Malcolm Needs

A diphthong is when two letters are pronounced as one (for want of a better way of putting it), so that US English will spell the word as "fetus", whilst UK English (or, at least, old fashioned fuddy-duddies like me) will spell the word as "foetus" - the "oe" bit being the diphthong. Originally, the o and e ran into each other in the spelling, so that the left half of the "o" showed, but the right half of it sort of "slid" under the left half of the "e". You can see what I mean much easier in the attachment. :D:D:D Diphthong.doc

IMO, Yes.

Hi Mabel, Yes, transfused red cells do get sequestered in the spleen, or, should I say, at least small volume red cell transfusions get sequestered to the spleen for a time (unless they are destroyed by intravascular haemolysis). This was shown with radio-isotope-labelled red cells, in the days when they used to inject small volumes of incompatible red cells to see how long they survived in the circulation (and thus boosted the antibody titre!). The red cells disappeared into the spleen for a while before coming back out into the circulation. Obviously, this does not happen in cases of large volume transfusions. I have never read that such research was done on newly delivered mums, get I have a very strong suspicion that the situation was extrapolated from these isotope experiments. Whether or not it actually holds any water, I know not. :confused::):confused:

Good idea, but it'll be a HUGE thread. Better ask Cliff how big the site can go!!!!!!!!!!!!!!! :rolleyes::rolleyes:

It's UK English (with a bit of Greek and Latin derivation thrown in)! If it's any consolation, I am often accussed of thinking in a weird way too!!!!!!! :D:D:D

NHSBT has been inspected for many years by the MHRA - and they still seem to delight in making it as difficult as they can.

We had a case of a pregnant lady the other day that I was totally convinced was a partial DIII with anti-D in her plasma. I was wrong. Although it reacted with all of our anti-D sera (as would a partial DIII), when molecular studies were performed, it turned out to be a DOL with anti-D. :redface:

Ah, but nowadays, you have to be able to prove why you haven't killed anyone, including the bits that are totally and utterly irrelevant. Yes, without doubt, we did need to improve our Quality Systems, but now the world has gone completely "Quality Mad", and it has become thoroughly intrusive, to such an extent that it is preventing people doing things that actually help patients (which is our raison d'etre). :mad::mad::mad::mad::mad:

It seems to me that it depends for what you are using the pipettes. If it is for serology, as opposed to making up reagents (including red cell dilutions), if your pipettes are way out, your controls will not work (although the ratio of the volumes are still going to be okay in most cases).

HEAR, HEAR!!!! An excellent post. I'm glad it's not just me! :D:D:D:D

I am going to be extremely controversial here, and will probably end up being universally hated by all BBT Members, but I think that an awful lot of the posts on this thread are missing the point and are forgetting basic immunology...there I've said it, so I am now probably in deep trouble! The thing is that, as far as I can remember, the blood has to be taken from the mother after a certain time, but before an hour, because the red cells shed from the foetus/baby are, initially, sequestered into the maternal spleen (as is often found with "normal" transfusions) and then "released" back out into the maternal peripheral circulation. Hence, if the sample is taken too early, a falsely low number of the baby's red cells will be seen. On the other hand, after an hour, the maternal reticuloendothelium system (RES) will start to remove any D+ red cells that are sensitised by either the mother's own anti-D (or, indeed, anti-A and/or anti- and, once again, a falsely low count will be obtaained for the number of baby's red cells present. Therefore, there is a time, somewhere between half and hour and an hour, when the maximum number of baby's red cells will be in the maternal peripheral circulation. Once the sample has been taken, however, apart from the normal degredation of cells that happens in all samples, the mix of maternal and baby red cells will not change over a long period of time (assumming that the samples are stored correctly). This is because the antibodies themselves (the anti-D immunoglobulin that may already have been given during the pregnancy, or maternal anti-A and/or anti- will not destroy any of the baby's red cells. Antibodies themselves cannot destroy cells. The sensitised red cells in the maternal circulation will be destroyed (because they are sensitised) by the maternal RES (and, of course, there is no maternal RES in an EDTA bottle) or, in the case of, sometimes, ABO antibodies, by the maternal complement system. Even though the EDTA bottle will contain maternal plasma (and so maternal complement), the EDTA chelates Ca++, Mn++ and Mg++, all of which are required by the complement cascade, and so the cells in the bottle will not be destroyed by complement. Therefore, once a "good" smple is taken, the various counts will not change for some time afterwards, and so when the actual estimation of the amount of baby's red cells present is performed is largely irrelevent (as long as the result is obtained in time to llow the correct dose of anti-D imunoglobulin to be given in a timely manner). SORRY! :redface::redface:

