version=pmwiki-2.0.13 ordered=1 urlencoded=1
agent=Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) AppleWebKit/601.1.56 (KHTML, like Gecko) Version/9.0 Safari/537.86.1
author=twebster
host=76.127.131.195
name=Main.InteractAnswer
rev=42
targets=Main.Interactions
text=(:noheader:)%0a(:noleft:)%0a(:Title Answer:)%0a%0aThe intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is fine;%25blue%25 the issue lies in what we mean by ''additive''%25%25. The intuitive answer uses the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a%0aTo see why, suppose I tell you that ''A'' and ''B'' are actually the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up. Most toxicologists and pharmacologists would not call this synergism.%0a%0aOK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound with ''B'' exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. 5 uM of ''A'' and 10 uM of ''B'' thus yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of ''A'' (applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%0aAttach:interactfigure4.jpg%0a%0aThe combination again yields a larger effect than each component by itself. But rather than synergism, we have a special case of what is called additivity of doses, i.e., ''dose additivity'' or, as it is more frequently called, ''concentration additivity''.%0a%0aLet's examine these ideas mathematically. We'll define%0a->''f'''_a_'[''A''] = dose response curve for ''A''%0a->''f'''_b_'[''B''] = dose response curve for ''B''%0a->''f'''_ab_'[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a%0aThree definitions of additivity are typically used:\\%0a''effect summation: f'''_ab_'[''A'',''B''] %0a= ''f'''_a_'[''A''] %0a+ ''f'''_b_'[''B'']%0a%0a''independent action: f'''_ab_'[''A'',''B''] %0a= ''f'''_a_'[''A''] %0a+ ''f'''_b_'[''B'']%0a+ ''f'''_a_'[''A'']%0a''f'''_b_'[''B'']%0a%0a''concentration addition: A/E'''_i,a_' %0a+ ''B/E'''_i,b_' = 1%0a%0awhere ''E'''_i,a_' %0aand ''E'''_i,b_' are, respectively, the concentrations of ''A'' and ''B'' that individually lead to effect level ''i''.%0a%0a%0aReference: Berenbaum MC: What is synergy? ''Pharmacol Rev'' 1989; 41(2):93-141.%0a%0a%25red%25return to [[Interactions|Interactions]]%0a
time=1444430411
author:1444430411=twebster
diff:1444430411:1183834467:=1,2d0%0a%3c (:noheader:)%0a%3c (:noleft:)%0a
host:1444430411=76.127.131.195
author:1183834467=twebster
diff:1183834467:1183834421:=30,31c30,31%0a%3c + ''B/E'''_i,b_' = 1%0a%3c %0a---%0a> + ''B/E'''_i,b_' %0a> %0a
host:1183834467=68.163.106.71
author:1183834421=twebster
diff:1183834421:1167802058:=5,6c5,6%0a%3c To see why, suppose I tell you that ''A'' and ''B'' are actually the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up. Most toxicologists and pharmacologists would not call this synergism.%0a%3c %0a---%0a> To see why, suppose I tell you that ''A'' and ''B'' are actually the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a> %0a
host:1183834421=68.163.106.71
author:1167802058=twebster
diff:1167802058:1167542942:=13,35d12%0a%3c Let's examine these ideas mathematically. We'll define%0a%3c ->''f'''_a_'[''A''] = dose response curve for ''A''%0a%3c ->''f'''_b_'[''B''] = dose response curve for ''B''%0a%3c ->''f'''_ab_'[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a%3c %0a%3c Three definitions of additivity are typically used:\\%0a%3c ''effect summation: f'''_ab_'[''A'',''B''] %0a%3c = ''f'''_a_'[''A''] %0a%3c + ''f'''_b_'[''B'']%0a%3c %0a%3c ''independent action: f'''_ab_'[''A'',''B''] %0a%3c = ''f'''_a_'[''A''] %0a%3c + ''f'''_b_'[''B'']%0a%3c + ''f'''_a_'[''A'']%0a%3c ''f'''_b_'[''B'']%0a%3c %0a%3c ''concentration addition: A/E'''_i,a_' %0a%3c + ''B/E'''_i,b_' %0a%3c %0a%3c where ''E'''_i,a_' %0a%3c and ''E'''_i,b_' are, respectively, the concentrations of ''A'' and ''B'' that individually lead to effect level ''i''.%0a%3c %0a%3c %0a
host:1167802058=68.162.211.112
author:1167542942=twebster
diff:1167542942:1167542801:=7,8c7,8%0a%3c OK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound with ''B'' exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. 5 uM of ''A'' and 10 uM of ''B'' thus yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of ''A'' (applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound with ''B'' exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a> %0a11,12c11,12%0a%3c The combination again yields a larger effect than each component by itself. But rather than synergism, we have a special case of what is called additivity of doses, i.e., ''dose additivity'' or, as it is more frequently called, ''concentration additivity''.%0a%3c %0a---%0a> The combination again yields a larger effect than each component by itself. But rather than synergism, we call this additivity of doses, i.e., ''dose additivity'' or, as it is more frequently called, ''concentration additivity''.%0a> %0a
host:1167542942=68.162.211.112
author:1167542801=twebster
diff:1167542801:1167542784:=7,8c7,8%0a%3c OK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound with ''B'' exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound with ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a> %0a
