UWorld questions Flashcards
1
Q
Which opioid side effect is the most persistent?
A
Constipation
2
Q
How do opioids lead to urinary retention?
A
Block urinary voiding reflexes and increase sphincter tone and bladder volume
3
Q
What is the anatomical location of the psoas muscle?
A
Anterior surface of transverse process and lateral surface of vertebral bodies T12-L5. Flex thigh at hip, lateral rotation and abduction of hip
4
Q
Define ectopy
A
normal cells/tissues in an abnormal location due to embryonic maldevelopment (ex: Meckel diverticulum has ectopy)
5
Q
Difference between ectopy and metaplasia
A
Ectopy is congenital, metaplasia is replacement with different tissue later on in life
6
Q
How is the thyroid gland formed?
A
Evagination of pharyngeal epithelium and descent into lower neck
7
Q
What is a cause of lingual thyroid?
A
Failure of migration
8
Q
Which cells does a lingual thyroid lack?
A
C cells
9
Q
What is metronidazole used to treat?
A
Trichomonal vaginitis and bacterial vaginosis
10
Q
Which drug interaction with alcohol causes abdominal cramps, nausea, and headache?
A
Metronidazole or Disulfiram
11
Q
Why does Metronidazole-alcohol interaction lead to a reaction?
A
Accumulation of acetaldehyde
12
Q
What are the clinical features of hyperaldosteronism?
A
Hypertension due to water retention, Hypokalemic alkalosis (K+ and H+ being excreted excessive) leading to muscle weakness and parasthesias
13
Q
How does the inhibition of proteosomes affect a cell?
A
Accumulation of toxic intracellular proteins leads to an excess of proapoptotic proteins–> induces cell apoptosis
14
Q
Which condition are proteosome inhibitors (bortezomib) used for?
A
Multiple Myeloma
15
Q
What is multiple myeloma?
A
Malignancy of plasma cells. Neoplastic B cells differentiate into plasma cells and secrete a lot of Ig fragments, leading to bone pain, fatigue, anemia, kidney disease, hypercalcemia
16
Q
Which organ is the primary site of complement production?
A
Liver
17
Q
What are the 2 functions of splenic red pulp?
A
- Destroy aged and abnormal RBCs and serve as emergency store for blood cells and platelets
- Clearance of circulating bacteria that become lodged in cords
18
Q
How much of the body’s antibodies stores are produced by the spleen?
A
50%
19
Q
Asplenic patients are at risk of infection and death by which organisms?
A
Encapsulated bacteria, it Strep pneumo, H. Influenzae, N. meningitidis
20
Q
Patients with chronic granulomatous disease develop infections from which agents?
A
Catalase-positive (ie S. aureus)
21
Q
Defects in Type I interferon increase susceptibility to
A
viral infections
22
Q
Highly active antiretroviral therapy (HAART) is used for which virus?
A
HIV
23
Q
What are the consequences of long-term HAART?
A
High mutation rate of HIV genome, pol gene mutations and emergent of drug-resistant HIV strains
24
Q
HIV viral evasion of humoral immunity is more likely to occur with a mutation to which gene?
A
env
25
HIV Pol gene mutations cause resistance to which drugs?
reverse transcriptase inhibitors and HIV protease inhibitors
26
Which histopathologic finding is associated with Henoch-Schonlein purpura?
IgA deposition in mesangium
27
ATP binding to sarcomere causes
Myosin detachment from actin filament
28
What shifts tropomyosin away from myosin binding site on actin in muscle contraction?
Calcium binding to troponin C
29
What causes keloid or hypertrophic scar?
Excess collagen formation during remodeling phase of wound healing
30
which cytokine is expressed in excess in keloids
TGF-beta
31
What is the pathogenesis of homocystinuria?
AR mutation causing cystathionine synthase deficiency
32
Clinical findings of homocystinuria
optic lens dislocation, intellectual disability, marfanoid habitus (long limbs, long digits), thromboembolic complications
33
Which component is elevated in plasma and urine for homocystinuria?
