Everything week 6 Flashcards
1
Q
Smoking not only worsens the complications of ___ but increases the likelihood of developing this disease?
A
Diabetes
2
Q
This disease is characterized by abnormal systemic proliferation of mast cells and increased histamine release?
A
Systemic Mastocytosis
3
Q
How does histamine release in mastocytosis produce the symptoms seen in this disease?
A
Histamine release causes hypersecretion of gastric acid by parietal cells (diarrhea) + other symptoms including hypotension flushing & pruritus.
4
Q
Systemic mastocytosis is often associated with mutations in the ____?
A
KIT receptor tyrosine kinase
5
Q
How can galactosemia present?
A
Vomiting and lethargy soon after breastfeeding, impaired liver function (precursor accumulation), and renal dysfunction and predisposed to E Coli sepsis.
6
Q
What are the dysfunctional enzymes in the two types of galactosemia?
A
Galactokinase deficiency - GALK (galactokinase)
Classic galactosemia - GALT (galactose-1- phosphate uridyl transferase)
7
Q
The 2 most important factors for osteoclastic differentiation are?
A
M-CSF macrophage stimulating colony
and RANK-L (receptor for activated nuclear factor kappa -B)
Produced by osteoblasts and bone marrow stromal cells.
8
Q
What is the first line tx for gonorrhea infection?
A
Macrolide and 3rd generation cephalosporin (ceftriaxone and azithromycin) - due to concerns about resistance and chlamydia co-infection.
9
Q
Cavernous sinus thrombosis is most commonly due to contiguous spread of an infection from the ____ (3 places?
A
Medial third of the face, sinuses (ethmoidal or sphenoidal) or teeth.
10
Q
Cavernous sinus thrombosis often presents with these symptoms?
A
HA?fever, diplopia and injury to CN 3, 4, 6 (ocular muscles) and 5 (loss of corneal reflex and upper facial sensation).
11
Q
LH levels in PCOS are high/low?
A
High
**due to altered hormonal feedback response.
12
Q
What medication can be used to treat PCOS?
A
Clomiphene - SERM. Prevents -ve feedback inhibition in the hypothalamus and pituitary by circulating estrogen -> increased FSH and LH & ovulation.
**treats fertility
13
Q
Acute and painless monocular vision loss is characteristic of?
A
Central retinal artery occlusion.
Most common cause: emboli. Others: temporal arteritis (giant cell)
14
Q
This condition often occurs with more than half of patients with temporal arteritis?
A
Polymyalgia rheumatica (characterized by neck, torso, shoulder and girdle pain and morning stiffness).
15
Q
Presentation of temporal arteritis?
A
HA (focal over temple)
Craniofacial pain (jaw or tongue claudication and facial pain)
If with polymyalgia rheumatica - shoulder, neck, torso pain.
Sudden vision loss (dreaded complication)
16
Q
How do OCPs work?
A
Decrease LH -> decrease androgen production. Increase SBG (sex binding globulin) decrease free testosterone.
17
Q
DUring menopausal transition what happens to FSH levels?
A
Increase (due to resistant ovarian follicle and lack of feedback from inhibin)
**Elevated FSH levels is diagnostic
18
Q
The biggest risk of hookworm infection is?
A
Iron deficiency anemia.
Will aslo px with transient, pruritic, maculopapular rash.
** Dx - stool microscopy. Eosinophilia is also important diagnostic clue
19
Q
What is the enzymatic defect found in homocystinuria.
A
Unable to convert homocysteine -> cysteine (defect of cystathionine synthase). Converted instead to methionine.
**So cysteine will be essential in the diet
20
Q
What is the presentation for homocystinuria?
A
HOMOCYstinuria H- homocysteine in urine O- Osteoporosis M- Marfan habitus O - ocular disturbances (lens displacement) C - CV defects Y - kYphosis
21
Q
Colchicine is a treatment for _____ gout?
