Medicine 3 Flashcards
Theory of spontaneous generation
Microbes were created by decaying matter (rotting food)
What spontaneous generation lead people to believe
Disease caused germs
What led to Pasteur’s discovery
1857 - employed to find explanation for souring of sugar beet in fermenting industrial alcohol - blamed germs
How did Pasteur prove germs were in the air
- showed sterilised water in swan-necked flash on Paris streets stayed sterile
- open flask bred germs
Pasteur’s theory
1861 - Germ Theory
Germ Theory
- microbes in air cause decay, not other way round
- some germs caused disease
How did Pasteur prove theory
1867 - published evidence proving there was link between germs + disease - showed germs caused disease in silkworms
Development of microscopes
- 17th century - Antonie van Leeuwenhoek invented them
- more advanced by 1800s
- 1830 - Lister made one 1000 times stronger
Why did it take Germ Theory many years to be useful
Each disease had to be identified originally
Impact of Germ Theory
- inspired Joseph Lister to develop antiseptics
- confirmed Snow’s findings on cholera
- encouraged 1875 Public Health Act - linked disease to poor conditions
Microbe hunting
Linking specific diseases to microbe that caused them
Famous microbe hunter
Robert Koch
What disease microbes did Koch discover
- 1833 - cholera
- 1876 - anthrax
- 1878 - scepticaemia
- 1882 - tuberculosis
What did Koch do
Use dyes to identify microbes
Koch’s method
- created solid cultures for breeding bacteria with agar jelly
- used dyes to stain bacteria - more visible under microscope
- used newly invented photography to take photos of findings
How did Koch discover germ causing sheep anthrax
- extracted it from organ of dead sheep
- injected it into 20 generations of mice, all got anthrax
Impact of Koch
Allowed other microbe hunters to find other bacteria causing other diseases
Vaccines developed by Pasteur
- sheep anthrax
- rabies
Why did Pasteur want to combat new microbes so fast
Heard of Koch’s discoveries, wanted to race him
Who discovered cholera vaccine
Charles Chamberland
Who was Charles Chamberland
Pasteur’s assistant
How did Chamberland find cholera vaccine
- injected chickens with cholera culture - had been weakened by accidentally being left on desk during holiday
- chickens survived
- tried with newly cultured cholera - chickens survived
When did Pasteur do public anthrax experiement
1881
Other germs found by others with Koch’s method
Diptheria - Edwin Klebs 1883
Magic bullets
Nickname for antibodies as they only attacked specific microbes
What did Paul Ehrlich try to find
1905 - magic bullet treating syphillis
First magi bullet
Salvarsan 606
How was Salvasan 606 discovered
- tested 605 compounds
- nearly missed 606th until another experimenter (Sahashire Hata) retested it
Problem with Salvarsan 606
Could kill patient as well as microbes
Importance of Salvarsan 606
First time chemical compound used to destroy bacteria
Second magic bullet to be discovered
Prontosil
Who discovered Prontosil
Gerhard Domagk
What did prontosil treat
Blood poisoning
How did Domagk test prontosil
- 1932 - tried it on mice, found it had effect on bacteria causing blood poisoning
- tested on his daughter with blood poisoning in larger dose, healed
Why could Domagk test on humans quickly
- daughter Hildgarde playing with guinea pig near medical equipment
- pricked finger on infected medical equipment - developed blood poisoning
- near to death - Domagk quickly tested prontosil
Order of anaesthetics
- 1799 - Humphry Davy - nitrus oxide
- 1842 - Crawford Long - ether
- 1847 - James Simpson - chloroform
Why was nitrus oxide ignored
American dentist Horace Wells did public demonstration (1845) - patient unaffected by nitrus oxide by bad luck
Who dd public demonstration of ether
1846 - William Morton
Problems with ether
- irritatant
- explosive
Who discovered chloroform could be used as anaesthetic
James Simpson
How did James Simpson discover chloroform worked as anaesthetic
- professor of midwifery at Edinburgh University
- wanted to find safer alternative to ether for women in childbirth
- tested chemicals on himself
- found chloroform worked quicker than ether + less was needed
What aided popularity/trust in chloroform
Queen Victoria gave birth to 8th child with it
Problem with chloroform
Killed many patients
Who worked out problem with chloroform
John Snow
What did John snow realise about chloroform deaths
Victims mostly young and fearful
How did Snow investigate problems with chloroform
- measured amounts in dead victims’ bodies
- tested it on animal bodies
What did Snow work out was problem with chloroform
- reduces rate of cells working - especially brain cells
- can slow heart cells to point of death
- young/fearful need more to slow brain cells - more slowing of heart - increased chance of death
What did Snow invent
Chloroform inhaler
Effect of chloroform on surgery
- unconscious patients easier to operate on, could work for longer + more complex
- this was bad - higher chance of dying from infection (more deaths) due to longer exposure of unhygienic methods
What was period of 1846-1870 called
‘Black Period’
What was the ‘Black Period’
Higher death rates in surgery due to long complex surgeries
Unhygienic surgery in 19th century
- surgeons wore same coats for years - blood/pus from previous operations
- operations in unhygienic conditions - patient’s house
- operating instruments not washed
What are antiseptic methods
Methods used to kill germs that get near surgical wounds
What are aseptic methods
Surgical methods aiming to stop any germs getting near surgical wounds
What did Semmelweis aim to do
Reduce deaths of postpartum infections - childbed fever
What did Semmelweis do at his hospital
Posted notice on maternity ward, ordering all doctors to wash hands using chloride of lime (antiseptic) between patients
