Step 1 Fundamentals Flashcards
(410 cards)
1
Q
What is Carbachol?
A
Muscarinic direct agonist. Constricts pupil and relieves intraocular pressure in OA glaucoma.
2
Q
Describe Job syndrome and list cause.
A
AKA Hyper-IgE syndrome. Deficiency of Th17 due to STAT3 mutation. Impaired recruitment of neutrophils (are increased in blood). Coarse facies, cold staph abscesses, retained primary teeth, increased IgE, dermatologic problems, bone fractures from minorr trauma.
3
Q
What cancers are Psammona bodies found in?
A
Papillary thyroid carcinoma, serous papillary cystadenocarcinoma of ovary, meningioma, mesothelioma.
4
Q
What is Amanita phalloides?
A
Death cap mushroom - can cause hepatic necrosis.
5
Q
What is aldesleukin? What’s it used in?
A
IL-2 mimic. Used in renal cell carcinoma, metastatic melanoma.
6
Q
What causes rubor in inflammation?
A
Vasodilation - histamine, bradykinin, prostaglandins.
7
Q
How does ciguatoxin work (what are the symptoms) and where is it found?
A
Reef fish (barracuda, snapper, moray eel). Opens Na+ channels and causes depolarization. GI upset, perioral numbness, bradycardia, heart block, HTN, reversal of hot and cold symptoms.
8
Q
Where is Collagen III found and what’s its other name?
A
Reticulin. Found in blood vessels, skin, uterus, fetal tissue, granulation tissue.
9
Q
What is Homocystinuria? How do you treat it?
A
AR. Homocystine in urine, osteoporosis, marfanoid, ectopia lentis, CV effects, kyphosis, ID. Can be cystathione synthase deficiency, decreased affinity of cystathione synthase for PLP (B6), deficiency of methionine synthase. For first 2, give B6 and Cys in diet. In cystathione synthase deficiency, also give B9, B12, decreased Met. For last one, give Met (don’t in the others).
10
Q
What are the HLA-DQ2/DQ8 alleles associated with?
A
Celiac disease.
11
Q
What does VEGF mediate?
A
Angiogenesis.
12
Q
What is the mechanism behind transfusion-related acute lung injury?
A
Donor anti-leukocyte antibodies against recipient neutrophils and pulmonary endothelial cells.
13
Q
Describe McArdle Disease.
A
GSDV. Skeletal muscle phosphorylase deficiency. Increased glycogen in muscle, blood glucose usually normal, myoglobinuria with strenuous exercise, arrhythmia with exercise intolerance. Flat venous lactate curve with normal rise in ammonia levels during exercise.
14
Q
What Apos does HDL give to chylomicrons?
A
CII and E.
15
Q
What LNs do the kidneys drain to?
A
Para-aortic.
16
Q
Where are D2 and D3 converted to 25-OH D3 and 1,25-(OH)2 D3?
A
25-OH D3 (storage form) in liver and 1,25-(OH)2 D3 (active form) in kidney.
17
Q
What degrades and replaces the RNA primer in DNA replication?
A
DNA Pol I.
18
Q
Mechanism of action and toxicity of Basiliximab.
A
IL-2R antibody. Used for kidney transplant rejection prophylaxis. Edema, hypertension, tremor.
19
Q
What LNs does the anal canal below the pectinate line drain to?
A
Superficial inguinal.
20
Q
Describe Wiskott-Aldrich Syndrome.
A
WASp gene XR mutation - leukocytes and platelets unable to reorganize actin cytoskeleton, defective antigen presentation. Thrombocytopenia, eczema, recurrent pyogenic infections. Decreased to normal IgM and IgG, increased IgE and IgA. Fewer/smaller platelets.
21
Q
What is affected in Ehlers-Danlos classical and vascular type?
A
Collagen IV and III procollagen respectively.
22
Q
How does propionyl-CoA enter the TCA cycle?
A
Turns to methylmalonyl-CoA via propionyl-CoA reductase. Methylmalonyl-CoA converted to Succinyl-CoA.
23
Q
What is Bethanechol?
A
A muscarinic direct agonist. Activates bowel and bladder SM. Good for postop/neurogenic ileus, urinary retention.
24
Q
How do NorE and E compare in terms of HR and PVR?
A
NorE has reflex bradycardia and E doesn’t. NorE increases PVR due to unopposed α action and E decreases it due to β > α.
25
Are ionized or nonionized forms of drugs peed out better?
Ionized.
26
What kind of cells secrete IFNα and β?
Virus-infected ones.
27
What is the mechanism of fat necrosis?
Damaged cells release lipase.
28
What LNs does the uterus drain to?
Para-aortic.
29
What are the ketone bodies?
Acetone, acetoacetate, β-hydroxybutyrate.
30
What chromosome is associated with Williams syndrome?
7 (long arm microdeletion).
31
How do you treat heparin toxicity?
Potamine sulfate.
32
Do you see nuclei in coagulative necrosis?
No.
33
What LNs does the bladder drain to?
Internal iliac.
34
How do you diagnose B1 deficiency?
Increased RBC transketolase activity following B1 administration.
35
What is Mirtazapine?
α2 selective blocker. Used for depression. Increases appetite.
36
Describe Leukocyte Adhesion Deficiency Type 1 and list cause.
AR defect in LFA-1 integrin (CD18) on phagocytes, impaired migration and chemotaxis. Increased neuts in blood, absence of neuts at infection sites. Recurrent skin/mucosal bacterial infections but no pus, impaired wound healing, delayed separation of umbilical cord (\>30days)/
37
What is Malonyl-CoA?
Acetyl-CoA turns into it on the way to synthesizing fatty acids.
38
What process is defective in Fanconi anemia and Ataxia Telangiectasia?
Non-homologous end joining (NHEJ).
39
How do Mycophenolate and Ribavirin work?
They inhibit IMP dehydrogenase in purine synthesis.
40
What is cystinuria? How do you test for it?
Usually AR, defect of PCT AA transporter that reabsorbs Cystine, Ornithine, Lysine, Arginine. Test for it with cyanide-nitroprusside test - CN converts cystine to cysteine and nitroprusside binds to make purple hue.
41
What is Pilocarpine?
Muscarinic direct agonist. Contracts ciliary muscle (OA glaucoma), pupillary sphincter (CA glaucoma). Can cross BBB.
42
What genetics cause Huntington's?
AD CAG repeat in Huntingtin chromosome 4 . Caudate affected.
43
Where does T cell positive and negative selection happen?
Positive - cortex Negative - medulla
44
Describe hyperchylomicronemia.
Familiar Dyslipidemia I. AR. LPL or ApoCII deficiency. Increased chylomicrons, TG, and cholesterol in blood. Xanthomas, creamy layer in supernatant, pancreatitis. No increased risk of atherosclerosis.
