NBME 25 Flashcards
GVHD mediated by?
T-Ls
Diarrhea, abdominal pain, hepatitis, raised UCB
A RCT done with 2 grps - members randomly assigned - 1 grp receives new drug and 1 receives old drug. Benefit?
randomization tends to dec bias (any confounding bias)
Has to effect on power, statistical significance
The grps are not mandated to be equalized
Grp of ppl who have HIV and CD4 > 500mm3. Divided into control and study grp. Both grp have sexually active ppl. Its imp to enquire abt what other infection?
Candida
Cryptococcus
CMV
H.ducreyi
Trichophyton
H.ducreyi
All options are common in HIV infected IC pts except this cuz it mainly has to do with being a STD
Fibular nerves?
Deep - is for tibialis ant - dorsiflexes the foot
Common - PEDs
Superficial - Only eversion!!
Flat line - spike - flat line for both C/P and pdtn of infectious agents seen in which virus?
Yellow fever - ss RNA +ve sense
In HIV - it is a -ve sense ssRNA virus that has similar pattern for C/P but the infectious agent is produced throughout.
Atelectasis pathophysiological mechanism?
Consolidation
Contraction
B
A - is a etiology yes
MC neuro tumor involving the spinal cord as well is?
Meningioma
Astrocytoma
Meningioma mainly
Acyclovir MOA?
DNA polymerase inhibition
CN3 synd v/s Horners Synd?
CN3 - Pupil dilated + ptosis unilat
Horners - Pupil constricted + facial anhidrosis + ptosis unilat
Can’t maintain erection and lost sensation over penis post trauma. Nerve involved?
Pudental
Sacral splanchnic
Sacral sphlanchic is involved in the automic fn but is efferent
Afferent is pudental - more likely to get damaged post trauma as its very close to bony pelvis
Meningitis C/P + LP confirms + Gram +ve cocci spore forming seen + Widened Mediastinum. Bact has what on PM?
Polyglutamic acid
Its Bacillus anthrax - transmitted via meat consumption
Cross section of pons given with right sided CN8 lesion. Asks what part is damaged?
CN8 is lat not medial + look at inf CB peduncle - all in in its vestibular schwannoma same sided lateral pons lesion
A study on ADHD and new trtmt. Researcher realizes that its more common in boys - so 2 grps with boys and girls seperate. Method used?
Random assignment
Stratification
If some1 realizes a RF and separates the team accordingly, like here based on gender - its Stratification.
post FFPs has chills, abdominal pain, diarrhea etc. Cause is def of?
IgA acute response to FFP its this!!
Not complements or Abs as in acute rejection
Tenderness on RLQ that inc with cough is a mass. What is medial to it? Pg 43 NBME 25 shows a mass on the abdomen.
Apparently its a Spigelian hernia - medial is rectus abdominus and lat is Linea seminularis.
I-cell disease is a issue in?
Synthesis of Lysosomal enzymes
Docking translated proteins with Mannose-6-P
B
Enzyme is already translated, issue is its not docked by Mannose-6-P residue to go to the lysosomes from golgi
Plasma Volume when Hct and BV goven how?
Plasma vol = Total BV x (100 - Hct)
BV = Total body wt x 70ml/Kg
PO2 v/s Hb Sat% curve - when abv dashed line?
Left shift
cuz of high HbF etc
Dec 2,3 BPG, dec pH, dec Temp!
Man with SOB + never smoked + has bullous spaces in LL. Cause?
EGF
Protease inhibitor
B - its A1AT def - neutrophil elastase
P=0.035 matlab?
If the drug really does not work, there is a 3.5% chance of finding an average difference.
Pt has chronic abdominal pain for past 3 months. Has tressful job + hi pain worsens with eating. Nl endoscopic exam. H2R blocker has mixed results. Cause?
IBS
Non-ulcer dyspepsia
MDD
GAD
Nonulcer dyspepsia - epigastric pain, work-related stress, and normal endoscopic evaluation. The most common causes of dyspepsia include peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD)
Right cerebral Cx damage with signs of left LL sided UMN signs. 10 days post acst removal where will we have DTRs exaggerated?