I know that, when I was working in the hospital environment, the cord samples were taken at birth (as would be expected), but those taken on a Friday night were, on occasion, not tested until Monday morning and, apart from it being a bit close to 72 hours, nobody ever seemed to moan. That having been said, I don't recall ever having seen any protocols. :confused::confused:

Well I agree that making a patient scowl might be against the rules, but, in my case, I'm just too darn scared to scowl!!!!!!!!!!!! :eek::eek:

In the (very) old days, when we were making AHG from the raw serum of sheep, we had to get rid of the xenoantibodies by adsorbing with washed group O, group A and group B packed human red cells. To test to make sure that the red cells had been adequately washed free of human plasma, so that the "good bits" of the AHG were not neutralised during this phase, we used to dilute some standard AHG in the supernatant (say 1 drop of neat AHG in 100 drops of the supernatant) to ensure that this did not happen (in other words, it was free of protein). I am just musing, but I wonder if this could be a cheap and easy way of testing the amount of protein left in washed red cells? It certainly work ed with AHG production and, although we never produced any figures, I'm sure that if it is "clean enough" not to ruin AHG, it's "clean enough" for the patient. Should we be quite so fixated with actual figures???????????? :confused::confused::confused::confused:

PLEASE, will you teach my wife how to "shake gently"? Sometimes when she bashes me when I'm snoring, it's a wonder I don't end up in a coma!!!!!!!!!!!!! :eek::eek:

Excellent idea.

I fully accept, John, that a card stating the patient has an antibody directed against a low frequency antigen is not terribly enlightening, but for reasons given by me in an earlier post in this thread, there are very good reasons why, often, nothing more specific can be written on such a card. That having been said, however, it would serve to alert a Blood Bank of the potential, albeit tiny, danger of issuing blood by electronic issue (EI). I fully accept that there must have been hundreds of patients with such antibodies who have already been safely and successfully transfused with EI blood, but, one day, it is going to happen that such a transfusion will result in a haemolytic transfusion reaction (possibly fatal, but more likely resulting in renal failure, but not a fatality), and if we know that a patient has such an antibody, a serolgical cross-match should be performed, so that this tiny gamble is not taken. It's the old thing, "If it were my mother....". :):)

Thanks! That's the one!!!!!!!!!

Somebody posted the Wise Ole Saying, "It's better for people to think you a fool, than to open your mouth and prove it" (although I can't find the post to quote it right now), but it looks like I've done it (AGAIN)!!!!!!! :eek::eek:

You are quite right. We normally do these tests at 20oC and/or 4oC, but the colleague put them in the wrong incubator (one used by another Department - but they worked, so hey)!!!!!!!!!!!!!!!!!!! :D:D:D:D

I have two alternative creative ideas. Either tell the nurses to get educated about how blood components need to be stored if they are to be effective, or (my favourite), shoot the nurses! :eek::eek:

I couldn't agree more. Tim's depth and breadth of knowledge is astoundingly - almost frightening! :):)

I should have added (one of the most important things - so, of course, I left it out!!!!!!!!!!!!!!:rolleyes:) that we have done a Risk Assessment on this.

I suspect that the rules and regulations in the USA will bevery different to those used in the UK, but we do this all the time, if the antigens are rare (or extremely common), and, as long as the antigen is stilld etectable at a reasonable strength (or, in the case of antigen negative cells, the antigens on a cell of equal age and condition is detectable), I see no reason why not. In some cases, it rather begs the question, how else are you going to do it? :confused: