Mixed Flashcards
1
Q
What is the cause of a hydatid cyst in the liver?
A
Echinococcus granulosus is most common (tapeworm from dogs, sheep)
2
Q
What can occur if you rupture a hydatid cyst?
A
Anaphylaxis from spilling of the larvae
3
Q
Where does the trigeminal nerve exit the brainstem?
A
Lateral aspect of the mid-pons, at the level of the middle cerebellar peduncles
4
Q
What do infarcts in the anterior portion of the medial pons produce?
A
Dysarthria and contralateral ataxic hemiparesis
5
Q
What is the latent period?
A
Time elapsed from clinical exposure to clinically apparent disease, OR when exposure to risk modifiers occurs a significant amount of time before the exposure’s effect on the disease process in clinically evident
6
Q
What is the inheritance of classical galactosemia?
A
Autosomal recessive
Like most diseases due to enzyme deficiency
Defective galactose-1-P uridyltransferase gene
7
Q
What is the inheritance of Lesch-Nyhan?
A
X linked recessive
Deficiency of hypoxanthine phosphoribosyltransferase, an enzyme that promotes conversion of hypoxanthine to IMP and guanine to GMP (pure salvage)
8
Q
What is missing in typical PKU?
A
Phenylalanine hydroxylase, which converts Phe to Tyr
9
Q
What is missing in atypical PKU?
A
Dihydrobiopterin reductase (BH4)
This is a coenzyme for the Phe > Tyr and Tyr > DOPA rxns
10
Q
What are the signs of fragile X in males?
A
- Mild-mod mental retardation
- Long face, prominent jaw, large ears, cleft palate
- Macroorchidism (large testes)
- Mitral valve prolapse
- Joint laxity, scoliosis, pes cavus, double jointed thumbs, single palmar crease
11
Q
What is the advantage of selective COX2 inhibitors over COX1 & 2?
A
COX2 selective have anti-inflam effects without side effects of bleeding and GI ulceration assoc with non-selective.
Selective COX2 do not impair platelet fx because platelets express COX1
12
Q
What is the treatment for an infant undergoing opioid withdrawal?
A
Tincture of opium
13
Q
What is the mechanism of pathogenicity that allows E coli to cause UTIs?
A
P pili/fimbriae
These allow adherence to urothelial cells
14
Q
What is the mechanism of pathogenicity that allows E coli to cause watery diarrhea?
A
Heat stable/heat labile enterotoxins
Promotes fluid and electrolyte secretion from intestine
15
Q
What is the mechanism of pathogenicity that allows E coli to cause bloody diarrhea?
A
Shiga-like toxin/verotoxin
Inactivates 60s ribosomal component, halting protein synth and causing cell death
16
Q
What is the mechanism of pathogenicity that allows E coli to cause neonatal meningitis?
A
K1 capsular polysacchardie
Prevents phagocytosis & complement-mediated lysis
17
Q
What is the mechanism of pathogenicity that allows E coli to cause bacteremia & septic shock?
A
Lipopolysaccharide (LOS)
Macrophages activates by LOS causes widespread release of cytokines IL-1, IL-6, & TNF-a
18
Q
What is treatment for narcolepsy?
A
Madafenil, a psychostimulant
19
Q
Where is resistance in the airway the highest? the lowest?
A
Most of the total airway resistance comes from the first 10 generations of bronchi.
Relatively high in the trachea and mainstem bronchus.
Then increases to maximal in the 2nd-5th gen airways.
The small airways contribute very little because sum of x-sectional area increases massively.
20
Q
What is the root of the sciatic nerve?
A
L4-5, S1-3
21
Q
What symptoms does compression of S1 produce?
A
Pain purely in the posterior thigh and leg, shooting into inner foot, + LESS ANKLE JERK
22
Q
What symptoms does compression of L5 produce?
A
Posterior AND lateral thigh pain, leg pain, shooting into inner foot.
23
Q
What is the cellular receptor for Rabies?
A
nicotinic acetylcholine R (the glycoprotein studs of the virus bind)
24
Q
What is the cellular receptor for CMV?
A
Cellular integrins
25
What is the cellular receptor for EBV?
CR2 (CD21)
26
What is the cellular receptor for HIV?
CD4 and CXCR4/CCR5
27
What is the cellular receptor for Rhinovirus?
ICAM1 (CD54)
28
What is the motor result of hydrocephalus?
Muscle hypertonicity and hyperreflexia
Result of UMN damage caused by stretching of perventricular pyramidal tracts
29
What recognizes stop codons to terminate protein synth?