A
Acute (especially in patients with NSAIDs contraindications e.g PUD).
22
Q
Methadone ( a mu opioid agonist) is metabolized by?
A
P450 system - especially CYP3A$4.
**Inhibitors can increase plasma concentration and lead to opioid toxicity.
23
Q
Prodrome of measles?
A
Cough, congestion and conjunctivitis followed by maculopapular rash that spreads, cephalocaudal and centrifugally.
24
Q
Which vitamin is a recommended supplementation during a measles infection?
Why?
A
Vitamin A (prevents and treats ocular complications and reduces risk of other comorbidities (pneumo & encephalitis))
Measles depletes vitamin A stores
25
What is the Thayer-Martin medium used to identify?
Pathogenic Neisseria organisms.
26
What Antibiotics does the Thayer Martin Medium contain?
Vancomycin (to inhibit gram +)
Colistin & TMP (to inhibit gram -ve other than Neisseria)
Nystatin (to inhibit yeast)
27
In breast cancer, overlying skin retractions (puckering) signal involvement of ___?
Suspensory ligaments of the breast (cooper ligaments). Malignant infiltration leads to shortening and fibrosis.
28
Treatment of streptococcal upper respiratory infection with __ can prevent development rheumatic fever.
Penicillin V
29
Candidemia (systemic candida infection) can be attributed to these causes?
Vascular catheter, skin & soft tissue infection.
30
Which pathway is the main source of NADPH?
PPP
| affected in G6PD deficiency
31
Why is this pathway important?
Major pathway for generation of reduced glutathione (an antioxidant)
Biosynthesis of FA, cholesterol and CYP450
Phagocytic cells generating respiratory burst via NADPH oxidase
32
MOA of Adalimumab?
Recombinant igG that binds to TNF -alpha (inflammatory cytokine involved in promoting leukocyte migration, neutrophil and macrophage function and granuloma activity).
33
Mechanism of failure of Adalimumab?
Can become less effective overtime due to formation of anti drug antibodies and les to more rapid drug clearance.
34
Dx of HSV encephalitis?
Temporal lobe hemorrhage/edema on brain imaging, PCR for HSV.
35
How are the two ways that HSV can become present in the body?
Oropharyngeal infection that travels via the olfactory tract or from the reactivation of latent virus in trigeminal ganglion.
36
Functions of LH and FSH in males?
LH -> testosterone from Leydig cells
FSH -> inhibin from Sertoli cells in the seminiferous tubules. Also produces Androgen binding hormone (responsible for high local testosterone concentration)
37
MAOis are especially helpful in the treatment of this type of depression?
Treatment-resistant depression with atypical features; mood reactivity - mood improves in response to positive events, leaden paralysis - patients limbs feel heavy, rejection sensitivity and increased sleep and appetite).
38
Functions of LH and FSH in the ovaries?
LH -> androgen and progesterone synthesis in theca interna
FSH-> aromatase converts androgen to estradiol in granulosa cells.
Theca externa serves as connective tissue
39
A posterior hip dislocation will present physically as?
Adducted and Internal rotated
** Sciatic nerve will be affected.
40
What pathway connects the hypothalamus to the pituitary gland and is responsible for the tonic inhibition of prolactin secretion?
Tuberoinfundibular pathway.
**antipsychotics disrupt this pathway
41
What neural pathway connects the Broca and Wernicke areas?
Arcuate fasciculus
**disruption -> conduction aphasia (fluent speech, intact comprehension and impaired repetition)
42
What type of medication is Anastrozole?
Aromatase inhibitor (often used to treat ER+ breast cancer) by decreasing the synthesis of estrogen from androgens, decreasing estrogen levels.
43
The superior gluteal nerve innervates what muscles?
Lesion to this nerve can cause?
Gluteus medius and minimus & tensor fascia latae.
+ trendelenburg sign
44
Psoas abscess presents with these symptoms and is often due to ?
