Diagnostics Services Diagnosis determining the cause of an illness or condition Clinical Laboratory Scientists or Medical Technologists often do the tests Done in hospitals and independent labs often requires specific machines ID: 1036343
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1. Diagnostics and Forensic Science
2. Diagnostics ServicesDiagnosis – determining the cause of an illness or conditionClinical Laboratory Scientists or Medical Technologists often do the testsDone in hospitals and independent labs; often requires specific machinesReference Range – averaging the test results for large population + 2 S.D; helps define what is in “normal” ranges
3. Diagnostic Services CareersBloodUrinalysisCulturingBiopsyRapid Diagnostic TestsHome Medical Test kitsImagingGenetic TestsPathologistsMedical Lab Technologist/TechniciansNuclear Lab TechnologistsPhlebotomists RadiologistsRadiology Technologists
4. Uncertainty of TestingSensitivity – measures how often someone who has the condition tests positiveSpecificity – measures how often someone who does not have the condition test negative
5. ForensicsWhat is forensic medicine?Latin word - forensicsMeans public discussion or debateScience used in justice system for legal purposesFacts based on scientific investigationGoal is to determine facts and truthUses multiple science specialties
6. AutopsiesDefinition and PurposeTo see for oneselfSurgical operation done on a dead bodyTo learn about person’s health and cause of deathLegal RequirementsCoronerMedical examinerPathologist
7. AutopsiesReasons for autopsyDetermine which disease or injury caused deathDiagnosis - confirmation and understandingEvaluate possible public health issuePreparationIf not required by law, permission needed from next of kinLegal consent form
8. AutopsiesProcedureComplete medical history and review of recordsExternal physical examBody tagWeight and heightClothing and valuables identifiedScars, tattoos, injuries, wounds, bruises recordedForeign objects notedPhotos and x-rays taken, if needed
9. AutopsiesComplete internal examDissection of head and abdomenOrgans removed, weighed, measured, and examinedTissue samples examined under microscopeFluid samples tested for drugs, infectionAfter autopsy complete, legal death certificateResultsNatural death – disease or old ageUnnatural death – unnatural, unexpected, or unusual cases
10. AutopsiesMethods to determine time of deathTraditional indicatorsRigor mortis Begins three hours after death in face and eyelid muscles Takes twelve hours to affect entire body Process reverses after 36 hours Lividity (hypostasis) Visible 30-60 minutes after death Red cells settle and skin below turns red In 6-10 hours, color becomes permanent
11. Autopsies Body temperature Falls at rate of one degree per hour Obesity and warm environment slows coolingForensic EntomologyInvolves the life cycle of insects which is predictable None of the above are totally reliable and can be manipulated
12. DNA AnalysisDeoxyribonucleic Acid make of a chain of nucleotides consisting of a deoxyribose sugar, a phosphate (PO4), and a nitrogenous base (A,T,C,or G)Double stranded and helical (twisted) with A’s of one strand pairing with T’s of the other strand; G and C also pair up complementary.3 billion base pairs in human genome and 21,000 genesDNA 95% similar to chimpanzeeDNA sequence highly conserved among different species
13. DNA AnalysisUsed to identify people; uses 13 Short Tandem Repeats (STR) sequences found throughout genomeUsed to identify ancestory and relatednessAlso used to diagnose probability of having a genetic diseaseCan be used to access treatment optionsCan be used for newborn screening
14. DNA TechniquesKaryotyping – technique to look at an organisms chromosomes; allows us to determine chromosomal mutationsPolymerase Chain Reaction – copies DNA molecules in vitroGel Electrophoresis – allows us to cut and and visualize DNA fragments while studying them.Microarrays – allow scientists to study gene expression of 1000s of genes to determine if they are turned on or off at a particular time; good for studying cancer.
15. Forensic AnthropologySkeletal anatomy 206 bones Man = 12 pounds Woman = 10 poundsWhat bones show How person lived Debilitation illnesses (rickets, polio, healed fractures) Right handed or left handed Clues to occupation
16. Forensic AnthropologyQuestions about skeletal remainsAge of person at time of deathSex of person (skull and pelvis)RaceHeight
17. Forensic Odontology1. Characteristics of teeth after death a. No other part lasts longer b. In fires, teeth usually only means to ID remains c. No two people have identical teeth2. Requirements for identification a. Need dental records b. Dentists chart five surfaces of each tooth in a grid (odontogram) c. Can also provide “bite mark” evidence3. Teeth useful in determining subject’s age
18. Forensic ToxicologyInvestigate drugs and poisons in the body (hair, blood, urine, etc)Use Gas Chromatograph/Mass Spectrometer (GC/MS) to analyze the components of samples to identify the drug/poison or its metabolites in the sampleCan determine amount of substance and whether it could have had negative impact on victim resulting in death.Analytical chemist