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A 45-year-old woman comes to the physician because of a 6-month history of mouth ulcers, thickening of the skin, and throbbing pain in her hands when they are exposed to the cold. She also has had a 1-month history of severe headaches and difficulty swallowing. Physical examination shows small red lesions around the mouth and generalized muscle weakness. Laboratory studies show a high titer of anti-Scl 70 (anti-topoisomerase I) antibody. A biopsy specimen of the skin shows thinning of the epidermis, hyalinization and obliteration of arterioles, and dermal thickening. These dermatologic changes are caused primarily by the release of chemokines from which of the following inflammatory cell types?
A ) Endothelial cells
B ) Eosinophils
C ) Lymphocytes
D ) Mast cells
E ) Platelets
F ) Segmented neutrophils
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q2
During a meal, the vagus nerve stimulates secretion of acetylcholine, which stimulates the stomach to secrete HCl in a second-messenger pathway derived directly from membrane phospholipids. Which of the following second messengers is involved?
A ) cAMP
B ) cGMP
C ) Choline
D ) G protein
E ) Inositol 1,4,5-triphosphate
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q3
In an animal model of myocardial ischemia, morphologic and biochemical changes in myocardial cells are studied after ligation of a branch of the coronary artery. Degradation of membrane lipid bilayers and of cytoskeletal proteins occurs following activation of intracellular phospholipase A2 and proteases. An increase in which of the following is most directly responsible for activation of those enzymes?
A ) Calcium ion concentration
B ) Creatine kinase activity
C ) Endonuclease activity
D ) Sodium ion concentration
E ) Water content
q4
Embryonic chondrogenesis requires the formation of mesenchymal condensations at the sites of future cartilage. During this developmental step, cAMP concentrations in the cells comprising the condensation increase significantly. Treatment with a membrane-permeable form of cAMP (eg, dibutyryl cAMP) allows individual mesenchymal cells to differentiate into chondrocytes without first forming these condensations. Inhibition of which of the following enzymes would most directly inhibit dibutyryl cAMP-mediated induction of chondrogenesis from mesenchyme?
A ) Guanylyl cyclase
B ) Phosphodiesterase
C ) Proteasome
D ) Protein kinase A
E ) Tyrosine kinase
q5
. A healthy 26-year-old woman comes to the physician for a health maintenance examination. She says that her moods change easily and that she has seen numerous psychiatrists and therapists for "emotional problems." Physical examination shows multiple healing, self-inflicted wounds. At the end of the examination, she thanks the physician for "being the most skilled, compassionate, and understanding physician I have ever known." Which of the following is the most likely diagnosis?
A ) Bipolar disorder
B ) Borderline personality disorder
C ) Dysthymic disorder
D ) Histrionic personality disorder
E ) Major depressive disorder
q6
A 68-year-old man is brought to the emergency department because of a 2-day history of fever, headache, muscle weakness, and confusion. His temperature is 38.6°C (101.5°F). Physical examination shows generalized lymphadenopathy and weakness of the right lower extremity. Laboratory studies show antibodies to a virus that is maintained in wild birds, carried to humans by Culex species mosquitoes, and has a low fatality rate. Which of the following is the most likely causal virus?
A ) Coronavirus
B ) Dengue virus
C ) Norovirus
D ) Poliovirus
E ) West Nile virus
F ) Yellow fever virus
q7
An investigator has designed a drug that is transported into the cell through a membrane channel and remains isolated in the cytoplasm. This drug will most likely directly influence which of the following cellular processes?
A ) DNA transcription
B ) Electron transport
C ) Glycolysis
D ) Protein folding
E ) Transcription factor binding
q8
Which of the following genetic phenomena most likely accounts for the variability in biotransformation of compounds by a liver hydroxylase?
A ) Allelic exclusion
B ) Fragile sites
C ) Hypervariable DNA
D ) Multiple polymorphisms
E ) Multiple pseudogenes
q9
Treatment of respiratory syncytial virus with 70% ethanol destroys its infectivity. The loss of infectivity is the result of a direct effect of the treatment on which of the following viral functions?
A ) Entry of the nucleocapsid into the nucleus
B ) Fusion of the virion membrane with the target cell membrane
C ) Replication of the virus genome
D ) Transcription of mRNA
q10
In nucleotides, the sugars are attached to nitrogen-containing bases by which of the following?
A ) Electrostatic interactions
B ) Hydrogen bonds
C ) N-glycosidic bonds
D ) Phosphodiester bonds
E ) Stacking interactions
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1. C
2. E
3.A
4. D
5. D(attention seeking behaviour)
6. F
7.E
8. ???
9.B??
10.D
Really tough ones. plz correct me if i'm wrong
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3.a
4.d
5.b. borderline personality
7. c
10.?! i'm confused.. arent PD bonds b/w nucleotides i.e P grps of the sugars?! so i think C
do these questions comes with answers?
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1) F
2) E
3) A
4) D
5) B
6) E
7) B
8) D
9) B
10) C
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wouldratherbeatthebe, can you give the rational of Q7, I thought it must be ion, It can not cross membrance either way, has to go through a channel. protein (transcription factor, ) are not permiable, has to go through endocytosis.
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