[ Pobierz całość w formacie PDF ]
.These areanti-toxins, anti-venoms and antidotes.Here, I would like to discuss and propose that together withmaking vaccines, introducing improved sanitation and making people familiar with the germ theory, theuse of anti-toxins and antidotes would also be a vital tool in the battle against disease.What precisely are antidotes?An antidote or anti-toxin can be defined as any substance which can counteract a toxin.A toxin is asubstance which causes bodily harm usually through poisoning.To differentiate a toxin from a simplefile:///D|/1011250031__17.htm (2 of 10)21-Dec-07 20:26:03 - Chapter 17poison, it is said that even though toxins come in a very wide variety of different molecules, they areoften proteins and produced by living (micro) organisms.Likewise, antidotes are often antibodies whichbind and neutralize toxins.The easy way to envision the action of an antidote is to think of differentlocks and keys.For the body to work correctly, different locks and keys (proteins called enzymes whichdo anything and everything from help you create usable energy in your cells to making new buildingblocks for your proteins or DNA) have to work perfectly together.If a toxin interferes with a specifickey being able to fit in a lock, that process is disrupted.If this process is something essential, the toxincan be deadly.An antidote can work in different ways but usually it binds to the toxin and prevents itfrom interfering with the lock and key in question.Toxins we have commonly heard of are Tetanus,Botulinum and Diphtheria.Although Botulinum toxin is the most deadly toxin known to man, it iscurrently more associated with the temporary removal of wrinkles than with death.Why should Grantville bother making these antidotes?These days everyone in the Western world and even most of the developing world gets immunizedagainst tetanus and diphtheria.What we are actually immunized with are the tetanus and diphtheriatoxoids, the inactivated forms of the toxins that are produced by the tetanus and diphtheria bacteria.Inaddition, when we go into the hospital for a tetanus shot when we have scratched ourselves on a dirtynail and we haven't had a shot for a decade or longer, the tetanus shot may come with some tetanusimmunoglobulin, a concentrated antidote, in addition to the tetanus toxoid.Without these vaccinations,diphtheria and tetanus would manifest themselves widely as the very deadly diseases they are.The development of the first antidotes against these toxins during the 1880's was one of the first steps inmodern medicine, together with smallpox vaccinations, that made a major impact on the childhoodmortality rate.I believe this technique will be favored by the up-time medical staff because they couldmake such a large difference and most of all because they can be used and still be successful aftersomeone is already infected.What are antibodies and how are they produced?Antibodies are the end product of one of the two major branches of vertebrate immune systems.Thesetwo are called the cellular and the humoral branches.I will not be discussing the cellular branch, aside tosay that it provides for a massive amount of professional literature and still keeps a lot of researchscientists quite busy.The humoral branch is so-called because the end product can be found in thehumor "blood" and these are antibodies.They are proteins which evolve so that they can bind very manydifferent kinds of molecules.The manner in which they are developed in the body is reminiscent of thetheory of evolution.A type of cell called a "naïve B-cell" is stimulated to differentiate, i.e.to start todevelop down the pathway to become an antibody-producing cell called a plasma cell.During thisprocess, the cell is presented with an antigen, a sample of what the antibody is going to be binding to,the B-cell divides and of the offspring only those making an antibody with some capacity to bind to theantigen survive.Those cells that fail to make binding antibodies commit suicide.This process isrepeated at least three times with increasingly higher hurdles for the binding.In the end, it results in aspecialized cell producing lots of an antibody with strong binding to the antigen.This whole evolutioncan take as long as three weeks.The process in itself, of course, is much more intricate involving manydifferent changes in the cells and requires interaction with other cells and their protein products whichcan stimulate or break off this process, called differentiation, from a naïve B-cell to a plasma cell.Once a plasma cell has been produced, it will now continue to pump out antibodies.These cells arefile:///D|/1011250031__17.htm (3 of 10)21-Dec-07 20:26:03 - Chapter 17terminally differentiated, which is to say they no longer divide and they no longer develop any further.They do, however, have a tendency to settle down in the bone marrow where some of them continue topump out antibodies for sixty to a hundred or so years.Not all plasma cells are that long-lived, somesurvive for merely a few weeks, others months or years.That is why vaccinations for tetanus arerepeated every 10 years but you only need two shots of measles vaccine.If you actually have a disease,you tend to have a very long lived memory of that particular form of the disease in the form of longsurviving plasma cells churning out antibodies all day every day.This immunological memory is muchenhanced by some of the progenitors of the plasma cells in the B-cell differentiation process calledmemory B-cells.In the process of producing the plasma cells, the intermediates have a step where thecells can already bind fairly well to an antigen, however these cells retain the capacity to divide andenhance their capacity to bind to the antigen.These memory B-cells also stick around, favored hangoutsfor them can be found in the spleen, tonsils as well as the appendix and other locations around theintestines.If you come across a particular pathogen again, after you are vaccinated or have had thedisease, these memory B-cells can rapidly multiply and develop to become many more plasma cells thatcan produce an overwhelming quantity of antibodies to corral the disease in a much shorter period oftime, a mere matter of days a compared to the few weeks it takes to develop immunological memory thefirst time
[ Pobierz całość w formacie PDF ]