45
What function does BRCA1 contribute to?
Homologous recombination.
46
What is Refsum Disease?
AR alpha-oxidation disorder where phytonic acid is not metabolized to pristanic acid. Scaly skin, ataxia, cataracts/night blindness, epiphyseal dysplasia,short fourth toe. Treat with diet + plasmaphoresis.
47
What is Rotenone?
ETC Complex I inhibitor.
48
What causes tumor in inflammation?
Endothelial contraction leading to increased vascular permeability - LTC4, LTD4, LTE4, Histamine, Serotonin.
49
What is the difference between dystrophic and metastatic calcification?
Dystrophic is localized, in abnormal tissue, and the patient is normocalcemic. See Psammona bodies. Metastatis is widespread, in normal tissue, and usually associated with hypercalcemia.
50
Mechanism of action and uses of Natalizumab.
α4 integrin antibody. MS, Crohn's.
51
Describe classic galactosemia.
AR absence of Gal-1P uridyltransferase, toxic substances accumulate. Failure to thrive, jaundice, hepatomegaly, infantile cataracts, intellectual disability, can predispose to E. coli sepsis.
52
What are TRECs?
Small circles of DNA made in T-cells during their maturation/passage through the thymus. They are decreased in SCID.
53
What LNs does the prostate drain to?
Internal iliac.
54
What drugs can cause hyperglycemia?
Tacrolimus, PIs, Niacin, Hydrochlorothiazide, Corticosteroids.
55
What are the functions of the α2 receptor?
Decreased insulin release, decreased sympathetic outflow, increased platelet aggregation, decreased aqueous humour outflow.
56
What is ApoE?
In everything but LDL, mediates remnant uptake.
57
What LNs does the skin below umbilicus (excluding the popliteal area) drain to?
Superficial inguinal.
58
Describe a vitamin E deficiency.
Hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract demyelination.
59
What type of receptor is the H1 receptor and what is its function?
Gq. Allergy!
60
How do you treat abetalopoproteinemia?
Restriction of LCFAs, large doses of vitamin E.
61
What is CA125 a marker for?
Ovariancancer.
62
How does a noncompetitive inhibitor affect Km and Vmax?
Unchanged Km, Vmax decreased.
63
Mechanism of action and uses of Alemtuzumab.
CD52 antibody for MS, CLL.
64
In B9 deficiency, what do labs show for homocystine and methylmalonic acid levels?
Homocystine increased, methylmalonic acid levels normal.
65
What mediates acute transplant rejection and what is the effect?
CD8 and CD4 cells activated against donor MHCs (type IV hypersensitivity). Antibodies also have effect, but they develop after transplant. Vasculitis of graft vessels with dense interstitial lymphocytic infiltrate.
66
Describe B3 deficiency.
Pellagra: Dermatitis (C3/4 circumferential), Diarrhea, Dementia.
67
Describe Pompe Disease.
GSDII. Lysosomal α-1,4-glucosidase deficiency. Early death, cardiomegaly, HCM, hpotonia, exercise intolerance.
68
What is a Type II hypersensitivity?
Antibodies bind to cell-surface antigens.
69
What does TGBβ mediate?
Angiogenesis and fibrosis.
70
Describe Gaucher disease.
AR glucocerebrosidease deficiency - glucocerebroside accumulates. Hapetosplenomegaly, panctopenia, osteoporosis, bone crises, avascular necrosis of femur, Gaucher cells (lipid-laden macrophages resembling crumpled tissue paper).
71
What is the function of a Th1?
Activates macrophages and CD8s.
72
What are the functions of the β2 receptor?
Vasodilation, bronchodilation, increased insulin release, decreased uterine tone, increased aqueous humour production.
73
What does fructokinase do? What is its deficiency called?
Converts Fructose to F1P. Deficiency is called essential fructosuria.
74
What does a Th17 secrete?
IL-17, IL-21, IL-22.
75
What is alkaptonuria?
AR Homogentisate oxidase decifiency. Usually benign. Blue-black CT, ear cartilage, sclerae, uring turns black on exposure to air, may have arthralgias.
76
Where in the spleen do APCs capture blood-borne antigens?
The marginal zone.
77
What cytokines induce differentiation into a Th1?
IFNγ and IL-12.
78
Where is Collagen I found?
Bone, skin, tendon, dentin, fascia, cornea, scars (late wound repair).
79
Describe diapedesis/transmigration in leukocyte extravasation.
PECAM-1/CD31s bind.
80
What kind of nephrolithiasis is precipitated by vitamin C excess?
Calcium oxalate.
81
What is hereditary angioedema?
C1 Esterase Inhibitor deficiency - unregulated kallikrein activation leading to increased bradykinin. Characterized by decreased C4 levels.
82
What is CD16?
Binds Fc of bound Ig activating an NK cell, kills via ADCC.
83
In B12 deficiency, what do labs show for homocystine and methylmalonic acid levels?
Both increased.
84
What is cytokeratin a stain for?
Epithelial cells.
85
What cofactors does PDH need?
TPP (B1), B2, B3, AcCoA (B5), Lipoic acid.
86
What does a Th2 secrete?
IL-4, IL-5, IL-6, IL-10, IL-13.
87
What is Methacholine?
Muscarinic direct agonist. Airway specific.
88
What cells cause liquefactive necrosis?
Neutrophil digest (macrophages also involved in early).
89
Which part of the lymph node houses the T cells?
The Paracortex. Has high endothelial venules through which T and B cells enter from blood.
90
What is the function of Vitamin E? What is a possible side effect of high dose supplementation?
Antioxidant that protects RBCs and membranes from free radical damage. Altered VitK metabolism, enhanced warfarin anticoagulant effects.
91
How do 6-mercaptopurine and Azathioprine work?
Aathioprine is the prodrug. Inhibit xanthine oxidase in purine synthesis.
92
Where in the spleen do you find T cells?
In the PALS within the white pulp.
93
What part of RNA do miRNAs target?
3'UTR
94
What are essential AAs that can be both ketogenic and glucogenic?
Ile, Phe, Thr, Tyr.
95
Name 3 ETC uncoupling agents.
2,4-Dinitrophenol, aspirin, thermogenin.
96
Mechanism of action and uses of Cetuximab.
EGFR antibody. Stage IV colorectal cancer, head and neck cancer.
97
How does Leflunomide work?
It inhibits dihydroorotate dehydrogenase in pyrimidine synthesis.
98
What are the 4 stages of leukocyte extravasation?
1) Margination&rolling 2) Adhesion/tight binding 3) Diapedesis/transmigration 3) Migration
99
Describe the urea cycle metabolite order.
