Things I just can't seem to remember for STEP 1 Flashcards
What structures form the Hesselbach’s triangle
- Inferior epigastric artery
- Inguinal ligament
Lateral border of rectus abdomens - Direct inguinal hernias
Medial inferior gastric artery
Amino acids necessary for Purine
“GAG”
Glycine
Aspartate
Glutamine
Enzyme that converts ribonucleotides to deoxyribonucleotides
Ribonucleotide reductase
What is the rate limiting step of Pyrimidine base produciton
Carbamoyl Phosphate synthetase II
requires 2ATP molecules
What is the rate limiting enzyme of purine synthesis
Glutamine phosphoribosylpyrophosphate (PRPP) amidotransferase
DNA Polymerase in prokaryotes and their function
DNA polymerase III: leading and lagging strand elongation
(5’–>3’)
- exonuclease activity proof reads (3’-5’)
DNA polymerase I: excises RNA primer and replaces it with DNA
-excises RNA primer in a 5’-3’
DNA polymerases in Eukaryotes and their functions
DNA polymerase alpha: puts down RNA primer and makes okazaki fragments on lagging strand
DNA polymerase beta: DNA repair
DNA polymerase delta: leading strand
DNA polymerase gamma: mitochondrial DNA
mutation in DNA is transversion vs. transition
Transition – purine to purine (or pyrimidine to pyrimidine)
Transversion – purine to pyrimidine (vice versa)
Bloom syndrome
mutation of helicase
* blocks DNA replication and repair
clinically:
- hypersensitivity to sunlight
- preceptibility to cancers (leukemias)
- immunosuppression
- facial anomilities
What is the start codon and who are the stop codons
Start codon: AUG – Methionine
Stop codon:
UGA – U Go Away
UAA– U Are Away
UAG— U Are Gone
Causes of meningitis in Newborn (6months)
Group B strep
E coli
Listeria monocytogenes
Causes of meningitis in Children (6m-6years)
S. pneumoniae
N. meningitidis
H. influenza type B
Enterovirus
Causes of meningitis 6-60years old
N. meningitidis ( #1 in teens)
S. pneumoniae
Enteroviruses
HSV
Causes of meningitis 60+ years old
S. pneumoniae
Gram negative rods
Listeria
What is the enzyme that attaches an amino acid to the tRNA
aminoacyl- tRNA synthetase
_attaches amino acid to 3’ CCA sequence
“Can Carry Amino”
If charged an incorrect amino acid, bond is hydrolyzed and aminoacyl- tRNA synthetase will put on the correct one
Triad of tuberous sclerosis
seizures, intellectual disability, angiofibromas
Enzyme missing in I-cell disease
N-acetylglucosaminyl-1-phosphotransferase — failure of golgi to phosphorylate mannose 6 phosphate. Proteins are secreted rather than going to lysosomes
- course facial features, clouded corneas, restricted joint movements, and high plasma levels of lysosomal enzymes.
Menkes disease
X linked recessive connective tissue disease caused by impaired copper absorption and transport
Defective Menkes protein : ATP7A (recall 7B is Wilson’s disease GI chapter)
clinical presentation:
- kinky hair
- Growth retardation
- Hypotonia
Biochemical cause of Marfan?
defect in Fibrillin – a glycoprotein made by fibroblasts that forms a sheath around elastin
What bug causes Q fever?
Coxiella burnetii
Why can’t muscle cells completely break down glycogen? (glycogenolysis)
Muscle cells do not posses Glucose -6-phosphatase. This does not mean that muscle cells cannot undergo gluconeogenesis. They can get up to Glucose-6 phosphate and then use that in glycolysis/ energy but they cannot distribute glucose to other organisms ( like the liver can)
What enzyme catalyzes the rate limiting step in carbohydrate digestion?
oligosaccharide hydrolases – found on intestinal brush border
Describe Pyruvate Dehydrogenase Complex
- mechanism
- findings
- treatment if congenital
- can it be acquired?
X- linked build up of pyruvate that gets shunted to Lactate and Alanine
neurological defects, lactic acidosis, high serum alanine starting in infancy
Increase intake of ketogenic nutrients ( high fats, lysine, leucine)
Yes, arsenic poisoning, thiamine deficiency (alcoholics)
What causes Phenylketonuria and what are the physical findings?
Tx?
