Biochem - Stuff Missed Flashcards
1
Q
Hartnup disease
A
results from niacin deficiency
- niacin deficiency may be due to loss of dietary tryptophan, resulting from defective intestinal and renal tubular absorption of amino acid
2
Q
Niacin/Vitamin B3
A
synthesized from tryptophan
- tryptophan is an essential amino acid
3
Q
Signs of Riboflavin deficiency
A
Chelosis Glossitis Keratitis, Conjunctivitis, Photophophoia Lacrimation Marked Corneal vascularization Seborrheic dermatitis
4
Q
Vitamin E
A
- aka tocopherol
- functions as scavenger of free radicals (antioxidant)
5
Q
Signs of Vitamin E deficiency
A
myelopathy
neurologic dysfunction
6
Q
Vitamin B2 (Riboflavin)
A
- form FMN and FAD to form enzymes for electron transport
7
Q
Pyroxidine (Vitamin B2)
A
coenzyme for decarboxylation and transamination of amino acids
8
Q
Deficiency of Pyroxidine
A
Anemia
Peripheral neuropathy
Dermatitis
9
Q
Phenylketonuria
A
inborn deficiency of phenylalanine hydroxylase to metabolize phenylalanine.
- manifests developmental delay, mental retardation, mousy body odor, and fair skin coloring
10
Q
Niemann-Pick disease
A
- AR
- deficiency in sphingomyelinase
- progressive neurodegenerative disease
- hepatosplenomegaly
- cherry red macula
- foamy macrophages filled with spingomyelin
11
Q
Fabry’s disease
A
- X-linked disease
- deficency in alpha-galactosidase A
- peripheral neuropathy of hands/feet
- angiokeratomas
- CV/renal disease
- accumulation of ceramide trihexosidase
12
Q
Gaucher’s disease-
A
- Autosomal recessive
- deficiency in GLUCOcerebrocisidase
- very common
- hepatosplenomegaly
- asceptic necrosis of femur
- Bone crises
- Gaucher cells (macrophages that look like crumpled tissue paper)
13
Q
Tay-Sachs disease
A
- Autosomal recessive
- deficient in Hexosaminidase A
- accumulation of GM2 ganglioside
- progressive neurodegeneration
- developmental delay
- cherry red spot of macula
- lysosomes with onion skin
- NO HEPATOSPLENOMEGALY (vs. Niemann-Picks disease)
14
Q
Krabbe’s disease
A
- AR
- deficient in GALACTOcerebrocidase, leading to accumulation of galactocerebroside
- leads to peripheral neuropathy
- developmental delay
- optic atrophy
- globoid cells
15
Q
Metachromatic leukodystrophy
A
- AR
- deficient in arylsulfatase A
- accumulation of Cerebroside sulfate
- central and peripheral demyelination with ataxia
- Dementia
16
Q
Hurler’s syndrome
A
- deficient in alpha-L-iduronidase
- accumulation of heparan sulfat, dermatan sulfate
- presents with developmental delay,
- gargoylism (abnormal facial features)
- corneal clouding
- hepatosplenomegaly
17
Q
Hunter’s syndrome
A
- deficient in Iduronate sulfatase
- Mild Hurler’s sndrome (no corneal clouding)
- ## mild developmental delay
18
Q
Acyclovir
A
- monophosphorylation of viral thymidine kinase is the first step in the active conversion of acyclovir to active stae
- more effective against HSV and VZV than CMV or EBV
19
Q
Pituitary adenomas
A
- causs symptoms from mass effect
- produce endocrine disorders
- prolactinomas are most common
- excess prolactin causes amenorrhea and galactorrhea
- bitemporal heminopsia from compression of optic chiasm is common
20
Q
Interferons
A
- produced by eukaryotic cells in response to viral infection
- act as cytokins on neighboring cells, to stimulate neighbors to produce antivural proteins that impair viral synthesis
21
Q
Edwards Syndrome
A
- Trisomy 18
- presents as micrognathia, low set ears, rockerbottom feet
- clenched hands with index finger overring the middle finger and fifth finger overriding fourth finger
22
Q
Patau Syndrome
A
- Trisomy 13
- presents as holoproscephapy
- microcepthaly
- polydactly and rocker bottom feet
- multiple facial abnormalities including cleft lip/cleft palat
23
Q
Most common cause of pneumonia, otitis media, and meningitis in adults
A
S. pneumoniae
- appears as Gram positive lancet shaped cocci in pairs
24
Q
Most common cause of bacteria in adults of all ages
A
S. peneuomoniae
25
Fragile X Syndrome
- defect in FMR1 gene on long arm of chromosome Z
- increased number of CGG trinucleotide repeats leads to hypermethylation of cytosine bases and gene activation
- leads to mental retardation, facial dysmorphism, macro orchidism
26
Chromosomal instability disorders
- Xeroderma pigmentosum
- Ataxia-telegientascia
- Fanconi's anemia
- Bloom syndrome
27
Lynch syndrome
associated with defect in DNA mismatch repair genes
| - increased risk of hereditary non-polyposis cancer (HNPCC) and extraintestinal malignancies
28
Homocystinuria Findings
- Increased levels of homocysteine in urine
- Mental retardation
- Osteoporosis
- Tall stature
- Kyphosis
- Lens subluxation (downward and inward)
- Atherosclerosis (stroke and MI)
29
Homocystinuria
- autosomal recessive - comes in 3 forms:
- can result from cystathionine deficiency (tx with less MEt and increased methionine, B12 , and folate in diet)
- decreased affinity for cystathionine synthase for pyroxidase (increased B6)
- Homocysteine methyltransferase deficiency (*requires B12)
30
Maple syrup urine disease
- autosomal recessive
- blocked degradation of branched amino acids (Isoleucine, Leucine, Valine)
- alpha ketoacid dehydrogenase (b1)
- caused increased of serum alpha-ketoacids
- can cause severe CNS defects, mental retardation, and death
- urine smells like maple syrup
31
Hartnup disease
- autosomal recessive disorder
- defective neutral amino acid transporter on renal and intestinal epithelial cells
- causes tryptophan excretion in in urine and decreased absorption in gut
- can lead to pellagra
- associated with B6 deficiency
32
Alkaptonuria
congenital deficiency of homofentisic acid in degradative pathway of tyrosine to fumate
- autosomal recessive and benign
- Dark connective tissue, Brown pigmented sclera, black urine upon exposure to ait
- may have debilitating arthralgia ( Homocysteine not good for cartilage)
33
Listeria
- transmitted through contaminated food
- causes sepsis and meningitis in immunocompromised adults
- common cause of infantile meningitis
- grows well in cold temps
- gram positive but tumbling motility key feature
34
Aspergillosis
- neutropenic patients are at risk for Aspergillus fumigatus
- produces septate hypate with ACUTE V-shaped branching
- causes invasive aspergillosis (seen in immunosuppressed patients)
- aspergillomas (seen in TB, emphysema and sarcoid pts)
- allergic pulmonary aspergillosus (seen in asthma patients)
