Topic 5 – Health, disease and the development of medicines

• What is the definition of health as defined by the WHO?

  Complete physical, mental, and social well-being.
• What is the difference between a communicable and a non-communicable disease?

  Communicable diseases are spread from person to person and non-communicable diseases are not spread from person to person.
• The presence of a disease can makes you more susceptible to other diseases.
• A pathogen is a disease-causing organism. It is caused by viruses, bacteria, fungi and protists.
• What is cholera? What are the symptoms? How does it spread? How do you prevent it?

  Cholera is a bacterial infection. Symptoms include severe diarrhea and vomiting. It spreads through contaminated water and food. Prevention involves clean water, proper sanitation, and vaccination.
• What is tuberculosis? What are the symptoms? How does it spread? How do you prevent it?

  Tuberculosis is a bacterial infection that primarily affects the lungs. Symptoms include coughing, weight loss, fatigue, and fever. It spreads through the air when an infected person coughs or sneezes. Prevention involves vaccination, good hygiene practices, and early detection and treatment.
• What is Malaria? What are the symptoms? How does it spread? How do you prevent it?

  Malaria is a protist. Symptoms include fever, headache, and fatigue. It spreads through the bite of infected mosquitoes. Prevention methods include using insect repellent, sleeping under mosquito nets, and taking antimalarial medication.
• What are stomach ulcers? What are the symptoms? How does it spread? How do you prevent it?

  Stomach ulcers are bacterium. Symptoms are stomach pain and vomiting. It spreads via oral transmission. It can be prevented by practicing good hygiene.
• What is Ebola? What are the symptoms? How does it spread? How do you prevent it?

  Ebola is a viral hemorrhagic fever. Symptoms include fever, fatigue, muscle pain, headache, and bleeding. It spreads through direct contact with bodily fluids. Prevention involves practicing good hygiene, avoiding contact with infected individuals, and using protective measures.
• What is Chalara ash dieback? What are the symptoms? How does it spread? How do you prevent it?

  Chalara ash dieback is a fungal disease that affects ash trees. Symptoms include leaf loss, crown dieback, and diamond-shaped lesions on the bark. It spreads through spores and can be prevented by monitoring and removing infected trees, and planting resistant varieties.
• What is the lytic pathway of the viral life-cycle?

  1. The virus attaches to a specific host cell and injects its genetic material into the cell.
  2. The virus utilizes proteins and enzymes in the host cell to replicate its genetic material and generate components of new viruses.
  3. The viral components assemble.
  4. The host cell ruptures, releasing the new viruses that proceed to infect more cells.
• What is the lysogenic pathway of the viral life-cycle?

  1. The injected genetic material becomes part of the genome (DNA) of the host cell.
  2. The viral genetic material is replicated along with the host DNA during each host cell division, but the virus remains dormant (inactive), and no new viruses are produced.
  3. Eventually, a trigger prompts the viral genetic material to exit the genome and initiate the lytic pathway.
• What are STIs?

  Sexually transmitted infections (STIs) are infections that are primarily spread through sexual contact.
• What is Chlamydia? What are the symptoms? How do you prevent it?

  Chlamydia is a sexually transmitted infection caused by the bacterium Chlamydia trachomatis. Symptoms can include pain during urination, and infertility. It can be prevented by practicing safe sex.
• What is HIV? What are the symptoms? How do you prevent it?

  HIV is a virus that attacks the immune system. Symptoms include fever, fatigue, and swollen lymph nodes. Prevention methods include practicing safe sex and using a condom.
• Plants defend themselves from pathogens using physical barriers like the leaf cuticle and the cell wall.
• Plants can defend themselves from pathogens using chemical barriers. For example, willow trees produce aspirin - used for humans too.
• How can plant diseases be detected in a lab?

  1. The observation of symptoms
  2. Compare the symptoms with the current environment of the plants
  3. Detecting antigens and DNA produced by the pathogens.
• What are the physical barriers to pathogens in the human body?

  Platelets produce blood clots, Mucus, and hairs that trap the pathogens.
• What are the chemical barriers to pathogens in the human body?

