bme 301 lecture three. review of lecture two developing countries leading causes of mortality: ages...
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BME 301
Lecture Three
Review of Lecture Two
Developing countries Leading causes of mortality: ages
15-44 Developing world
1. HIV/AIDS2. Road Accidents3. Interpersonal violence
Developed world1. Road accidents2. Self-inflicted injuries3. Interpersonal violence
Overview of Lecture 3 What are the major health problems
worldwide? Leading causes of mortality by age
Developed world Developing world
Global health challenges
Leading Causes of Mortality Ages 45-60
Developing World1. Heart Disease - ARF2. Cerebrovascular Disease3. Tuberculosis
Developed World1. Heart Disease – IHD2. Respiratory Cancers3. Cerebrovascular Disease
Epidemiology: ARF United States
1940: mortality was 20.6/100,000 population
1982: mortality was 2.2/100,000 population Occasionally outbreaks in localized areas of
US (Salt Lake City, Pittsburgh in the 1980s) Developing countries
Still a significant health problem 15-20 million new cases a year
Risk factors Low standard of living Crowding
ARF – Clinical Course Begins with group A strep infection
“strep throat” resolves (NOT SERIOUS) Small group (3%) of propel go on to
develop rheumatic fever (CAN BE VERY SERIOUS)
Cause not fully understood Heightened immunologic reactivity to
streptococcal antigens; makes antibodies that are cross-reactive to human tissue antigens
Individual develops autoimmune reaction induced by strep infection
ARF – Clinical Course Initial attack
1-5 weeks after strep throat infection
Migratory polyarthritis and fever
One joint after another becomes painful and swollen for a few days and then gets better
Carditis – inflammation of lining of the heart, can induce heart arrythmias. Usually heals
Prognosis for first attack is usually quite good, 1% die
ARF – Clinical Course
Subsequent attacks Increased vulnerability to reactivation of
disease with subsequent strep infections Same symptoms with each attack Carditis worsens with each attack Heart valves are frequently deformed
(mitral) Hear failure develops after decades
Long Term Consequences: ARF
Healing of rheumatic valvitis can lead to valvular stenosis
Heart pumps against a closed valve with stenosis and/or regurgitation
heart pumps against an open valve with regurgitation Can lead to heart failure Can lead to death
My Uncle Gene
Treatment: ARF
Treat first strep throat infection with penicillin
Treat other manifestations symptomatically
Prophylactic long term anti-strep therapy given to anyone who has had RF
Ischemic Heart Disease: Epidemiology
United States 11 million people have coronary artery disease Causes more deaths, disability and economic
cost than any other illness Risk factors
Positive family history Diabetes Hyperlipidemia Hypertension Smoking
Ischemic Heart Disease: Pathogenesis
Atherosclerosis Causes a decrease in myocardial perfusion
Stable angina Typically a 50-60 yo man or 65-75 yo woman Heaviness, pressure, squeezing, smothering or
choking Localized to chest Lasts 1-5 minutes Radiates to left shoulder and both arms
Unstable angina Patients with angina that is:
New onset and severe and frequent Accelerating Angina at rest
Ischemic Heart Disease: Diagnosis
Usually made by history Physical exam may reveal other
disorders Lipid disorders Hypertension Diabetes
Testing EKG Stress Testing Coronary arteriography
http://www.columbiasurgery.org/divisions/cardiac/images/novartis_207B.jpg
Ischemic Heart Disease: Treatment
Medical management Nitrates
Increase myocardial oxygen supply, systemic vasodilation
Beta blockers Inhibit increases in heart rate and contractility Decrease myocardial oxygen demand
Calcium channel agonists Coronary vasodilators
CABG PTCA
CABG PTCA
Cerebrovascular Disease: Epidemiology
Third leading cause of death in the US
Most prevalent neurologic disorder Morbidity Mortality
Cerebrovascular Disease: Stroke
Abrupt onset with focal neurologic deficit Usually mini-event or warning signs
5-20% transient ischemic attacks Reversible ischemia
Some lasting 24-72 hours Completed stroke
Maximal deficit within hours Often patient awakens with completed stroke Usually preceded by TIA Progressive stroke Ischemia worsens min. to min. or hour to hour
Cerebrovascular Disease: Pathogenesis
Causes of stroke: Blood vessel supplying the brain is
blocked Thrombosis (clot in vessel) Embolism (clot breaks off and lodges in
blood vessel in brain) Vasoconstriction or spasm Venous collapse
Cerebrovascular Disease: Diagnosis
History Exam Imaging
CT Scan MRI CT/MR Angiography
Cerebrovascular Disease: Treatment
Thrombolysis Rehabilitation Experimental
Angioplasty Heparin Coumarin Aspirin
Lung Cancer: Epidemiology
United States 99,000 males die per year 78,000 females die per year Five year survival: 14% Only 15% of patients are diagnosed with
localized disease Risk factors
Smoking Actively: increases relative risk 13X Passively: increases relative risk 1.5X
