Project Lead The Way Medical Intervention Exam 1 Review Disclaimer This review is an overview. There is no possible way to revisit every single item we have covered thus far. This should be used as 1 tool in your preparation for the exam. Major Focus Key Terms – Crossword Puzzles 1.1 – 1.3 Key Concepts – Each Activity/Project Essential Questions – Each Unit Conclusion Questions – Each Activity/Project Knowledge and Skills – Each Unit Quizzes Exam 1 Review Unit 1.1.1 through Unit 1.3.3 Activity 1.1.1 Medical Interventions Inventory Activity 1.1.2 Investigating an Outbreak Activity 1.1.3 Using DNA to Identify Pathogens Problem 1.1.4 What's the Concentration? Activity 1.1.5 ELISA Activity 1.1.6 Final Diagnosis Activity 1.2.1 Antibiotic Therapy Project 1.2.3 Attack of the Superbugs Activity 1.2.4 When Antibiotics Fail Activity 1.3.1 Good Vibrations Activity 1.3.2 Can You Hear Me Now? Activity 1.3.3 Cochlear Implant Debate Unit 1 - The Mystery Infection Activity 1.1.2 Investigating an Outbreak What do you think of when you hear the term infection? What is an infection? Infection is the invasion of a host organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Unit 1 - The Mystery Infection Activity 1.1.2 Investigating an Outbreak Are there different types of infections? Infectious agents: Viruses Bacteria Prions (misfolded protein) Parasites (nematodes, arthropods) Fungi Unit 1 - The Mystery Infection Activity 1.1.2 Investigating an Outbreak Ebola • disease of humans and other primates • caused by the ebola virus Late Stages: • Dec. liver & kidney function • Internal & external bleeding Unit 1 - The Mystery Infection Activity 1.1.2 Investigating an Outbreak Strep throat • Streptococcus bacteria • gram-positive bacterium Symptoms: Fever sore throat enlarged lymph nodes Cause of 37% of sore throats among children Cause of 10-15% of sore throats among adults Unit 1 - The Mystery Infection Activity 1.1.2 Investigating an Outbreak Necator americanus (Hookworm) • Nematode that lives in the small intestine of hosts • Parasitic infection • 740 million people Symptoms: abdominal pain, diarrhea, cramps, weight loss, anorexia and iron deficiency Unit 1 - The Mystery Infection Activity 1.1.2 Investigating an Outbreak Athlete's foot • most commonly caused by the fungi Trichophyton rubrum or T. mentagrophytes • Fungal infection Symptoms: Scaling Flaking Itching Inflammation blistering Activity 1.1.2 Summary Investigating an Outbreak A number of patients showed up at infirmary Sue, Jill, Anthony, Wanda, Maggie, Maria, Arnie Objective: To determine cause of illness of each patient Analyzed medical history, symptoms, cause of illness, possible routes of transmission four major illnesses – bacterial meningitis, infectious mononucleosis, Strep throat, and influenza Activity 1.1.3 Using DNA to Identify Pathogens DNA What does DNA stand for? What is DNA? What does DNA do? Who discovered DNA? Where is DNA found? DNA deoxyribonucleic acid (DNA) DNA What is DNA? What does DNA do? DNA Comprised of 4 Nucleotides There are only 4 DNA nucleotides • adenine • thymine • cytosine • guanine Chromatin DNA → RNA → Protein DNA carries genetic information that codes for proteins DNA is transcribed into RNA (DNA → RNA ) RNA is translated into protein (RNA → Protein) Proteins are used for Enzymes (catalysis), structures, antibodies, hormones, etc DNA Who discovered DNA? History of DNA In 1953 James Watson and Francis Crick proposed the double helix for DNA Awarded Nobel Prize in 1962 History of DNA Information from other sources including X-ray diffraction studies from Rosalind Franklin Rosalind Franklin died so she wasn’t eligible for the Nobel Prize. DNA Where is DNA found? DNA DNA Is DNA found anywhere else? DNA Mitochondrial DNA (mtDNA) • In multicellular organisms, mitochondrial DNA is double stranded and codes for 37 genes and containing approximately 16,600 base pairs • Each mitochondrion is estimated to contain 2-10 mtDNA copies • mtDNA is derived from the circular genomes of the bacteria that were engulfed by the early ancestors of today's eukaryotic cells Endosymbiotic Theory • mtDNA is inherited maternally inherited Of the 37 genes: 13 are for proteins (enzymes) involved in oxidative phosphorylation 