Homocystine
34
Treatment for homocystinuria
B6, methionine restriction and cysteine supplementation
35
What is a dominant negative mutation
Abnormal gene negatively affects product of wild-type gene in same cell (ie cancer)
36
What is pleiotropy
Occurrence of multiple, seemingly unrelated phenotypic manifestations resulting from a single genetic defect
37
What is locus heterogeneity
Ability of one disease or trait to be caused by multiple mutations in multiple different genes (ie familial hypercholesteremia)
38
What is polycythemia vera?
Myeloproliferative disorder characterized by uncontrolled erythrocyte production
39
What are the symptoms of polycythemia vera?
Aquagenic pruritus, facial plethora (reddish complexion), splenomegaly. Elevated erythrocyte, thrombocyte, leukocyte mass and low EPO.
40
What is mutated in polycythemia vera
Usually cytoplasmic tyrosine kinase (JAK2) of EPO receptor
41
What is c-myc?
Growth-stimulating transcription factor
42
In periods of starvation, what is the primary source of glucose for the first 12-18 hours?
Glycogenolysis (glycogen --> glucose-1-P)
43
After 18 hours of starvation, which process serves to maintain plasma glucose levels in the body?
Gluconeogenesis
44
Which enzyme is part of the committed step in gluconeogensis?
Pyruvate carboxylase
45
Which cofactor is involved in converting pyruvate to OAA via pyruvate carboxylase in gluconeogenesis?
Biotin
46
Which enzymes are unidirectional in Glucose metabolism?
hexokinase, phosphofructokinase and pyruvate kinase
47
McCardle disease is a disorder of which metabolic process?
Glycogen breakdown (Storage disease type V)
48
Which enzyme is deficient in McArdle disease?
Myophosphorylase
49
Clinical presentation of McArdle disease?
Poor exercise tolerance, muscle cramps, rhabdomyolysis ("feel like jelly" exercise, severe muscle cramping and urine discoloration), no rise in blood lactate after exercise
50
Treatment for McCardle?
Consume simple sugars before beginning physical activity
51
Which sequence at the 5' site do spliceosomes recognize
GU
52
Which sequence at the 3' end of an intron do spliceosomes recognize?
AG
53
What is the Pringle maneuver?
Occlusion of hepatoduodenal ligament to prevent bleeding from hepatic artery (can also be used to ID source of bleeding after RUQ trauma)
54
Which structures are contained in hepatoduodenal ligament?
Hepatic artery, portal vein, and common bile duct
55
If bleeding does not cease after Pringle maneuver, what is the likely source?
Inferior vena cava or hepatic vein
56
What is carcinoid syndrome?
Excess release of neurohormonal mediator like serotonin (5-HIAA) from metastatic midgut neuroendocrine tumor
57
How do carcinoid syndrome patients typically present?
Facial flushing, bronchospasm, diarrhea and hypotension
58
What is internuclear ophthalmalgia?
Disorder of conjugate horizontal gaze in which affected eye cannot adduct and contralateral eye abducts with nystagmus
59
which structure is typically damaged in internuclear ophthalmalgia?
MLF in dorsal pons of eye that cannot adduct
60
Which condition causes bilateral internuclear ophthalmalgia?
Multiple Sclerosis
61
What is the most common cause of blood-tinged discharge from the breast?
Intraductal papilloma (Papillary cells with fibrovascular core)
62
How does intraductal papilloma present?
Blood-tinged discharge at breast nipple without masses or skin changes
63
What are some ionic complications of tumor lysis syndrome
Hyperkalemia (K+ leaks out of cell), Hyperuricemia due to rapid turnover
64
What is the function of rasburicase?
Reduce uric acid levels in body by breaking it down into soluble metabolits (allantoin)
65
What are neoplastic colonic polyps?
Serrated
| Adenomatous (tubular, villous, tubulovillous)
66
What are non-neoplastic colonic polyps?
Hyperplastic, submucosal, inflammatory, mucosal
67
Does fibroblast migration occur in PNS, CNS or both?
PNS only
68
What is a rheumatoid factor an antibody against?
Fc component of IgG
69
How does rheumatoid factor lead to synovitis and joint destruction?
Binds Fc portion of IgG, which binds ACPA, forming immune complex that deposits in cartilage and synovium. Complexes activate complement
70
Which condition are anti-centromere antibodies specific for?
CREST syndrome
71
Which condition are anti-dsDNA antibodies specific for?
Systemic Lupus Erythematous
72
Which condition are antimitochondrial antibodies specific for?
Primary biliary cholangitis
73
Antinuclear antibodies are found in which patients
Connective tissue disorders (nonspecific)
74
Which cytokine is anti-inflammatory?
IL-10 (reduces production of TH1 cytokines and MHCII expression)
75
Which leg nerve is most commonly injured?
Common peroneal
76
What can lead to peroneal nerve injury?
Prolonged immobility (hospitalization, surgery, casting) or fibular neck fractures
77
What are the side effects of antimuscarinic/anticholinergic drugs?
Blurry vision, dry mouth, urinary retention, constipation
78
Which nuclei is responsible for perception of motion and orientation and which neurostransmission pathways does it use?
Vestibular nuclei, muscarinic and histaminic
79
What is the presentation of DiGeorge syndrome? (CATCH)
Conotruncal cardiac defects (Tetrology of Fallot, truncus arteriosus, interrupted aortic arch)
Abnormal facies
Thymic hypoplasia/aplasia (T cell deficiency)
Craniofacial deformities (cleft palate)
Hypocalcemia/hypoparathyroidism
80
What is the mutation in DiGeorge syndrome?
22q11 deletion
81
What causes thymic and parathyroid hypoplasia/aplasia in DiGeorge syndrome?
Lack of 3rd and 4th pharyngeal pouches (failed migration of NC cells)
82
Which cardiovascular abnormality does Marfan syndrome present with?
medial necrosis of aorta
83
Which gene defect leads to Marfan syndrome?
Fibrillin mutation
84
Which syndrome presents with crowded teeth and a narrow face?
Marfan syndrome
85
What are the serum levels of calcium and phosphorus in primary hyperparathyroidism?
High calcium, low phosphorus
86
What bone change is seen in primary hyperparathyroidism?
Subperiosteal resorption with cystic degeneration
87
Which three mechanisms lead to hypercalcemia in PHP?
1. increased renal tubular Ca+2 resorption
2. Increased vitamin D production to increase GI Ca+2 rabsorption
3. Bone resorption via osteoclast activation
88
Disorganized lamellar bone structure in mosaic pattern is characteristic of which disease?
Paget's disease
89
Osteoid matrix accumulation around trabeculae is seen in which bone issue?
Vitamin D deficiency
90
Persistence of primary spongiosa in medullary cavity with no mature trabeculae is a classic finding in
Osteopetrosis
91
Which cell is defective in osteopetrosis?
Osteoclast
92
Trabecular thinning with fewer interconnections is characteristic of
Osteoporosis
93
Which clinical feature is characteristic of PTSD?
flashbacks to traumatic event
94
How long is the duration of symptoms for diagnosing PTSD?
over 1 month
95
Where does cutaneous fungi sporothrix schenckii reside?
Bark of trees, shrubs, garden plants and plant debris
96
What is the mode of transmission for Sporotrichosis?
Thorn prick (breaks in skin)
97
How does sporotrichosis spread in the body?
Lymphatics
98
How does a biopsy of sporotrichosis present?
Granuloma consisting of histiocytes, multinucleated giant cells, and neutrophils surrounded by plasma cells
99
What are the clinical features of Wernicke encephalopathy?
```
Oculomotor dysfunction (horizontal nystagmus, bilateral abducens palsy)
Ataxia
Encephalopathy (mental status changes)
```
100
What are the clinical features of Korsakoff syndrome?
Memory loss and confabulation (fabricating stories); anterograde amnesia
101
Which lesion causes Korsakoff syndrome?
damage to anterior and dorsomedial thalamic nuclei
102
During which trimester is there a greatest risk of vertical CMV transmission/
1st trimester
103
What are CMV-related complications in a newborn?
chorioretinitis, sensorineural deafness, seizures, jaundice, hepatosplenomegaly, microcephaly
104
Which congenital viral infection is associated with cataracts?
Rubella
105
How do you calculate TPR of vessels arranged in parallel?
1/TPR= 1/R +1/R' +....
106
How do you calculate TPR of vessels arranged in series?
TPR = R + R' + R''....
