How do we know there are T-cells left over after positive and negative selection?
109688
The lack of T-cells would be an almost complete collapse of the immune system.  T cells become CD4 (helper T) and CD8 (cytotoxic T, "killer T").\nAIDS is the condition a person has once the HIV virus has killed off all there helper T cells and thus they are very susceptible to infections.
597481
Briefly, the immune system scours the organism for what appear to be foreign invaders.  When it goes haywire, we now have an autoimmune disease -- rheumatoid arthritis, MS, poly myalgia rheumatic,and of course many others.  Interestingly, as sperm develop, the immune system does not attack the sperm, though they are in essence a different type of organism within the body.S[perm cells are guarded by what is commonly called a "nurse" cell.  As well it is interesting that the body does not attach a growing fetus -- usually -- (When it does, it is generally an rH problem).  In essence there is no "interrelationship".  The immune system is tolerent, at times to what appears a foreign living thing,(sperm) and intolerant at times to the body in which it is housed.(rheumatoid arthritis in which the immune system attacks its own cartlidge.) { Heart transplants, and other organ transplants can only succeed if the immune system is weakened.  Transplants would be immediately attacked otherwise.  And interestingly, weakened immume systems in the end, open us all up to cancer.  We all have cancereous cells in us  at all times -- normal cells that have become malignant.  The immune system recongnizes them and eliminates them.  Those with weakened immune systems are more prone to cancer.}  Maybe more information that you wanted to know....?
566347
The plasmacytoid T cell or plasmacytoid monocyte--a sessile lymphoid cell with unique immunophenotype and unknown function, still awaiting lineage affiliation.\n\nClusters of cells with a plasmacytoid appearance have been identified in T zones of human lymphoid tissue. These cells were shown to express the CD4 antigen in the absence of B-cell antigens. Thus, they were named "plasmacytoid T cells" (PTCs). Recent studies, however, have suggested a myelomonocytic origin of this cell type, which led to the designation "plasmacytoid monocytes." In order to obtain a comprehensive immunophenotype of this cell, we used frozen serial sections of lymph nodes, an indirect immunoperoxidase technique, and a broad panel of well-defined monoclonal antibodies (mAbs). On PTCs, the antigenic density was high for CD4 and CD26 antigens and low for CD2; they furthermore reacted with the mAb OKM5 recognizing an undefined antigen associated with the myelomonocytic lineage and expressed the monocyte-associated antigen CD68. PTCs expressed HLA-A, B, C, HLA-DR, and the HLA-D associated invariant chain (Ii) while HLA-DP antigens were expressed only in low amounts and HLA-DQ antigens were lacking entirely. PTCs further expressed the adhesion molecule CD11c. The absence of detectable transferrin receptor and the proliferation antigen defined by Ki-67 indicated that PTCs were nonproliferating. Other well-defined antigens confined to the T-, B-, and myelomonocyte lineages could not be detected in the target cell population. For us, antigenic equipment is still suggestive of a sessile, terminally differentiated T cell likely to exert a secretory function as yet unknown.
488236
if the test came back positive no you do not have to take it again ever. and no you don't have TB that just shows that you have been exposed to it. yes it will come back positive every time. in my case it is negative until i came around someone with it. from that point on the antibodies will be in my system and will always say positive. you should have just told the nurse or whoever the test was required for that you have been exposed and you do not need another. it will be in your records just show it to your employer.
753317
Bored at work:\n\nYou could look for reverse transcriptase activity in infected cells.  This is a sure sign of RNA being turned into DNA.\n\nYou could purify virus from the aftermath of infected cells.  Then set up experiments to determine the nature of what you've isolated and what its properties are.
939038
I agree with every one else, try not to stress to much, and think positive, they may have picked a slight abnormality, which needs to be rechecked.\n\nPap tests are the best way to pick up infections and precancerous cells and abnormal cells. \n\nWishing you all the best and good luck!
637126
See in\nhttp://www.biosophia4jrf.com/volume_i.htm\nAllophenic mice (embryo aggregation mouse chimeras) enable us to dissect the process of spontaneous autoimmunity under physiological conditions.\nhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7997856&dopt=Abstract
1066627
I am a Christian and I have found remarkable facts that have bolstered my faith in Intelligent Design. To name one, Irreducable Complexity. It is the fact, (Not Theory) that the simplest cell in our body was created completely in a moment's time, instead of a gradual evolution. It is like a mouse trap. There's a board, spring, lever, and latch. The cell, like the trap, has components that compliment each other in the same way the trap does. If you took one component away the trap would be defective, likewise if the cell is left without all the necessary systems it will perish leaving no time for evolution.