host:1167542801=68.162.211.112
author:1167542784=twebster
diff:1167542784:1167542755:=7,8c7,8%0a%3c OK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound with ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound and that ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a> %0a
host:1167542784=68.162.211.112
author:1167542755=twebster
diff:1167542755:1167542737:=7,8c7,8%0a%3c OK, maybe that seems like cheating. Suppose instead that ''A'' and ''B'' are different compound and that ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that '''' and ''B'' are different compound and that ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a> %0a11,12c11,12%0a%3c The combination again yields a larger effect than each component by itself. But rather than synergism, we call this additivity of doses, i.e., ''dose additivity'' or, as it is more frequently called, ''concentration additivity''.%0a%3c %0a---%0a> The combination again yields a larger effect than each component by itself. But rather than synergism, we call this additivity of doses, i.e., ''dose additivity'' or, as it is more frequnetly called, ''concentration additivity''.%0a> %0a
host:1167542755=68.162.211.112
author:1167542737=twebster
diff:1167542737:1167542712:=7,8c7,8%0a%3c OK, maybe that seems like cheating. Suppose instead that '''' and ''B'' are different compound and that ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that"A" and ''B'' are different compound and that ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a> %0a
host:1167542737=68.162.211.112
author:1167542712=twebster
diff:1167542712:1167542689:=7,8c7,8%0a%3c OK, maybe that seems like cheating. Suppose instead that"A" and ''B'' are different compound and that ''B'' is exactly half as potent as ''A'' at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that"A" and ''B'' are different compound and that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a> %0a
host:1167542712=68.162.211.112
author:1167542689=twebster
diff:1167542689:1167542632:=7,8c7,8%0a%3c OK, maybe that seems like cheating. Suppose instead that"A" and ''B'' are different compound and that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a> %0a
host:1167542689=68.162.211.112
author:1167542632=twebster
diff:1167542632:1167542608:=5,6c5,6%0a%3c To see why, suppose I tell you that ''A'' and ''B'' are actually the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a%3c %0a---%0a> To see why, suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a> %0a
host:1167542632=68.162.211.112
author:1167542608=twebster
diff:1167542608:1167542574:=5,6c5,6%0a%3c To see why, suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a%3c %0a---%0a> But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a> %0a
host:1167542608=68.162.211.112
author:1167542574=twebster
diff:1167542574:1167542496:=3,4c3,4%0a%3c The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is fine;%25blue%25 the issue lies in what we mean by ''additive''%25%25. The intuitive answer uses the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a%3c %0a---%0a> The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is fine;%25blue%25 the issue lies in what we mean by ''additive''%25%25. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a> %0a
host:1167542574=68.162.211.112
author:1167542496=twebster
diff:1167542496:1167542458:=3,4c3,4%0a%3c The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is fine;%25blue%25 the issue lies in what we mean by ''additive''%25%25. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a%3c %0a---%0a> The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is fine; the issue lies in what we mean by ''additive''. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a> %0a
host:1167542496=68.162.211.112
author:1167542458=twebster
diff:1167542458:1167542204:=3,4c3,4%0a%3c The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is fine; the issue lies in what we mean by ''additive''. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a%3c %0a---%0a> The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a> %0a
host:1167542458=68.162.211.112
author:1167542204=twebster
diff:1167542204:1167541961:=13,14d12%0a%3c Reference: Berenbaum MC: What is synergy? ''Pharmacol Rev'' 1989; 41(2):93-141.%0a%3c %0a
host:1167542204=68.162.211.112
author:1167541961=twebster
diff:1167541961:1167541872:=11,12c11,12%0a%3c The combination again yields a larger effect than each component by itself. But rather than synergism, we call this additivity of doses, i.e., ''dose additivity'' or, as it is more frequnetly called, ''concentration additivity''.%0a%3c %0a---%0a> The combination again yields a larger effect than each component by itself. But rather than synergism, we call this additivity of doses, i.e., ''dose additivity' or, as it is more frequnetly called, ''concentration additivity''.%0a> %0a
host:1167541961=68.162.211.112
author:1167541872=twebster