Fever, flank pain, pain with extension (psoas sign)
Direct or Hematogenous spread in immunocompromised patients (or IV drug use)
45
Psoas sign is also present in this condition?
Retrocecal appendicitis (irritates r. psoas m)
46
In lactate dehydrogenase deficiency, why is glycolysis inhibited?
Because exercising muscle cells cannot regenerate NAD+ (from pyruvate conversion to lactate).
47
Px for congenital hypothyroidism?
```
slowed metabolism (constipation, poor feeding lethargy).
Umbilical hernia macroglossia and large anterior fontanelle.
```
**may progresses to irreversible neuro damage.
48
Tx for hypothyroidism?
Levothyroxine
49
In tetanus (clostridium tetani) from puncture wounds, the toxin blocks release of?
Glycine and GABA (leads to disinhibited motor neurons -> muscle spasms and hyperreflexia).
**is a clinical diagnosis only
**The toxin migrates by retrograde axonal transport. Other symptoms; lock jaw or trismus and backward arching (opisthotonos)
50
What food product is often implicated in infant botulism?
Honey
**blocks release of Acth
51
What is often the first manifestation of infant botulism?
DX?
Constipation.
Days to weeks later: mild weakness, lethargy & reduced feeding, flaccid paralysis.
Toxin in stool samples
52
What is often the first line therapy for Essential tremor treatment?
B - blocker (often propranolol) - prevent Epi and NE interaction with receptor.
53
A cystic tumor in the cerebellum of a child is most likely?
pilocytic astrocytoma
**well differentiated neoplasm composed of spindle cells with hair like glial processes associated with microcysts. Mixed with Rosenthal fibers and granular eosinophilic bodies
54
This is an indication of damage to the facial n. close to its origin from the brainstem?
Hyperacusis (increased sensitivity to sound)
*Nerve to the stapedius m, is one of first branch of facial n.
55
These drugs and hepatic cholesterol production;
Simvastatin?
Cholestyramine
Decreased (by inhibiting HMG COA reductase) -> decreased hepatic synthesis ->
upregulate LDL receptors -> increasing uptake
Increased
Bile acid binding resins interfere with enterohepatic circulation of bile acids -> increased excretion -> increased synthesis of new bile acids -> deplete liver stores.
56
Meningioma histopathology?
Slow growing, well circumscribed, whorled pattern of cellular growth that forms nests that may calcify into round eosinophilic psammoma bodies.
** can px with seizures
57
Which is the most sensitive test for primary hypothyroidism TSH or T3/T4?
TSH
58
The golgi tendon circuit is -ve feedback system that regulates and monitors?
Muscle tension (not length aka stretch).
Intrafusal muscle fibers are sensitive to muscle length
59
Monomicrobial cases of Necrotizing fasciitis can be due to this bacteria?
Strep pyogenes
**is also PYR +ve (pyrrolidonyl arylamidase)
60
Primary blood supply to the ACL?
Middle geniculate artery
**ACL tears -> acute onset of hemarthrosis.
61
I primary osteoporosis what are the serum concentrations of calcium, phos and PTH?
All typically normal
62
Craniopharyngiomas arise from?
How many components do these tumors typically have?
What are they?
Rathkes pouch
3 components
Solid, cystic and calcified
63
What is the most common disorder of the urea cycle?
Ornithine transcarbamylase deficiency (OTC)
64
How do urea cycle disorders typically present?
Vomiting, tachypnea and confusion coma (secondary to
| Increased ammonia) and increased urinary orotic acid.
65
Most common cause of nipple discharge (serous or bloody)?
Intraductal papilloma ( proliferation of papillary cell in a cyst wall or duct with fibrovascular core).
** patients will typically have no masses or skin changes
66
The etiology fo Polyhydramnios is due to? (2)
Decreased fetal swallowing (GI obstruction -- duodenal, esophageal or intestinal atresia) and anencephaly or increased fetal urination
67
What is a Rheumatoid factor?
IgM antibody that targets IgG Fc region
**will also see HLA-DR4 (4 walled rheum)
68
In distal clavicle fracture, the deltoid muscle and weight of arms cause ____ displacement of lateral fragment?
Inferolateral
**SCM and trapezius cause superior medial displacement
69
Dermatomyositis or polymyositis may occur alone or in combination with?
Paraneoplastic syndrome associated with underlying adenocarcinoma (ovary, lung, pancreas).
70
Insulin dependent transporters (GLUT 4) is expressed in these cells?
Skeletal muscle cells and adipocytes
| Translocate GLUT4 to membrane in response to increasing insulin levels.
71
These two physical features are specific for Graves dz?
Pretibial myxedema and Graves ophthalmopathy. Accumulation of glycosaminoglycans in these tissues
72
Symptoms of spinal stenosis are ____ dependant?
Positional/posture
73
The most common cause of spinal stenosis?
Degenerative arthritis
This leads to narrowing of the spinal canal due to disc herniation, ligamentum flavum hypertrophy and osteophyte formation.
74
Which muscle form the levator ani muscles?
Illiococcygeus, pubococcygeus and puborectalis
*injury to these muscles lead to urethral hypermobility and/or prolapse
75
Why does propofol have short duration of action?
Rapidly distributed to others organs (initially accumulates in organs with increased blood flow then redistributes to organs receiving less blood flow).
76
Treatment of CAH should target this hormone.
ACTH - low dose exogenous steroids will negatively feedback on ACTH decreasing androgen production.
77
In Niemann-Pick disease, what is deficient, what accumulates?
Sphingomyelinase deficiency
Sphingomyelin ( lipid constituent if cell membranes)
Lipid foam cells accumulate in the liver and spleen (hepatosplenomegaly). in neurons - neurodegeneration, in the retina - cherry-red spot.
78
MI in which leads often lead to bradycardia?
Inferior leads.
**MI affects RCA which controls SA and AV node.
79
What can be used to treat bradycardia caused by inferior MI?
Atropine (prevents vagal stimulation)
80
WHat effect does atropine have in the eye?
Mydriasis (contraindicated in pts with glaucoma)
81
Most common causes of HIV esophagitis?
Candida, CMV and HSV
82
Functions of osteocytes?
Osteocytes communicate via?
Detect mechanical stress and modulate activity of surface osteoblasts (regulate bony remodeling) & control short term release and deposition of calcium.
Gap junctions in their calculi
83
Enzymes for the following rxns?
Tyrosine -> Dopa
Dopa-> Dopamine
Dopmaine -> NE
NE-> E
Tyrosine hydroxylase
Dopa decarboxylase
Dopamine B-hydroxylase
PNMT (this is regulated by cortisol)
84
While dopamine and NE are produced primarily in the CNS, where is Epinephrine primarily produced?
Primarily stimulated by?
Adrenal medulla
Cortisol
85
What do COMT and MAO do to NE & Epi?
Inactivates NE & E (turns them normentanephrine & metanephrine -> MAO converts to vanillymandelic acid.
86
What component of the prostate gland in BPH does finasteride work on?
Epithelial component
They can be either predominant epithelial or stromal component (collage or smooth muscle predominance)
87
What is finasteride?
5-alpha reductase inhibitor
88
What is the most sensitive imaging method for diagnosis vertebral osteomyelitis?
MRI
89
Carnitine deficiency impairs what function in fatty acid metabolism?
Transport across the plasma membrane from the cytoplasm to mitochondria (preventing B-oxidation into acetyl-coa)
**this will px with cardiac and skeletal myocyte injury due to lack of ATP and impaired production of ketone body by liver during fasting (acetyl-coa -> TCA cycle or Ketone body)
90
When is Reverse T3 (rT3) generated?