```
Releasing factors recognize:
UAA
UGA
UAG
and facilitate release of polypeptide chain form ribosome, and dissolution of ribosome-mRNA complex
```
30
What is the role of microglia in ischemic infarct?
Move to area of infarct after 3-5 days, and phagocytose fragments of neurons, myelin, and necrotic debris.
ASTROCYTES form the glial scar later.
31
What do penicillins and cephalosporins bind to?
Penicillin binding proteins, such as transpeptidases
These fx to cross link peptidoglycan in the cell wall
PBPs can mutate so that antibiotics can no longer bind (one method of resistance)
32
What accumulates in the phagocytes of patients with hemolytic anemia or those who receive repeated blood transfusions?
Hemosiderin
Iron chelation therapy
33
What nerves provide motor innervation of the tongue
Hypoglossal, CN XII
Palatoglossus muscle is CN X
34
What nerves provide generally sensory innervation to the tongue (touch, pain, pressure, temp)?
Anterior 2/3 = CN V3 (mandibular)
Posterior 1/3 = CN IX (glossopharyngeal)
Posterior area of the tongue root = CN X (vagus)
35
What nerves provide gustatory innervation to the tongue?
Anterior 2/3 = CN VII (chorda tympania of facial nerve)
Posterior 1/3: CN IX (glossopharyngeal)
Posterior area of the tongue root + taste buds of larynx and upper esophagus = CN X (vagus)
36
When is serum b-hcg detectable?
Implantation occurs 6 days post-fert
b-hcg may be detectable in maternal serum by 6-8 days
Low threshold for detection (1 IU/L)
37
When is urine b-hcg detectable?
14 days after ovulation (4 wks LMP)
Threshold for detection is much higher (20 IU/L)
38
What is the most common benign vascular tumor in adults?
Cherry hemangiomas
Small, bright red, papular lesions
Common with aging adults
Do not regress spontaneously and increase in number with age
39
What are the negative side effects of Lithium?
Hypothyroidism
Nephrogenic DI
Monitor routinely
40
What are the clinical features of rabies infection?
Encephalitic
- Hydrophobia
- Aerophobia
- Pharyngeal spasm
- Spastic paralysis
- Agitation
Paralytic
- Ascending flaccid paralysis
41
What is the treatment for rabies exposure?
Post-exposure prophylaxis includes rabies IgG and vaccination
- Not effective after onset of sx
42
What is the germinal matrix?
high cellular and vascular layer in the subventricular zone of fetuses
- area from which many neurons and glial cells migrate out during brain development
- contains thin walled vessels without glial fibers that support other blood vessels
- risk of hemorrhage if premature
43
Where does intraventricular hemorrhage (IVH) originate in a premature neonate?
Germinal matrix
44
What is the primary route of entry for Cryptococcus?
lungs
45
What is the cause of hyperacusis (increased sensitivity to sound?)
Paralysis of the stapedius muscle
Innervated by the stapedius nerve, branch of the facial nerve
46
Where are enhancer sequences located relative to the transcription start site?
Anywhere upstream, downstream, or within the transcribed gene!
47
Where are promoter sequences located relative to the transcription start site?
Usually 25-70 bases upstream from associated genes
48
What is akithesia?
Subjective restlessness, inability to sit still
Extrapyramidal side effect of antipsychotic meds
Decrease the dose of meds or prescribe a beta blocker/benzo to add on
49
What is caused by occlusion of the anterior cerebral artery?
Motor and sensory deficit of contralateral LOWER extremity
| - Also behavioral changes and urinary incontinence
50
Why isn't production of antibodies to the envelope proteins of hepatitis enough to confer immunity?
Envelope proteins vary their antigenic structure
51
What type of bond is responsible for the secondary structure of proteins?
Hydrogen bonds
| - Form alpha helices or beta sheets
52
What types of bonds are responsible for the tertiary structures of proteins?
Ionic bonds, hydrophobic interactions, hydrogen bonds, disulfide bonds
53
What is the main measure of association in a case-control study?
Exposure odds ratio
| Compares exposure of people who have the disease already to those who do not
54
What is the main measure of association in cohort studies?
Relative risk and relative rate
| People are followed over time
55
What is the cause of the rapid plasma decay of thiopental anesthesia?
Tissue redistribution
| - Not metabolism/elimination
56
What does the arteriovenous concentration of a drug tell us about its effect?
AV concentration reflects the overall tissue solubility of the anesthetic.
