Saturday, December 31, 2016

Panama & Tribology: New Rx & Old Principles!

Panama Canal © 2008 Am Ang Zhang

Most people probably know about the French failure to build the Panama Canal. Many thought that this was due to yellow fever and malaria which were diseases thought to be due to some toxic fume from exposed soil.

In 1879, Ferdinand Marie de Lesseps, with the success he had with the construction of the Suez Canal in Egypt just ten years earlier, proposed a sea level canal through Panama. He was no engineer but a career politician and he rejected outright what the chief engineer for the French Department of Bridges and Highways, Baron Godin de Lépinay proposed, a lock canal.

The engineer was no match for a career politician:

“There was no question that a sea level canal was the correct type of canal to build and no question at all that Panama was the best and only place to build it. Any problems – and, of course, there would be some - would resolve themselves, as they had at Suez.”

“The resolution passed with 74 in favor and 8 opposed. The ‘no’ votes included de Lépinay and Alexandre Gustave Eiffel. Thirty-eight Committee members were absent and 16, including Ammen and Menocal, abstained. The predominantly French ‘yea’ votes did not include any of the five delegates from the French Society of Engineers. Of the 74 voting in favor, only 19 were engineers and of those, only one, Pedro Sosa of Panama, had ever been in Central America.”

The French failed in a spectacular fashion.

Diseases like yellow fever and malaria played their part as a sea level canal involves a good deal more digging.

The discovery of yellow fever being carried by mosquito must be credited to one Cuban physician:Carlos J. Finlay.

For twenty years of his professional life, he stood at the center of a vigorously debated medical controversy: the etiology of yellow fever. Finlay believed that it was waterborne and carried by common mosquitoes: Stegomyia fasciata.

Finlay's advice and experiences proved invaluable to the United States Army Yellow Fever Commission. When the Commission decided to test the mosquito theory, Finlay provided the mosquitoes andWalter Reed of the Commission wrote triumphantly after the success of the experiments of inducing yellow fever by mosquito bites, ‘The case is a beautiful one, and will be seen by the Board of Havana Experts, to-day, all of whom, except Finlay, consider the theory a wild one!’ The US experiments vindicated Finlay's two-decade-long struggle.

Reed acknowledged that ‘it was Finlay's theory, & he deserves much for having suggested it.’

William Crawford Gorgas wrote of Finlay:

"His reasoning for selecting the Stegomyia as the bearer of yellow fever is the best piece of logical reasoning that can be found in medicine anywhere."

The discovery by Major Ronald Ross that malaria was transmitted by mosquitoes (Anopheles)had tremendous impact on the Panama Canal. 

Crude oil was used on stagnant water to prevent the mosquito proliferation and nets were used to protect workers. Quinine was extensively used to treat malaria. A lock canal was eventually built by the Americans. 

Some say that a large part of the eventual success on the part of the United States in building a canal at Panama came from avoiding the mistakes of the French. Knowing the causes of diseases must have helped.

David McCullough in his book "The Path Between the Seas" wrote: "The fifty miles between the oceans were among the hardest ever won by human effort and ingenuity, and no statistics on tonnage or tolls can begin to convey the grandeur of what was accomplished………It is a work of civilization."


There are things in medicine that we knew nothing about and often we are surprised at how some very basic scientific principle is behind some apparently strange conditions.

Panama reminds me of my friends visit. I have not seen him for years as we went our separate ways as he children were growing up. He was a sporty person and played rugby to a professional level. Here is the blog:

Tribolgy: One Patient, One Disease.

Wednesday, July 27, 2011

© Am Ang Zhang 2011
Did you enjoy your Cruise?


So you can get away from blogging and from Medicine.

I got away from blogging but then it was only the slowness of the Internet that was prohibitive.

Then I realised that perhaps we doctors never could get away from medicine and in a sense I did not want to either.

Medicine has become a hobby.

Cruising is an interesting way to have a holiday, you do not have to pack everyday and you get to meet some really interesting people.

On our Cruise we had dinner with an eminent professor and his wife.


Yes, a world class Medical Engineer and all I might want to know about hip and knee replacements.


A friend came to our tropical resort to play golf with me. 

He was walking a bit funny on the golf course.

“I used to hit 280 yds.”

“What happened”. He now hits 160 yds if he is lucky.

“Bilateral hip replacements.”

Good old rugby.

But that was not all. A year before he had bladder cancer that was diagnosed and luckily it was caught early.

“It was painful but the BCG treatment was good!”

So perhaps my professor was wrong: one patient one disease.

He obviously had hip problems from rugby and then bladder cancer.

So I asked my new found friend.

“There is a theoretical risk as the cobalt in the alloy in particular could be a problem. Check out the Swedish research.”

I told him about my friend and my professor.

“Interesting approach!”

“I know. But it concentrates the mind.”

Lisa B. Signorello et al

In summary, overall cancer risk among hip implant patients was close to expectation. However, we observed these patients to have a statistically significant excess of melanoma and prostate cancer and, after a latency of 15 years or more, of multiple myeloma and bladder cancer.

In contrast, we noted a statistically significant deficit of stomach cancer and suggestive evidence for decreased colorectal cancer risk. The incidence of bone and connective tissue cancers was not statistically significantly higher than expected for either sex in any follow-up period.

Further evidence suggesting an antibiotic effect  comes from a study in Denmark (14),   where a lowered risk of stomach cancer was found among patients with osteoarthritis who underwent hip implant surgery (presumably exposed to both NSAIDs and antibiotics) but not among those who did not have surgery (presumably exposed only to NSAIDs).

However, because this investigation provided the first opportunity to adequately evaluate the long term cancer-related effects of hip implants, the associations that we observed with bladder cancer and multiple myeloma, while also potentially attributable to chance or bias, should be considered carefully and require further in-depth study.

 J Natl Cancer Inst 2001;93:1405–10

A year later my friend called me:

"But Cockroach Catcher, you wrote about it in July of last year! Some even had bladder cancer!"

I suppose Medicine is still of great interest to me and one should never accept what is known now as the whole truth. Medicine cannot stagnate nor should we forget basic principles. 

The Telegraph:

One of the participants in the trial, David Jose, 51, from Clifton, near Bristol, had a hip "resurfacing" operation in 2007, a year before retiring as a police officer.

The father of two had been suffering hip pain from playing football and rugby.
In May last year he was told that the tests had found atypical cells which were not at this stage cancerous.

He saw Angus Maclean, an orthopaedic surgeon at Southmead Hospital involved in the study, who said that the trial had established three cases in which patients had developed bladder cancer, and 14 more including Mr Jose who had changes to their chromosomes.

The doctor told him researchers "could not believe" what had been found, describing the findings as "shocking".

Not as shocked as my friend.

To remember our eminent yet formidable Professor of Medicine, Professor MacFadzean: One Patient One Disease.
I would like to pay tribute to our eminent yet formidable Professor of Medicine, Professor MacFadzean, 'Old Mac' as he was 'affectionately' known by us. He taught us two important things right from the start:

First - One patient, one disease. It is useful to assume that a patient is suffering from a single disease, and that the different manifestations all spring from the same basic disease.

Second - Never say never. One must never be too definitive in matters of prognosis. What if one is wrong?

Mysterious Psychosis: One Patient One Disease

Teratoma: An Extract,

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