Disease occurrence and spread
Where and when
Epidemiology
The underlying cause
- infectious, idiopathic, iatrogenic
Etiology
Formal name to describe a pt’s disease
Diagnosis
Made based on signs, symptoms and results of diagnostic tests
Diagnosis
Unknown cause or source
Idiopathic
Source of disease is medical professional or procedure
Iatrogenic
Infectious disease that is acquired from a hospital-type setting
Nosocomial
Referring to the disease process
Pathogenesis
The study of disease, especially changes in cells/tissues/organs that cause or are caused by disease
Pathology
Something that you measure
Sign
Something the patient tells you
Symptom
Bridges basic sciences and medicine
Pathology
Etiological factors from the outside
Extrinsic
Examples of extrinsic etiological factors
Biological
Chemical
Physical
Nutritional
Etiological factors that come from within
Intrinsic factors
Examples of intrinsic etiological factors
Genetic
Congenital
Immunological
Psychological
Rapid onset and short duration
- no necessarily severe
Acute
Disease that is lasting for >/= 3 months
Chronic
Ill defined time between acute and chronic
Subacute
How many diseases can be cured?
7 out of 10
List in order the leading causes of death in Americans
Heart disease Cancer Stroke Type 2 DM Obesity
What are the 4 phases of disease
Latency
Prodrome
Clinical symptoms
Recovery
What is the latency period
Quiet phase
- no/few signs/symptoms
What is prodrome
Symptoms start
- usually ‘flu-like’ are most common
What are different outcomes of disease
Death
Recovery
- complete or incomplete recovery
Deaths per 100,00
Mortality
Illnesses per 100,000
Morbidity
And abrupt and unexpected increase in the incidence of disease over endemic rates
Epidemic
Has a relatively stable and expected incidence and prevalence within a geographic area
Endemic disease
Spread of disease beyond continental boundaries
Pandemic
Looks at new or newly diagnosed cases
Incidence
Looks at all current cases alive
Prevalence
Transmission to surrounding people/strangers
Horizontal
Transmission to fetus or to baby through breast milk
Vertical
What happens to incidence and prevalence if:
-new effective treatment ins initiated
Prevalence dec
Incidence constant
What happens to incidence and prevalence if:
- new effective vaccine gains widespread used
Both incidence and prevalence dec
What happens to incidence and prevalence if:
- number of deaths from the condition decline
Prevalence inc
Incidence constant
What happens to incidence and prevalence if:
- recovery is more rapid than it was 1 year ago
Prevalence dec
Incidence constant
Collects data from a population to assess frequency of disease at a particular point in time
Cross sectional study
Study referring to “what’s happening”
Cross-sectional study
Study that measures disease prevalence
Cross-sectional study
Compares a group of people with disease to a group without disease
- looks for prior exposure or risk factor
Case-control study
Refers to “what happened”
- from effect to cause
Case-control study
Study that measures odds ratio
- starts with disease
Case-control study
Compares a group with a given exposure or risk factor to a group without such exposure
- looks to see if exposure affects the likelihood of disease
Cohort study
Refers to “who gets it”
- from cause to effect
Cohort study
Study that measures relative risk
- starts with exposure
Cohort study
Common measurements about the disease
Sensitivity or specificity
Common measurements about the test
Positive predictive value and negative predictive value
True positive rate
Sensitivity
True negative rate
Specificity
Likelihood that a positive test is found only in sick people
- true and false POSITIVES
Positive predictive value (PPV)
Likelihood that a negative test is found only in non-sick people
- true and false NEGATIVE
Negative predictive value (NPV)
Formula for sensitivity
TP/(TP+FN)
Formula for specificity
TN/(TN+FP)
Formula for positive predictive value
TP/(TP+FP)
Formula for negative predictive value
TN/(TN+FN)
High prevalence does what to positive predictive value
Improves
Low prevalence does what to positive predictive value
Harms
Likelihood a sick person will test positive
Sensitivity
Likelihood a positive test identifies a sick person
Positive predictive value
What is the percentage of a normal population that is included in 1SD
68%
What is the percentage of a normal population that is included in 2SD
95%
3 things that affect normal reference ranges
Age
Geographical location
Gender
What happens at a higher altitude
Lower oxygen
Higher RBC
What must be low to be anemic
Hemoglobin AND hematocrit
Normal fasting blood glucose (FBG) levels
60-100 mg/dL
FBGL threshold
126 mg/dL
HbA1c level indicating diabetes
> /= 6.5%
Normal HbA1c value
<5.7%
Gold standard for diagnosing diabetes
HbA1c of >/= 6.5%
Reflects 2-3 month glucose average
HbA1c
Found only 2 hours after meal
Fasting blood glucose level
Liver tests dealing with INJURY/DAMAGE
ALT and AST
Liver test dealing with FUNCTION
Bilirubin
What levels are affected if there is a loss of liver function
HIGH bilirubin
What comes first, liver damage or loss of liver function
Liver damage
What levels help estimate GFR
BUN and creatinine
Dialysis or transplant when at this level
GFR <15
See nephrologist is GFR is at what level
<30
Most specific biomarker for heart
Troponin
Which cholesterol is the good one
HDL-C
Which cholesterol is the bad one
LDL-C
Goal for total cholesterol
<200
Goal of HDL-C
> 40
Goal for LDL-C
<100
Goal for triglycerides
<150
Transports cholesterol to liver
HDL-C
Deposits cholesterol into vascular walls
LDL-C
Which metabolic panel looks at liver function, CMP or BMP
CMP
Which metabolic panel measures cardiac function, BMP or CMP
Neither
3 most common lab tests
CMP
CDC
Urinalysis
Levels of HGB and HCT in anemia
BOTH will be low
What level is checked to determine the type of anemia
MCV (size of RBC)
the primary indicators of inflammation
ESR and CRP
High ESR suggests
Inflammation
Vitamin K dependent factors
2, 7, 9 and 10
Which is ULTRA vit K dependent
7
Vitamin K antagonist
Coumadin
Coumadin hits what factor mainly
7
Coumadin is monitored with
PT/INR
PT/INR measures which pathway
Tissue factor pathway
Extrinsic path
Antithrombin activator
Heparin
Targets 10 mainly and also 2
Heparin
Heparin is monitored with
aPTT
aPTT measures which path
Contact factor pathway
Intrinsic path
Most common serious bleeding disorder
Hemophilia A
Absence of factor 8
Hemophilia A
Hemophilia A is monitored by
aPTT
Neutrophilia may suggest
Bacterial source
Lymphocytosis may suggest
Viral source
Eosinophilia suggests
Allergies or worms
How are the values of hematocrit and hemoglobin related
HGB x 3 = hematocrit
Is RBC low in anemia? HGM and HCT?
Not always
HGM and HCT are always low
HGB levels in women
<12 g/dL
HGB levels in men
<13.5 g/dL
If 7 g/dL or less, what needs to be done
Transfusion
When transfusing, how do you determine how many units of blood to give
Enough to reach 10 g/dL
MCV value in microcytic anemia
<80
MCV value in normocytic anemia
80-100
MCV value in macrocytic anemia
> 110
Iron deficiency anemia
Microcytic anemia
Recent blood loss or renal failure are related to which anemia
Normocytic anemia
Vit B12 deficiency or Folic acid deficiency are related to which anemia
Macrocytic anemia
Which anemia will have low RBC
Normocytic and macrocytic anemia
Which anemia will have normal to high RBC
Microcytic anemia
Most common cause of anemia
Iron deficiency
Most common screening test for syphilis
RPR
Is RPR specific and sensitive for syphilis
Sensitive but not specific
What tests confirm syphilis
FTA-ABS or MHA-TP
Can syphilis be seen on a gram stain
No
How is lupus confirmed
Anti-dsDNA and anti-Sm
How are autoimmune conditions screened
ANA
Best indicator for UTI
Leukocyte esterase
What will also likely be seen in UTI
Blood, protein and nitrite
Least valuable test for imaging soft tissue
X-ray
Penetrate soft tissue but not dense tissue
X-ray
Multiple angle X-ray
- can image soft tissue
CT scan
Uses magnetic fields/radio waves
- image areas where soft and tissues meet
MRI
Uses sound waves to image various tissues
Ultrasound
Uses radioactive material to produce image
Nuclear scan
Indicates current or recent infection (acute)
IgM
Indicated past infection (convalescent)
IgG
Indicates allergy
IgE
Antibody found in tears, sweat and breast milk
IgA
2 test used to SCREEN for syphilis
RPR and VDRL
When do providers become concerned with fatigue
When it becomes persistent
When do providers tend to become concerned with weight loss
When the loss is unexplained/unintentional
Top 2 proinflammatory cytokines
IL-1 and TNF-alpha
Threshold for a high temperature in the morning
99 degree
Threshold for a high temperature in the evening
100 degrees
Low grade fever in kids and adults
= 101 degrees
Moderate fever in kids and adults
102
High grade fever in kids and adults
> /= 103 degrees
High grade fever in newborns
99 degrees
3 criteria for defining fever of unknown origin
- illness of at least 3 weeks
- temperature > 101 on several occasions
- failure to diagnosis after 3 visits
Top 3 causes of fever of unknown origin
Infection
Neoplasms
Autoimmune disorders
Most common cause of FUO
Infection
Headache warning signs indicating a serious etiology
- Visual loss
- disequilibrium
- confusion/lethargy
- new onset seizure
Headache typically affecting young women
Migraine
Headache typically affecting all ages and both genders
Tension
Headache typically affecting middle aged men
Cluster
Headache typically affecting patients over 60
Temporal arteritis/giant cell arteritis
HA lasting 4-72 hours, throbbing, unilateral and aggravated by physical activity and light
Migraine
HA late in the day, may precede a migraine, and has a BAND LIKE DISTRIBUTION
Tension
HA that wakes people up, last less than an hour 1-2 times a day, in smoker/drinkers, orbital or temporal
Cluster
“Killer HA”
Cluster
HA presents with red eyes and or nasal stuffiness
Cluster
HA may cause transient or permanent ipsilateral horner’s syndrome
Cluster
Horner’s syndrome
Ptosis, miosis (small pupil), and anhydrosis
If GCA (giant cell arteritis) is suspected, therapy with what should be immediately initiated
Prednisone (steroid)
Acronym for stroke victims
FAST
For stroke: f stands for
Face paralyzed?