High tissue solubility = large AV gradient = slower onset of action
This means you need more anesthetic to replace that which is being absorbed peripherally
57
What symptom remains a risk after organophosphate poisoning is treated with atropine?
Muscle paralysis
- Atropine stops the muscarinic effects but not the nicotinic
Pralidoxime reverses both musc and nic effects by restoring cholinesterase
58
What are the muscarinic effects of organophosphate poisoning?
```
Diarrhea, diaophoresis
Urination
Miosis (constriction)
Bronchospasm
Emesis
Lacrimation
Salivation
```
59
What are the possible cytogenetic roots of Down's Syndrome?
1. Meiotic nondisjunction (95%)
2. Unbalanced Robertsonian Translocation, extra 21 attached to another chromosome (2-3%)
3. Mosaicism: parents have 2 cel lines, one with normal and another with trisomy 21 (minority)
60
What is the function of neuraminidase inhibitors?
Stop release of virus from infected cells
61
What is a neuraminidase treatment for flu?
Oseltamivir
- Used in influenza A and B
- Impairs release of newly formed virions
62
What is the best way to prevent neonatal tetanus?
Vaccinate pregnant women with tetanus toxoid, allowing transfer of IgG antitoxin Abs across the placenta to the fetus
63
What lesion along the optic tract is most likely to cause nasal hemianopia?
Impingement upon the optic chiasm at the ipsilateral temporal (lateral) side, taking out fibers that read the nasal visual field
Note: lesion to the retina will more likely produce a scotoma/blind spot, because you'd have to take out the whole hemi-retina to lose the entire nasal field of vision
64
In the neuronal AP, when is K+ permeance highest?
At the start of reploarization
65
What NTs require dihydrobiopterin reductase (BH4)?
Catecholamines
- DA, NE, E ( Phe > Tyr > DOPA)
- Serotonin (Tryp > 5HT)
BH4 is a cofactor in the starting reactions listed here
66
What is Toxic Shock Syndrome?
Staph aureus produces toxic schock syndrome toxin (TSST-1), a superantigen that activates a lot of T cells.
T cells: release IL-2
Macros: release IL-2
Create capillary leakage, circulatory collapse, hypotensino, shock, fever, skin findings, and multiorgan failure.
67
What are the toxins with superantigen activity?
Enterotoxins
Exfoliative toxins
Toxic Shock Syndrome Toxin
Superantigens interact with MHC on APCs and the variable region of the T-lymphocyte receptor to cause nonspecific, widespread activation of T cells.
68
What determines whether a protein that has ben clonally expanded can be identified by a DNA probe?
The protein must be able to bind DNA, so must be:
- TF
- Steroid
- Thyroid protein
- Vitamin D receptor
- Retinoic acid receptor
- DNA transcription/rep protein
- Etc.
69
What is the mechanism of terbinafine?
Terbinafine inhibits squalene epoxidase, thereby inhibiting fungal membrane ergosterol synthesis.
Used for rx in dermatophytosis
70
What is the most severe complication of halothane anesthesia?
Liver failure
- Massive centrilobular hepatic necrosis
- Injury by halothane metabolites and formation of autoantibodies against liver proteins
71
What does a trachea deviated towards the side of the lung problem indicate?
Volume loss of some sort, atelectasis
72
What does a trachea deviated away from the side of the lung problem indicate?
Pleural effusion
73
What does pulmonary opacification and deviation of the mediastinum towards the opacified lung indicate?
Likely obstructive lesion in mainstem bronchus, preventing ventilation of entire lung
74
What is the most common cause of meconium ileus?
CF
75
What does the S100 tumor marker indicate?
Neural crest origin
Likely Schwannoma or melanoma
76
What occurs when the maxillary prominence fails to fuse with the intermaxillary segement?
Cleft lip
77
What happens when the palatine shelves of the maxillary prominence fail to fuse with one another, or with the primary palate?
Cleft palate
78
What is the malformation in cleft lip?
The maxillary prominence fails to fuse with the intermaxillary segment
79
What is the malformation in cleft lip?
The palatine shelves of the maxillary prominence fail to fuse with one another, or with the primary palate
80
What is the treatment for Chlamydia (+Gonorrhea)?
Macrolides!
- Azithromycin
- Erythromycin
And Doxycycline
81
What is the treatment for genital herpes?
Acyclovir (valacyclovir, famiciclovir)
Nucleoside analog, terminates DNA synth
82
What is the distinction between brief psychotic disorder, schizophreniform disorder, and schizophrenia?
