penicillin as a paradigm for medical research

8/8/2019 Penicillin as a Paradigm for Medical Research

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Penicillin as a paradigm formedical research

ex

THEORIESAND

EXPLANATIONS:

Do theories explain anythingin clinical medicine?

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SSS


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St Johns College Oxford


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Formal Hall andscruffy students


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St Johns College OxfordResearch Centre


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But to return to the

themeon Theories andexplanationsin various disciplines-


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But first

What is a theory?


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The noun"theory"

has 3 sensesin WordNet.

(web dictionary for those too lazy tovisit the library!)


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1

. theory -- (a well-substantiatedexplanation of some aspect of thenatural world; an organized system ofaccepted knowledge that applies in a

variety of circumstances to explain aspecific set of phenomena; "theoriescan incorporate facts and laws and

tested hypotheses"; "true in fact andtheory")


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2

. theory -- hypothesis, possibility, (atentative theory about the naturalworld; a concept that is not yet verifiedbut that if true would explain certain

facts or phenomena; "a scientifichypothesis that survives experimentaltesting becomes a scientific theory";

"he proposed a fresh theory of alkalisthat later was accepted in chemicalpractices")


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3. theory -- (a belief that can guidebehavior; "the architect has a theorythat more is less"; "they killed him

on the theory that dead men tell notales")


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In su

mmary

An explanationA possibility

or

a belief


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"When I use a word," Humpty-Dumptysaid, in rather a scornful tone, "it means

just what I choose it to mean -- neither

more nor less."

So what have othersconsideredtheory to be


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Theory becomes a spiritual force

when it is gripped by the masses

Karl Marx Critique of Hegels Philosophy of Right


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"A hypothesis or theory is clear,decisive, and positive, but it isbelieved by no one but the man whocreated it. Experimental findings, on

the other hand, are messy, inexactthings, which are believed byeveryone except the man who didthat work." Harlow Shapley

(1885-1972).


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Thegreattragedyof Science

theslayingofabeautiful

hypothesisbyanuglyfact.

Thomas Huxley (1825-1895)


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"The most exciting phrase tohear in science, the one thatheralds new discoveries, is

not 'Eureka!' ('I found it!') butrather 'hmm....that'sfunny...'" Isaac Asimov.


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And finallyWhy think?

Why not try theexperiment?

John Hunter (letter to Edward Jenner)


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Some major achievements in modern medicine

Asepsis

Anaesthesia

Pasteu

rs germ theoryX rays

Aspirin

Penicillin

CT/MRIMonoclonal Antibodies

Human genome project


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Lets take Penicillin as a paradigm for looking atthe mechanics of medical research

Norman Heatley 1911-2004


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AlookatthestoryofPenicillininalittlemore

detail.

Today, the use of penicillin and other antibioticsis common place. It is something that we all take

for granted, today. However, many diseases andsimple wounds that are so easily treated todaybecause of the availability of antibiotics has notalways been available. Antibiotics are arelatively recent discovery and the first practical

one, penicillin, was not available until the early1940s.


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Is the concept (theory) of using fungal productsnew?c1000BC- Chinese put mouldysoybean curd onboils.

Othercultures have used warm earth, whichcontains moulds and otherfungi, as first aid ininjuries. So, although the concept of antibiotics isrelativelyrecent, its use has been around for

some time.

Theory Experiment


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The discovery ofpenicillin has often been

described as a miracle


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The usual story is that penicillin was discoveredaccidentally, at St. Mary's Hospital, in London,by Dr.AlexanderFleming who noticed that thegrowth ofStaphylococcus aureus,

contaminated by aspecies ofPenicilliumwas inhibited.Flemingwrote a paper on his

findings in 1929 and therest is history.


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was it that simple?did Fleming discover penicillin by

chance?are any others deserving of credit?


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Luck was involved at several points -AlexanderFleming did not intend to be adoctor.1900 Boer War (LSR-shooting,

swimming and water polo).1901- Uncle John died and left him andhis brothers with a sizeable inheritance

(250 each).


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His older brother, Tom, advised him to invest hismoney on his career and suggested that heattend medical school.Fleming selected St.Mary's Hospital, in London, only because he had

once played water polo against them.Aftergraduation, he had the option of leaving St.Mary's to be a surgeon or he could join theInoculation Service and stay at St. Mary's. The

major influence was St. Mary's rifle club.


