Ideas about the cause of illness and disease:
Germ Theory:
- For over a decade, people have understood the causes of common diseases such as cholera.
- In the 20th century, doctors did not refer to "four humours," etc., when diagnosing; instead, they observed the patient's symptoms and then diagnosed the disease.
- In the 20th century, the accuracy of diagnosis increased with the use of samples such as skin, blood, or biopsies (flashcards). The lab examined these samples using tools like microscopes.
- The 19th century also improved the accuracy of diagnosis through medical testing, such as x-rays, lab techs, and electrocardiograms.
- Understanding the symptoms of a doctor through medical experience is crucial for testing. The most significant shift in the 19th century was the diagnosis process.
Genetics:
- During the first half of the 20th century, doctors were uncertain about how children inherited certain traits from their parents and how this could relate to hereditary diseases.
- In 1900, Mendel noticed that genes came in pairs, one from each parent, establishing the fundamental laws of inheritance.
- Microscopes, while powerful enough, do not provide sufficient scientific evidence to prove laws.
- In 1951, scientists used chromatography, a technique passed down from parents to children, in human cells.
- This allowed geneticists to successfully map how genes passed on, proving what Mendel discovered.
- In 1953, Watson and Crick used x-rays provided by Franklin and Wilkins to discover DNA and its structure. They discovered that DNA had a double helix structure, which could unzip itself to make copies.
- In April 1953, Watson and Crick published a paper stating that their understanding of the shape of DNA enabled them to examine diseases and damaged parts that cause hereditary diseases.
Mapping of the human genome:
- Mapping DNA's code was vital to helping scientists understand and find the cause of genetic diseases that had unknown causes.
- 1990: Launch of the Human Genome Project, originally led by James Watson.
- For one decade, 1000s of scientists around the world worked to decode and map the human genome.
- 2000: First draft was completed.
- This made it possible for scientists to locate precise DNA for each individual, as well as misprints in DNA, and search for mistakes.
- For example, if a woman with hereditary breast cancer carries a gene, it indicates that her son has a higher risk of developing cancer than the average person. By identifying the incorrect gene, scientists can recommend preventative measures such as a mastectomy to remove the breasts.
- Despite the lack of a treatment, prevention plays a significant role.
Factors helping development of genetics:
Technology:
- Scientists were able to identify DNA and study its formation thanks to advancements in microscope technology that produced higher-focus images.
- Ruska and Knoll first developed electron microscopes in 1931, and within two years, they were able to magnify more than any optical microscope in use at the time.
- Electron microscopes operate by using an electron beam, enabling magnification up to 1000000x.
Science:
- "Big science" refers to the collaboration of thousands of scientists worldwide on the human genome project.
- All produced data is made public to benefit as many people as possible.
Impact of Genetics:
- Gain a deeper understanding of the genome, identify the body's DNA, pinpoint the affected body, pinpoint the affected genes, and comprehend and recognise genetic disorders like Down syndrome.
- Missing or incorrect genes cause 15% of diseases.
- Although there is currently no treatment for most of these diseases, it has helped doctors understand the causes of genetic diseases.
Lifestyle and Health:
Smoking:
- It gained popularity in the 1920s, when it was young and free.
- In the 1950s, doctors observed a significant increase in the number of men afflicted with lung cancer.
- Consequences of Smoking include cancer, heart disease, gum disease, tooth decay and high blood pressure.
- Smoking is the leading cause of preventable disease globally, and it poses a significant risk to those who inhale secondhand smoke, increasing the likelihood of children developing asthma.
Diet:
- Consuming too much sugar leads to Type 2 diabetes, an incurable disease where the body cannot process sugar in the bloodstream.
- Too much fat leads to heart disease.
- Not getting the right amount of nutrition or eating enough can cause health problems.
Other lifestyle factors:
- The trend of tanning has led to an increase in the number of skin cancer cases worldwide.
- Sharing body fluids through unprotected sexual activity can spread disease and lead to unwanted pregnancy.