NH3+CO2 -\> Carbamoyl Phosphate (CPSI) CP+ornithine -\> citrulline (+Asp) -\> Argininosuccinate -\> Arg -\> Ornithine (urea is byproduct).
100
What are Weibel-Palade bodies?
On endothelial cells, release P-selectin.
101
What kind of reactions is B7 a cofactor for?
Carboxylation reactions. E.g. Pyruvate carboxylase, Acetyl-CoA Carboxylase, Propionyl-CoA Carboxylase.
102
Describe Galactokinase deficiency.
AR, galactitol accumulates. Galactosemia and galactosuria, ifantile cataracts.
103
What does urine dipstick test for?
Glucose - sometimes can detect reducing sugar.
104
What cancer is HTLV-1 associated with?
Adult T-cell Lymphoma/Leukemia.
105
What transport is clathrin involved in (from where to where?)
trans-golgi-\>lysosomes
PM-\>endosomes
106
Describe metachromatic leukodystrophy disease.
AR arylsulfatase A deficiency - cerebroside sulfate accumulates. Central and peripheral demyelination with ataxia, dementia.
107
What LNs does the vagina middle 1/3 drain go?
Internal iliac.
108
What is IPEX?
Genetic deficiency of FOXP3 - defective Treg cells, autoimmunity. Enteropathy, endocrinopathy, autoimmune dermatologic conditions. Associated with diabetes in male infants.
109
Describe orotic aciduria.
De novo pyrimidine synthesis deficiency, inability to convert orotic acid to UMP. Megaloblastic anemia is caused.
110
Mechanism of action and uses of Bevacizumab.
VEGF antibody. Colorectal cancer, renal cell carcinoma, non-small cell lung cancer.
111
How does tetrodotoxin work (what are the symptoms) and where is it found?
Pufferfish - works by binding fast VG Na+ channels in cardiac/nerve tissue and preventing depolarization. GI upset, paresthesias, weakness, dizziness, loss of reflexes.
112
What is TRAP a stain for?
Hairy cell Leukemia.
113
What LNs does the cervix drain to?
Internal iliac.
114
How many kcal do you get from 1g of carbs?
4.
115
Does Pyruvate -\> AcCoA make or use NADH?
Makes NADH (needs NAD+).
116
What does Fomepizole do?
Inhibits alcohol dehydrogenase. Treats methanol/ethylene glycol (antifreeze) toxicity.
117
What type of receptor is the V1 receptor and what is its function?
Gq. Vasoconstriction.
118
What is CD55?
AKA DAF - prevents complement activation on self cells.
119
Where is Collagen IV found?
BM, basal lamina, lens.
120
What is required for B3 synthesis?
Tryptophan, B2, B6.
121
What is GFAP a stain for?
Neuroglia.
122
What cytokines induce differentiation into a Treg?
TGFβ, IL-2.
123
What does the lymph node medulla do?
Communicates with efferent lymphatics, contains reticular cells and macrophages.
124
Describe Vitamin A toxicity.
Acute toxicity—nausea, vomiting, vertigo, and blurred vision. Chronic toxicity—alopecia, dry skin, hepatic toxicity and enlargement, arthralgias, and pseudotumor cerebri.
125
Describe Tay-Sachs disease.
AR Hexaminidase A deficiency - GM2 gangliosides accumulate. Developmental delay, "cherry-red" macula, progressive neurodegeneration, onion-skin lysosomes.
126
What are the negative acute phase proteins in inflammation?
Transferrin (internalized by macrophages) and albumin.
127
Describe a tRNA.
3' end carries AAs (has CCA+chemically modified bases). T-arm has TΨC needed for ribosome binding. D-arm is for the aminoacyl-tRNA synthetase to recognize the tRNA.
128
What cancer can have dermatomyositis as a paraneoplastic syndrome?
Adenocarcinoma (especially ovary).
129
Where do you get VitK?
Intestinal flora.
130
In which part of the thymus are immature and mature T cells?
Immature in cortex, mature in medulla.
131
What is CD14?
Macrophage receptor for PAMPs.
132
What are the symptoms of Graft-Versus-Host Disease?
Maculopapular rash, jaundice, diarrhea, hepatosplenomegaly.
133
Acanthosis nigricans and Leser-Trélat sign are paraneoplastic syndromes of what kind of malignancies?
GI adenocarcinoma and visceral.
134
What LNs does the vulva drain to?
Superficial inguinal.
135
Difference between the Salk and Sabin vaccine.
Salk = killed/inactivated, taken IV Sabin = live-attenuated, taken orally
136
What are Hassall corpuscles?
Areas in the thymic medulla containing epithelial reticular cells.
137
What chromosome is associated with Cri-du-chat?
5 (short arm deletion).
138
What LNs do the gonads drain to?
Para-aortic.
139
What is the role of PGE2 in inflammation?
Dolor/pain. Also rubor (with other PGs).
140
What steps in glycolysis make ATP?
1,3-BPG -\> 3PG PEP -\> Pyruvate
141
Where are aromatic amines (benzidine, 2-naphthylamine) found and what cancer are they associated with causing?
Textile dyes, cigarettes. Transitional cell carcinoma.
142
Where do people get D2 and D3?
D3 (cholecalciferol) from exposure of skin (stratum basale) to sun, ingestion of fish, milk, plants. D2 (ergocalciferol) from ingestion of plants, fungi, yeasts.
143
What cofactor do collagenases need?
Zinc.
144
How many kcal do you get from 1g of alcohol?
7.
145
What is lysyl oxidase?
Copper containing enzyme that cross links collagen to make collagen fibrils.
146
Name the soluble TNFα antibodies and their uses.
Adalimumab, Certolizumab, Golimumab, Infliximab. IBD, RA, ankylosing spondylitis, psoriasis.
147
In what process does the membrane bleb and is it reversible?
Apoptosis and yes.
148
Mechanism of action and uses of Trastuzumab.
HER2 antibody. Breast cancer, gastric cancer.
149
What cancer is ionizing radiation associated with causing?
Papillary thyroid cancer.
150
What sort of tissues/organs more typically have red vs pale infarcts?
Red: tissues with \>1 blood supply undergoing venous occlusion. Pale: solid organs with single end-arterial supply that is infarcted.
151
Describe Myotonic Type I Muscular Dystrophy and list cause.
AD, CTG repeat in DMPK. Myotonia, cataracts, testicular atrophy, frontal balding, muscle wading, arrhythmia.
152
What cancers is H. pylori associated with?
Gastric adenocarcinoma, MALT lymphoma.
153
How does a reversivle competitive inhibitor affect Km and Vmax?
Increased Km, Vmax unchanged.
154
What amino acid is needed for heme synthesis?
Gly. Gly-\>porphyrin (needs B6)-\>heme.