Lung Cancer: Clinical Manifestations
Signs and symptoms Coughing, wheezing, difficulty breathing,
recurrent pneumonia Diagnosis:
Screening: Trials of CXR, sputum cytology, NOT SUCCESSFUL
Diagnostic: CXR CT directed biopsy Bronchoscopically directed biopsy
Staging: concept of localized vs. distant disease
Lung Cancer: Treatment
Localized Small: Possibly surgery Large: Chemo or XRT + surgery
Metastatic: Chemo + XRT
Tuberculosis: Epidemiology
Reported cases: 3.8 million new cases per year reported to
WHO 90% occur in developing world Probably underreported
Likely 9 million new cases per year 3 million deaths per year (98%) in developing
world
Tuberculosis: Pathogenesis
Bacterial infection of the lungs Drug susceptible TB is curable If untreated, results in death in 5 years
in half of all cases
Tuberculosis: Clinical Manifestations
Primary disease Results from initial infection Usually occurs in children Lesion in lower or middle lungs Heals spontaneously, may leave calicified
scar Secondary disease
Endogenous reactivation of latent infection May involve massive amounts of lung
1/3 of patients: cavity formation liquefied necrosis spills into airway pneumonia
2/3 of patients: spontaneous remission chronic, progressively debilitating course ‘consumption’
Tuberculosis: Clinical Manifestations
Symptoms Fever Night sweats Weight loss Weakness Coughs (productive with bloody sputum)
Tuberculosis: Diagnosis CXR
Shows nodules Sputum culture
Tuberculosis: Treatment
Chemotherapy with streptomycin Four new drugs available for oral
therapy NPR Story: TB and AIDS
http://www.npr.org/rundowns/segment.php?wfId=1520699
Global Health Challenges
$200 million medical research initiative Grand challenges in global health Bill and Melinda Gates Foundation Encourage scientific and technological
solutions to diseases that disproportionately affect the developing world
Announced in January 2003
What is a grand challenge? Scientific or technical innovation that:
Removes a critical barrier to solving an important health problem in developing world
High likelihood of global impact and feasibility Different than:
Simple statement of a “big problem” in global health
HIV/AIDS, malnutrition, lack of access to medical care, lack of resources
Meant to: Direct investigators to specific breakthrough
that provides solution to a significant health problem(s)
Call for Grand Challenges
Call For Ideas I (May 2003) 1048 submissions from scientists and
institutions in 75 countries Scientific Board heard proposals
(August 2003) Problem Roadblock (obstacle to progress) Challenge List of potential benefits
Goals and Grand Challenges Seven Long Range Goals 14 Grand Challenges Heavily oriented toward infectious
disease Infectious diseases account for the most
profound discrepancies between advanced and developing economies
Causes of infectious diseases are well-known Can more easily formulate technical and
scientific obstacles to progress Results reported in Science (Oct 17,
2003)
Goals and Grand Challenges Improve childhood vaccines
GC1-Create effective, single dose vaccines that can be used soon after birth
GC2-Prepare vaccines that do not require refrigeration
GC3-Develop needle-free delivery systems for vaccines
Create new vaccines GC4-Devise reliable tests in model systems to
evaluate live attenuated vaccines GC5-Solve how to design antigens for effective
protective immunity GC6-Learn which immunological responses
provide protective immunity
Goals and Grand Challenges Control insects that transmit infectious disease
GC7-Develop a genetic strategy to deplete or incapacitate a disease-transmitting insect population
GC8-Develop a chemical strategy to deplete or incapacitate a disease-transmitting insect population
Improve nutrition to promote health GC9-Create a full range of optimal bioavailable
nutrients in a single staple plant species Improve drug treatment of infectious disease
GC10-Discover drugs and delivery systems that minimize the likelihood of drug-resistant organisms
Goals and Grand Challenges Cure latent and chronic infections
GC11-Create therapies that can cure latent infections
GC12-Create immunologic methods that can cure chronic infections
Measure disease and health status accurately in economically in poor countries GC13-Develop technologies that permit
quantitative assessment of population health status
GC14-Develop technologies that allow assessment of individuals for multiple conditions or pathogens at point-of-care
Next Steps
NIH issues request for proposals to address challenges Grants of up to $20M over five years of
less Due June 2004 Awards in October 2004
Summary of Lecture Three
Leading causes of mortality: ages 45-60
Developing World1. Heart Disease - ARF2. Cerebrovascular Disease3. Tuberculosis
Developed World1. Heart Disease – IHD2. Respiratory Cancers3. Cerebrovascular Disease
Global health challenges
Assignments Due Next Time
WA2 Poll on Global Attitudes