- Drinking too much alcohol can lead to liver disease and kidney problems.
Improvements in diagnosis:
Impact of technology:
- Huge leaps in technology in 1900, it made diagnosing diseases more accurate and helped doctors treat patients better.
New diagnosing methods:
- The development of machines and computers allowed doctors to have a better understanding of patients' symptoms than ever before.
- Doctors no longer have to use surgery to diagnose all diseases.
Magic bullets:
- This term describes a chemical cure that would attack disease-causing microbes while leaving the body unharmed.
- Late 19th century: As more microbes causing disease were found, scientists could search for substances to attack them.
Treatment breakthrough:
- Doctors understood the body and produced antibodies to fight diseases that had previously infected it.
They showed that vaccines work and searched for chemical antibodies that would work in the same way.
- Syphilis was a persistent problem throughout the 19th and 20th centuries, with no significant improvement in treatment. The 16th century saw the introduction of mercury treatments.
Syphilis:
In 1909, Hata conducted tests on various arsenic compounds and discovered one that could cure syphilis. Salvarsan 606 - 1st magic bullet.
Proton-sil:
In 1932, Domagk discovered that prontosil inhibited the growth of bacteria, thereby enabling the body's immune system to eradicate them. These drugs are known as bacteriostatic antibiotics.
- Scientists then started to look for other drugs that would work in the same way as a bacteriostatic antibiotic.
British scientists created M&B 693, a bacteriostatic antibiotic, in 1938 to treat pneumonia.
Antibiotics:
- First antibiotic - Penicillin.
- Created using microorganisms.
- In 1928, Fleming isolated penicillin from a mold sample, and Florey & Chain developed it as a useful treatment in 1940.
- This discovery inspired other scientists to investigate more moulds and find antibiotics.
- In 1943, Watson created streptomycin, a drug so potent that it proved effective in treating tuberculosis, a condition previously believed to be incurable.
- From 1950s to 1960s more antibiotics discovered.
Antibiotics in the 21st century:
- Pharmaceutical companies continue to conduct research and test substances.
- This is because some bacteria have developed a resistance to the antibiotics we currently have.
- If we don't develop new treatments, old antibiotics will become ineffective against diseases we believe we have conquered, e.g., septicaemia (blood poisoning).
Impact of Science and Technology on Medical Advancements:
- Scientists have developed medicines that pinpoint and treat specific diseases. Scientists have developed treatments to manage illness, even if they can't cure some diseases like diabetes.
- Improved scientific understanding of drug use involves better testing and trialing easier new treatments before administering them to patients.
- Before drugs didn't have to go through this process, mistakes were made.
For instance, the 1960s drug thalidomide, used to treat morning sickness, resulted in birth defects.
- Currently, it takes several years for a drug to undergo thorough testing before its use slows down progress but increases safety.
New technology:
1. Mass production of pills made distribution of drugs much easier.
2. The development of capsules, which dissolve in the stomach to release the drug, makes taking drugs easier.
3. Hypodermic needles enable the direct introduction of precise doses into the bloodstream.
4. Insulin pump: This device delivers insulin without the need for injections.
Start of NHS:
- Initially, the NHS launch didn't significantly alter hospitals, as post-war Britain had limited resources for medical care.
The government was responsible for 1143 voluntary projects and 1545 large-scale city hospital projects.
- The 19th century saw the construction of many of these hospitals, which required updating.
Additionally, London and the South East have more hospitals than the rest of the country.
Phase One: Improved access to care:
- 1948: The government launched the NHS to provide medical care for all of Britain, which was paid for by National Insurance contributions.
- The largest government intervention in medical care occurred when the NHS took over existing hospitals.
Aim: In 1911, the goal was to ensure that all workers, regardless of their wealth or poverty, received equal access to medical care. The National Insurance Act did not cover women living at home.
In contrast to women at home, the National Insurance Act was abolished in 1949.