107
Why is visual acuity in the macula greater than any other area of the retina?
Each macular cone synapses to a single bipolar cell, which synapses to a single ganglion cell
108
Define scotoma
Visual defect surrounded by relatively unimpaired field of vision
109
What causes arcuate scotomas ?
Damage to optic nerve head
110
Why do adolescents typically have irregular menstrual cycles?
Immature hypothalamic-pituitary axis leads to presence of anovulatory cycle
111
What is an anovulatory cycle and what does it cause?
Failure of LH to induce ovulation, leading to high estrogen levels and low progesterone so uterus remains in proliferative phase. Can lead to irregular periods with heavy bleeding
112
Which patients are at risk of atypical hyperplasia of endometrium?
Older obese women and women receiving estrogen without progesterone (HRT)
113
Which settings lead to hypertonic volume contraction (increased serum osmolarity, decreased ICF and ECF)
Free water loss (Diabetes insipidus, excess sweating, dehydration)
114
Which setting leads to isosmotic volume contraction? (lower ECF, no change in ICF)
GI hemorrhage (diarrhea) because you're losing both water and electrolytes
115
Which ICF and ECF compartment changes does adrenal insufficiency lead to?
Loss of salt in ECF leads too ICF expansion and ECF contraction (decreased osmolarity)
116
Which gene mutation is found in follicular thyroid cancer and some follicular adenomas?
RAS gene mutation (MAP kinase)
117
Which gene mutation leads to familial medullary thyroid cancers?
RET proto-oncogene (MEN2)
118
What is the histologic presentation of medullary thyroid cancer
(parafollicular calcitonin C cell cancers)?
spindle-shaped cells in amorphous background
119
Which nerve is associated with the first pharyngeal arch?
Trigeminal (CN V)
120
Which bony derivatives are associated withe first pharyngeal arch?
Maxilla, zygoma, mandible, incus, malleus
121
What are the muscular derivatives of the first pharyngeal arch?
muscles of mastication
122
Which nerve is associated with the second pharyngeal arch?
Facial (CN VII)
123
Which bony and muscular derivatives come from the 2nd pharyngeal arch?
styliod process of temporal bone, lesser horn of hyoid, stapes; muscles of facial expression
124
List the nerves affiliated with pharyngeal arches 1, 2, 3, 4 and 6 respectively
CN V, VII, IX, X
125
What is Osgood-Schlattler disease?
Overuse injury to second ossification center of tibial tubercle?
126
What causes Osgood-Schlatter disease?
Repetitive quadriceps contraction, common in adolescent athletes after growth spurt
127
Runners presenting with anteromedial knee pain likely hav ewhich condition?
Pes anserinus bursitis
128
List the 5 stages of Elizabeth Kubler-Ross's grief model
Denial, Anger, Bargaining, Depression, Acceptance
129
What is the micturition reflex?
Autonomic spinal reflex at S2-S4 that regulates urination
130
What causes urge incontinence in MS patients?
Demyelination of S2-S4 leads to loss of communication with cortical inhibitory centers so detrusor and internal urethral sphincter are hyperactive
131
Monitoring the degree of chest expansion in a patient with HLA-B27 antigen serves to monitor which disease?
Ankylosing spondylitis
132
What is the most common cardiovascular complication of ankylosing spondylitis?
Ascending aortitis (can lead to aortic insufficiency)
133
What is the respiratory complication of ankylosing spondylitis?
Involvement of thoracic spine and costovertebral/costosternal junctions leading to hypoventilation
134
What is a visual complication in patients with ankylosing spondylitis?
Anterior uveitis (pain, blurred vision, conjunctiva, photophobia)
135
Lateral epicondylitis of the elbow can lead to issues with which muscular function?
Wrist extension
136
Where are receptors containing zinc-fingers (zinc bound to cysteine and histamine) likely found?
Intracellularly in cytoplasm or nucleus interacting with DNA
137
Which molecules usually bind zinc-finger receptors?
Steroids, steroid hormones, thyroid hormones, and fat-soluble vitamins
138
How does estrogen activity influence Thyroid binding globulin, free T4 and T3 levels?
Increase in estrogen increases TBG levels, leading to reduced free T4 and T3
139
What is the transient effect of increased estrogen on TBG, total T4 and T3
Leads to an increase total T4 and T3 until increase TBG is saturated
140
What is the clinical presentation of acute arsenic poisoning?
Nausea, vomiting, watery diarrhea, delirium, hypotension, QTc prolongation and garlic odor of breath**
141
How does arsenic poisoning lead to sx?
binds to sulfhydrl groups, disrupts cell respiration and halts gluconeogenesis and glutathione metabolism
142
What is the first-line treatment for arsenic poisoning?
Dimercaprol
143
How does dimercaprol treat arsenic poisoning?
Increases urinary excretion of heavy metals by forming stable, nontoxic chelates
144
What does CaNa2EDTA treat?
Acute lead poisoning
145
How does acute lead poisoning present?
constipation, anemia, irritability and confusion
146
What is the antidote for cyanide poisoning?
Hydroxycobalamin (B12 precursor)
147
How does cyanide poisoning present?
Confusion, skin flushing, abdominal pain, vomiting
148
What is the Tensilon test (edrophonium infusion) used for?
dx myasthenia gravis (sx improve) and cholinergic crisis (sx do not improve)
149
What causes a cholinergic crisis in a myasthenia gravis patient?
Overstimulation of nicotinic receptors leading to prolonged refractory periods
150
How does one treat cholinergic crisis in a myasthenia gravis patient?
Temporarily stop AchE inhibitor (pyridostigmine)
151
What is pralidoxime used for?
Organophosphate poisoning
152
What does minimal alveolar concentration serve to measure?
potency of an inhaled anesthetic (lower MAC = higher potency)
153
What measures solubility of an anesthetic in tissues?
Arteriovenous concentration gradient (onset of action... high = slow)
154
What measures solubility of anesthetic in blood?
Blood/gas partition coefficient (higher coefficient = slower onset)
155
Where in the cell is structural (rRNA) syntehsized?
nucleolus
156
How does insulin promote glycogen synthesis?
Activates PI3K, which activates protein phosphatase, which activates glycogen synthase
157
What is the surface receptor for insulin?
Intrinsic tyrosine kinase
158
Which second messenger system do peptide hormones and and cytokines rely on?
JAK kinase
159
What is Colchicine used for?
Acute or chronic gout
160
What is the mechanism of Colchicine?
Binds tubulin and inhibits microtubule polymerization to inhibit neutrophil chemotaxis and phagocytosis to reduce inflammation
161
Which drugs are the most affective for acute treatment of RA?
Glucocorticoids and NSAIDs
162
Which drugs is first-line for chronic management of RA?
Methotrexate
163
Which lesion leads to a positive Babinski sign?
UMN
164
Describe Metronidazole's bacteriocidic function
Disrupts DNA structure and causes strand breakage
165
Describe vancomycin's bactericidal function
Inhibits cell wall synthesis.
166
Which three antibiotics are used to treat C Diff?
Metronidazole, Vancomycin and Fidaxomicin
167
How is Fidaxomicin bacteriocidal against C. Diff?
Inhibits sigma subunit of RNA polymerase (protein synthesis impairment)
168
Which part of the intestine is commonly involved with Crohn's disease?
Terminal ileum
169
Which substances are absorbed at the terminal ileum?
Bile acids and Vitamins ADEK
170
What is status epilepticus?
Long-lasting, continuous seizures that can be life-threatening (treat with benzos)
171
Which caspases are activated by the extrinsic pathway? (FasL-Fas)
Caspases 8 and 10--> 3 and 6 (executioners)
172
How does defective Fas-FasL lead to autoimmune disease?
Allows accumulation of autoreactive T cells
173
Which interaction stimulates isotype switching?
CD40 on B cells interact with CD40L on T cells
174
Clinical signs of Multiple Myeloma
60s, bone pain, fatigue, anemia, kidney disease, hypercalcemia
175
How do proteosome inhibitors lead to apoptosis?
Allow accumulation of toxic intracellular proteins, which leads to excess of proapoptotic proteins
176
Which structures does the femoral nerve run through?
Laterally between psoas and iliacus, and beneath inguinal ligament into thigh
177
Which enzyme breaks down glycogen in glycogenolysis?
Glycogen phosphorylase
178
What activates glycogen phosphorylase?
Phosphorylase kinase
179
What activates phosphorylase kinase in the liver for glycogenolysis?
cAMP (via increased Gs protein activation by epinephrine and glucagon)
180
What activates phosphorylase kinase in the muscle?
Increased intracellular calcium for glycogenolysis?
181
Clinical presentation of Acute Rheumatic Fever pancarditis
Young child, new holosystolic murmur, nonspecific fever, fatigue and anorexia. Biopsy shows Aschoff body.
182
What is an Aschoff body?
Plump macrophage with abundant cytoplasm and central, slender chromatin; replaced by fibrous scar tissue
183
How does hypersensitivity myocarditis manifest?
Interstitial infiltrate of eosinohils after medication admin (antibiotics, diuretics)
184
Which two anthracyclines cause dilated cardiomyopathy?
Doxorubicin, danorubicin
185
Biopsy of doxorubicin cardiomyopathy
Patchy fibrosis with vacuolization and lysis of myocytes
186
What agent causes Chagas disease?
Trypanosoma Cruzi (from South America)
187
What causes hypoxic-ischemic encephalopathy?
Profound systemic hypotension (eg due to cardiogenic shock or arrest)
188
How does hypoxic-ischemic encephalopathy appear on biopsy?
Bilateral Wedge-shaped strips of necrosis over cerebral convexity
189
Which 2 neural cells are most vulnerable to ischemic injury?
Pyramidal cells of hippocampus and Purkinje cells of cerebellum
190
What would cause unilateral wedge-shaped infarcts in the brain?
Severe carotid artery stenosis
191
Hemorrhage involving deep brain structure (basal ganglia, pons, thalamus) occurs due to
Charcot-Bouchard aneurysm rupture (hypertension, smoking)
192
Lacunar infarcts in the BG, internal capsule, pons or thalamus occur due to
Hypertensive arteriolar sclerosis in pts with long-standing hypertension
193
Clinical presentation of hypertensive encephalopathy
Headache, vomiting, confusion-- eventual coma and death
194
In cardio, "right and left" refer from perspective of
patient
195
What is capitation?
Arrangement in which payor (individual, employer, government entity) pays a fixed, predetermined fee to cover all the medical services required by a patient (underlies HMO provider networks)
196
What is global payment
Insurer pays doctor a single payment to cover all expenses associated with care (elective surgery)
197
Antibiotic/antifungal CYP450 inhibitor (increase potency)
Metronidazole, -azoles
198
List 8 CYP450 inhibitors
1. Acetominophen/NSAIDs
2. metronidazole, -azoles
3. Amiodarone
4. Cimetidine
5. Cranberry juice, Ginkgo biloba, Vitamine E
6. Omeprazole
7. Thyroid hormone
8. SSRI
199
List 5 CYP450 inducers (decrease efficacy)
1. Carbamazepine/phenytoin
2. Ginseng, St. John's wort
3. oral contraceptives
4. phenobarbital
5. rifampin
200
Weaknness in thumb opposition indicates damage to
median nerve
201
Weakness in thumb adduction and finger abduction indicates damage to
ulnar nerve
202
In which two parts of the arm is the radial nerve vulnerable to injury?
humeral midshaft and superficial course of axilla
203
Which precursor gives rise to beta-endorphins, ACTH, and MSH (melanin precursor)?
POMC (proopiomelanocortin)
204
Which hormone is prolactin structurally similar to?
Growth hormone
205
Which hormone is Somatomedin C similar to?
Insulin
206
What is the function of Somatomedin C?
Released in response to growth hormone, stimulates growth in target cells
207
What is the difference between inactivated (killed/component) viral vaccines and live-attenuated viral vaccines?
Inactivated vaccines generate a humoral immune response (B cells). Live attenuated vaccines generate a strong cell-mediated response in addition to humoral immunity
208
How do inactivated vaccines prevent viral entry into cell?
Humoral antibodies bind to viral glycoproteins and inhibit its entry
209
What is the function of interferon alpha and beta released from infected cells?
Induce synthesis of antiviral proteins in neighboring cells to reduce viral infectivity (replication and assembly)
210
How do alkylating agents in chemotherapy induce damage?
