot involves death in a plane but only being a computer simulation write whole novel then unpin/save heroine at end.

dikranmarsupial
“Also the mud in the abyssal ocean has no carbonates because it is below the CCD,”

Mud in the abyssal ocean with no carbonates.
because it is below the CCD.

Chemistry and knowledge and assertion.
“Mollusks from many different groups live in the deep sea. Our shell-makers can be found at all depth levels of the ocean bottom; no limit is known on the depths at which they can live. Mollusks have been found in the deepest point of all oceans, the Challenger Deep in the Marianas Trench, at 11,022 m (about 36,000 feet) depth”
I presume the 11,022 is well below the CCD.
I presume the molluscs have shells.
Therefore your contention that the CCD is the last word on the chemistry is wrong.
I point out to you the white cliffs of Dover Possibly thousands of meters deep CaCO3.
I point out sea shells in the highest Himalayas just to remind both of us of the vast, interminable  aeons that the earths crust has been forming and deforming.
The earths crust, even under the sea, is not just some miserable thin layer deposited in the last 10,000 years.
It is a vast amalgam of CaCo3 deposited over 2 billion years, crushed, serpentined, vapourised frozen, glaciated, vented, heated and pressured into all sorts of minerals and deposits.
It is intermixed with less important stuff for our argument like basalt etc which occur in bigger percentages at greater depths.
The sea sits on the crust. It has input from the earth’s crust not just from the bottom but from every drib and drab where water comes into contact with land as it drains back into the oceans. Wind blows dust particles, some of them CaCo3 into the sea. The volcanic ocean floor rips up this buried crust and periodically exposes great swathes of billion year old CaCO3 to the ravages of the abyssal deep waters [despite the mud layer].
Vast undersea rivers carry silt and debris down to the abyssal depths daily. Bacteria and worms live in the silt and mud, yes even at those depths and burrow and break their way through it exposing rich veins of CaCO3 to the water.
It might look quiet in a nautilus for a week but over a decade the floor is a vibrant freeway of activity, not a quilted protective blanket of CaCO3 less mud.

The salient points surely are the supersaturated CaCO3 and pH of 8.1 of the whole ocean overall. How did it get that way?
The Ca part of the mix did not form from the CO2\H2O acid pathway.
It is there because the ocean sits in and on a pitcher of earth which has a CaCo3 matrix which has formed over billions of years,
The ocean is alkaline because of the dissolved earth chemicals in it and available to it at this particular temperature, earth size and water volume. They cannot dissolve out and leave us with pure water which would be acidic with the level of CO2 in the air.
The dissolved salts and CaCO3 are innumerably more abundant and available in the earths crust than all the CO2 that nature and Humanity can produce. The balance is robust, not delicate and is much more a feature of how much CO2 [DIC] is present in water due to the CaCO3  putting it into the atmosphere or stopping it from being absorbed into the sea than a simple current small oversupply.

I am not arguing AGW, or being obstreperous, I am trying to understand the pH conundrum better.
Some of these ideas must make sense

angech says:

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“During 2013 and 2014, only 4 of 69,406 authors of peer-reviewed articles on global warming, 0.0058% or 1 in 17,352, rejected AGW. Thus, the consensus on AGW among publishing scientists is above 99.99%, verging on unanimity.”
Not Surprising is it.

How many theology texts would repudiate the existence of god?
How many authors actually wrote peer reviewed articles on global cooling?
How many authors wrote climate papers with no consideration of either point of view?

“The U.S. House of Representatives holds 40 times as many global warming rejecters as are found among the authors of scientific articles.
More impressive is that the number 160 out of 238 That is over 67% against compared to 0.01% of publishing consensus scientists. so 670,000 times as many global warming rejecters as are found among the authors of scientific articles.
Presume the maths is right?