Loss of phenylalanine hydroxylase or it’s co-factor tetrahydrobiopterin (BH4)
Autosomal recessive
Excess phenylalanine– excess phenylketones in urine
+ neurotoxic effect
Findings: Intellectual disability, growth retardation, seizures, fair skin (melanin is in phenylalanine pathway), eczema, musty body odor
Tx: decrease phenylalanine and increase tyrosine in diet, tetrahjydrobiopterin supplementation
AVOID ARTIFICIAL SWEETENER ASPARTAME
What is the name of the disease that is deficient in homogentisate oxidase?
Presentation?
Alkaptonuria (ochronosis)
enzyme is in degenerative pathway of tyrosine to fumarate –> pigment forming homogentisic acid accumulates in tissues.
Autosomal recessive
Findings: dark connective tissue, brown pigment sclerae, urine turns black on prolonged exposure to air. May have debilitating arthralgia (homogentisic acid toxic to cartilage)
What is maple syrup urine disease
- mechanism
- who is involved?
- Presentation?
- Tx?
Blocked degradation of branched amino acids due to decrease in alpha-ketoacid dehydrogenase (B1)
” I Love Vermont maple syrup”
Isoleucine
Leucine
Valine
Autosomal recessive
Causes severe CNS defects, intellectual disability, and death
Urine smells like maple syrup
Tx: restriction of isoleucine, leucine, and valine in diet, and thiamine supplementation
What is hartnup disease?
- deficient mechanism?
- what do you see clinically?
- treatment?
Autosomal Recessive defect of transporter in intestine and kidneys
-deficiency of neutral amino acids transporters in proximal renal tubular cells and enterocytes
- deficiency of neutral AAs – tryptophan
- without tryptophan you can’t make Niacin
- without Niacin you get Pellagra
- dermatitis, diarrhea, dementia
- tx: high protein diet and nicotic acid
What type of infection is a patient with IL-12 receptor deficiency at highest risk for developing?
mycobacterial infections
What are the toxins produced by Strep pyrogens?
Streptolysin O:
Hemoysis on blood agar, oxygen labile
Streptolysin S: oxygen stable
Streptococcal pyrogenic exotoxins: A, B, C
- erythrogenic toxins: red rash of scarlet fever
- B : necrotising fascitus
- can work as super antigens TSS
Which bacteria secrete enterotoxins?
Vibrio Cholera ETEC S. aureus Shigella Yersinia Clostridium spp
What organisms are most commonly implicated in subacute endocarditis?
Viridins strep
Enterococci
Staph epidermidis
why are ahminoglycosides ineffective against gram (+) anaerobes
require O2 in order to work
- require O2 to enter bacterial cell
What is considered low birth weight
less than 5 lbs 8 ozs or 1500 grams
What are the tumor markers for pancreatic cancer?
CA 19-A and CEA
*CA 19-A is more specifi; CEA can be seen in other GI cancers
What diseases specifically damage the anterior horn?
Polio
West Nile
ALS
Who are the hormones that share an alpha subunit (endocrine)?
FSH
LH
TSH
hCG
Who share the precursor molecule Proopiomelanocortin?
(POMC) is the abreviation for precursor
ACTH
MSH
Lipotropins
Beta-endorphin
What is pulsus paradox and what are its causes?
> 10mmHg systolic blood pressure drop with inspiration
Causea are anything that hyperinflates the lungs: COPD, asthama and Cardiac tamponade (doesn’t inflate lungs but inhibits filling)
What are the 4 Erythropoietin secreting tumors?
Pheochromocytoma
Renal Cell carcinoma
Hemangioblastoma
Hepatocellular carcinoma
Malignancies associated with hypercalcemia
squamous cell cancers ( PTH-related peptide)
Renal cell carcinoma
Breast metastasis (mets to bone)
Multiple Myeloma (vialocal osteolytic factors)
neoplasm associated with Hashimoto’s Thyroiditis
lymphoma of the thyroid
Who utilizes tyrosine-Kinase Receptors and JAK/STAT signaling pathway?
Colony stimulating factors, prolactin, GH, and cytokines
Who utilizes Protein Kinase A
Gs
TSH, Glucagon, PTH, and beta-adreneric receptors
What are the amino acids necessary for purine synthesis?
Glycine
Aspartate
Glutamine
Adrenoleukodystrophy
Adren = adrenal Leukodystrophy = what matter issue
X- linked genetic disorder
Disrupts metabolism of very long chain fatty acids –> excessive buildup in nervous system, adrenal gland, testes.
Progressive disease that can lead to long-term coma/death and adrenal gland crisis
who make up the limbic system?