Cause DNA cross-linking
211
What is pulsus parvus et tardus
slow-rising, low amplitude pulse due to diminised stroke volume and prolonged LV ejection time (due to aortic stenosis or LV outflow tract obstruction)
212
How are acute obstructive pulmonary exacerbations treated?
beta-adrenergic agonists (relax bronchial smooth muscle)
213
What is the second messenger of the Gs pathway in beta2 receptors?
cAMP
214
Increased calcium influx in smooth muscle leads to
Increased contraction (worsens shortness of breath)
215
Which pathogens are most often responsible for secondary bacterial pneumonia following a viral infection?
Strep pneumo, Staph aureus, H. influenzae
216
Which pathogen is most responsible for pneumonia in alcoholics and IV drug users
Klebsiella pneumoniae
217
What is heteroplasmy
The condition of having different mitochondrial genomes within a single cell, affecting severity of mitochondrial dz based on proportion of abnormal to normal mitochondria
218
Baker's cysts and peripheral artery aneurysms are usually due to dysfunction in which artery
Popliteal
219
Penetrating the anterior superior iliac spine would damage which nerve/
Lateral cutaneous nerve of thigh
220
Presence of cord factor in TB, giving it a "serpentine" appearance corresponds with its
Virulence (Mycobacteria without cord factor cannot cause disease)
221
What is the function of cord factor in TB
Inactivate neutrophils, damage mitochondria and indce release of TNF
222
What is the function of sulfatides in TB/
Inhibit formation of phagolysosomes, allowing mycobacteria to persist intracellularly iin macrophage
223
What type of channel is the CFTR protein?
ATP binding cassette
224
Which ion does the CFTR channel transport
Cl- out of the cell
225
What is the probe in a Southwestern blot and what does it detect?
dsDNA, DNA-binding proteins (transcription factors)
226
What is probe in Northern blot and what does it detect
RNA; ssDNA or RNA
227
What is probe in Southern blot and what does it detect
DNA; ssDNA or RNA
228
What is probe in Western blot and what does it detect?
Antibody; protein
229
Which two factors affect separation on gel electrophoresis?
Size and charge
230
What type of molecules are c-Jun and c-Fos
Nuclear transcription factors that directly bind DNA via leucine zipper motif
231
What does Ras code for
membrane-bound G protein (MAP kinase pathway)
232
What type of molecule is S-100
Homodiemeric calcium-binding protein; marker for cells of neural crest derivation, Langerhans cells and other dendritic cells
233
Which enzyme metabolizes cGMP in cells?
Phosphodiesterase
234
What causes severe hypotension when Nitrates and PDE inhibitors are taken together
Accumulation of cGMP
235
How does pregnancy increase the risk of venous thromboembolic disease?
compression of vena cava and internal iliac veins leading to stasis and increase in coagulation factor production
236
Best management of early pregnancy thromboembolic disease
Low-molecular-weight heparins (enoxaparin)
237
Clopidogrel mechanism and 3 uses
Blocks platelt ADP receptor and limits aggregation; used for coronary artery disease, acute coronary syndrome and prevenvtion of ischemic strokes
238
Reddish skin discoloration, tachypnea, headache, tachycardia and N/V with confusion and weakness indicates which poisoning?
Cyanide
239
How do inhaled amyl nitrites treat cyanide poisoning?
Convert Fe+2 to Fe+3 (methemoglobin), which binds cyanide more avidly and precipitates out in urine
240
Hydroxycobalamin (B12 precursor) and sodium thiosuflate are antidotes for which poisoning
Cyanide
241
Nutritional deficiencies (wet beriberi, chronic anemia) can result in which type of cardiomyopathy?
Dilated
242
What is the vascular origin of IVH in neonates?
Germinal matrix
243
Which murmur is best heard over cardiac apex while patient is in left lateral decubitus position at end of expiration?
S3 (brings heart closer to chest wall)
244
Arterial puncture of the common femoral artery above the inguinal ligament increases risk of hemorrhage in which location?
Retroperitoneal space
245
Where does a ruptured ectopic pregnancy bleed into?