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St Marys c1900


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St Marys c1900


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ThatAlexanderFleming discovered penicillin by

chance is a myth.Before Fleming, there were a seriesof observations that influenced his research andallowed him to come to the correct conclusion when achance contamination in his bacterial culture was

observed. This same opportunity came to others aswell but their only response to the contamination wasthat it had ruined their experiment and they haddiscarded the cultures and thought nothing more of it.


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Discoveries in science are rarely made bychance.

"stood on the shoulders of giants.Einstein on Newton

1500 B.C. moulds and fermented materials inthe treatment of diseases.C19. Pasteur Germ Theory of Disease, i.e.,

diseases were caused by microorganisms.


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This led to the search for "The Magic Bullet".

The most common problem was thecontamination of bacterial cultures by othermicroorganisms especially fungi.

These contaminations led to a number ofobservations in the late 1800s:


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1871 Joseph Lister -urine samples contaminated

with mould did not allow the growth of bacteria.

1874 William Roberts -bacterial contaminationis generally absent in cultures of the mould

Penicillium glaucum.

1877 Louis Pasteur & Jules Francois Joubertanthrax contaminated with unidentified moulds

was inhibited.


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1897 Ernest Duchesne M.D. observed

that E.Coli was eliminated bypenicillin when both were grown onthe same culture and in inoculationof laboratory animals prevented theanimal from contracting typhoid.Although, he urged that further research be carried out, he wasunable to do so. Upon completing his degree, he went into thearmy and while serving, died of tuberculosis.

1874-1912


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1920'sAndre Gratia and Sara Dath(Brussels)fungal contamination in one of theirStaphylococcus aureus cultures wasinhibiting the growth of the bacterium.

Theyidentified this as a species ofPenicillium and presented their observationsas a paper.GRATIA, A. and S. DATH, 1925 Propritsbacteriolytiques de certaines moisissures. C. R.

Soc. Biol. 91:1442-1443. 92: 461462.

There was little attention paid to this paper and the two scientists did not pursue this line ofresearch further. missed being a major part of the penicillin story in not pursuing this researchfurther.


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Fleming and WW1

Lister's concept of antiseptic surgery.Flemingargued that antiseptics had an adverse effect by

destroying leukocytes more rapidly than theinvading bacteria. They recommended the useof a saline solution to cleanse wounds.(ignored till WW2)


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1922 Fleming discovered lysozyme, ("littlebrother" of penicillin).Lysozymes are enzymespresent in biological substances as varied asegg whites, tears and mucus that causesbacteria to lyse or burst. The first biologicalsubstance that he tested was mucus from hisnose (he had a cold at the time).

This would later be a major discovery, but at the time, though

interesting there was no obvious clinical application.


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1928 staphylococcal research frequentcontamination with airborne moulds.sloppy scientist lab in disarray.month long vacation threw the plates in a tray oflysol.Retrieved for a visitor.

It was only then that he

noticed the unusual inhibitionzone around the fungus.


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Isolated and named it penicillin Published 1929but no interest

Failed to purify and concentrate penicillin

unable to prove that it had any therapeutic valueand doubted it himself at this time.


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the verge of a great discovery.

"yellow magic"

P. rubra incorrect but penicillin.

Charles Thomas Penicillium notatum.


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penicillin diluted 1,000 times effective in killingbacteria

?translated to practical use

Fleming only worked on and off with with penicillinbetween 1928-1931quantity and quality problems

colleagues bored xc Howard Florey


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Cecil Paine (Sheffield) the

forgotten man in the developmentof penicillin.

Inspired by paper not Fleming

"a shocking lecturer, the worst you could possibly

imagine-not because of inherent shyness, but because henever appeared enthusiastic about his subject


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sycosisbarbae(staphyloccus)

soaking gauzewiththecrudepenicillin extract-failure

minerseyePneumococcusbabyseye congenital gonorrhea

irrigated theeyewiththecrudepenicillin extract-success


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Paine never published his results concerningthese patients nor did he ever present an oralpaper on these patients

Crude extract + new job

Fleming was still flounderingrequired the expertise of a chemist


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Sheffield University 1932

Paine discussed his penicillin work with a newlyarrived Professor of Pathology. The professor, saidPaine "took not the slightest interest at that time."