Similarly, many GP surgeries required the modernisation of their standards.
- The 1950s study revealed that one-fourth of GPs were not satisfied, and the situation with the NHS worsened as more people visited GPs, leading to longer waiting times and appointment times.
- Despite improvements, access did not improve in the short term.
- During the 1960s, the government implemented changes to improve the NHS.
- The government ensured that hospitals were distributed evenly across England. The introduction of the GP charter in 1966 encouraged GPs to stay up to date with medical developments. The government managed the NHS (rather than just funded it), which led to improvements in the standard of care.
The extent of the change in care and treatment:
- 1900-25: Deaths caused by an infectious disease.
- By 1990 < 1%.
- In 1900, the majority of people were still using herbal remedies or patent medicines.
- Today, a wide range of targeted, efficient treatments are available to match the diseases they treat.
Problems in developing treatments:
- It is difficult to develop a vaccine against some viruses. Every year, a flu vaccine is developed in response to the most common flu virus strain.
- Scientists must return to the laboratory and continue testing compounds in the hopes of finding one that is effective, as new diseases keep appearing that don't respond to any chemical treatments.
- Lifestyle factors have led to an increase in diseases such as heart disease and cancer, which are difficult to cure.
- Drug-resistant bacteria like MRSA have evolved.
- They faced many new problems when researching herbal medicines; acupuncture and homoeopathy are still popular.
Improved access to care:
- In 1900, women continued to care for the majority of sick people in their homes.
- Only serious cases required the payment of doctors.
- In 1919, the government set up the Ministry of Health to help determine the level of healthcare across the country.
- The availability of care (outside the home) rapidly improved starting in 1948. NHS was free; everyone had access to medical care and treatment.
- The NHS made it clear that hospitals were for treating the sick only; the gap in services meant that people without families spent their final days in hospitals until the end of World War II.
Preventing Disease:
- The government assumed responsibility for the removal of waste from public water and clean water due to the germ theory.
- People are becoming increasingly aware of the significance of voting. The government gave more attention to what its citizens wanted.
At the beginning of the 20th century, the laissez-faire attitude was abolished:
1. An enhanced comprehension of causality. Government-led interventions can significantly influence public health.
2. Increased understanding of methods of prevention.
- Once we understood the causes of disease and health problems, we could test methods of prevention. These included:
- The positive impact of smallpox vaccination inspired the introduction of compulsory vaccinations.
- Passing laws to provide a healthy environment.
- Clean Air Act.
- Adding fluoride to water supply to help prevent tooth decay.
Communicating health risks:
- Lifestyle campaignsglobal epidemics, e.g., Ebola in West Africa,
- The government tracked travellers from affected regions and quarantined them to stop the spread.
- Communicating risks to the population is key.
Mass vaccinations - First national campaign
1942: Diphtheria
1950: Whooping cough and poliomyelitis
196: Tetanus
1968: Measles
1970: Rubella
- Before the central government funded diphtheria vaccination campaigns, local governments did so in a less widespread manner.
3000 children per year died of diphtheria.
- During World War II, the government launched a campaign to immunise all children against diphtheria, leading to a significant decline in infection rates. By the mid-1900s, diphtheria had become a rare disease.
- Poliomyelitis (polio) was a very contagious disease that caused paralysis.
- In the early 1950s, there were up to 8000 cases annually; however, following the introduction of the vaccine, the number of infections rapidly decreased, with the last case occurring in Britain in 1984.
- Rubella wasn't deadly for most but can be very dangerous if a pregnant woman catches it, as it'll affect the unborn child.
- Other vaccines target diseases that lead to other diseases; e.g., the HPV vaccine protects women from STDs linked to cervical cancer.
- There is still controversy around vaccines; many resent government intervention and choose not to vaccinate.
- Lack of trust in the medical profession led to fears vaccines are unsafe.
- While vaccination is the best way to prevent epidemics, there's still freedom to reject them.
New approaches to prevention:
Government Legislation:
- The government passed laws to provide a healthy environment for the population.
