Wrong set-1

Question 1

What is the protein that acts as anterograde mediator and uses energy derived from ATP hydrolysis to move along the microtubule?

Answer 1

Kinesin

Question 2

What is the enzyme that catalyzes the conversion of N.E. to Epi?

Answer 2

Phenylethanolamine-N-Methyltransferase (PNMT)

Question 3

How is epinephrine affected in a pt with pituitary dysfunction?

Answer 3

Pituitary dysfunction will lead to a decrease in ACTH—-decrease cortisol—- lack of upregulation of PNMT (enzyme needed for the conversion of NE to Epi)

Question 4

What is the MOA of Daptomycin? What is a common SE and lab values?

Answer 4

Daptomycin disrupts the bacterial membrane by creating transmembrane channels that cause intracellular ion leakage. The resulting cellular membrane depolarizaion and macromolecular synthesis inhibition ultimately lead to cell death.

Daptomycin cannot permeate the outer membrane of Gram(-) bacteria, so it is ineffective in the tx of those infections.

Daptomycin is associated with increased creatine phoosphokinase (CPK) levels and an increased incidence of myopathy.

Question 5

What organism is daptomycin limited to?

Answer 5

Daptomycin is a lipopedtide anitbiotic with activity limited to gram-positive organisms, including methicillin-resistant Staph. Aureus.

It causes depolarization of bacterial cellular membrane and inhibition of DNA, RNA, and protein synthesis.

Associatted with increased incidence of myopathy and CPK levels.

Question 6

How does an infection producing pharyngitis and laryngotrachetis with coalescing exudates (pseudomembranes) can be prevented?

Answer 6

With a childhood vaccine. Diphteria-Pertussis-Tetatus (DPT) vaccine contains diptheria toxoid, which stimulates production of neutralizing antibodies against the binding component (B subunit) of the diphtheria exotoxin.

Ab binding prevents the exotoxin from attaching to host cell membrane receptors.

Question 7

How does the AB exotoxin from diphtheria works?

Answer 7

B (binding) subunit allows penetration of the A (active) subunit into the cell to inhibit ribosome function.

Neural and cardiotoxicity are serous potential sequelae.

Question 8

In what disease we can find antiphospholipid antibodies?

Answer 8

In systemic lupus erythematosus and antiphospholipid antibody syndrome. Anti-phosp. ab cause a hypercoagulable state with paradoxical PTT prolongation.

Question 9

What are the immunologic markers for Rheumatoid arthritis?

Answer 9

RA results from an immune response directed agains autoantigens in the joints. Inflitrating CD4+ T cells secrete cytokines that promote inflammatory synovits. They also stimulate B cells to produce rheumatoid factor (IgM antibody specific for Fc component of IgG) and anti-citrullinated protein ab that contribute to chronic inflammation and joint destruction.

Question 10

Why do erythrocytes sickle with HbS?

Answer 10

Hemoglobin S contains valine inplace of glutamic acid at teh 6th amino acid position of the beta globin chain. This promotes hydrophobic interaction among Hb molecules and results in HbS polymerization and erythrocyte sickling.

Question 11

What is the time frame for Bipolar I disorder? criteria?

Answer 11

Bipolar I disorder is dx in pts with a lifetime history of >1 episode of mania. Manic episodes are characterized by elevated / irritable mood, hyperactivity, decreased need for sleep, pressured speech, and grandiosity and may occur with psychotic features.

Question 12

What are the cephalosporin-resistant organism?

Answer 12

Listeria monocytogenes
Methicillin-resistant staphylococcus
Enterococci
Atypicals (Mycoplasma, chlamydia)

Question 13

What are the most common cause of aseptic meningitis?

Answer 13

Enteroviruses (coxsackievirus, echovirus, poliovirus). The present with fevers, meningeal signs (neck stiffness); and cerebrospinal fluid that shows lymphocyteic pleocytosis.

Question 14

What virus occurs primarily in young and middle ages adults living i Asia, sub-Saharan Africa, and Mexico. Cause fulminant hepatitis. How is it spread?

Answer 14

Hepatitis E virus in an unenveloped , ssRNA virus spread through fecal-oral route. It has an average incubation period of six weeks. While the virus is shed in the stool during the acute illness, the disease is typically self-limited and not associated with either chronic liver disease or a carrier state. HEV ag or HEV RNA can be detected in the stool or liver in the earliest stages of infection.