Peripheral conversion of T4
91
What is the function of aromatase in the ovaries, placenta, testes and other peripheral tissues?
Convert androgen -> estrogens
**Placental aromatase deficiency causes accumulation of androgen during pregnancy -> affects infant.
92
A patient with carpel tunnel syndrome will present with?
Thenar atrophy, weakness of thumb opposition and pain and numbness.
**can be treated with surgical decompression (longitudinal incision)
93
Acalculous cholecystitis commonly occurs in this population?
Critically ill patients (sepsis, severe burns, trauma, immunosuppression).
**Will see fever, RUQ pain +ve murphy, and leukocytosis in absence of stones
94
In stress hyperglycemia which GLUT transporter is up regulated? down-regulated?
GLUT 1 brain and macrophages
GLUT 4 - to prevent uptake by peripheral tissues.
95
What is implicated in the pathology of giant cell (temporal arteritis)?
Cell-mediated process. Production of cytokines especially IL6 correlates with severity of disease.
**Tx with a monoclonal antibody against IL-6 (tocilizumab)
96
Which ovarian tumor will present with virilization?
Leydig-sertoli tumor
**Arise from sex chord stroma and secrete testosterone
97
How can anticonvulsants that induce CYP450 lead to osteoporosis?
Increased vitamin D catabolism
98
Where do medullary thryoid cancer arise?
Often seen in the context of?
Associated with mutations in?
C cells (calcitonin secereting parafollicular cells)
MEN (A&B)
RET prontoncogene
99
Examples of HLA class II proteins?
DR, DQ, DP
100
Seronetive spondlyitis are associated with this disorder?
Individuals expressing this are at greater risk for seronegative spondyloarthropathies?
IBD
HLA B27
101
Cancers from the pelvis to the lumbosacral spine (e.g spread of prostate cancer) occur via this path?
Vertebral venous plexus, which communicated the the prostatic venous plexus.
102
1 alpha hydroxylase that activates vitamin D is down regulated by this?
FGF23 (which in increased in
| CKD)
103
Inheritance pattern on duchenne muscular dystrophy?
This condition induces weakness of these muscles?
X-linked recessive
Proximal muscles (will see hypertrophy of distal muscles which are later replaced by fat)
104
iron absorption occurs mainly in the ___ of the stomach?
Duodenum and proximal jejunum
| will be affected in gastrojejunosomy
105
In primary hyperaldosteronism, what happens to sodium concentration
Despite increased re-absorption, the levels remain normal due to aldosterone escape (limits edema and hypernatremia via activation of atrial naturetic peptide).
106
What are clue cells?
Epithelial cells covered with gram variable rod, found in bacterial vaginosis (Gardenella)
107
How many days after fertilization does a blastocyte implant?
6 day. B-hCG is produced by the syncytiotrophoblast after implantation. Can start seeing B-hCG in serum after day 8.
Urine -> after 14 days
108
Can the liver use ketone bodies? Yes/No
| Why/ Why not?
No
Does not have the enzyme to convert acetoacetate -> acetoacetyl cOA
109
What is an important predictor of insulin resistance?
Visceral obesity (waist circumference or waist -hip ratio)
110
What are the factors that make up metabolic syndrome?
Insulin resistance, increased visceral adiposity, hypertension & lipid abnormalities (high TAGs or low HDL)
111
Loss of red reflex is often indicative of these conditions?
Retinoblastoma or cataracts
112
What is the pathology of cataracts formation in diabetics?
Poly-ol pathway becomes saturated. Poly-ol pathway is glucose -> sorbitol -> fructose. In diabetes, the pathway is overwhelmed and accumulation of sorbitol which leads to oxidative and osmotic stress -> diabetic retinopathy -> catarcts
113
What hyperlipidemia drug can lead togallstones?
How does this occur?
Fibrates
Fibrates inhibit cholesterol 7-alpha hydroxylase (rate limiting step in synthesis of bile acids -> decreased cholesterol solubility -> formation of stones.
114
Intermittent administration of PTH analog (e.g teriparatide) causes?
osteoblast activity > osteoclast activity -> net increase in bone formation
115
What is neurophysin?
Carrier proteins for oxytocin and ADH (from production in paraventricular and supraoptic nuclei -> site of release in posterior pituitary)
** point mutations in neurophysin underlie most cases of diabetes insipidus (due to decreased ADH)
116
Pathogenesis of alchohol induced hepatic steatosis?
Decreased in fatty acid oxidation due to Excess NADPH produced by two major alcohol metabolism enzymes alcohol and aldehyde dehydrogenase
117
MOA of leuprolide?
GnRH analog. Long term use surpress LH release -> decreased testosterone production.
**leuprolide can be used in lieu of GnRH
118
The most common cause of a pneumoperitoneum is?
A perforated duodenal ulcer.
119
What is the most common outcome for pneumoperitoneum?
Peritonitis -> diffuse abdominal pain with rebound and guarding and referred shoulder pain due to diaphragmatic irritation
120
What are some risk factors for primary psoas abscess development?
IV drug use, HIV and diabetes mellitus
121
What is an accurate and non invasive method of diagnosing pancreatic insufficiency?
Low fecal elastase
122
How would leukocyte adhesion deficiency present?
| What is the genetic basis for LAD?
Constant infection without purulence and persistent leukocytosis (unable to migrate out of blood vessels). Also late separation of umbilical cord.
Autosomal recessive - absence of CD18 (necessary for integrin formation).
123
Where do squamous cell carcinomas of the neck typically spread first to?
Cervical (jugular) LN via lymphatics
124
Carbon monoxide affects the ___ NOT the ____ of oxygen in the blood.
Carrying capacity not the partial pressure (amount of O2 dissolved in the blood)
125
Explain the process of a cohort study?
Follow a group over time and track development of disease.
126
Bile stone color and associated conditions.
Black pigment stone? Contain what?
Brown stones?
Chronic hemolysis (hemolytic anemia) and increased enterohepatic cycling of bilirubin. Both increase levels of unconjugated bilirubin and increase levels of Calcium bilirubinate(ileal disease)
Brown stone s- biliary tract infection (microbes producing B-glucorinidases)
127
When does carcinoid tumor cause problems?
After metastasis (extra intestinal). If confined to the Gi often o not cause any symptoms because they are metabolized by the liver.
128
What is the function of the Kozak consensus sequence?
Helps with initiation of translation. Occurs on eukaryotic mRNA.
**gCCgCC (Rcc) preceeds start codon AUG. Where R is either A or G.
129
Apart from hereditary spherocytosis what other situations can cause spherocytosis?
Bone marrow response to immune mediated hemolytic anemia (igG coated RBC are taken out by spleen)
**will also see reticulocytes, larger than RBC (with bluishish coloration due to presence of ribosomes) AND RBC with nucleus (immature)
130
What genetic mutation is often associated with myeloproliferative disorders?
JAK/STAT Tyrosine kinase
131
Function of Ristocetin cofactor assay?
Activates GP Ib so in vWF disorder, this will be abnormal.
132
A delayed hemolytic transfusion reaction is often due to?
This reaction occurs in patients that were previously exposed to foreign minor RBC blood cell antigens.
** these are often mild and occur >24 hours after a transfusion.
133
Exertional heat stroke can trigger this condition?
DIC - leads to increase in thrombin, fibrin and plasmin
**will show thrombocytopenia and prolonged PT & PTT
134
How is hemophilia inherited?
X-linked recessive
135
Patients that undergo splenectomy often develop this cells with this feature?
Target cells - increased cell membrane or reduced cell volume (because the spleen often trims excess cell membrane)
136
What are the two mechanisms by which hydroxyurea works?