- Bad smog episodes in 1952 triggered the Clean Air Acts of 1956 and 1968.
- Smog: Heavy fog caused by air pollution; everyone burnt coal to heat homes, so there was a lot of smoke and soot in the air, especially in London.
- Smog is no longer a significant problem in the UK, but the government still passes laws to protect the population from air pollution, e.g., limiting car emissions.
- The government also passed a rule making it illegal to smoke in an enclosed work/public place → came into force on 1st July 2007.
Fleming and discovery of penicillin:
- In 1928, Fleming completed the development of penicillin in his lab by identifying the mould that killed the harmful bacteria that had been growing in the dish.
- In 1929, Fleming published his results and findings during a period when scientists were searching for chemical treatments for disease, which had a significant impact on bacteria. He didn't believe it would work on bacteria, nor did he believe it would secure funding to continue his research.
- In 1940, Florey and Chain decided to further test Fleming's findings proved that it could treat infected mice with penicillin.
- The year 1941 demonstrated the effectiveness of penicillin in combating infections within the human body.
- Mass Production:
- Florey and Chainere were struggling to produce penicillin and needed a large-scale factory where penicillin could grow and be extracted industrially.
- July 1941: Florey visited the USA and convinced pharmaceutical and chemical companies to start producing penicillin. They started in beer vats and slowly started; after that, they only had enough to treat 10 people.
- Once the production of penicillin began, its impact became evident; the US government provided funding, and by the time of D-Day in June 1944, Britain had begun mass production in 1943, with enough available to treat all Allied casualties.
- The US government funded individuals to work; drug companies built their own factories and patented Florey and Florey's research, so they used Fleming's work. Chain made it more affordable and accessible for everyone to produce in large quantities.
Uses of penicillin:
- Penicillin is effective in treating diseases caused by a certain family of bacteria.
- Patients who have had teeth extracted often use penicillin to prevent infection.
- The discovery of penicillin in 1943 prompted scientists to search for other moulds that could combat bacterial infections, such as streptomycin against tuberculosis.
- Scientists began working on synthetic versions of penicillin after Hodgkin mapped its chemical structure in 1945, studying how to adapt it to treat specific diseases.
- In 1957, C. Sheehan created a chemical copy of penicillin.
- Coincidence → In medical treatment, more direct and conditions in medical facilities improved, there could offer patients a single penicillin agent → Side effects squashed and treatment more streamlined and treatment more streamlined and treatment standardised.
- In 1947, there was a 1% resistance to a specific type of penicillin, prompting drug companies to develop a new penicillin that would not only kill the bacteria but also specifically target the resistant strains.
Lung Cancer:
- The second most common cancer in the UK primarily affects people over the age of 40.
- 85% of cases involve individuals who smoke or have previously smoked.
- Few cases in the 19th century.
- Lung tumours cause 1% of all cancers.
- 1918 - 10% →1927 - 14%.
- In 1950, the British Medical Research Council released a study that linked the rise in lung cancer to cigarette smoking.
- Since WWI, aggressive advertising by tobacco companies has led to a significant increase in the number of smokers.
- Despite the study's results, the number of men dying from lung cancer has continued to rise.
- In 1973, lung cancer claimed nearly 26,000 lives.
- The death rate among women also continued to rise until the 1990s.
Diagnosing lung cancer:
- Before more advanced technology had been developed, it was diagnosed using an x-ray machine.
One could have mistaken butt cancer for another condition.
4 x-rays weren't detailed enough to accurately diagnose cancer.
Now we use CT scans, which are much more accurate.
Science and technology in diagnosis:
- Lung cancer presents significant challenges in treatment due to its advanced stage by the time of detection. Patients mistake symptoms.
- There is no national lung cancer screening program, which prevents people from routinely testing for the disease.
Because tests are not accurate enough to offset the negative effects of screening,
- Diagnosis is also difficult, but technology has helped it improve.