Left Achilles tendon
Left Biceps tendon
Left Achilles tendon obv
Lesion on neck on a person who doesn’t wear sun protection. Looks a 10-mm] pearly pink; raised nodule. Arises from?
BCC - epidermis
Both the papillary and reticular dermis will contain the basaloid islands found in basal cell carcinoma but are not the
origin of the tumor. The dermis contains fibroblasts, capillaries, post-capillary venules, and small nerves. Pathologic proliferations of these cell types include dermatofibromas, hemangiomas, and neurofibromas
A uncoupling protein 2 inhibitor discovered that inc insulin secretion. How?
Inc glucokinase activity
Inc GLUT 2
Inc ATP:ADP ratio
To inc insulin secretion - G binds to GLUT 2 - inc Glycolysis - inc ATP:ADP ratio –> all that helps wit downstream final effect of inc ATP:ADP ratio!
Killing of cells when MHC 1 is completely inhibited via what cell?
CD8 TCs
CD4 TCs
NK cells
Just NK cells cuz CD8 cant help with killing when MHC 1 is not expressed!
Patient with chronic pancreatitis. Cause of abdominal pain?
Its dec duodenal pH not inc fecal elastase
Inc fecal elastase - common to exocrine dysfn
Cause of abdominal pain is dec pH as HCO3 not secreted as much
Lactulose MOA?
Trapping ammonia by convertion of it into an acidic metabolite
Pt has abdominal pain and tenderness, fever, wt loss, generalized muscle pain. Nephritic synd + high ESR. Muscle Bx shows Transmural necrotizing arteritis. Cause?
Polyarteritis nodusa
Wegener’s
A
b - has nasopharynx + lung issue with nephritic
If a plasmid can’t replicate in the bact. Mutation where?
At origin of DNA synthesis - no enzyme can bind to cont the process
The origin of DNA synthesis, also called the origin of replication, is a sequence of DNA within a plasmid where replication is initiated and binds replicative enzymes (eg, DNA gyrase, polymerase, ligase) which permit the initiation of plasmid duplication and
reproduction. A mutation at the origin of DNA synthesis would prevent replication of the plasmid. Plasmids are extrachromosomal segments of double-stranded DNA that are commonly present in bacteria; they may contain genes that confer survival advantages to
the host and are usually classified by their function
Palpable purpura in a pt with chronic hep C. Cause?
Cryoglobulin
D-dimer
RFs: hepatitis B and C viruses,
(HIV), malaria,Ebstein-Barr virus (EBV), SLE and Sjogren syndrome, multiple myeloma. Mixed cryoglobulinemia is characterized by the triad of weakness, arthralgias, and palpable purpura. Can also cause Hepatosplenomegaly and hematuria.
Viral Hep A. HPCs die via?
Necrosis via ROS
Apoptosis via extrinsic pathway
Apoptosis via intrinsic pathway
B it is!
Viral hepatitis A infection leads to hepatocyte death primarily through apoptosis caused by activation of the death receptor extrinsic pathway. Though both converge but the the extrinsic pathway is dependent on external cellular signals as with the binding of Fas and Fas-ligand OR the release of perforin and granzyme B from cytotoxic CD8+ T Lymphocytes responding to intracellular viral pathogens.
Lymphocytic infiltrates are frequently seen on liver histology in the setting of an acute hepatitis infection
genetic amniocentesis says XX but bby born with all male internal and external genetilia.n Cause?
SRY gene translocation
Use of primaquine?
In malaria pts it trts hypnozoites and prevents future relapse (doesn’t resolve the disease earlier)
Levidopa + carvidopa faida?
Carvidopa does’nt cross BBB. Levodopa is converted to dopamine by the enzyme dopa decarboxylase in the peripheral
circulation and the brain. Carbidopa inhibits dopa decarboxylase peripherally - no peripheral SEs
IV Insulin given to pt. Now has hypoG with High E:NE ratio. Cause:
Activation of catechol-O-methyltransferase
Selective activation of medullary epinephrine release
B is the answer
post hypoG –> SNS gets activated via adrenal medulla. . A selective
activation of adrenal medullary epinephrine release via chromaffin cells has been proposed to explain the difference. In the case of hypoglycemia, glucagon and epinephrine are the principal mediators that will restore euglycemia in the short term.