For stroke: A stands for
Arms - can they be held out
For stroke: S stands for
Speech slurred?
For stroke: T stands for
Time is critical - get to hospital quickly
4 mechanisms of cell injury
- free radical formation
- hypoxia and ATP depletion (<5-10% normal ATP levels)
- disruption of intracellular Ca homeostasis
- membrane damage
How is free radical injury a key to multiple diabetes-related complications
Oxidative modification of proteins
- forming protein-protein cross linkages
How does free radical injury cause a BP disruption
Damage nuclei acid
5 mechanisms that can cause membrane damage
- inc cytosolic Ca
- loss of membrane phospholipids
- cytoskeleton damage
- reactive oxygen species
- lipid breakdown products
Indicator of significant body damage
Lactic acid
Fat soluble vitamins
D
A
K
E
Most toxic fat soluble vitamin
A
- polar bear liver
Smaller cell size
Atrophy
Bigger cell size
Hypertrophy
Increase in number of cells
Hyperplasia
Change in cell TYPE
- One mature cell type is replaced by another mature cell type
Metaplasia
Abnormal cell growth that vary in size, shape and organization
Dysphasia
Atrophy is most often due to
Lack of use
Aging
Pressure
Lack of blood
Physiological example of hypertrophy
- Bodybuilder
- breasts in prego ladies
Pathological example of hypertrophy
Hypertension or faulty valves in heart
Caused by increased functional demand or specific hormonal stimulation
Hypertrophy
Physiology example of hyperplasia
Uterine and breast growth during pregnancy
Pathologic example of hyperplasia
Benign prostatic hyperplasia
Metaplasia is common in who
Smokers
Precursor of cancer
Dypslasia
tests to test liver FUNCTION
Bilirubin, PT/INR, fibrinogen, and albumin
Liver inflammation
Hepatitis
Bilirubin levels in hepatitis
Increased
What is often seen in all body tissues due to hepatitis
Jaundice
Hepatitis can be induced by
Acetaminophen
Wilson’s disease
Copper deposits in descemets mem
Key sign in Wilson’s disease
Kayser-fleischer rings
How to treat Wilson’s disease
Zinc
What happens to protein production in hepatitis
It STOPS
Prolonged infection of silver salts
- blue discoloration
Argyria
Intracellular accumulations of normal substances in abnormal amounts
Endogenous products
Is bilirubin accumulation endo or exogenous
Endogenous
Is silver accumulation endo or exogenous
Exogenous
Intracellular accumulations of environmental agents and pigments
Exogenous products
Messy lysis of dead cells
Necrosis
Programmed cell death
Apoptosis
Which has inflammation, necrosis or apoptosis
Necrosis
Is there membrane damage in necrosis
Yes
What happens to cell and organelles in necrosis
They swell
What happens to the cell in apoptosis
It shrinks
If there are high protein levels in fluid
Exudates
If there are low protein levels in fluid
Transudate
Cloudy/pus
Exudates
Clear fluid
Transudate
Cells in acute inflammation
Neutrophils
Cells in chronic inflammation
Lymphocytes and macrophages
Sign of chronic inflammation
Granulomas
- macrophages and dead material surrounded by a rim of lymphocytes
Produced when inflamed vessels leak fluid and cells
Exudates
Produced when fluid is pushed through capillary due to high pressure
Transudate
Biological clock is associated with what structure
Telomere shortening
Cellular mechanisms of aging
- cross-linked DNA and proteins
- accumulation of toxic byproducts
- aging genes
- loss of repairing
- telomere shortening
Process of deterioration with age
- los of cells power of division and growth
Senescence
Werner’s syn
Pangeria
Premature aging after puberty with short stature
- Benjamin button
Pangeria