Yet six years later, he was to begin aprogram of research that would leadto the mass production of penicillin.The Professor's name was HowardFlorey


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mid 1930's

Sulfa drugs Germany

M and B May and Baker

Fleming began working with both these drugs

and had stopped working with penicillin by 1934


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1928-1938 Howard W.Florey lysozyme

1938 penicillinTeam: Ernst B. Chain, LeslieFalk, Norman Heatley andtwenty other scientists and

technicians.

Where Fleming had a poorlyequipped lab with no staff

support, Florey's lab was wellstaffed and equipped.


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Florey and Chain

Chain began the work with sub-cultures fromFleming's original isolate of P. notatum.Florey in charge of the research program

-on the editorial board-knew Fleming quite well-Paine in 1932 (Florey forgotten)

former students remembered quite distinctly that Florey mentioned Paine'swork in a lecture, at Oxford, in 1936.


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Florey and Chain and scientific interest

I became interested - immediately - in Fleming's paper, notbecause I hoped to discover a miraculous drug for the treatment ofbacterial infection which for some reason had been overlooked, butbecause I thought it had great scientific interest.In fact, ifI had been

working at that time in aim-directed scientific surroundings, say inthe laboratory of a pharmaceutical firm, it is my belief that I wouldnever have obtained the agreement of my bosses to proceed with

my project to work with penicillin(Chain)


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Chain purified penicillin for two mice

injected by J.M.Barnes not Florey

The last time he requested his assistance, Florey turnedto Mrs. Margaret Jennings, who was in the lab, and

said, pointing to Chain, "in one of my weak momentsIpromised this man to test his fractions and here he

comes pestering me again."After what Chain describedas "these humiliating remarks in front of others notinvolved in the project, it became clear to me that Floreywas not really interested in penicillin"


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fifty white mice Streptococcus

25 penicillin alive 25 nopenicillin died

ready for human subjects

in 1940, on human subjects, it had required twoprofessors, five graduatesand ten assistantsworking almost every day of the week forseveral

monthstoproduce enough penicillin totreat sixpatients.


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AlbertAlexander, a 48 year old Londonpoliceman had nicked himself while shaving.sulfa drugs failed."purified" penicillin administeredBy 5 days the patient was recovering. Urine

recovery but no more penicillinrelapsed and died

"the treatment was a success, but the patient died."


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15 year old boy hip -success

48 year old laborer carbuncle -success

4 year old boy infected eye ?failure

following measles. Sulpha drugs were usedunsuccessfully. semi-comatose meningitisthird day of penicillin treatment swelling down andemerging from the coma.

sudden convulsion and he died four days later. ( burstblood vessel)


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Fleming obtained Penicillin from Florey for old

friend HarryL

ambert

Fleming injected the penicillin into his friend'sspine and the treatment proved completely

successful.

Florey injected penicillin into the spines ofartificially infected animals, with the result that

they had all died!

Although the relationship between Florey and Fleming seemed to be anamiable one.It would later turn sour.


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Florey's "famous pinched

smilealways gave him alook of caustic severitybut it allegedly hid tootherosion caused by his

drinking dilutehydrochloric acidprescribed forachlorhydria

An alternative suggestion concernsa nervous dentist pulling out the

wrong front tooth


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1941: Florey& Heatley to

USARockefellerFoundationmouldy cantaloupe in amarket in Peoria, Illinois(Penicillium chrysogeum)bed pans to 25,000 gallonmetal tanks


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Fleming the discoverer of penicillin, was almost

forgotten by the time penicillin was being massproduced.

However, he would be rescued from oblivion, in1943, when he was knighted along with HowardFlorey, and two years later was awarded theNobel Prize in Physiology and Medicine along

with Florey and Chain.


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Fleming predicted that the use of penicillin

would, in time, be of limited value because

bacteria would eventually recombine genetically

to resist the effects of penicillin.By as early as

1952, as much as three-fifths of all staph

infections were penicillin resistant.


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So does any theory explain any of the penicillin

story possibly the greatest medical advance in the

20c?

or was it a case of

experimental preparation

careful observation

hard workand luck?


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"Penicillin cures, but wine makes people happy.-- Sir Alexander Fleming

Maureen and Bernie's Wine Travel Guides

penicillin as a paradigm for medical research

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