155
What is Menkes Disease?
X-linked recessive APT7A defect. Leads to decreased copper absorption and so decreased lysyl oxidase activity. Kinky/brittle hair, hypotonia, growth retardation.
156
What type of collagen is a hypertrophic and keloid scar made of?
Hypertrophic: III Keloid: I and III
157
What does tyrosinase deficiency cause?
Albinism (it's the enzyme converting DOPA to melanin).
158
What is TAP?
Delivers antigens to RER for loading to MHCI.
159
What serum findings are there in Ataxia-telangiectasia?
Increaesed AFP, decreaed IgA, IgG, IgE, lymphopenia, cerebellar atrophy.
160
What is a cell surface protein that is a suggestive marker for NK cells?
CD56.
161
What does PDGF mediate?
Fibroblast growth, vascular remodeling, SMC migration.
162
What LNs does the skin above the umbilicus drain to?
Axillary.
163
What is Oligomycin?
ATP synthase inhibitor.
164
What gene is defective in Ataxia-telangiectasia?
ATM (failure to detect DNA damage).
165
What is Mirabegon?
A β3 agonist. For urinary urge incontinence or overactive bladder.
166
What drugs do you give for osteogenesis imperfecta?
Bisphosphonates.
167
What type of receptor is the M1 receptor and what are its functions?
Gq. Mediates higher congnitive functions, stimulates ENS.
168
Where in the cell is pyruvate turned into Acetyl-CoA?
In the mitochondria.
169
Describe pyruvate carboxylase.
Turns Pyruvate to OAA, needs B7 cofactor and an ATP.
170
What is the function of a Treg?
Maintaining tolerance to self-antigens.
171
What is the difference between the direct and indirect Coombs test?
Direct: detects antibodies attached directly to the RBC surface. Indirect: detects antibodies unbound and floating in serum
172
What is Terbutaline?
A β-agonist.
173
Where in the cell does the TCA cycle take place?
In the mitochondria.
174
What is the difference between hexokinase and glucokinase?
Hexokinase is in most tissues, inhibited by G6P. Glucokinase is in the liver and β-cells of the pancreas, is induced by insulin and inhibited by F6P. It also has a higher Km and Vmax.
175
What LNs do the head and neck drain to?
Cervical.
176
What steps in glycolysis need ATP?
Glucose -\> G6P F6P -\> F-1,6-BP
177
What is vimentin a stain for?
Mesenchymal tissue. Also RCC, endometrial carcinoma, meningioma.
178
Describe a B5 deficiency.
Dermatitis, enteritis, alopecia, adrenal insufficiency.
179
Describe adhesion/tight binding in leukocyte extravasation.
Leukocyte CD11/18 integrins (LFA-1, Mac-1) bind ICAM-1/CD54.
180
What LNs does the upper limb drain to?
Axillary.
181
How do sarcomas and carcinomas typically spread?
Most sarcomas hematogenously, carcinomas via lymph EXCEPT Follicular thyroid carcinoma, Choriocarcinoma, Renal Cell Carcinoma, Hepatocellular carcinoma.
182
Describe the HMP shunt. Where does it occur?
G6P turned to 6-photphogluconolactone via G6PD, then to R5P., Produces NADPH. Occurs in liver, RBCs, adrenal cortex, lactating mammary glands.
183
What is the HLA-B27 allele associated with?
Seronegative arthropathies.
184
What is paraneoplastic encephalomyelitis?
Antibodies against Hu antigens in neurons as a paraneoplastic syndrome of small cell lung cancer (paraneoplastic cerebellar degeneration).
185
What drugs can cause SIADH?
Carbamazepine, Cyclophosphamide, SSRIs.
186
What are the functions of Vitamin C?
Hydroxylation of Proline and Lysine in collagen synthesis, reduces Fe3+ to Fe2+ to facilitate absorption, necessary for dopamine beta hydroxylase (converts dopamine to NorE)
187
Mechanism of action and uses of Palivizumab.
RSV F Protein antibody. RSV prophylaxis for high risk infants.
188
Where is IgA produced?
GI tract. In the Peyer patches. The plasma cells that secrete them live in the lamina propria.
189
What are the four base-base conversions you can do?
All deaminations. C-\>U, A-\>hypoxanthine, G-\>xanthine, 5-methyl-C-\>T
190
What chromosome is affected in Marfan syndrome?
15
191
What are CA15-3 and CA27-29 markers for?
Breast cancer.
192
What is Gower sign?
Using upper extremities to help stand.
193
What RNAs do RNA Pols I-III make?
I - rRNA II - mRNA III- tRNA, 5s RNA
194
Describe B2 deficiency.
Cheilosis, corneal vascularization.
195
What modifications does the golgi make?
Modifies N-oligosaccharides on Asn, adds O-oligosaccharides on Ser and Thr, adds M6P on proteins for trafficking to lysosomes.
196
What is ALP a marker for?
Mets to bone/liver, paget disease of bone, seminoma.
197
After exposure to which toxins/microorganisms are unvaccinated people supposed to be given preformed (passive) antibodies?
Tetanus toxin, Botulinum toxin, HBV, Baricella, Rabies, Diptheria toxin.
198
Describe von Gierke Disease.
GSDI. Glucose-6-phosphatase deficiency. Provides problems in gluconeogenesis, glycogenolysis. Severe fasting hypoglycemia, increased glycogen, increased blood lactate, hepatorenomegaly.
199
What do terminal complement deficiencies predispose a person to?
Recurrent Neisseria bacteremia.
200
How does 5-FU work?
5-F-dUMP inhibits thymidylate synthase in pyrimidine synthesis.
201
What is the function of a Th2?
Activates eosinophils and promotes IgE production.
202
What cofactors does αKG dehydrogenase need?
Same as PDH - TPP (B1), B2, B3 (NAD+), B5, lipoic acid.
203
How does Prader-Willi happen?
c15 UPD (paternal chromosome deleted/silenced).
204
What is the function of IL-5?
Promotes growth and differentiation of B cells. Enhances class switching to IgA. Stimulates growth and differentiation of eosinophils.
205
What cancer are alkylating agents associated with causing?
Leukemia/lymphoma.
206
What are Benztropine and Trihexylphenidyl?
Muscarinic antagonists for CNS - Parkinson's and acute dystonia.
207
What is Phenoxybenzamine?
An irreversible α-blocker. Give preop for pheochromocytoma.
208
Describe chronic granulomatous disease and list cause.
XR (most commonly) defect of NADPH oxidase. Increaesd susceptibility to catalase+ organisms. Negative nitroblue tetrazolium dye reduction test.
209
Describe ornithine transcarbamoylase deficiency.
XR, often evident in first few months of life. Increased orotic acid in blood and urine, symptoms of hyperammonemia, decreaed BUN.