22 are for transfer RNA (tRNA) and 2 are for ribosomal RNA (rRNA) which help assemble amino acids into functioning proteins Mitochondrial DNA (mtDNA) Nuclear DNA Human Genome • 3 billion base pairs • Organized into 23 paired chromosomes • Approx 20-25,000 genes Beta Globin Gene Hemoglobin • Gene found on chromosome 11 • Beta globin Protein • Primary component of RBCs – 4 sub-units – 2 of Alpha-globin – 2 of Beta-globin – Each carries 1 oxygen molecule Beta Globin People with sickle cell have abnormal hemoglobin How can computers and genetic information be paired to help prevent, diagnose or treat disease? Activity 1.1.3 Summary Using DNA to Identify Pathogens You are introduced to the field of bioinformatics as you learned how to analyze DNA to identify pathogens Questions: How can scientists identify specific bacteria when they are amplifying and studying the same region of DNA in each species? How can DNA sequencing be used to identify genetic risk for certain diseases and disorders? Activity 1.1.3 Summary BLAST results show that the Neisseria meningitidis bacterium is found in Sue’s system. Neisseria meningitidis bacterium is the leading cause of? Bacterial Meningitis Meningitis is an infection found where in the body? The fluid of a person's spinal cord and the fluid that surrounds the brain Problem 1.1.4 What's the Concentration? Problem 1.1.4 Summary What is the Concentration? You were presented with a 1L container of solution with an unknown amount of solute and asked to devise a method to determine the concentration of the solute. What was the purpose of this exercise (activity)? What is a spectrophotometer? How can a spectrophotometer be used to investigate a disease? How is this relevant to health/medicine? Absorbance Absorbance Why is a red ball red? Any object will appear red when it absorbs all wavelengths of visible light except for red So how does knowing the frequency of light that is absorbed help you determine the concentration? Absorbance Beer-Lambert Law (aka Beer’s Law) A=ebc A is absorbance (no units) e is the molar absorbtivity (units = L/mol/cm) b is the path length of the sample (units = centimeters) c is the concentration of the compound in solution (units = mol/L) ** molar absorbtivity is the same as molar extinction coefficient Absorbance Unknown ? Unknown Set of Standards 1 2 3 4 5 Set of Standards 6 What does serial dilutions have to do with an ELISA? Activity 1.1.5 ELISA Activity 1.1.5 Summary ELISA ELISA assays were used to detect the presence of the Neisseria meningitidis antigen. What is an ELISA? What are the types of ELISA assays? How does an ELISA work? Activity 1.1.5 Summary Activity 1.1.5 Summary You were asked to diagram or model how the ELISA test can be used to detect Neisseria meningitidis. Activity 1.1.5 Summary An ELISA assay can provide qualitative or quantitative results. What does this mean?? Antibodies What is an antibody? Antibodies An antigen-binding immunoglobulin, produced by B cells, that functions as the effector in an immune response Antibodies Important regions of an antibody Antibodies 5 known antibody isotypes IgA IgD IgE IgG IgM GAMED Activity 1.1.6 Final Diagnosis Bioinformatics data and lab testing will eventually reveal the following results: Patient Diagnosis Sue - Bacterial meningitis Jill - Bacterial meningitis Anthony - Influenza Wanda - Infectious mononucleosis Maggie - Strep throat Maria - Bacterial meningitis Arnie - Influenza Marco - Bacterial meningitis Alvin - Infectious mononucleosis Alvin does not submit to molecular testing; however, his association with Wanda and his symptoms will lead students to a diagnosis of infectious mononucleosis. Activity 1.1.6 Final Diagnosis Outbreak Assessment: Who is patient zero on campus? Sue How did this disease spread on campus? • One possible hypothesis: Sue brought the bacteria back from her visit to the other college • Jill lives with Sue and plays on the same sports team, they share many cups, utensils and water bottles. • Either Jill or Sue passed the infection to Maria, who is always in their room. • Sue had lab with Marco. They may have shared a soda during the break and had other contact leading to transmission of the bacterium Activity 1.1.6 Final Diagnosis Outbreak Assessment: What is the appropriate treatment? Use antibiotics to treat those infected What other medical interventions should be used? • Provide the bacterial meningitis vaccine to those who are unaffected • Test other students at the college that Sue visited Unit 1.1 Essential Questions 1) What is a medical intervention? 