Man with SOB + headaches. 1 month later retired and moved to a place abv sea level. RR is 16 and RBCs>4 million/mm3. Hx of disease where?
Lungs
Kidneys
Lungs nhi cuz except SOB no other issue like cough, sputum etc.
Kidney yes produces EPO mainly!
Two hours later she drinks a 16-ounce bottle of cola sweetened with high fructose corn syrup and sucrose. The activity of which enzyme is increased in this patient’s liver?
A ) Carnitine palmitoyltransferase I
B) Fatty acid synthase
C ) Glycogen phosphorylase
D ) Phosphoenolpyruvate carboxykinase
E) Protein kinase A
Insulin inc - meaning inc FA synthesis
Not A, C, D(gluconeogenesis)
If LDL binds to R but can’t be internalized. Cause:
a) Apo B
B) Apo E
c) Cytoplasmic domain of the LDL receptor
d) Extracellular domain of the LDL receptor
The LDL receptor is a transmembrane receptor that resides in clathrin coated pits along the cell membrane. When Apo B, an embedded component of LDL particles; binds to the LDL receptor the entire receptor-ligand complex is internalized (endocytosis). The acidic environment of the endosome leads to dissociation of LDL from its receptor followed by fusion with the lysosome where LDL and Apo B are degraded. The LDL receptor is then recycled back to the cell membrane. Signaling for endocytosis occurs via the cytoplasmic domain of the LDL receptor so defects in this portion would affect endocytosis. Absence or dysfunction of the LDL receptor results in familial hypercholesterolemia.
Mechanism of resistance in E.coli v/s Staph aureus/viridins?
E.coli - Beta-lactamase
Staph - PCN-BP altered
Labia majora drains into what LNs?
Internal iliac or inguinal?
inguinal LNs
Inguinal nodes drain lymphatic fluid from the labia majora, vulva, scrotum, anal canal below the pectinate line, and the skin below the umbilicus with the exception of the popliteal fossa.
If IVC has obstruction, blood from LL comes via what to SVC?
Lumbar –> azygous and hemizygous
RA changes in C3, TNF-alpha, Ns and IL1?
IL1 - inc
TNF-alpha- inc
C3 - dec
Ns - inc
Pt has blurred vision in right eye and resolved within 2 weeks. Then she had a right afferent pupillary defect. Later she also had weakness of the lower two thirds of the right side of the face and a right pronator drift. She later also developed dysmetria. Cause?
MS
Neurocysticercosis
B - Neurocysticercosis is a CNS infection caused by the pork tapeworm Taenia solium that occurs most commonly in endemic rural regions. Symptoms include headache, seizures, signs of increased intracranial pressure, and. rarely, altered vision. Typical
manifestations on CT scan or MRI include cystic, enhancing, and calcified lesions in the brain parenchyma, meninges, ventricles, or spinal cord. This patient possesses no risk factors for neurocysticercosis.
MS - many issues usually started off with optic neuritis and then C/P differ in time and space. On MRI, there are lesions in multiple anatomic locations. T
Had PE + spontaneous abortion 2 years ago. PLT + PT nl but inc PTT. Cause:
Antiphospholipid Ab
Factor V Leiden mutation
Increased factor VIII
Protein C deficiency
Prothrombin G2021GA mutation
Ans: A
B, c,d - inc bleeding! yes but will effect PT and PTT.
VSD thats Hx is female side of the family? % of inheritance?
Inheritance of disease is based on autosomal , mitochondrial, and X-linked genetics of the parents. Parents unaffected to % of kid to be affected is 2-3%.
Post Trauma, what causes apoptosis in brain. Like what substance diffuses via cerebral capillaries to brain and induce apoptosis?
Excitotoxicity describes the phenomenon in which neurons endure additional damage or cell death beyond an initial inciting insult such as a traumatic brain injury, stroke, spinal cord injury neurodegenerative disease, or withdrawal from gamma-aminobutyric acid
receptor agonists (eg,alcohol, benzodiazepines). In response to damage to the central nervous system, glutamate may be released rapidly into the synaptic clefts. When such concentrations persist at high levels, neuronal apoptosis ensues.