6mo = schizophrenia
83
What is Enterococcus' resistance to aminoglycosides?
Produce modifying enzymes that transfer chemical groups (Acetyl, adenyl, phosphate) to the antibiotic outside of the bacterium, decreasign the ability of the drug to bind to ribosomes and exert antimicrobial effets
Gentamicin is an affected aminoglycoside
84
What are the indications of Diazepam?
1. Anxiolytic: GAD, panic
2. Sedative-hypnotic: insomnia
3. Anticonvulsant: status epi
4. Muscle relaxant: anit spasticity
85
What is the most common side effect of Diazepam (and what meds should be avoided with it for this reason)?
Sedation
Avoid other sedation causing drugs, like first-gen antihistamines
86
Which DNA polymerase has exonuclease activity to remove improper base-pairs during replication?
All of them! I, II, and III
87
What enzyme removes supercoils in DNA rep in prok?
Topoisomerase II
88
What enzyme unwinds the double helix in prok?
Helicase
89
What enzyme stabilizes unwound template strands in prok?
Single stranded binding proteins (SSB)
90
What enzyme makes RNA primer in prok?
Primase (of RNA polymerase)
91
What enzymes do DNA synthesis in prok?
Leading strand: DNA pol III
| Lagging strand: DNA pol III (also)
92
What enzyme removes RNA primer and replaces RNA with DNA (Proofreading) in prok?
DNA pol I (5' exonuclease)
93
What enzyme joins Okazaki fragments (lagging strang) in prok?
DNA ligase
94
What are the symptoms of Serotonin Syndrome?
1. NMJ excitation: hyperreflexia, clonus, myoclonus, rigidity
2. Autonomic stimulation: hyperthermia, tachycardia, diaphoresis, tremor
3. Altered mental status: agitation, confusion
95
What is an antibiotic that can cause Serotonin Syndrome?
Linezolid
96
What are some non-antidepressants that cause Serotonin Syndrome?
I TOLT you not to take those together!
Tramadol (analgesic)
Ondansentron (anti-emetic, 5HT3 antag)
Linezolid (antibiotic)
Triptans (neuropsychiatric)
97
What are some antidepressants that cause Serotonin Syndrome?
SSRIs
SNRIs
MAOIs
Tricyclics
98
What is rebound rhinorrhea?
Nasal congestion without cough, sneezing, or postnasal drip that results from overuse of topical nasal decongestants
This is an example of tachyphylaxis
99
What is tachyphylaxis?
Rapidly declining effect of a med after a few days of use
In the example of ephedine nasal decongestants:
- Alpha adrenergic agonists cause vasoconstriction of nasal mucosa, thereby decongesting
- Overuse results in decreased production of endogenous NE because of negative feedback
- Resulting relative vasodilation
100
What is the function of the ventromedial hypothalamus?
Satiety center.
| - Lesion = hyperphagia, obesity, and aggression
101
What is the function of the lateral hypothalamus?
Signals hunger.
| - Lesion = starvation, failure to thrive
102
What is the function of the anterior hypothalamus?
Cooling center.
| - Lesion = no vasodilation or sweating, hyperthermia
103
What is the function of the posterior hypothalamus?
Heating center
| - Lesion = can't conserve heat or produce heat when body is cold
104
What is the function of the supraoptic nucleus of the hypothalamus?
Supraoptic and paraventricular nuclei produce ADH, oxytocin.
| Carried down axons to the posterior pituitary, which releases them.
105
What is the function of the suprachiasmatic nucleus of the hypothalamus?
Regulate circadian rhythm
- Receive retinal input
- Relay info to pineal gland
106
What does a Schilling Test with normal excretion after B12 excretion tell you?
The problem is B12 intake
Need B12 + IF + good gut to absorb and excrete properly. If you add back the first ingredient and get excretion > 5%, know the other factors are functioning and you were missing B12.
107
What does a Schilling Test with normal excretion after B12 + IF tell you?
Pernicious anemia
Gut absorbs B12 + IF, and if you don't have both, can't absorb normally or excrete normally.
108
What does a Schilling Test with low excretion after B12 + IF tell you?
Malabsorption
- Pancreatic insufficiency
- Bacterial overgrowth
- Short gut
Normally, radiolabeled B12 + IF is absorbed int he gut and excreted in the kidneys. If it isn't absorbed, can't be excreted normally.
109
When red neurons seen after ischemia?
12-28 hours
Eosinophilic cytoplasm, pyknotic nuclei, loss of Nissl substance
110
What does propionic acidemia indicate?
Deficiency of propionyl coA carboxylase
Propionyl coA is derived from amino acids:
- Val, Ile, Met, Thr
Cannot be fully metabolized in this condition.
111
What is pica?
Abnormal compulsive consumption of a non-food or non-staple food. Associated with iron deficiency anemia.
Ice is the most common ingested substance!
112
What is the number needed to harm? How is it calculated?
Calculate the percent of the adverse event happening int he treatment group (ex. 60/80 = .75)
Calculate the percent of the adverse event happening in the placebo group (ex. 38/76 = .5)
NNH = 1/attributable risk
NNH = 1(.75-.5) = 4
113
What is the syndrome underlying facial dysmorphia + cleft palate + chromosome 22 del?
DiGeorge
22q 11.2 deletion!!!
114
What is the syndrome underlying cystic hygroma + lymphedema + diminished peripheral pulses?
Turner's Syndrome! XO
115
What is phenotypic mixing of bacteria?
Co-infection of a host cell by two virus strains, resulting in progeny virions that contain surface proteins from both strains
BUT there is no change in the underlying viral genome (no genetic exchange), so the next gen reverts to the normal unmixed phenotypes
116
What is the cause of ataxia telangiectasia?
AR disorder in DNA repair genes
Hypersensitivity to ionizing radiation
117
What are the manifestations of ataxia telangiectasia?
- Cerebellar ataxia
- Oculocutaneous telangiectasias
- Repeated sinopulmonary infections
- Increased incidence of malignancy
118
What nerve is responsible for the afferent limb of the pupillary light reflex?
CN II (optic nerve)
119
What nerve is responsible for the efferent limb of the pupillary light reflex?
CN III (oculomotor nerve)
120
What is a thalamic stroke/syndrome?
Total sensory loss on the contralateral side of the body
- No motor deficits
- Proprioception is affected > fall
121
What is a risk factor for lacunar infarct?
Small vessel lipohyalinosis and atherosclerosis involving the penetrating vessels supplying deep brain structures
122
What does vitamin E deficiency cause?
Neuro changes; degen of:
- Spinocerebellar tracts
- Dorsal column of spinal cord
- Peripheral nerves
Mimics Friedrich's ataxia
123
What are precipitating factors of a G6PD deficiency (hemolytic anemia)?
1. Infections
2. Drugs: dapsone, antimalarials, sulfas
3. DKA
4. Fava beans
124
How do most enveloped viruses acquire a lipid bilayer envelope, and how do herpesviridae differ?
1. Most bud through the plasma membrane of host cell
| 2. Herpes bud through the host cell nuclear membrane
125
What meds cause anti-muscarinic side effects (flushing, mydriasis)?
```
Atropine
TCAs (Amitryptyline)
H1 receptor antihistamines (Diphenhydramine)
Neuroleptics
Antiparkinsonian drugs
```
126
What is the product of c-myc?
TF controlling cell prolif, diff, and apoptosis
Seen in Burkitt's lymphoma t(8, 14)
127
What are long-acting benzos?
| What are the advantages/disadvantages?
Chlordiazepoxide
Chlorazepate
Diazepam
Flurazepam
Severe daytime drowsiness
Less withdrawal
128
What are short acting benzos?
| What are the advantages/disadvantages?
Alprazolam
Triazolam
Oxazepam
Less drowsiness
Severe dependence + withdrawal
129
What are medium acting benzos?
Estazolam
Lorazepam
Temazepam
130
What is the mnemonic for benzos by time of action?`
Don't BE ATO/TLE Chld
BEnzo
Alprazolam
Triazolam
Oxazepam
Temazepam
Lorazepam
Estazolam
Chlordiazepoxide
Chlordiazepate
Diazepam
(Flurazepam)
131
How do Triptans work to treat migraines?
Postsynaptic serotonin receptor stimulation
132
From what type of cells are melanocytes derived?
Neural crest cells
NOT NEUROECTODERM
133
What is the treatment of psoriasis?
Calicipotriene (or calcitriol, tacalcitol)
Binds the vit D receptor and inhibits keratinocyte proliferation + stimulates keratinocyte differentiation
134
What is the difference between Clozapine and other antipsychotics?
Clozapine acts on D4 receptors vs. D2 receptors
135
What are the side effects of Clozapine?
Agranulocytosis! Measure WBC
Seizures
Do not see the typical DA advrxn:
- Pseudoparkinsonism
- Tardive dyskinesia
- Hyperprolactinemia