210
What is β2-microglobulin amyloidosis?
Dialysis-related amyloidosis.
211
What is Apo B-100?
In VLDLs, IDLs, LDLs - binds LDL receptor.
212
Describe Fabry disease.
XR α-galactosidase A deficiency - ceramide trihexoside accumulates. Episodic peripheral neuropathy, angiokeratomas, hypohidrosis, late: progressive renal failure, CV disease.
213
What cytokines induce differentiation into a Th17?
TGFβ, IL-1, IL-6.
214
What is systemic senile amyloidosis?
TTR (normal transthyretin) found mainly in ventricles.
215
How does an irreversible competitive inhibitor affect Km and Vmax?
Unchanged Km, Vmax decreased.
216
How do you treat hyperammonemia?
Limit protein, can give lactulose (acidifies GI tract and traps ammonia for excretion).
217
What type of receptor is the M2 receptor and what are its functions?
Gi. Decreases HR andcontractility of atria.
218
What is podagra?
B3 excess: facial flushing (can avoid with aspirin), hyperglycemia, hyperuricemia.
219
What is the inflammasome?
Cytoplasmic protein complex that recognizes products of dead cells, microbial products, and crystals. Activates IL-1 and inflammatory response.
220
What HPV types are oncogenic?
16, 18.
221
What is the intrinsic pathway of apoptosis?
After exposure to injurious stimuli, BAX and BAK form pores in mitochondrial membrane, release cytochrome C from IM into cytoplasm, and activate caspases (starting with caspase 9).
222
What type of receptor is the V2 receptor and what is its function?
Gi. Increases H2O permeability via aquaporin 2 on CT.
223
Describe Chediak-Higashi syndrome and list cause.
AR defect in LYST gene (lysosomal trafficking), microtubule dysfunction in phagolysosome fusion. Progressive neurodegeneration, lymphohistiocytosis, albinism, recurrent infection, neuropathy. Giant granules in granulocytes and platelets. Pancytopenia. Mild coagulation defects.
224
What does FGF mediate?
Angiogenesis.
225
How does Ribulose-5-Phosphate return to glucose metabolism?
Via transketolase, turns back to F6P.
226
What is Fragile X Syndrome? Describe some physical features.
X-linked dominant FMR1 CGG expansion resulting in hypermethylation. Macrooorchidism, long face, large everted ears, autism, MVP.
227
What is Antimycin A?
ETC Complex III inhibitor.
228
What are the glucogenic essential AAs?
Met, His, Val.
229
What paraneoplastic syndromes can small cell lung cancer have?
Cushing (ACTH) and hyponatremia (ADH).
230
What does EGF mediate?
Cell growth via TKs.
231
What are the functions of the α1 receptor?
Vascular SM contraction, pupillary dilation, intestinal and bladder sphincter contraction.
232
Describe PDH deficiency. How do you treat it?
X-linked. Pyruvate gets shunted to lactate and alanine. Neuro defects, actic acidosis, increased serum alanine. Treat with ketogenic nutrients/high fat diet. Increased Lys and Leu (ketogenic AAs).
233
What amino acid is involved in serotonin synthesis?
Trp. Needs BH4 and B6.
234
What is Scopolamine?
Muscarinic antagonist for CNS.
235
What is AA amyloidosis?
Serum amyloid A, secondary systemic amyloidosis. From chronic inflammatory conditions.
236
What genetics cause Friedrich's Ataxia?
AR GAA repeat on chromosome 9.
237
Mechanism of action of glucocorticoids.
Inhibit NF-κB. Suppress B and T cell function by reducing transcription of many cytokines. Induce T-cell apoptosis.
238
What are the ketogenic essential AAs?
Lys, Leu.
239
What is Zellweger syndrome?
AR PEX mutation leading to empty peroxisomes. Hypotonia, seizures, hepatomegaly.
240
What is the difference between Kwashiorkor and Marasmus?
Kwashiorkor is protein malnutritions, causes edema, skin lesions, liver malfunction (fatty liver due to decreased apolipoprotein synthesis). Marasmus is malnutrition not causing edema - not enough calories but no nutrients entirely absent.
241
Mechanism of action and uses of Rituximab.
CD20 antibody. B-cell NHL, CLL, RA, ITP, MS.
242
What are the functions of the β1 receptor?
Increased HR and contractility, increased renin release,
243
What is Trousseau syndrome? What can it be a paraneoplastic syndrome of?
Migratory superficial thrombophlebitis. Adenocarcinoma (esp. pancreatic).
244
What are Oxybutinin, Solifenacin, and Tolterodine?
Muscarinic antagonists for GU - reduce bladder spasms.
245
Describe hypertriglyceridemia.
Familial dyslipidemia IV. AD. Hepatic VLDL overproduction. Related to insulin resistance. Can cause acute pancreatitis.
246
What is familial amyloid polyneuropathy?
ATTR (mutated transthyretin). Can cause polyneuropathy, also can cause cardiomyopathy - deposits in ventricular endomyocardium.
247
In what phase of the cell cycle does mismatch repair take place and in what conditions is it defective?
S phase. Lynch syndrome/HNPCC
248
Mechanism of action and toxicity of Azathioprine.
Prodrug of 6-mercaptopurine. Used as an immune suppressant. Pancytopenia.
249
What are the two primary opsonins in bacterial defense?
C3b and IgG.
250
What is Isoproterenol?
A β-agonist (β \> α). Similar effects to Epinephrine.
251
What sort of transport is COPI involved in (and from where to where?)
Retrograde: golgi-\>golgi and cis-golgi-\>ER
252
How many kcal do you get from 1g of fats/FAs?
9.
253
What are Hyoscyamine and Dicyclomine?
Muscarinic antagonists. GI - antispasmodics for IBS.
254
What is the invariant chain?
Is associated with MHCII, is released in an acidified endosome for antigen loading.
255
What is the order of enzymes in base excision repair?
Glycosylase makes AP site, AP ednuclease cleaves 5' end, Lyase cleaves 3' end, DNA Pol beta fills in, Ligase seals.
256
Mechanism of action and uses of Daclizumab.
CD25 (part of IL-2R) antibody. Relapsing MS.
257
What is CA19-9 a marker for?
Pancreatic adenocarcinoma.
258
What LNs do the trachea and esophagus drain to?
Mediastinal.
259
Describe familiar hypercholesterolemia.
Familiar dyslipidemia II. AD. Absent/defective LDLR or Apo B-100. Increased LDL, cholesterol in blood. Heterozygotes have cholesterol ~300, homo can have ~700. Increased risk of atherosclerosis, tendon zanthomas, corneal arcus.
260
What heart defect is associated with Cri-du-chat?
VSD.
261
Where is Collagen II found?
Cartilage, nucleus pulposus, vitreous body.
262
What is Glycopyrrolate?
Muscarinic antagonist for GI and resp, preop.
263
What is CD95?
FasR (apoptosis).
264
What is ApoCII?
Catalyzes cleavage by LPL.
265
How does Methotrexate work?
Inhibits DHFR in pyrimidine synthesis.
266
What cancer can have hypertrophic osteoarthropathy as a paraneoplastic syndrome?
Lung adenocarcinoma.
267
Where in the cell does ketogenesis take place?
In the mitochondria.
268
What parts of the brain are damaged in Wernicke-Korsakoff syndrome?
Medial dorsal nucleus of thalamus and mammillary bodies.
269
What is Edward's Syndrome?
Trisomy 18. Prominent occiput, Rocker-bottom feet, Intellectual disability, Nondisjunction, Clenched fists with overlapping fingers, Ears low set, micrognathia, congenital heart disease. Death by age 1.
270
How does hyperammonemia affect neurotransmitters?
It depletes all the Glu in the CNS (is turned to Gln) and so depletes GABA.
271
What LNs does the posterior calf and dorsolateral foot drain to?
Popliteal.
272
What are the dominant mediator cells of chronic inflammation?
Macrophages.
273
What is P-glycoprotein?
MDR1, pumps out toxins like chemo drugs. Is classical in adrenocortical carcinoma.
274
What is the role of IgA?
Prevents attachment of bacteria and viruses to mucous membranes. Does NOT fix complement.
275
Mechanism of action of Abciximab.
Platelet glycoproteins IIb/IIIA antibody.
276
What is paraneoplastic cerebellar degeneration?
Antibodies against antigens in Purkinje cells as a paraneoplastic syndrome of small cell lung cancer (anti-Hu), gyne&breast cancers (anti-Yo), HL (anti-Tr).
277
What is the inheritance of Hyper-IgM Syndrome?
XR.
278
Describe Zinc deficiency.
Delayed wound healing, suppressed immunity, hypogonadism, decreaed adult hair, dysgeusia, anosmia, acrodermatitis enteropathica. May predispose to alcoholic cirrhosis.
279
How is cancer staged?
T (tumor size/invasiveness), N, M.
280
Mechanism of action of Etanercept.
Decoy TNFα receptor.
281
What kind of signalling pathway does glucagon use?
Gs (cAMP).
282
What type of receptor is the D2 receptor and what are its functions?
Gi. Activates striatum indirect pathway.
283
What kind of signalling pathway does insulin use?
RTK.
284
Describe dysbetalipoproteinemia.
Familial dyslipidemia III. AR. Defective ApoE. Increased chylomicrons, VLDLs in blood. Premature atherosclerosis, tuboeruptive xanthomas, palmar xanthomas.
285
What is Midodrine?
An α1 agonist. Good for autonomic insufficiency and postural hypotension.
286
What is Patau Syndrome?
Trisomy 13. Severe intelectual disability, rocker-bottom feet, micropthalmia, microcephaly, cleft lip/palate, polydactyly, holoprosencephaly, cutis aplasia, PCKD, congenital heart disease. Death by age 1.
287
Where is arsenic found and what cancers is it associated with causing?
Herbicides, metal smelting. Liver angiosarcoma, lung cancer, SCC.
288
Describe Selective IgA deficiency.
Majority asymptomatic. Can see some symptoms, anaphylaxis to IgA-containing products. Increased susceptibility to Giardiasis.
289
What are the Atropine ADEs?
Increased body temp "hot as a hare", dry skin/mouth "dry as a bone", flushed skin "red as a beet", cycloplegia "blind as a bat", disorientation "mad as a hatter", urinary retention "full as a flask".
290
How do you treat arsenic poisoning?
Dimercaprol, succimer.
291
What type of receptor is the D1 receptor and what are its functions?
Gs. Activates striatum direct pathway. Relaxes renal vascular SM.
292
How many kcal do you get from 1g of protein?
4.
293
How do you treat coppre toxicity?
Penicillamine, trientine.
294
Mechanism of action and toxicity of Sirolimus AKA Rapamycin.
mTOR inhibitor - binds FKBP. Prevents response to IL-2. Used for kidney transplant rejection prophylaxis. Pancytopenia, insulin resistance, hyperlipidemia.
295
What are the functions of the β3 receptor?
Bladder relaxation, thermogenesis in skeletal muscle.
296
What part of the GI absorbs B12?
Terminal ileum.
297
How does B9 improve the symptoms of B12 deficiency?
It can mask the hematologic symptoms but not the neurologic ones.
298
What does a Treg secrete?
TGFβ, IL-10 (major immune attenuators), IL-35.
299
What is Xeroderma Pigmentosum?
A condition with defective nucleotide excision repair (G1, fixes dimers).
300
What type of receptor is the M3 receptor and what are its functions?
Gq. All the PNS shit. Increases exocrine gland secretions, peristalsis, bladder constriction, bronchoconstriction, pupillary constriction, ciliary muscle contraction, increases insulin release.
301
What is the function of IL-3?
Supports growth and differentiation of BM stem cells. Functions like GM-CSF.
302
What sort of transport is COPII involved in (and from where to where?)
Anterograde: ER-\>cis-golgi
303
Where is vinyl chloride found and what cancer is it associated with causing?
PVC pipes. Liver angiosarcoma.
304
What are bitot spots?
Foamy cornea spots from VitA deficiency.
305
What cancer can have anti-NMDA receptor encephalitis as a paraneoplastic syndrome?
Ovarian teratoma.
306
Mechanism of action and uses of Ustekinumab.
IL-12/IL-23 antibody. Psoriasis, psoriatic arthritis.
307
Mechanism of action and uses of Denosumab.
RANKL antibody. Osteoporosis.
308
What is S-100 a stain for?
Neural crest cells. Melanoma, scheannoma, langerhans cell histiocytosis.
309
Describe Hurler Syndrome.
AR α-L-iduronidase deficiency - Heparan sulfate and dermatan sulfate accumulate. Developmental delay, gargoylism, airway obscturction, corneal clouding, hepatosplenomegaly.
310
Describe Margination/rolling in leukocyte extravasation.
First stage of leukocyte extravasation. Leukocyte sialyl-LewisX binds E-selectin and P-selectin on venule. Leukocyte L-selectin binds GlyCAM-1, CD34.
311
What is CEA a major marker for?
Colorectal and pancreatic cancer.
312
Describe IL-12 receptor deficiency.
AR decreaed Th1 response. Disseminated mycobacterial and fungal infections (may present after BCG vaccine). Decreased IFNγ.
313
Describe a B6 deficiency.
Convulsions, hyperirritability, peripheral neuropathy, sideroblastic anemias.