Increases HgbF
| And inhibits ribonucleotide reductase (causing cell cycle arrest of rapidly diving hematopoietic cells)
137
What is responsible for the thrombotic and thromboembolic complications of nephrotic syndrome?
Loss of anticoagulant factors especially antithrombin III
138
How does Heparin induced thrombocytopenia occur?
IgG against heparin and platelet 4. Ab coated platelets are taken out by the spleen.
139
How does follicular lymphoma present?
Painless waxing and waning lymphadenopathy
| 14:18) -> Bcl-2 over expression (has anti-apoptotic effects
140
What is the most common cause of anti-phospholipid syndrome?
SLE
141
What features would you need to diagnose Antiphospholipid syndrome?
```
Lab findings of lupus anticoagulant (prolonged PTT not corrected by addition of plasma).
Anti cardiolipin (can cause false + VDRL/RPR) & anti- Beta 2-glycoprotein I
Recurrent thrombosis or spontaneous abortions.
```
142
In acute intermittent porphyria (AIP), what is the deficient enzyme?
Px?
Tx?
Porphobilinogen deaminase.
Px: Precipitated by drugs, with Painful abd, Port wine colored stain, Poly neuropathy, Psych disturbance
Tx with dextrose infusion and hemin (heme preparation)
143
Maturing erythrocytes lose their ability to synthesize heme when they loose their?
Mitochondria
144
How do you notice B cell in histology?
Abundant basophillic cytoplasm & Clockface (peripheral) chromatin
145
Enzyme deficiency in the early stages of heme synthesis present with?
Late stage?
Early stage - Neuro symptoms and Abd pain
Late stage - photosensitivty (blister formation in sun exposed areas, edema, pruiritus)
146
This drug is a factor Xa decoy without proteolytic effect, it is given to reverse Xa inhibitors who have life threatening bleeding?
Andexanet alfa
147
Most carcinoma spread to other sites via?
Lymphatics
148
Rituximab targets whats antigen?
CD20
149
EPO uses this signal transduction pathway?
JAK/STAT
150
G6PD deficiency has this inheritance pattern?
X-linked recessive
**males are most affected
151
Spherocytosis inheritance pattern?
Autosominal Dominant
152
What signal transduction pathway does HER2 oncogene use?
What does HER2 code for?
Tx?
Tryosine Kinase
Human epidermal growth factor (activation -> apoptosis resistant & increased proliferation)
Tratuzumab
153
Warfarin induced skin necrosis is often caused by patients that are deficient in?
Protein C or S
154
How is epidermal growth factor receptor activated?
Constitutive KRAS activation.
155
Adhesion to cells of the ECM involves integrin binding to these components extracellularly?
Intracellularly?
Extra: Collagen, fibronectin and laminin
Intra: Actin and keratin (intermediate filaments)
156
In Polycythemia Vera, the bone marrow is more sensitive to?
Growth factors (via JAK Kinase mutation)
157
vWF is inherited in this pattern?
AD
158
The surface marker for macrophages is?
CD14
159
Wiskott-Aldririch syndrome is characterized by the triad of?
Eczema, thrombocytopenia and combined B and T cell deficiencies (infections).
160
Pathology and presentation of cyanide poisoning.
Cyanide binds to Fe3+ (ferric) -> inhibition of cytochrome C - oxidase > inhibition of ETC -> switch to lactic acidosis.
Px: red discoloration of skin, tachypnea/cardia, HA -> progress to seizure and death
161
Treatment for cyanide poisoning? MOA?
Inhaled amyl nitrite.
MOA; Converts iron in Hgb from Fe2+ -> Fe3+ -> conversion of Hgb to methamoglobin -> binds and sequesters cyanide (has preference for ferric iron state)
162
Anemia of chronic disease is a consequence of chronically elevated cytokines especially?
Hepcidin. Inactivates iron channels on enterocytes and macrophages -> decreased iron absorption.
