Week 4 Random Flashcards
Standard stain for blood
Wright or Giemsa stain
Monocytes differentiation
Liver = Kupffer cells
Connective Tissue = Macrophage
Lung = Macrophage
Brain = Microglia
Religion vs. Spirituality
Religion has collective strict approach WHILE Spirituality has individual broad aproach
Cystic Fibrosis
Pleiotropic
Allelic Heterogenity
Affects multiple organs exocrine pancreas, intestine, respiratory tract, male genitalia, hepatobillary system, and exocrine glands.
CFTR mutations: nonsense, block in processing deltaF508 (70%), regulation block, altered conductance, reduced synthesis
Obstruction of lungs, pancreating inefficiency,
Inheritance complicating factors
- allelic heterogeneity (dominant / recessive) – CF, IGHD, Osteogenesis imperfecta
- locus heterogeneity (X-linked / autosomal) – OI, Hemophilia, Charcot-Marie-Tooth disease
reduced-penetrance – Retinoblastoma, Van der Woude Syndrome
variable expressivity – NF1, Marfan, Van der Woude Syndrome
pleiotropy
new mutations - Achrondroplasia
germline mosaicism - NF1, OI, DMD
delayed age of onset - Hunington disease
IGHD
Familial isolated growth deficiency
Mutation in GHI gene csome 17 that encodes pituitary growth hormone
GHI protein acts as a dimer
LOF (recessive) and GOF dominant negative (dominant)
Osteogenesis imperfecta
Clinically heterogeneous disease characterized by brittle bones.
All forms caused by defects in type I collagen.
All forms autosomal dominant, but differ in severity.
Two forms mild (recessive 50% expression) and severe (DN) caused by one mutation in COL1A1 gene on csome 17
Also can be caused by COL1A2 mutations (locus heterogenity)
Type 1 collagen composition
a1(I) collagen (COL1A1 gene, grey)
a2(I) (COL1A2 gene, black)
Rb
Retinoblastoma
Mutation in tumor supressor RB gene
60% sporadic 40% familial
Rb is a “two-hit” process.
Penetrance: 10% of obligate (familial) carriers do not express the disease
NF1
Neurofibromatosis type I
Approximately half of NF1 cases are due to spontaneous new mutations
Most (2/3) have only mild cutaneous involvement.
Marfan
Defect in connective tissue; affects skeletal muscle, eye, and heart.
All affected individuals in one family have the identical mutation
very different manifestation
Rate of allele loss across diseases
DMD 1/3 lost every generation
Achondroplasia 7/8 lost every generation
Tay Sachs all alleles are lost
CF loss is low
OI type II all alleles are lost
3 types of standard stains
- Stains that differentiate between acidic and basic components of the cells
- Specialized stains that differentiate the fibrous components of the extracellular matrix
- Metallic salts that precipitate on tissues, forming metal deposits on them
The most common stain
Hematoxylin and Eosin
Nucleus, rER - blue;
Cytoplasm-varying shades of red;
Collagen-very pale pink;
Cartilage and calcium deposits-dark blue;
Red blood cells-bright red
Classic blood stain
Wright and Giemsa Stains
Erythrocytes, eosinophilic granules- pink
Neutrophilic granules-pink to purple
Basophilic granules-dark blue
Leukocyte nuclei, basophilic granules-purple
Cytoplasm of monocytes and lymphocytes-blue
HPI
OLDCARTS: Onset Location Duration Characteristics Aggravating Factors Relieving Factors Treatment
PMH
MASHI: Medications, surgeries, allergies, hospitalizations, immunizations
Fam Hx
CHADS: Cancer, Heart&Hypertension, Astma, Diabetes, Stroke
Soc Hx
SODAS: Smoking, occuptation, diet&drugs, alcohol, sexual history
ROS
Head to toe
Taking history settings
Introduce yourself
Address patient properly
Eye contact
Respectful to symptoms & pain
Flexible
No assumptions
Comfort for all involved
Removal of physical barriers
Sit dow
Good lighting
Privacy
Noise level
Simple Talk
Simple Notes
No leading questions
Clarify uncertainty
Verify and Summarize
H&P characteristics
Legal Document
Patient’s history and exam
Means of communicating information
HPI (class)
O – onset – “when did it start?”
P - provocation/palliation – “anything make it better or worse?”
Q – quality – “what do you mean by ‘tired’?”
R – radiation – (best for pain) “does the pain radiate anywhere?”
S – severity – “how bad is it on a scale of 1-10…” or “what can you do now vs what could you do before this started?”
T – timing – “when did this start?”
HPI example
Bill is a X yo gentleman/lady who presents with the chief complaint of X for time with PMH of X since X time .
Sensitive Issues
Ensure Privacy
Direct
Act comfortable
Explain why
No preaching
Remain respectful
Clinic introduction
Introduce yourself
Explain who you are
Explain the purpose of the interview/exam
Ask for permission to proceed
My name is X and I am a first year medical student working in the clinic today with X. I will be taking your initial history and doing a physical exam, if that is okay with you.