675906
The spleen filters blood and gets rid of the old and dying red blood cells.  The spleen also hold extra blood within it.\n\nBone marrow is where red blood cells are produced.
765683
As far as I know there are two types of T-cells: CD4 and CD8. Normal levels of T cells in general are about 800-2500 cells per microliter of blood. If your CD4 count gets below 500-600 cells/cubic millimeter, it is recommended to begin antiviral therapy. If the CD4 count drops below 200-300 cells/cubic millimeter, then doctors usually begin preventative treatments for Pneumocystis carinii pneumonia, an opportunistic infection that is also used as a positive diagnostic marker for AIDS. Hope this helps some, and I hope I answered your question...
447360
ok,I try to make it clear,\nimagine an antigen is invading the body,it is going to be diagnosed and captured by innate immune system like Mq,Neu...they represent the antigen to TCR on Tcell,so Tcell become activated and produce cytokines,some of them are going to activate Bcell and makes Bcell to produce Antibodies,antibodies will join antigens and some protein in blood may join them and they all destroy the antigen.\n\nBone marrow is the most important source of Bcell in lifetime.the most important responsibility of Bcell is to produce Antibodies.Antibodies are the most important part of the immune system for the extracellular pathogenes like toxins.B acts as an APC specially in the secondary response.Bcell secretes IL1,6,12 and INF alpha and beta.B has a memory so it plays an important role in the secondary response to antigen.B has some markers such as CD1,5,9.10,14,19,20,21,23,25,32,35,38,40,45,55,59,80,86,126,85,81.\n\nthere are two kinds of B,\n1)B1cell : mostly in newly borns,bigger than the other one,mostly produce IgM and respoce to Ti Ag.it doesn't have memory.it's only 5% of all the Bcells.\n2)B2cell:in older people,95% of all Bs,response to TD antigens and have memory..\n\nsome clues about Abs:there are five class of them,\nIgA(1,2),IgD (it's Ag receptor on Bcell),IgE(role in Allergies),IgG(more than others ,in 4 froms,activate the complemets,role in ADCC,feed back inhibition of Bcells),IgM(antigene receptor on Bcell,activates complemetns)\n\nthat's it,hope it helps;)
690403
start immediately on postexposure prophylaxis wit antivirals even if tests are negative. the tests may take a few weeks to show positive for the hiv.
173439
Sequential blood samples were evaluated from 3 subjects with AHIV (negative HIV EIA, positive HIV RNA), identified 2-3 days before peak viremia (pre-peak). HIV RNA levels and CD4 counts before antiretroviral therapy were used to estimate HIV doubling time (t(d)) and, the basic reproductive number (R(0)). HIV t(d) was calculated from the slope of ln(RNA) vs. time during rising viremia. Maximal estimates of t(d) were 1.6-3.5 days.\nhttp://www.aegis.com/conferences/croi/1998/521.html
413968
http://dev.biologists.org/cgi/content/full/130/17/4123?ck=nck
54920
If the virus is dormant, it will still be detected by the test.  It's a bit confusing, but when people talk about the virus being dormant they basically mean it's chilling out in the patient's body but not making him/her sick (in which case the patient is HIV-positive but does not have AIDS).  The virus is not immediately detectable (I believe whoever it was that said 3-6 months after exposure is right), but a patient can have HIV that will be detectable by an HIV test for several years without showing any symptoms.  The risk of a false negative on an HIV test is fairly low (I don't remember the exact number), but if you've had an HIV test that came back negative and are still worried about it you can always get tested again in a couple months.
1012745
Helper T, I beleive.  Of course new research states that it can move from attacking one type of T-cell to another.
206545
Several possibilities include hepatitis B and C.  You'd probably know if you had these.  Another possibility is cytomegalovirus (CMV) -- it is a virus that is present in a large portion of the population.  It is dormant and has no effect until the immune system goes down.  Sometimes the plasma is given to people with poor immunity and thus needs to be CMV negative.  The people who rejected your plasma should tell you why.  Good luck!