research - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 07-31-2011
USMLE Forums Master
 
Steps History: Not yet
Posts: 674
Threads: 264
Thanked 959 Times in 393 Posts
Reputation: 969
Send a message via Yahoo to ricko335
Default research

In an attempt to combat a new liver virus, a research scientist seeks to amplify gamma interferon. Which of the following cells will not be useful in increasing gamma interferon?
A. Dendritic cells
B. Macrophages
C. Natural killer cells
D. T helper cells
E. Cytotoxic T cells
Reply With Quote Quick reply to this message
The above post was thanked by:
pass7 (08-01-2011)



  #2  
Old 07-31-2011
qurat21's Avatar
USMLE Forums Master
 
Steps History: 1 + CK
Posts: 623
Threads: 62
Thanked 287 Times in 186 Posts
Reputation: 297
Default

Quote:
Originally Posted by ricko335 View Post
In an attempt to combat a new liver virus, a research scientist seeks to amplify gamma interferon. Which of the following cells will not be useful in increasing gamma interferon?
A. Dendritic cells
B. Macrophages
C. Natural killer cells
D. T helper cells
E. Cytotoxic T cells
the ans is E
Reply With Quote Quick reply to this message
  #3  
Old 07-31-2011
pass7's Avatar
USMLE Forums Guru
 
Steps History: 1+CK+CS+3
Posts: 406
Threads: 30
Thanked 141 Times in 109 Posts
Reputation: 151
Default

Quote:
Originally Posted by ricko335 View Post
In an attempt to combat a new liver virus, a research scientist seeks to amplify gamma interferon. Which of the following cells will not be useful in increasing gamma interferon?
A. Dendritic cells
B. Macrophages
C. Natural killer cells
D. T helper cells
E. Cytotoxic T cells
i think its D. T helper cell.
Reply With Quote Quick reply to this message
 
  #4  
Old 07-31-2011
USMLE Forums Scout
 
Steps History: Not yet
Posts: 45
Threads: 0
Thanked 32 Times in 21 Posts
Reputation: 42
Default

Ans D helper T cells
Reply With Quote Quick reply to this message
  #5  
Old 08-01-2011
USMLE Forums Veteran
 
Steps History: Not yet
Posts: 258
Threads: 118
Thanked 292 Times in 115 Posts
Reputation: 302
Default

I think it is dendritic cell
Reply With Quote Quick reply to this message
  #6  
Old 08-01-2011
jaimin's Avatar
USMLE Forums Veteran
 
Steps History: 1+CK+CS+3
Posts: 264
Threads: 15
Thanked 98 Times in 56 Posts
Reputation: 108
Default

C. Natural Killer cells - Not sure..
Reply With Quote Quick reply to this message
  #7  
Old 08-01-2011
USMLE Forums Veteran
 
Steps History: ---
Posts: 253
Threads: 20
Thanked 43 Times in 39 Posts
Reputation: 53
Default

yea i was thinking a or c... i'll guess c
Reply With Quote Quick reply to this message
  #8  
Old 08-01-2011
USMLE Forums Guru
 
Steps History: Not yet
Posts: 417
Threads: 74
Thanked 131 Times in 94 Posts
Reputation: 141
Default

good q, i think its EEE
Reply With Quote Quick reply to this message
  #9  
Old 08-01-2011
USMLE Forums Master
 
Steps History: Not yet
Posts: 674
Threads: 264
Thanked 959 Times in 393 Posts
Reputation: 969
Send a message via Yahoo to ricko335
Thumbs Down

The correct answer is B.
The correct answer is "macrophages" because they secrete numerous cytokines (e.g. IL-8 and IL-1), but they do not secrete gamma interferon. Gamma interferon is secreted by T helper cells, cytotoxic T cells, dendritic cells and natural killer cells.
Reply With Quote Quick reply to this message
The above post was thanked by:
bebix (08-01-2011), pass7 (08-01-2011), qurat21 (08-01-2011)
  #10  
Old 08-01-2011
USMLE Forums Master
 