314
What is isolated atrial amyloidosis?
ANP amyloidosis. Common in aging, increases risk of A-fib.
315
What is lipofuscin made of?
Oxidized/polymerized autophagocytosed organellar membranes.
316
Describe Cori Disease.
GSDIII. α-1,6-glucosidase deficiency. ilder form of von Gierke with normal blood lactate level.
317
What type of receptor is the H2. receptor and what is its function?
Gs. Increased gastric acid secretion by parietal cells.
318
How is Leber hereditary optic neuropathy inherited?
Mitochondrially.
319
What is Carbidopa?
Inhibits DOPA decarboxylase to reduce peripheral metabolism.
320
What is Phentolamine?
A reversible α-blocker.
321
What is Hartnup Disease?
AR deficiency of neutral AA transporters on PCT and on enterocytes. Can cause Pellagra-like symptoms.
322
What are pyknosis and karrhyorexis?
Pyknosis is nuclear shrinkage, karyorrhexis is fragmentation.
323
Describe PFK2.
AKA FBP2. Fasting turns on FBPase activity. High glucose turns on PFK2 activity which makes F-2,6-BP which stimulates glycolysis.
324
What is adrenoleukodystrophy?
AR beta-oxidation disorder where VLCFAs build up in the adrenal glands, white matter, testes. Can cause adrenal crisis.
325
Describe Bruton/X-linked Agammaglobulinemia and list cause.
X-linked recessive BTK defect. Recurrent bacterial and enteroviral infections after 6 months. Absent B-cells in peripheral blood, decreased Igs of all classes, absent/scanty LNs and tonsils. Live vaccines contraindicated.
326
What are two genetic causes of SCID?
Adenosine deaminade deficiency (AR) and IL-2R gamma chain defect (XR, most common).
327
What triggers the extrinsic pathway of apoptosis?
CD8s or FasL binding or TNFα binding.
328
What is a cell surface protein expressed by hematopoietic stem cells?
CD34.
329
What kind of cardiomyopathy is associated with Duchenne's?
DCM.
330
Where are nitrosamines found and what cancer is it associated with causing?
Smoked foods. Gastric cancer.
331
What is Good syndrome?
Hypogammaglobulinemia. Can be a thymoma paraneoplastic syndrome.
332
What is PEP carboxykinase?
Turns OAA to PEP irreversibly in gluconeogenesis. Needs a GTP.
333
What type of hypersensitivity is fibrinoid necrosis?
Type III.
334
How does ethanol affect NADH?
Metabolism increases NADH+NAD+ ratio in liver.
335
What origin is sarcoma?
Mesenchymal.
336
What does a Th17 do?
Induces neutrophilic inflammation.
337
What LNs does the scrotum drain to?
Superficial inguinal.
338
Describe Hunter syndrome.
XR iduronate-2-sulfatase - Heparan sulfate and dermatan sulfate accumulate.
339
Describe how EtOH is metabolized.
Turned into a acetaldehyde via alcohol dehydrogenase (cytosol - makes NADH), catalase (peroxisome), or CYP2E1 (microsome - cost of NADPH). In mitochondria turned into acetate (acetaldehyde dehydrogenase) - makes NADH.
340
What is Apo B-48?
It's in chylomicrons and their remnants - mediate secretion into lymphatics.
341
What is paroxysmal nocturnal hemoglobinuria?
PIGA gene defect preventing formation of anchors for complement inhibitors such as MIRL (CD59) and DAF (CD55). Causes complement-mediated lysis of RBCs.
342
Which part of the lymph node is the site of B-cell proliferation?
Follicle. Primary are dormant, secondary are pale and are active with central germinal centers.
343
What is a chylomicron remnant?
A chylomicron that has lost CII and has had TGs distributed.
344
Describe Niemann-Pick disease.
AR Sphingomyelinase deficiency - sphingomyelin accumulates. Similar to Tay-Sachs, foam cells.
345
What are Gottron papules a sign of?
Dermatomyositis.
346
What are Atropine, Homatropine, and Tropicamide?
Muscarinic antagonists - used largely for eyes, and atropine for bradycardia.
347
What is heteroplasmy?
Variable expression in mitochondrially inherited disease if normal and mutated mtDNA present.
348
Where are chylomicrons and VLDL assembled?
Chylomicrons in the intestine and VLDL in the liver.
349
Describe Krabbe disease.
AR Glucocerebrosidase deficiency - galactocerebroside psychosine accumulates. peripheral neuropathy oligodendrocyte destruction, developmental delay, optic atrophy, globoid cells.
350
What is glucose-6-phosphatase?
Converts G6P to glucose in gluconeogenesis in ER.
351
Mechanism of action and toxicity of Cyclosporine.
Calcineurin inhibitor - binds cyclophilin. Blocks T-cell activation by preventing IL-2 transcription. NEPHROTOXIC, htn, hyperlipidemia, nerotoxicity, gingival hyperplasia, hirsutism.
352
What is the HLA-A3 allele associated with?
Hemochromatosis.
353
What amino acid is involved in melatonin synthesis?
Trp. Trp-\> Serotonin-\>Melatonin.
354
What is LDH a marker for?
Testicular germ cell tumours, ovarian dysgerminoma.
355
Mechanism of action and uses of Omalizumab.
IgE antibody. Refractory allergic asthma.
356
Where in the body does the urea cycle take place?
Liver (and a little kidneys).
357
What mediates cachexia?
TNFs, IFNγ, IL-1, IL-6.
358
What cytokine is a major chemotactic factor for neutrophils?
IL-8.
359
Where is aflatoxin found and what cancer is it associated with causing?
Aspergillus (stored grains/nuts) and Hepatocellular carcinoma.
360
How do you treat BDZ overdose?
Flumazenil.
361
What does aldose reductase do?
Turns glucose to sorbitol and galactose to galactitol. Takes NADPH.
362
What is chronic mucocutaneous candidiasis?
T-cell dysfunction (can be from congenital defect in IL-17 or IL-17R). Absent cutaneous reaction to Candida antigens, absent in vitro T-cell proliferation to Candida antigens.
363
Mechanism of action and toxicity of Tacrolimus.
Calcineurin inhibitor - binds FK506. Blocks T-cell activation by preventing IL-2 transcription. NEPHROTOXIC, htn, hyperlipidemia, increased diabetes risk, neurotoxicity (more than cyclosporine).
364
How does hydroxyurea work?
Inhibits ribonucleotide reductase. Also increases HbF.
365
How is glycogen broken down?
Glycogen phosphorylase removes G1P branches off glycogen until 4 remain, then 4αDglucanotransferase (debranching enzyme) moves 3 off the branch Then α-1,6-glucosidase cleaves off the last residue, freeing glucose. G1Ps are later converted to G6P.
