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What cell type is visible with Vimentin stain?

Connective tissue

What cell type is visible with Desmin?

Muscle

What cell type is visible with cytokeratin?

Epithelial cells

What cell type is visible with GFAP?

Neuroglia

What cell type is visible with neurofilaments?

Neurons

During the cycle of the Na+/K+ exchanger, what is the status of the pump?

Phosphorylated

What drug inhibits the Sodium pump by binding to the K+ site?

Ouabain

What drugs directly inhibit the Na+/K+ ATPase?

Cardiac glycosides (digoxin, digitoxin)

What result does inhibition of Na+/K+ pump have on Na+/Ca2+ exchange?

Makes it less favorable, so more intracellular calcium, so better contractility

What is the most abundant protein in the human body?

Collagen

What structures does type I collagen make?

Bone, skin, tendon

What disease is caused by defective type I collagen?

Osteogenesis Imperfecta

What structures does type II collagen make?

Cartilage

What structures does type III collaged make?

Vascular stuff, skin, uterus

What is the name for defective type III collagen synthesis?

Ehler-Danlos syndrome

What structures does type IV collagen make?

Basement membrane

What disease is caused by defective type IV collagen production?

Alport syndrome

Where is preprocollagen synthesized?

Rough ER

What type of collagen chains make up preprocollagen?

α chains

What is the pattern of collagen polypeptide?

Gly - X - Y

What are X and Y, usually?

Proline, lysine

What posttranslational modification takes place on collagen in the ER?

Hydroxylation of proline and lysine residues

What cofactor is required for hydroxylation of proline and lysine?

Vitamin C

What other posttranslational modification takes place in the ER?

Glycosylation

What residue is glycosylated?

Hydroxylysine on the pro-α-chain

After glycosylation, procollagen forms. What is the structure of procollagen?

triple helix of 3 α chains

How are the 3 helices held together?

Hydrogen and disulfide bonds

What never forms in osteogenesis imperfecta?

Procollagen

After hydroxylation and glycosylation, what happens to procollagen?

Exocytosis into extracellular space

Once in the extracellular space, what happens to procollagen?

Cleavage of terminal regions (trimming) to form insoluble tropocollagen

Staggered tropocollagen molecules are bound together by bonds between what residues?

Lysine-hydroxylysine

What enzyme catalyzes this reaction?

Lysyl oxidase

What is the end-product of these links?

Collagen fibrils

What is the mode of inheritance of Osteogenesis Imperfecta?

Autosomal Dominant

What is the most commonly defective type of collagen in Osteogenesis Imperfecta?

Type I

Name 4 presenting symptoms of osteogenesis imperfecta

Fractures
Blue sclera
Hearing loss
Dental imperfections (due to lack of dentin)

Type II of osteogenesis has what kind of prognosis?

Usually fatal in utero

A defect in type III collagen causes what 3 symptoms?

Hyperextensible skin
Tendency to bleed
Hypermobile joints

What is the name for this condition?

Ehlers-Danlos

What 3 conditions are associated with Ehlers-Danlos syndrome?

Joint dislocation
Berry aneurysm
Organ rupture

An abnormality of type IV collagen results in what defective structure?

Basement membrane

Abnormalities in the basement membrane causes what symptoms? (3)

Hereditary nephritis
Deafness
Ocular disturbances (sometimes)

What is the name for this condition?

Alport syndrome

What is the mode of inheritance for Alport syndrome?

X-linked recessive

Where is Elastin found?

Lungs
Large arteries
Ligaments
Vocal cords

What two amino acid residues are very common in elastin?

Proline and Glycine

A defect in fibrillin causes what syndrome?

Marfan's

What two conditions can occur as a result in α-1 antitrypsin?

Emphysema
Cirrhosis

What does a Southwestern Blot identify?

DNA-binding proteins

Give an example of codominance

Blood types (A, B, AB)

Give an example of variable expression

2 patients with NF2 have different levels of severity

Give an example of incomplete penetrance

2 people with the gene for a specific disease, only one has symptoms

Give an example of pleiotropy

PKU causes a spectrum of varying symptoms

Give an example of imprinting

Prader-Willi and Angelman's syndrome (depends which parent gives the disease)

Give an example of loss of heterozygosity

Mutation in tumor suppressor gene, complementary allele must be deleted before cancer develops

Give an example of a dominant negative mutation

Nonfunction protein formed by mutation also keeps normal protein from binding

Give an example of locus heterogeneity

Marfan's, MEN2B, homocystinuria, all cause marfinoid habitus.

Define heteroplasmy

Both normal and mutated mtDNA are present, so variable expression in mitochondrial diseases

Define uniparental disomy

Offspring receives 2 copies of a chromosoem from one parent, none from the other

Give the 2 Hardy-Weinberg equations

p squared + 2pq + q squared = 1, and p+q = 1

Hardy-Weinberg theory assumes what 4 things?

1. No mutation at locus
2. No selection for any genotypes at locus
3. No migration
4. Completely random mating

Explain imprinting

One allele is defective, but the other "backup" allele is deleted, so the defect becomes clinically significant

Name a syndrome caused by a deleted paternal allele. Describe the symptoms.

Prader-Willi
Retardation
Hyperphagia
Obesity
Hypogonadism
Hypotonia

Name a syndrome caused by a deleted maternal allele. Describe the symptoms.

Angelmann's syndrome
Retardation
Seizures
Ataxia
inappropriate laughter

In an autosomal recessive disease, what percent of offspring from 2 carrier parents are affected?

25%

In an x-linked recessive disease, what is the likelihood of a son of a heterozygous mother being affected?

50%

Is male-to-male transmission ever seen in x-linked recessive disorders?

Nope

Who can be affected by an x-linked dominant disorder?

Either male or female offspring of mother
ALL female offspring of affected father

Mitochondrial inheritance - who can be affected?

All offspring of affected mothers

Give 3 examples of a mitochondrial linked disorder. What are its symptoms?

Leber's hereditary optic neuropathy (acute loss of central vision)
Myoclonic epilepsy
Mitochondrial encephalopathy

ALL show "ragged red fibers"

Achondroplasia - what factor is defective?

Fibroblast growth factor receptor 3

What is achondroplasia associated with?

Advanced paternal age

ADPKD - unilateral? Bilateral?

ALWAYS bilateral.

ADPKD - Symptoms?

Flank pain
Hematuria
Hypertension
Progressive renal failure

Mutation responsible for ADPKD?

PKD1 on Chromosome 16

ADPKD associations?

Polycystic liver
Berry aneurysms
Mitral valve prolapse

Familial Ademoatous Polyposis - presentation?

Colon covered with adenomatous polyps AFTER PUBERTY.

Mutation responsible for FAP?

Chromosome 5 - APC gene

Pathogenesis of Familial Hypercholesterolemia (IIA)?

Absent or defective LDL receptor

What are the blood cholesterol levels of a heterozygote with Familial Hypercholesterolemia? How about a homozygote?

300 or so
700 or so

Describe the tetrad of symptoms in Osler-Weber-Rendu syndrome (hereditary hemorrhagic telangiectasia)

1. Telangiectasia
2. Recurrent epistaxis
3. Skin discolorations
4. Arteriovenous malformations

What condition is caused by a defect in erythrocyte structural proteins?

Hereditary spherocytosis

What are the names of those proteins?

Spectrin, ankyrin

What are the symptoms of hereditary spherocytosis?

Hemolytic anemia
Increased MCHC

What is the cure for hereditary spherocytosis?

Splenectomy

What two neurotransmitters are decreased in Huntington's disease?

GABA and ACh

What is the trinucleotide repeat in Huntington's disease?

CAG

What chromosome is the Huntington gene located on?

4

What pathologic change occurs in Marfan's syndrome to the aorta?

Cystic medial necrosis

What heart abnormality is found in Marfan's syndrome?

Floppy mitral valve

What ocular defect is found in Marfan's syndrome?

Subluxation of lenses

MEN 2A and 2B are associated with what gene?

the ret gene

Name the 3 findings in neurofibromatosis type I

Cafe' au lait spots
Neural tumors
Lisch nodules

Give the name for Neurofibromatosis type I

von Recklinghausen's disease

What are two other possible symptoms found in Von Recklinghausens' disease?

Scoliosis
Optic pathway gliomas

What chromosome is the locus for the Von Recklinghausen gene?

17 (long arm)

What chromosome is the locus for the Neurofibromatosis type II gene (NF2)?

Chromosome 22

What are the two symptoms of NF2?

Bilateral acoustic schwannomas
Juvenile cataracts

What are the dermatologic symptoms of Tuberous Sclerosis?

Anedoma Sebaceum
"Ash Leaf Spots" on skin (white)

What are the ocular/neurologic symptoms of Tuberous Sclerosis?

Cortical and retinal hamartomas
Seizures
Mental Retardation
Astrocytomas

What are the renal symptoms of Tuberous Sclerosis?

Renal cysts
Renal angiomyolipomas

What are the cardiac symptoms of Tuberous Sclerosis?

Rhabdomyomas

In von Hippel Lindau disease, where are hemangioblastomas usually found?

Retina/cerebellum/medulla

Half of the individuals who have von Hippel-Lindau disease develop carcinomas where?

Kidneys, bilaterally

What gene is deleted in Von Hippel Lindau disease? What is its function?

VHL gene
Tumor suppressor

What chromosome holds the locus for the VHL gene?

3p

Deletion of the VHL gene causes what?

Constitutive expression of HIF (transcription factor)
Activation of angiogenic growth factors

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