The most concerning feature of hepatitis E is the high mortality rate observed in pregnant women.

Question 15

What medications inhibit transpeptidases?

Answer 15

Penicillins and cephalosporins function by irreversibly binding to penicillin-binding proteins. Transpeptidases are one from of penicilling-binding protein that function to cross-link peptidoglycan in the bacterial cell wall.

Inhibition of transpeptidase leads to cell wall instability and bacteriolysis. Many bacterial species synthesize multiple different penicillin-binding proteins.

Question 16

What diseases are associated with Rb mutation?

Answer 16

Osteosarcoma
Retinoblastoma
Breast adenocarcinoma
Small cell carcinoma of the lung
Bladder carcinoma.

Question 17

What is the use of Niacin, and what are its side effects

Answer 17

Niacin is used for triglycerimia , it treat hyperlipidemia. It is effective in raising HDL as well as lowering LDL.

Niacin S.E. includes cutaneous flushing, warmth, and itching, these are primarily mediated by release of prostaglandis (particularly PGD2 and PGE2)

Question 18

What is substance P?

Answer 18

It is a polyeptide neurotransmitter involved in mediating pain signals in the peripheral and central nervous systems. Topical capsaicin causes release of substance P, resultaing in burning pain in the area of application. Prolonged use causes depletion of substance P, and the pain diminishes with time.

Question 19

What are the possible triggers of Prinzmetal angina?

Answer 19

Cigarette smoking
Cocaine/amphetamines
Dihydroergotamine /triptans.
P.A. is characterized by episodic transient attacks of coronary vasospasm (at rest and at night) producing temporary transmural myocardial ischemia with ST-segment elevation.

Question 20

Dihydroergotamine

Answer 20

It is an ergot alkaloid commonly used to treat acute migraine headache. This drug may induce vasospastic angina as it constricts vascular smooth muscle via stimulation of both alpha adrenergic (partial agonist) and serotonergic receptors.

Question 21

What is the alkaline phosphatase level on CML and leukemoid reaction?

Answer 21

CML and Leukeomoid reaction can have presentation similar to leukocytosis; however, leukocyte (neutrophil) alkaline phosphatase level is normal or elevated in a leukemoid reaction but decreased in CML.

Question 22

How do Beta blockers affect QT interval, QRS, ST, and PR ?

Answer 22

Beta blockers decrease AV nodal conduction, leading to an increase AV nodal refractory period. This correlated to PR interval prolongation on an ECG.

The do not affect any other interval.

Question 23

what are the cause of dilated cardiomyopathy?

Answer 23

ABCCCD
Alcohol abuse
Beri Beri
Coxsackie B
Coacaine use
Chaga's disease
Doxorubicin

Question 24

What mutation we can find in genes of pt. with Hypertrophic cardiomyopathy

Answer 24

Beta-Myosin heavy chain

HCM is characterized by asymmetric (septal) left ventricular hypertrophy that can result in sudden cardiac death. AD mutations affecting the cardiac sarcomere genes (Cardiac beta-myosin heavy chain gene and myosin-binding protein C gene) are responsible for the majority of cases.

Question 25

What is Pure red cell aplasia and what is associated with?

Answer 25

PRCA often involves the inhibition of erythropoietic precursors and progenitors by IgG ab or cytotoxic T cells. It has been associated with immune system diseases such as:
1- Thymomas
2- Lymphocytic leukemias
3- Parvovirus B19 infection
The infection w parvovirus preferentially attacks and destroys proerythroblasts.

Question 26

What should you suspect in a pt. with migratory thrombophlebitis?

Answer 26

Migratory thrombophlebitis should raise the suspicion for cancer. Hypercoagulability is a very common paraneoplastic syndrome seen most frequently in visceral adenocarcinomas of the:

• Pancreas
• Colon
• Lung

Question 27

Pt. present with stable andina due to underlying coronary heart disease. Pt is not able to take aspirin, which other medication can be used in replacement of aspirin on this pt.?

Answer 27

Clopidogrel. It is as effective as aspiring for prevention of cardiovascular events and should be used in pts with aspirin allergy.

Question 28

What is the p27 protein function?

Answer 28

The p27 protein is a cell cycle inhibitor. It acts during G1 phase by inhibiting cyclin dependent kinases. Normal tissues contain high levels of p27, while malignant tissues contain very low levels of p27.