366
Mechanism of action and toxicity of Mycophenolate mofetil.
Reversibly inhibits IMP dehydrogenase. Used for lupus nephritis. GI upset, pancytopenia, htn, hyperglycemia, less nephrotoxic and neurotoxic. Associated with invasive CMV infection.
367
What is Prazosin?
A α1 selective blocker. Used for BPH, PTSD, HTN.
368
How do Trimethoprim and Pyrimethamine work?
Inhibits DHFR in pyrimidine synthesis.
369
Describe medium-chain acyl-CoA dehydrogenase deficiency.
Accumulation of FA-carnithines in blood with hypoketotic hypoglycemia. Vomiting, lethargy, seizures, coma, liver dysfunction, hyperammonemia. Can lead to sudden death in young kids, treat by avoiding fasting.
370
What is the risk of vitamin E excess?
Enterocolitis in infants.
371
Mechanism of action and uses of Eculizumab.
C5 antibody. Paroxysmal nocturnal hemoglobinuria.
372
How does allopurinol interact with azathioprine?
Allopurinol increases 6-MP toxicity by reducing xanthine oxidase activity (degrades 6-MP).
373
What is F-1,6-BPase?
An irreversible gluconeogenesis enzyme, activated by citrate and inhibited by F-2,6-BP.
374
Describe the TCA cycle metabolite order.
OAA + AcCoA -\> Citrate -\> Isocitrate -\> αKG -\> Succinyl CoA -\> Succinate -\> Fumarate -\> Malate -\> OAA.
375
How does p53 function?
It induces p21, which inhibits CDKs (phosphorylate Rb)/ This leads to hypophosphorylation of Rb and the inhibition of G1-\>S progression.
376
What can have pure red cell aplasia as a paraneoplastic syndrome?
Thymoma.
377
What is the mechanism behind febrile nonhemolytic transfusion reaction?
Either type II hypersensitivity against donor HLA and WBCs or it's cause dby cytokines that are created and accumulate during the storage of blood products.
378
Describe systemic primary carnithine deficiency.
Inherited defect of LCFA entry into mitochondria. Weakness, hypotonia, hypoketotic hypoglycemia.
379
What cancers is alcohol associated with causing?
Esophageal SCC and hepatocellular carcinoma.
380
Does insulin phosphorylate or dephosphorylate?
Insulin dephosphorylates.
381
Where does leukocyte extravasation occur?
At the post capillary venule.
382
How far into starvation do you start dipping into adipose stores?
Day 3.
383
What drains to the Celiac LNs?
Liver, stomach, spleen, pancreas, upper duodenum.
384
What does Disulfiram do?
Inhibits acetaldehyde dehydrogenase.
385
What does a Th1 secrete?
IFNγ.
386
What is VitK a cofactor for?
Gamma-carboxylation of Glu residues on clotting proteins, II, VII, IX, X, C, S.
387
How can you be histamine poisoned?
From spoiled dark-meat fish.
388
How are granulomas maintained?
They are made of epithelioid cells with surrounding multinucleated giant cells and lymphocytes. Th1 cells secrete IFNγ which stimulates macrophages to secrete TNFα which induces/maintain granulomas.
389
What receptors do E and NorE prefer?
E prefers β, NorE prefers α1 \> α2 \> β1.
390
What mediates chronic transplant rejection?
CD4 cells respond to recipient APCs presenting donor peptides, including allogeneic MHC. Type II and IV. Recipient T cells react and secrete cytokines - proliferation of vascular SM, parenchymal atrophy, interstitial fibrosis. Arteriosclerosis.
391
What is dry and wet beriberi?
B1 deficiency. Dry is polyneuropathy and muscle wasting, wet has heart failure and edema.
392
What cancer is Schistosoma haematobium associated with?
Bladder squamous cell cancer.
393
How do B cells class switch?
B-cell presents Ag on MHCII to T-cell, CD40 on B cell binds CD40L on Th cell. Th cell secretes cytokines that determines B cell's Ig class switching.
394
What is the function of TNFα?
Activates endothelium - causes WBC recruitment, vascular leak. Causes cachexia in malignancy.
395
Where in the cell does β-oxidation of fatty acids take place?
In the mitochondria.
396
Describe phenylketonuria. How do you treat it?
AR Phe hydroxylase of BH4 deficiency. Intellectual disability, growth retardation, seizures, eczema, fair complexion, musty body odour. Treat by reducing Phe in diet, giving extra Tyr and BH4.
397
How does glucose get converted to fructose?
Glucose to sorbitol via aldose reductase, sorbitol to fructose via sorbitol dehydrogenase.
398
What cytokines induce differentiation into a Th2?
IL-2 and IL-4.
399
What LNs does the anal canal above the pectinate line drain to?
Internal iliac.
400
What does Aldolase B do? What is its deficiency called? What are the symptoms?
Essential in fructose metabolism. Converts F-1,6-BP to G3P and to DHAP (which can be converted to G3P). Also F1P to DHAP and to glyceraldehyde (can be converted to G3P). Deficiency is Fructose Intolerance (AR). F1P accumulates - limited available phosphate which inhibits gluconeogenesis and glycogenolysis. Hypoglycemia, jaundice, cirrhosis, vomiting following consumption of fructose or sucrose.
401
How does the urea cycle connect to the TCA cycle?
Argininosuccinate from the urea cycle can become fumarate from the TCA cycle.
402
What are the proteins for microtubule movement (anterograde and retrograde)?
Kinesin is anterograde and Dynein is retrograde.
403
What is the HLA-DR5 allele associated with?
Hashimoto thyroiditis.
404
What is I-cell disease?
Failure of adding M6P on proteins in the golgi (defect in N-acetylglucosaminyl-1-phosphotransferase) so proteins are secreted extracellularly instead of given to lysosomes. Symptoms: coarse facial features, gingival hyperplasia, kyphoscoliosis, high plasma [] lysosomal enzymes.
405
Where is radon found and what cancer is it associated with causing?
In basements (byproduct of uranium decay). Lung cancer.
406
What can nonbacterial endocarditis be a paraneoplastic syndrome of?
Adenocarcinoma (esp. pancreatic).
407
What mediates hyperacute transplant rejection and what is the effect?
Pre-existing antibodies to donor antigen (type II hypersensitivity). Widespread thrombosis of graft vessels.
408
What does Selective IgA deficiency increase susceptibility to?
Giardiasis.
409
What is the Kozak sequence?
Analogous to the Shine-Dalgarno sequence in E. coli. Initiates translation.
gccgccRccAUGG (where R is a purine A or G)
410
What amino acids are needed for de novo purine and pyrimidine synthesis?
Both: Asp
Purine: also Gly and Gln