Parent 1,2 affected - 1 kid has same allele combo with recombinant freq of 0.1. % if affected?
90%
99%
99% (Choice E) would be the risks of inheriting the disease (99%) if the recombination fraction was 0.01 (1%) and the fetus inherited allele
Since recombination fraction is 0.1 its 90%
CRC MC locations?
Sigmoid> Ascending > descending
No rectum!
What is placebo effect and when is it most noteful?
Placebo causes a belief in the control grp that they are receiving trtmt, thus spp for pain, placebo v/s trtmt is not the best study plan.
Why can’t heart cells repair themselves post MI?
a) T-tubules
b) Satellite cells
B
In normal skeletal muscle cells, satellite cells play a role in muscle fiber repair and regeneration after both routine exercise and catastrophic injury. They reside in a quiescent state between the sarcolemma and basal lamina of muscle fibers. Cytokines released during exercise or injury: such as IL-1. IGF-1, myostatin and IL-6/MGF directly activate satellite cells and lead to proliferation.
heparin ke saath later we + warfarin given together keeps INR and PT nl. How?
Warfarin inhibits the hepatic synthesis of factor 2,7,9,10
in addition to proteins C and S. Factor II exhibits a long half-life of nearly 60 hours. For the effect of warfarin to be shown in an increased prothrombin time (PT)/INR, circulating
prothrombin must first degrade. This explains why the patient’s PT/INR remains unchanged 24 hours after starting warfarin.
Lingula of the lung?
Is a small medial part of LUL
What is inc in REM sleep?
GH secretion
Muscle activity
thermoreg
Cerebral BF
Delta EEG
Cerebral BF
Delta EEG - in stag 3 n 4
Muscle activity dec
Thermoreg dec
GH secretion more in deep sleep
How does Doxorubicin cause DCM?
Via ROS pdtn and lipid peroxidation of CMs
Cocaine MOA?
Cocaine blocks the presynaptic reuptake of DA, SRT and NE
increased sympathetic tone (tachycardia, hypertension, pupillary dilation) cuz of NE
Increased synaptic serotonin leads to euphoria
increased synaptic dopamine leads to addiction (and in severe cases, hallucinations and paranoia),
Lap cholecystectomy done. What is not inspected?
Stomach
large Intestine
small intestine
Pancreas
Lap chole is intraperitoneal so all seen except retroperitoneal pancreas
DMD - cant stand straight without using hands. Which muscles effected and where is their insertion?
Calf muscles are effected and insert in ischium
The adductor muscles of the hip include adductor magnus, longus, brevis, and minimus. Adductor longus, brevis, and minimus originate from the
pubic bone, whereas adductor magnus originates on the ischium and inferior pubic ramus.
How to inc pulmonic Lymph flow?
To increase lymphaticflow, the investigator must increase the hydrostatic pressure inside the capillaries, decrease the hydrostatic pressure in the interstitial space, decrease the plasma oncotic pressure, or increase the interstitial fluid oncotic pressure. Of the choices, the intravenous
infusion of 0.9% saline for 5 minutes is the only intervention that would result in increased lymphatic flow by increasing the capillary hydrostatic pressure.
COPD with Resp distress C/P. ABG shows?
Dec PO2
pH Low to Nl
HCO3 inc
Inc PCO2
Psaos abscess matlab what fn at hip is an issue?
Flexion at hip
The psoas originates from the lateral margins of the lumbar vertebrae and inserts on the lesser trochanter of the femur. It is innervated via the lumbar plexus and has the prime action of flexion at the hip. which would be limited in the case of a psoas abscess.
Sensory and motor axons are lost by Wallerian degeneration beyond the site of the
injury. Further study is most likely to show which of the following cell structures acting as a path-finding guide for the regeneration of the damaged axons?
Axon hillock
Myelin sheath
Nissl substance
Wallerian degeneration - mediate by Schwann cells for axonal regeneration so answer is B
A - helps with Signal transmission via Na channels
C - NTs dysfn