  The stomach produces Hydrochloric acid and the eyes produce lysozyme.
• As part of the immune system, Phagocytes undergo phagocytosis when seeing a pathogen. They engulf them.
• How does the immune system work?

  1. Exposure to Pathogen:

  • Encounter with a pathogen initiates the specific immune response.

  1. Antigens Trigger Immune Response (b):

  • Antigens on the pathogen surface activate the immune system, leading to the production of antibodies.

  1. Memory Lymphocytes in Secondary Response:

  • The immune response includes the generation of memory lymphocytes, which "remember" the pathogen.
• Immunization with an inactive pathogen stimulates the immune system, prompting antibody production and the formation of memory lymphocytes for enhanced future defense.
• What are the advantages and disadvantages of immunisation?

  Advantages: Protection against infectious diseases, prevention of outbreaks, and reduction of disease-related complications and deaths. Disadvantages: Potential side effects, rare adverse reactions, and limited effectiveness for some vaccines.
• How do antibiotics work?

  Antibiotics work by targeting and killing bacteria or inhibiting their growth. They do this by interfering with the bacterial cell wall, protein synthesis, or DNA replication.
• What are the aseptic techniques used for preparing a bacterium culture?

  1. Sterilization with Autoclave:

  • Utilize an autoclave to prepare sterile growth medium and petri dishes, ensuring the elimination of microorganisms and spores.

  1. Sterile Inoculation Techniques:

  • Employ sterile inoculating loops for transferring microorganisms, preventing contamination during the culturing process.

  1. Covering Petri Dishes and Culture Vials:

  • Maintain aseptic conditions by keeping petri dishes and culture vials covered to prevent airborne contaminants from compromising the experiment.
• What is the method for preparing a tissue culture?

  1. Autoclave Sterilization:

  • Use autoclave for Petri dish and medium sterilization.

  1. Inoculating Loop Prep:

  • Sterilize the loop in flame before bacterial transfer.

  1. Culture Vial Handling:

  • Keep bacterial cultures covered in the lid.

  1. Petri Dish Protection:

  • Cover Petri dishes with taped lids to prevent airborne contaminants.

  1. Upside-Down Storage:

  • Store Petri dishes upside down to avoid condensation on agar.
• You can calculate the size of inhibition zones by using $πr^2$
• What are the main stages for developing new drugs?

  1. Preclinical Testing:

  • Initial lab testing on human cells; progression to whole animals for effectiveness, toxicity, and optimal dosage.

  1. Clinical Testing:

  • Human trials follow successful animal testing.
  • Safety confirmed in healthy volunteers.
  • Patient trials determine effective, low-side-effect doses.
  • Placebo-controlled trials prevent bias in evaluation.
  • Blind or double-blind clinical trials avoid subconscious influences in monitoring and analysis.
• What are monoclonal antibodies?

  Antibodies are produced by identical lymphocyte cells.
• How are monoclonal antibodies created?

  By fusing a lymphocyte (produced from rats) with a tumor cell to create a hybridoma cell. The hybridoma cell divides rapidly (due to the tumor cell) which creates the monoclonal antibodies.
• How do monoclonal antibodies work on pregnancy tests?

  • Pregnancy tests use monoclonal antibodies to detect hCG, a hormone produced during pregnancy.
  • The test strip contains immobilized monoclonal antibodies that are specific to hCG.
  • When a urine sample containing hCG is applied to the test, it interacts with the immobilized monoclonal antibodies.
  • The results are shown based on the color changes.
• What is HCG?

  a hormone produced by pregnant women.
• Monoclonal antibodies can be used to find the certain location of blood clots and cancerous cells as they bind to their specific proteins. They can be used for radiotherapy treatments as you can attach a radioactive substance which allows you to visualise tumors and clots.
• non-communicable diseases are caused by several factors (problems) that lead to it.
• What are examples of risk factors?

  Smoking, obesity, high blood pressure, and family history of a disease.
• What is the formula for BMI?

  BMI = weight (kg) / height^2 (m^2) $m/h^2$
• What is the effect of alcohol on the liver?

  Liver damage and diseases - may lead to liver failure which means that a liver transplant is needed.
• Smoking can lead to cardiovascular disease.
• Cardiovascular disease can be treated by exercise and diet, surgery and lifelong medication.