Hippocamus, amygdala, fornix, mammillary bodies, cingulate gyrus
5 F’s
Dominant parietal-temporal cortex lesion
Agraphia (inability to write)
Acalcia (in ability to calculate - math)
finger agnosia
Left- right disorientation
( Gerstmann syndrome)
Lesion at basal ganglia
Tremor at rest, Chorea, athetosis (snake like movements of fingers) - huntington
Resting tremor – parkinsons
Lesion at paramedian pontine reticular formation
Eyes look away from side of lesion
Lesion at frontal eye fields
Eyes look toward lesion
Lesion at superior colliculi
Paralysis of upward gaze – Parinaud’s syndrome
lesion of non dominant parietal temporal cortex
hemispatial neglect (angora of the contralateral side of the world)
Acute disseminated encephalomyelitis
Post infectious
Periventricular inflammation and demyelination after infection – mealses and VZV or certain vaccines (rabies, small pox)
Charot Marie Tooth disease
aka Hereditary motor and sensory nueropathy
progressive hereditary nerve disorders related to the defective production of proteins involved in structure and function of peripheral nerves or the myelin sheath
Autosomal dominant
Scoliosis and foot deformities
Things that cause hyperviscosity
Polycyemia vera
Hyperproteinemic state (Multiple myeloma)
Hereditary spherocytosis
Who show psomma bodies
meningioma
papillary thyroid cancer
serous papillary ovarian adenocarcinoma
Normal P-wave duration?
Normal PR duration?
0.12-0.2 ms
Normal QRS
normal QTc
normal QT
0.36- 0.44 ms
Olser-Weber Rendu syndrome
Aka: Hereditary Hemorhagic Telangiectasia
- AD
- disorder of blood vessels:
branching skin lesions (telangiectasias)
recurrent epistaxis (nosebleed)
skin discolorations
atriovenous malformations
GI bleeding
Hematuria
Polymyositis vs. dermatomyositis on muscle biopsy
Polymyositis: CD8+ with endomysial inflammation
Dermatomyositis: CD4+ with perimysial inflammation
both affect the proximal muscles
Menmonic for epidermis layers
“californians like girls in string bikinis” (FA437)
Stratum Corneum (keratin) Stratum Lucidum Stratum Granulosum Stratum Spinosum (desmosomes) Stratum Basale (stem cell site)
what is the skin disorder that causes an increase in the stratum spinosum and a decrease in the stratum granulosa
psoriasis
What is leser- Trelat sign?
FA 440
a sudden appearance of multiple seborrheic keratoses, indicating an underlying malignancy (GI or lymphoid)
Seborrheic keratoses: “greasy”, keratin-filled cysts (horn cysts)
what is cellulitis (skin)
FA 440
acute, painful, spreading infection of deeper dermis and subcutaneous tissue
- S. pyrogenes or S. aureus
What is Erysipelas
Infection involving the upper dermis and superficial lymphatics usually caused by S. pyrogenes
In what skin layer is it that exotoxins from Staph aureus cause a degradation of attachments?
stratum granulosum
Staphylococcal scaled skin syndrome
Steven- Johnson syndrome
- what is it?
- what is it associated with?
- Fever, Bullae formation, necrosis, sloughing of skin, high mortality rate.
- typically two membranes are invovled
- > 30% (greater than 30 percent) of body surface area involved
- adverse drug reaction ( anti-seizure meds)
(micro bio FA 123) Type III secretion system and who uses it?
“injectisome”
Needle-like protein appendage facilitation direct delivery of toxins form certain gram-negative bacteria
Pseudomonas,
Salmonella,
Shigella,
E.coli
Jarisch- Herxheimer reaction
Flu-like syndrome (fever, chills, headache, myalgia) after antibiotics are started due to killed bacteria (usually spirochetes) releasing endotoxins
Glucagonoma
tumor of pancreatic alpha cells – overproduce glucagon
Dermatitis (necrolytic migratory erythema)
Diabetes (hyperglycemia)
DVT
Depression
DRESS syndrome
Drug Reaction with Eosinophilia and System Symptoms ( DRESS)
typically occurs 2-8 weeks after exposure to high-risk drugs such as:
- anticonvulsants (phenytoin, carbamazepine)
- allopurinol
- sulfonamides (sulfasalazine)
- antibiotics ( minocycline, vancomycin)
Patients typically develop fever, generalized lymphadenopathy, facial edema, diffuse skin rash, EOSINOPHILIA, and internal organ dysfunction