Pelvic artery
246
Define orthostatic hypotension
Frequent cause of lightheadedness and syncope; significant drop in systolic and diastolic BP on standing from supine position
247
Common cause of orthostatic hypotension
alpha-1 antagonists (terazosin, doxazosin)
248
Two malignancies associated with EBV
Nasopharyngeal carinoma and Burkitt lymphoma
249
Which to autoantibodies are highly specific for SLE?
Anti-Smith (snRNP) and Anti-dsDNA
250
What is tachyphylaxis?
Rapidly declining effect of medicine after a few days of use due to body's compensatory response
251
Long bone fractures increases the risk of which type of embolism and how is it stained?
Fat embolism, black stain with osmium tetroxide
252
Three key features of fat embolism
Respiratory distress, thrombocytopenia (petechiae), non-focal neurologic symptoms (confusion)
253
Side effect of Methotrexate when used for RA
Insterstitial pneumonitis and fibrosis
254
Performed between 6th and 8th ribs along midclavicular line, 8th and 10th ribs along midaxillary line, or 10th and 12th ribs along paravertebral line
Thoracentesis
255
Which ultrastructural change indicates irreversible cell injury?
Vacuolization and appearance of phospholipid-containing amorphous densities within mitochondria
256
What are psammoma bodies?
Laminated calcium deposits
257
What is a hallmark of ischemic injury
Cytoplasmic Ca++ accumulation
258
Why do cells depolarize in ischemic injury?
Intracellular ATP is depleted, Na+/K+ ATPase stops functioning so Na+ leaks into cell, K+ leaks out causing depolarization
259
Autosomal dominant mutation of fibrillin-1. Presents as Marfanoid habitus, aortic root dilation, upward lens dislocation
Marfan syndrome
260
Autosomal recessive mutation of Cystathione beta synthase. Presents with intellectual disability, thrombosis, downward lens, megaloblastic anemia, fair complexion and Marfanoid habitus
Homocystinuria (buildup of methionine and homocysteine in body)
261
Autosomal dominant disorder of joint hypermobility, skin laxity, abnormal wound healing and easy bruising- mutation in Type V collagen
Ehler-Danlos syndrome
262
Binds b-tubulin of microtoubules to inhibit their breakdown and halt cells in M phase. Coats stents to prevent intimal hyperplasia
Paclitaxel
263
Most common cause of congenital hyperammonemia
Deficiency of Ornithine transcarbamylase
264
What builds up in ornithine transcarbamylase deficiency?
Carbamoyl phosphate--> orotic acid
265
Which cerebral herniation compresses CN III
Uncal herniation (inner temporal lobe)
266
Which cerebral herniation compresses ACA
Subfalcine herniation
267
Hemangioblastoma in the cerebellum, cysts in kdneys in pancreas, clear cell renal carcinoma and pheochromocytoma are associated with which condition
Von Hippel Lindau syndrome
268
De novo pyrimidine synthesis with CO2 occurs in the
cytosol
269
De novo purine synthesis occurs in the
cytosol
270
Maturity onset diabetes of the young is a mild form of diabetes due to mutation in
Glucokinase
271
Which molecule stains positively with acid-Schiff
Glycogen
272
Pathogen that causes osteomyelitis in patients with SCD
Salmonella (H2S producing)
273
Vasogenic edema results from
Disruption of blood brain barrier, typically due to tumors
274
Best treatment for peripheral artery disease
Cilostazol
275
Treats PAD by reducing platelet activation. Inhibits platelet phosphodiesterase and dilates arteries to reduce claudication sx.
Cilostazol
276
Treatment of hepatic encephalopathy
Rifaximin and Lactulose
277
How does lactulose decrease serum ammonia
It's a sugar that is digested by intestinal flora, which release H+ and convert ammonia to soluble ammonium
278
How does Rifaximin treat hepatic encephalopathy
Nonabsorbable anitbiotic that acts on GI flora to decrease intestinal production and absorption of ammonia
279
Which diuretics are recommended in patients with acute decompensated heart failure and reduced ejection fraction?
Mineralocroticoid receptor antagonists (potassium sparing) like Spiirnolactone, eplerenone
280
What is the initial step in pathogenesis of beta thalassemia?
DNA mutations affect mRNA processing