Sticky ends
Cohesive ends
Electrophoresis probes and medium
probes: Ethidium Bromide, SYBR green
medium: -agarose and polyacrylamide
Vectors (cloning)
Double Stranded circular molecules
Occur naturally in bacterial cells
Self-replicating
Small size advantage
Plasmid vectors
ORI
Multiple Cloning Site
Antibiotic Resistance
Small Size
Screening Marker
2 types of genetic libraries
Genomic DNA library
cDNA library
Hybridization detail
Probes are complementary ssDNA/RNA
Must be single stranded to hybridize
Can be labeled with fluorescent dyes
Very sensitive = can detect 1 molecule per cell
Very selective = difference in 1 base pair
Recombinant DNA Techniques
Restriction Enzymes
DNA cloning
Nucleic acid hybridization
Sequencing of DNA fragments
Genetic engineering
RT-PCR
Quanitification in real time
absolute number of relative to normalized genes
Methods:
(1) Fluoresence dye that interacalate with dsDNA
(2) Fluoresent problem when hybridized
Mapping two types
Genetic (linkage), markers used SNP, SSLP, RFLP
Physical (DNA): restriction mapping, FISH, STS (unique sequences)
Analyzing region
DNA Probe
PCR Primers
Requirements for mammalian cell expression
cells: HeLa, HEK, 3T3
Mammalian promoter must be present in the plasmid
Antibiotic selection
Regulated gene expreesion
Tet repressor protein and inducer tetracycline
Transgenic mouse
- Embryonic Stem cell technology (homologous recombination) - Cre recombinase
* including IRES
- Pronucleus micro-injection
Describe the term genetic engineering.
manipulation of DNA sequences and re-introduction into viable organisms
recombinant DNA
DNA molecules that are generated by splicing together 2 or more fragments
Application of Southern and Norther blot
Identify the presence of a product
Determine the size
Detect the abundance
Map the positon of introns and exons and stop and start sites of transcription
Detect SNPs
Application of Microarrays
Study thousands genes at the same time
Determine gene expression
Determine expression patterns
Diagnostic and screening tool
Tumor classification, risk assestment, prognosis, drug development, monitoring
Application of PCR
Carrier screening
Prenatal diagnostic testing
Newborn Screening
Forensic/identity testing
Why allelic heterogeneity is important in cystic fibrosis?
One allele might cause pancrease to be sufficient, while another not (affect median age).
If no mutation is detected in a patient, does it mean that the patient is not affected?
Not, 2% of alleles are unknown.
70% are dF508 and 28% account for 96 mutations
What is important IGHD in terms of allelic heterogenity?
It can be both recessive (haplosufficient) and domiant (DN).
What is important about OI in terms of allelic heterogeneity?
Both forms are dominant but differ in severity
Type I = Reduce the alpha1 production (by 50%), and some alpha2 are degraded (Haploinsuficient)
Type II = All alpha2 that bind to alpha1 mutant are degraded
What is important about Hemophila in terms of locus heterogenity?
Two types of hemophila are due to the mutation in factor VIII and XI - type A and B.
What is important about congenital deafness in terms of locus heterogenity?
autosomal recessive = congenital deafness
Two individuals that are affected might produce health children.
What is important about Dwarfism (achondroplasmia vs. diastrophic dwarfism) in terms of locus heterogeneity?
Achondroplasia is autosomal dominant and nearly all (7/8 cases are sporadic).
Diastrophic dwarfism is autosomal recessive.
What is important about reinoblastoma in terms of non-penetrance?
An autosomal dominant disease where penetrance is 90%
10% of obligate carriers do not express the disease
* 60% are sporadic and 40% are familial
Penetrance
All or none phenomenon; refers to the frequency of expression of a dominant disorder in an obligate heterozygote
Defined quantitatively as the proportion of obligate heterozygotes that express the disease (determined empirically from population data).
Variable expressivity
Penetrance is complete
But the severity is variable
Individuals with mild forms of the disease may not be diagnosed. Mildly affected parent can have a severely affected child.
What is important about neurofibromatosis in terms of variable epxressivity?
Some cases might be mild and go unnoticed.
Children of mildly affected parents might severe effects.
2/3 of cases have mild effects.
What is important about Marfan Syndrom in terms of variable expressivity?
All individuals have one identical mutation.
However, the manifestation of the disease is very different.
Disease with both penetrance and variable expressivity
Van der Woude Syndrome
Disease associated with both Variable expressivity and penetrance
Van der Woude Synrome
(Cleft lip/palate)
Which disease are example of germline mosaicism?
DMD, NF1, and O1
Which disease is associated with nearly all new mutations?
Achondroplasia
O1 type II (possible germline mosaicism)
Germline mosaicism
The risk is elevated