Question 29

Dubin Johnson’s syndrome, what enzyme is deficient?

Answer 29

A deficiency in the hepatocyte canalicular organic anion transporter (cMOAT) .

This deficiency causes Dubin-Johnson syndrome, with elevated direct (conjugated) bilirubin, not indirect. Patients are usually asymptomatic and accumulations of pigment incorporated with melanin-like pigment would cause the appearance of a black liver.

Question 30

What is Choledocholithiasis, and how does it present?

Answer 30

Choledocholithiasis, a condition in which a gallstone becomes lodged in the common bile duct.

Stones occluding the common bile duct (choice C), or choledocholithiasis, result in colicky RUQ pain. There may be radiation of pain to the right shoulder. Patients may have jaundice and a conjugated hyperbilirubinemia. If the obstruction persists and the biliary tree becomes infected, the life-threatening condition cholangitis results.

Question 31

what is Cholangitis, and how does it present?

Answer 31

Charcotts triad: Fever, jaundice and RUQ pain.

Obstruction of cystic duct.

Question 32

What substance do we use to differentiate between pancreatic gastrinomas and other causes?

Answer 32

Secretin

One of the peculiarities of gastrinomas is that secretin strongly stimulates gastrin release. Secretin normally inhibits gastrin release from G cells (in addition to its main role of stimulating bicarbonate release from the pancreas). The secretin stimulation test is used to differentiate between gastrinomas and other causes of chronically-increased gastrin secretion

Question 33

The internal anal sphincter and urge to defecate are controlled by what nerves?

Answer 33

The urge to defecate involves a spinal reflex mediated by pelvic splanchnic nerves:
The defecation reflex is triggered by stool entering and distending the rectum.
Rectal sensory afferents travel in the pelvic splanchnic nerves, which arise from spinal cord segments S2 through S4.

Pudendal nerves control external anal sphincter.

Question 34

How does celiac disease affect bones?

Answer 34

For bone, decreased small bowel absorption of vitamin D and calcium leads to osteomalacia.
In addition, cross-reacting autoantibodies against osteoprotegerin (OPG) result in increased osteoclast activation via RANK-ligand, which can also decrease bone mass and produce osteoporosis.
Diagnostic suspicion raised via tissue transglutaminase IgA, endomysial IgA, and/or reticulin IgA, which are the most specific autoantibodies for this condition.

Question 35

what is the best diagnostic test for hypertrophic pyloric stenosis?

Answer 35

Abdominal ultrasound.

Question 36

What are the toxins of C. Diff?

Answer 36

Toxin A acts as a granulocyte attractant and toxin B is cytopathic.

Furthermore, toxin A attaches itself to the brush border of the intestinal cells causing diarrhea, while Toxin B acts as a depolarizing actin toxin that leads to pseudomembraneous colitis. It also causes colonic epithelial cell necrosis and fibrin deposition (colitis).

Question 37

What kind of bilirubinemia we would see with obstruction of common bile duct?

Answer 37

Increased conjugated bilirubin.

Question 38

What are cutaneous neurofibromas?

Answer 38

they usually manifest during early adolescence as multiple, raised, fleshy tumors (<2 cm) that often increase in size and number with age.

These are benign nerve sheath neoplasms predominantly comprised of Schwann cells, which are embryologically derived from the neural crest.

Question 39

What is a hepatoblastoma?

Answer 39

It is the most common liver neoplasm in children and is associated with familial adenomatous polyposis and Beckwith-Wiedemann syndromes.

This neoplams is usually fatal within a few year if not surgically resected.

Question 40

What is the drug that we use to treat repeated bouts of C.Diff and inhibits the sigma subunit of RNA polymerase as it’s MOA.

Answer 40

Fidaxomicin.

It is a mcrocyclic antibiotic that inhibits the sigma subunit of RNA polymerase, leading to protein synthesis impairment and cell death.

Question 41

When are aortocavitary fistulas present?

Answer 41

Aortocavitary fistulas are an uncommon complication of bacterial endocarditis caused by extension of the infection from the valve to the adjacent myocardium.

Doppler interrogation will most likely demonstrate continuous blood flow from the higher-pressure aortic root to the lower-pressure right ventricle. Can lead to continous murmur.

Question 42

Enterococcus

Answer 42

Gram (+) cocci in pairs and chains, and when grown on blood agar, reveal no hemolysis (gamma hemolysis).

• UTI , wound infection.
• Pyrrolidonul arylamidase (PYP) positivity
• Abilitiy to grow bile and in 6.5% sodium chloride.

Question 43

What is the function of hCG therapy on women with PCOS?

Answer 43

The alpha subunit of hCG is structurally similar to LH and therefore simulates the LH surge by inducing ovulation.

Question 44

what is the MOA of Cyproheptadine?

Answer 44

It is a first generation histamine antagonist with nonspecific 5-HT1, and 5-HT2 receptor antagonistic properties.

Can be use to treat SSRI overdose.

Question 45

Pts present with epigastric pain, telangiectasias, ulcers at the tips of the fingers, and calcium deposits. What does the pt has?

Answer 45

CREST sydrome.

Esophageal dysmotility is a result of atrophy and fibrous replacement of the muscularis in the lower esophagus.

Question 46

What is the MOA of Rifaximin?

Answer 46

Rifaximin or neomycin work by decreasing the NH3 producing gut bacteria.

Inhibits transcription by attaching to the beta subunit of the bacterial RNA pol.

Question 47

What is the MOA of orlistat?

Answer 47

It is used for weight loss

It inhibits gastric and pancreatic lipase, decrease breakdown and absorption of dietary fats.

Question 48

What are the osmotic laxatives?

Answer 48

Mg hydroxide / Mg citrate
Polyethylene glycol / lactulose

Provide osmotic load to draw water into lumen. Lactulose also tx hepatic encephalopathy because gut flora degrade it into metabolites (latic acid, acetic acid) that promotes nitrogen excretion as NH4+

Question 49

What is the MOA of Aprepitant

Answer 49

It is a substance P antagonist. It blocks NK1 receptors in brain.

Anitemetic effect for chemotherapy-induced nausea and vomiting.

Question 50

What is the drug that causes enteric nerve stimulation and colonic contraction?

Answer 50

Senna. Diarrhea, melanosis coli

Question 51

What is the MOA of Docusate

Answer 51

Osmotic draw into lumen, increases water absorption by stool, causing diarrhea.

Question 52

What are the S.E of Lithium?

Answer 52

Teratogenic
Polyuria and Nephrogenic D.I. 
Arrythmias
Hypothyroidism
Tremor, lethargy, sedation, dizziness

Question 53

what drugs do we use to treat alcohol dependence?

Answer 53

Drugs to treat alcohol dependence include oral and intramuscular depot naltrexone, disulfiram, and acamprosate.

Naltrexone blocks the mu-opioid receptor and can be initiated while the individual is still drinking. it block the rewarding and reinforcing effects of alcohol and has been shown to reduce the craving for it.

Acamprosate,modulates glutamate neurotransmission at the NMDR receptor and is recommended once abstinenece have been achieved

Question 54

What is the treatment for Tourette syndrome?

Answer 54

Antipsychotics (Fluphenazine, pimozide, tetrabenazine)

Fluphenazine and pimozide are D2 - receptor blocker, and increase cAMP.

Tetrabenazine: It is a VMAT inhibitor, thus decreasing the amount of dopamine release by vesicles.

Question 55

What is the MOA of Duloxetine and what does it treat?

Answer 55

Inhibit 5-HT and N.E. reuptake.

+ It has also been used to treat stress urinary incontinence in women because it enhances urethral closure.

+Generally rarely causes obstructive voiding symptoms.

+Also indicated for fibromyalgia

Question 56

What is adiponectin

Answer 56

It is a cytokine secreted by fat tissue that increases the number of insulin-responsive adipocytes and regulates fatty acid oxidation.

Question 57

What is Cerebral amyloid angiopathy and who does it affect?

Answer 57

Elderly pts are more propense to lobar hemorrhage due to cerebral amyloid angiopathy. Amyloid angiopathy is a consequence of beta amyloid depositon in the wall of small-medium sized cerebral arteries, resulting in vessel wall weakening and predisposition to rupture. The disease in not associated with systemic amyloidosis; rather, the amyloidogenic proteins are usually the same as those seen in Alzheimer disease. Amyloid angiopathy is the most common cause of spontaneous lobar hemorrhage, particularly in adults age >60. Hemorrhage tends to be recurrent and most often involves the occipital and parietal lobes.