2) What are the main categories of interventions that function to maintain human health? 3) How do scientists gather evidence during the potential outbreak of an infectious disease? 4) What is bioinformatics? 5) How can DNA sequences be used to identify disease pathogens? 6) What is an antibody? 7) How do antibodies identify and inactivate antigens? 8) How can the ELISA assay be used to detect disease? 9) Why is it important for doctors to know the concentration of disease antigen present in a patient’s system? 10) What steps do scientists take to diagnose, treat, and prevent future spread of a disease outbreak? Unit 1.2 - Antibiotics Unit 1.2 - Antibiotic Treatment Antibiotic Resistance The mass use of antibiotics has resulted in new strains of bacteria that are resistant to antibiotics Over the last decade, almost every type of bacteria known to cause disease has become stronger and less responsive to antibiotic treatment Increasing number of antibiotic resistant bacteria: Tuberculosis, gonorrhea, malaria, skin infections, pneumonia, & ear infections Antibiotic resistance has been called one of the world’s most pressing public health problems and is one of the Centers for Disease Control’s top concerns. Unit 1.2 - Antibiotic Treatment Mechanism of Action Specific antibiotics are effective at preventing the growth of certain strains of bacteria The effectiveness of antibiotics is dependent on the mechanism of action of the drug and the structure of the bacteria Unit 1.2 - Antibiotic Treatment Activity 1.2.3 – Attack of Superbugs Introduction In this activity, you learned about the structure of a bacterial cell in order to understand how different classes of antibiotics work. You also made a superbug from 2 separate plates containing bacteria Unit 1.2 - Antibiotic Treatment What is a bacterium? What are the types of bacteria? How do antibiotics kill bacteria? Unit 1.2 - Antibiotic Treatment What is a bacterium? • Bacteria are a large group of unicellular, prokaryote, microorganisms • Typically a few micrometers in length • A wide range of shapes (ranging from spheres to rods and spirals) • 40 million bacterial cells in a gram of soil • A million bacterial cells in a milliliter of fresh water • Approximately five nonillion (5×1030) bacteria on Earth Unit 1.2 - Antibiotic Treatment A Typical Bacterium Unit 1.2 - Antibiotic Treatment A Typical Bacterium Do Not Memorize This Particular Image. Although bacteria have all these features they can often look slightly different from image to image. Unit 1.2 - Antibiotic Treatment Bacterial DNA Chromosomal: bacteria possess a single chromosome composed of double‐stranded DNA in a closed loop. The DNA is located in the nucleoid of the cell and is not associated with protein. Transfer of chromosomal DNA is accomplished through replication then division to daughter cells. Plasmid: A small circular double-stranded DNA molecule that carries accessory genes separate from those of the bacterial chromosome. They carry a small number of genes. Easily transferred between bacteria in cellular contact. Unit 1.2 - Antibiotic Treatment Bacterial Gene Transfer Three primary types of gene transfer between bacterial cells 1) Bacterial conjugation is the transfer of genetic material (plasmid) between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells 2) Transduction is the process by which DNA is transferred from one bacterium to another by a virus. It also refers to the process whereby foreign DNA is introduced into another cell via a viral vector. 3) Transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material (exogenous DNA) from its surroundings and taken up through the cell membrane(s). Unit 1.2 - Antibiotic Treatment Gram Staining Gram-negative bacteria • Thin cell wall consisting of a few layers of peptidoglycan surrounded by a second lipid membrane containing lipopolysaccharides and lipoproteins • Do not retain crystal violet dye in the Gram staining protocol due to their lipopolysaccharide outer layer • In a Gram stain test, a counterstain (commonly safranin) is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color. Gram-positive bacteria • Do not have an outer membrane BUT they have a thickened peptidoglycan layer • Will retain the crystal violet dye when washed in a decolorizing solution Unit 1.2 - Antibiotic Treatment Gram Staining The higher lipid content of the gram-negative bacteria cell walls allows the alcohol destain to wash the purple colored stain out of the cells. Gram positive bacteria will retain the purple color because the alcohol is not able to destain the purple color from the cells. Gram negative bacteria stain reddish-pink Gram positive bacteria stain purple “Positively Purple” Unit 1.2 Antibiotic Treatment Gram Staining Gram Negative Gram Positive Unit 1.2 Antibiotic Treatment Gram Staining Unit 1.2 - Antibiotic Treatment Mechanism of Action Specific antibiotics are effective at preventing the growth of certain strains of bacteria The effectiveness of antibiotics is dependent on the mechanism of action of the drug and the structure of the bacteria Unit 1.2 - Antibiotic Treatment How do antibiotics work? A number of bacterial processes, including the synthesis of bacterial cell walls, proteins, metabolic pathways, and the integrity of the cytoplasmic membrane, are the targets of most antibacterial drugs. 4 Main Classes of Antibiotics: 1) β-Lactam Antibiotics 2) Tetracyclines 3) Fluoroquinolones 4) Sulfonamides Unit 1.2 - Antibiotic Treatment β-Lactam Antibiotics “Blocks cell wall synthesis” Irreversibly inhibit enzymes involved in the final steps of cell wall synthesis. These drugs vary in their spectrum of activity; some are more active against Gram positive bacteria; whereas, others are more active against Gram negative bacteria. Tetracyclines “Blocks protein synthesis” Reversibly bind to the 30S ribosomal subunit, blocking the attachment of tRNA to the ribosome and preventing the continuation of protein synthesis. They are effective against certain Gram positive and Gram negative bacteria. Unit 1.2 - Antibiotic Treatment Fluoroquinolones “Disrupts bacterial DNA organization” Inhibit one or more of a group of enzymes called topoisomerases, which maintain the supercoiling of the chromosomal DNA within the bacterial cells. The inhibition of these enzymes prevents essential cell processes. The fluoroquinolones are active against a wide variety of bacteria, including both Gram positive and Gram negative. Sulfonamides “Disrupts metabolic pathways” Inhibit the growth of many Gram positive and Gram negative bacteria. They are structurally similar to paraminobenzoic acid (PABA), a substrate in the pathway for folic acid biosynthesis. Because of this similarity, the enzyme that normally binds with PABA preferentially binds with the sulfonamide drugs, resulting in its competitive inhibition. Human cells are not affected by these drugs because they lack this enzyme. Unit 1.2 Antibiotic Treatment Unit 1.2.4.A – When Antibiotics Fail Exposure to an antibiotic naturally selects for the survival of the organisms with the genes for resistance. In this way, a gene for antibiotic resistance may readily spread through an ecosystem of bacteria. Antibiotic-resistance plasmids frequently contain genes conferring resistance to several different antibiotics. What does it mean by select? Unit 1.2 Antibiotic Treatment Antibiotic Resistance It may take the form of a spontaneous or induced genetic mutation, or the acquisition of resistance genes from other bacterial species by horizontal gene transfer via conjugation, transduction, or transformation. Many antibiotic resistance genes reside on transmissible plasmids, facilitating their transfer via conjugation. Unit 1.2 - Antibiotic Treatment Understandings • Antibiotics disrupt the pathways that bacteria use to survive. • Bacterial cells use multiple pathways to gain resistance to antibiotics. • Overuse and misuse of antibiotics promotes the selection of resistant bacteria. Knowledge and Skills It is expected that you will: • Label the structures of a bacterial cell. • Explain the method of action for different classes of antibiotics. • Describe the pathways through which bacterial cells transfer genes. • Explain the importance of taking antibiotics as prescribed. • Use proper laboratory techniques to “mate” a streptomycin resistant strain of E. coli with an ampicillin resistant strain of E. coli. • Simulate the effects of antibiotics on a bacterial population during an infection. • Simulate the effect of a missed dose of antibiotics on a bacterial population during an infection. Unit 1.2 - Antibiotic Treatment Unit 1.2 - Essential Questions 1) How do antibiotics work to fight bacterial infections? 2) What methods do bacteria use to share antibiotic resistant genes? 3) What actions are humans taking that are contributing to bacteria becoming resistant to commonly used antibiotics? Lesson 1.3 - Hearing Loss Lesson 1.3 The Aftermath: Hearing Loss As we continue to follow Sue Smith we learn that she is still dealing with the aftermath of her bacterial meningitis infection. The antibiotics eliminated the infection and Sue made a full recovery Although Sue has not noticed any symptoms of hearing loss, she has scheduled an appointment to have her hearing evaluated due to the high incidence of hearing loss in patients who have recovered from meningitis. In this lesson you will: • Investigate the physics of sound • Learn how hearing works • Conduct a variety of hearing assessments Lesson 1.3 The Aftermath: Hearing Loss Lesson Overview You will be assigned a patient with a specific type of hearing loss. Using the assigned patient case study you will: • Explore how damage to the outer, middle, and/or inner ear results in hearing loss • Learn how to interpret audiograms and match up their patient case study with the corresponding audiogram • Use what you have learned to make a recommendation as to what intervention is the most appropriate for the patient case study • Investigate both sides of the cochlear implant debate Lesson 1.3 The Aftermath: Hearing Loss Hearing loss affects millions of people in the United States Hearing loss can drastically impact a person’s ability to communicate A significant amount of time and money has been invested into research to develop interventions to treat hearing loss Although the degree of hearing loss varies from individual to individual, there are only three types of hearing loss: 1) Sensorineural hearing loss 2) Conductive hearing loss 3) Mixed hearing loss Lesson 1.3 The Aftermath: Hearing Loss Understandings Problems with one or more structures within the ear cause various types of hearing loss. There are a variety of interventions available to help people with hearing loss. Lesson 1.3 The Aftermath: Hearing Loss Knowledge and Skills It is expected that students will: • Identify the structures of the ear and describe their function in hearing. • Describe the pathway of sound vibrations from the time a sound is generated to the time the brain registers the sound. • Recognize that there are bioethical concerns and considerations related to the use of cochlear implant technology. • Demonstrate sensorineural versus conductive hearing loss on a model of the ear. • Perform several simple tests, such as Rinne Test and the Pure Tone Test, to evaluate hearing. • Interpret audiograms to identify different types of hearing loss. • Recommend the most appropriate type of intervention for a patient with hearing loss, given the patient’s audiogram. Lesson 1.3 The Aftermath: Hearing Loss 1.3.1 – Good Vibrations 1.3.2 – Hear Me Now 1.3.3 – Cochlear Implant Debate Lesson 1.3 The Aftermath: Hearing Loss 1.3.1 – Good Vibrations • Labeled structures of ear • The Physics of Sound • Patient case study Lesson 1.3 The Aftermath: Hearing Loss 1.3.2 – Hear Me Now • Rinne Test • Speech-in-Noise Test • Audiogram Analysis Lesson 1.3 The Aftermath: Hearing Loss 1.3.3 – Cochlear Implant Debate • Controversy • Effectiveness Lesson 1.3 The Aftermath: Hearing Loss Essential Questions 1) How do frequency and amplitude affect how humans interpret sound? 2) What causes different types of hearing loss? 3) How is hearing loss diagnosed? 4) What interventions are available for patients with hearing loss? 5) What are the bioethical concerns related to the use of cochlear implant technology?