What happened to Semmelweis’ death maternal death rates
Dropped from 10% - <3%
Why weren’t Semmelweis’ methods widely used
Chloride of lime was unpleasant
What prompted Lister’s work
- realised operations went well if kept free from infection
- Thomas Anderson suggested he read Germ Theory + use carbolic acid (used in sewers) to kill bacteria
What did Lister believe caused infection
When skin was broken and microbes got in to cause infection - needed chemical barrier
Lister’s method
- spray carbolic acid on:
-surgeon’s hands
-wounds
-instruments - soak in carbolic acid:
-bandaged
-ligatures
-dressings
How did Lister test method
- 1865 - James Greenlees run over by cart, fractured leg
- didn’t amputate - set fracture + dressed in carbolic acid to prevent infection
- made full recovery
Effect of Lister
- antiseptic method reduced mortality rate from 46% - 15% from 1864-70
- fear of surgery lessened - 10x more surgery in 1912 than 1867
Reactions to Lister
- controversial - people long debated whether its better to dress wounds or leave in open air
- John Bennett disagreed - thought infection came from dying cells
- unpopular method - carbolic acid made hands crack
Aseptic surgery
- since late 1800s
- instruments sterilised at 120°C
- theatre staff sterilise hands, wear sterile gowns + masks + hats + gloves
Invention of surgical gloves
1889 - William Halstead
Effect of asepsis
Reduced need for chemicals like carbolic acid
Public health problems in revolution Britain
-
overcrowding
-many moved over for industrial revolution
-houses built close together with bad ventilation
-4 or more children in single room -
sewage
-shared toilets outside (privy) or bucket in corner of room
-privies above cesspit, collected by nightmen who threw it into rivers
-water companies set up water pumps shared between houses, often contaminated
Public health reformers
- Chadwick
- Snow
- Bazalgette
- Chamberlain
Laissez-faire
- ‘leave alone’
- government policy didn’t believe it was their responsibility to keep towns clean
When did cholera reach Britain
1831
When did cholera become epidemic in Britain
1832
How many people died of cholera in Britain in 1832
21,000+
What caused cholera
Ingestion of water contaminated with bacteria spread through sewage getting into drinking water
Effect of cholera
- toxins from bacteria penetrate large intestine walls, preventing it from absorbing water
- dehydration + diarrhoea
Treatment of cholera
- salt solution
- intravenous fluids
- antibiotics
Cholera death rate
Up to 50% in unprepared areas
How did government respond to first cholera epidemic
- regulated burial of dead - mostly ineffective
- epidemic decline after 1932 - interest lost
What prompted Chadwick’s report
1840 - more cholera outbreaks, government asked him to do it
How did Chadwick research for report
- sent doctors questionnaires to doctors
- interviewed hundreds of people
Name of Chadwick’s report
1842 - Chadwick’s report on the sanitary conditions of the labouring population of Great Britain
What did Chadwick’s report say were problems
- living conditions worse in towns than countryside
- many people becoming sick caused taxes to increase to help them
What action did Chadwick’s report suggest
- improve drainage/sewers
- remove waste from streets
- provide clean water supplies
- appoint medical officers to check reforms
Spread of Chadwick’s report
30,000 free copies given to public/journalists/politicians
Government’s initial response to Chadwick’s report
- 1844 - refused to do anything as recommended (laissez-faire)
When was first public health act
1848
What put pressure on first public health act
- long-term - Chadwick’s report
- short-term - reports of new cholera epidemic reached Britain, worried government
First public health act
- set up national board of health with Chadwick as member
- local councils could collect taxes for public health improvements
- appointed medical officers to oversee public health improvements
Problem with first public health act
- not compulsory to make changes
- towns reluctant to spend money on improvements
Problem with board of health
- Chadwick annoyed lots of people - forced to retire in 1854
- dismantled in 1858
What did Snow link cholera to
Contaminated water
How did Snow investigate cholera + contaminated water
- removed handle from shared water pump on 1 side of street in Broad Street (London)
- most people with handle got cholera
- most people without handle didn’t
When did Great Stink happen
Summer 1858
What caused Great Stink
- hot weather caused river water levels to drop + bacteria to grow in waste
- produced awful smell
Effect of Great Stink
- stopped Parliament from meeting
- 1859 - government appointed engineer Bazalgette to redesign sewer system with £3 million
Bazalgette’s sewer design
- sewers transported waste normally dumped into Thames away from heavily populated areas to Thames Estuary
- about 1300 miles of sewers built
- system opened in 1865
- became blueprint for most Western European cities
Second reform act
- 1867
- gave nearly 1 million more men the vote - mostly industrial workers
- workers could pressure government to listen to public health concerns - politicians wanted to stay in power so acted
Benjamin Disraeli’s government acts
- 1875 - second public health act
- 1875 - Artisans’ Dwelling act
Second public health act
- actions compulsory
- councils appointed health + sanitary inspectors - made sure laws on sewage + street cleaning were followed
Artisans’ Dwelling act
Let local councils buy slums with poor living conditions to rebuild with government backed housing standards
Joseph Chamberlain
- Mayor of Birmingham
- persuaded city authorities to buy water/gas companies to ensure people had good supplies of both
- 1875 - built new street in place of slums (Artisans’ Dwelling)