Steps History: Not yet
Posts: 674
Threads: 264
Thanked 959 Times in 393 Posts
Reputation: 969
Send a message via Yahoo to ricko335
Default

I have taken his from wikipedia so dont know the authenticity run a background check but hope this helps

In contrast to interferon-α and interferon-β, which can be expressed by all cells, IFN-γ is secreted by Th1 cells, Tc cells and NK cells. Also known as immune interferon, IFN-γ is the only Type II interferon. It is serologically distinct from Type I interferons and it is acid-labile, while the type I variants are acid-stable.
IFN-γ has antiviral, immunoregulatory, and anti-tumor properties.[10] It alters transcription in up to 30 genes producing a variety of physiological and cellular responses. Among the effects are:
Promotes NK cell activity
Increase antigen presentation and lysosome activity of macrophages.
Activate inducible Nitric Oxide Synthase iNOS
Promotes Th1 differentiation by upregulating the transcription factor T-bet, ultimately leading to cellular immunity: cytotoxic CD8+ T-cells and macrophage activity - while suppressing Th2 differentiation which would cause a humoral (antibody) response
Cause normal cells to increase expression of class I MHC molecules as well as class II MHC on antigen presenting cells - specifically through induction of antigen processing genes, including subunits of the immunoproteasome (MECL1, LMP2, LMP7), as well as TAP and ERAAP in addition possibly to the direct upregulation of MHC heavy chains and B2-microglobulin itself
Promotes adhesion and binding required for leukocyte migration
Induces the expression of intrinsic defense factors - for example with respect to retroviruses, relevant genes include TRIM5alpha, APOBEC, and Tetherin, representing directly antiviral effects
IFN-γ is the primary cytokine which defines Th1 cells: Th1 cells secrete IFNg, which in turn causes more undifferentiated CD4 cells (Th0 cells) to differentiate into Th1 cells, representing a positive feedback loop - while suppressing Th2 cell differentiation. (Equivalent defining cytokines for other cells include IL-4 for Th2 cells and IL-17 for Th17 cells.
NK cells and CD8+ cytotoxic T cells also produce IFN-γ. IFN-γ suppresses osteoclast formation by rapidly degrading the RANK adaptor protein TRAF6 in the RANK-RANKL signaling pathway, which otherwise stimulates the production of NF-κB.
[edit]Therapeutic use

Interferon gamma 1b is used to treat chronic granulomatous disease[11] and osteopetrosis.[12] It is manufactured by InterMune as Actimune and costs around USD300 per vial.
[edit]Interactions

Interferon-gamma has been shown to interact with Interferon gamma receptor 1.[13][14]
[edit]Regulation

There is evidence that interferon-gamma expression is regulated by a pseudoknotted element in its 5' UTR.[15] There is also evidence that interferon-gamma is regulated either directly or indirectly by the microRNAs: miR-29.[16]
[edit]
Reply With Quote Quick reply to this message
  #11  
Old 08-01-2011
bebix's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,357
Threads: 194
Thanked 3,261 Times in 881 Posts
Reputation: 3271
Default

Quote:
Originally Posted by ricko335 View Post
The correct answer is B.
The correct answer is "macrophages" because they secrete numerous cytokines (e.g. IL-8 and IL-1), but they do not secrete gamma interferon. Gamma interferon is secreted by T helper cells, cytotoxic T cells, dendritic cells and natural killer cells.
good qs!
Reply With Quote Quick reply to this message



Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Research Opportunity in USA? kemoo USCE & Clinical Rotations 3 08-07-2011 05:22 AM
Research ??? dakshmalhotra General Topics Forum 0 07-31-2011 02:24 AM
Research Publication usmle2011 IMG/FMG Forum 0 07-19-2011 07:31 AM
Observership vs Research juanpabloq USCE & Clinical Rotations 2 06-26-2011 06:55 PM
Research or Externship? Sabio USCE & Clinical Rotations 5 05-05-2011 08:58 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)