163
What are some of the things that can disrupt INR findings in patient on warfarin?
Increase: Decrease in vitamin K (via diet or disruption of colonic flora which produce vitamin K)
Incr/Decr: CYP450 alteration
164
Where are the two places that heme is synthesized?
Liver cells (for CYP enzyme system) & Bone marrow fro Hgb use.
165
How does hypocalcemia occur in Multiple Myeloma?
Destruction of OPG and upregulation of RANK-L -> activation of osteoclasts and inhibition of osteoblasts (via cytokine secretion)
166
What molecule is considered to be the central regulator of iron homeostasis?
Hepcidin. Many of its function is via interaction with ferroporitin (transfers intercellular iron into circulation). High levels -> decrease iron levels. Low levels -> increase iron levels.
167
Cancer related cachexia is driven by __ and occurs via ____ pathway.
Cytokines (TNF-alpha & IL6)
Ubiqutin-proteosome pathway (targeted protein degradation)
168
Pure red cell aplasia (absence of erythroid precursors) is associated with these conditions?
Thymoma, leukemias (IgG or CD8 inhibit erythropoietic precursors) and parvovirus B19 infection (preferentially attacks proerythroblasts)
169
Proxysmal Nocturnal hemoglbinuria is due to mutated _____. This leads to the unattachment of CD ___ that helps RBC to _____?
PIGA gene
CD 55
Inactivate complement
170
What happens in Factor V Leiden?
Mutation in Protein C binding site, so it is unable to be inactivated by protein C
171
Patients with Sickle cell often have a ___ deficiency due to?
Folic acid deficiency due to increased folic acid requirement due to rapid RBC turnover.
172
What are melanocytes embryologically derived from?
Neural crest cells
173
Xeroderma pigmentosum is due to defect in?
Nucleotide excision repair caused by UV light
174
Erythema multiforme is a ____ shaped inflammatory skin lesion that typically arises in the setting of_____?
Caused by?
Target shaped
Setting of inflammation
deposition if infectious antigen in keratinocytes -> strong cell mediated cytotoxic immune response
175
Keloid formation is due to?
Inactivation of TGF-B (promote differentiation of fibroblasts into myofibroblast) on completion of wound repair.
176
Vitamin D analog is used in tx for psoriasis, why?
Inhibit T cell and kertinocyte proliferation.
**use corticosteroid as well
177
Along with antinflammatory actions, corticosteroids also affect the skin by?
decreasing production of ECM collagen and glycoaminoglycans
178
Deficiency of ascorbic acid can lead to petechial hemorrhages, how?
Defect in collage (vitamin C is needed in the hydroxylation of proline; a component of collagen)
* Pt will also px with gingivitis and impaired wound healing
179
Severity of leprosy is dependent on?
TH1 response. If strong -> tuberculoid (TH1 -> macrophage activation). If weak -> lepromatous
180
Acute allergic dermatitis (type IV HS) histology is characterized by?
Spongiosis (accumulation of edema fluid in intracellular spaces)
181
Hair loss (androgenetic alopecia) has this inheritance pattern?
Polygenic (genetic - hormonal and environmental)
**others- glaucoma, schizophrenia, T2D
182
What is Kobners phenomenon and in what condition is it commonly found?
Development of plaques on body surfaces that are prone to trauma/friction
Psoriasis
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How does late state radiation dermatitis present?
Ulcerating skin with hypopigmentation and telangiectasias at site of prior radiotheraphy.
Histo changes: vascular abnormalities & fibroblast proliferation and homogenization of dermal collagen due to Increased TGF-B
**occurs months to years after radiation
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Features of lichen planus?
CD 8 mediated response: Chronic hyperkeratosis
lymphocytic infiltrates at dermo-epidermal junction (interface dermatitis)
Scattered eosinophilic, colloid (civatte) bodies in papillary dermis
Thickened stratum granulosum with saw sooth ridges