diff:1167541872:1167541801:=4a5,12%0a> Let's examine this idea mathematically. We'll define%0a> ->''fa''[''A''] = dose response curve for ''A''%0a> ->''fb''[''B''] = dose response curve for ''B''%0a> ->''fab''[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a> %0a> Then ''effect summation'' means%0a> ->''fab''[''A'',''B''] = ''fa''[''A''] + ''fb''[''B'']%0a> %0a
host:1167541872=68.162.211.112
author:1167541801=twebster
diff:1167541801:1167541667:=15,16c15,16%0a%3c OK, maybe that seems like cheating. Suppose instead that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A" (it is equivalent to applying TEFs as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose instead that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A", i.e., it is equivalent to applying a TEF (as is done for dioxins). The results, shown below, look the same as before. %0a> %0a19,20c19,20%0a%3c The combination again yields a larger effect than each component by itself. But rather than synergism, we call this additivity of doses, i.e., ''dose additivity' or, as it is more frequnetly called, ''concentration additivity''.%0a%3c %0a---%0a> The combination again yields a larger effect than each component by itself. But rather than synergism, %0a> %0a
host:1167541801=68.162.211.112
author:1167541667=twebster
diff:1167541667:1167541644:=15,16c15,16%0a%3c OK, maybe that seems like cheating. Suppose instead that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A", i.e., it is equivalent to applying a TEF (as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A", i.e., it is equivalent to applying a TEF (as is done for dioxins). The results, shown below, look the same as before. %0a> %0a
host:1167541667=68.162.211.112
author:1167541644=twebster
diff:1167541644:1167541593:=13,14c13,14%0a%3c But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each 10 uM increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a%3c %0a---%0a> But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a> %0a
host:1167541644=68.162.211.112
author:1167541593=twebster
diff:1167541593:1167541291:=15,16c15,16%0a%3c OK, maybe that seems like cheating. Suppose that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose, i.e., ''B'' acts as if it is a two-fold dilution of ''A''. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalent to 10 uM of "A", i.e., it is equivalent to applying a TEF (as is done for dioxins). The results, shown below, look the same as before. %0a%3c %0a---%0a> OK, maybe that seems like cheating. Suppose that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalnet to 10 uM of "A", i.e., it is equivalent to applying a TEF (as is done for dioxins).%0a> %0a19,20d18%0a%3c The combination again yields a larger effect than each component by itself. But rather than synergism, %0a%3c %0a
host:1167541593=68.162.211.112
author:1167541291=twebster
diff:1167541291:1167540151:=15,18c15,16%0a%3c OK, maybe that seems like cheating. Suppose that ''B'' is a different compound from ''A'' such that ''B'' is exactly half as potent at every dose. Using 5 uM of ''A'' and 10 uM of ''B'' yield the same results. A combination of 5 uM of ''A'' and 10 uM of ''B'' is equivalnet to 10 uM of "A", i.e., it is equivalent to applying a TEF (as is done for dioxins).%0a%3c %0a%3c Attach:interactfigure4.jpg%0a%3c %0a---%0a> Maybe you feel tricked.%0a> %0a
host:1167541291=68.162.211.112
author:1167540151=twebster
diff:1167540151:1167540017:=13,16c13,14%0a%3c But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each increment separately because the dose-response curve is here concave up (supralinear). Most toxicologists and pharmacologists would not call this synergism.%0a%3c %0a%3c Maybe you feel tricked.%0a%3c %0a---%0a> But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each increment separately because the dose-response curve is here concave up (supralinear).%0a> %0a
host:1167540151=68.162.211.112
author:1167540017=twebster
diff:1167540017:1167540002:=13,14c13,14%0a%3c But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combination'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each increment separately because the dose-response curve is here concave up (supralinear).%0a%3c %0a---%0a> But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combinaiton'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each increment separately because the dose-response curve is here concave up (supralinear).%0a> %0a
host:1167540017=68.162.211.112
author:1167540002=twebster
diff:1167540002:1167538073:=13,14d12%0a%3c But suppose I tell you that ''A'' and ''B'' are in fact the same compound. The ''sham combinaiton'' of ''A'' and ''B'' is, in fact, just 20 uM of ''A''. The effect of the sham combination is larger than each increment separately because the dose-response curve is here concave up (supralinear).%0a%3c %0a
host:1167540002=68.162.211.112
author:1167538073=twebster
diff:1167538073:1167538039:=3,4c3,4%0a%3c The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly (perhaps) this turns out not to be a very useful way to think about it.%0a%3c %0a---%0a> The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a> %0a
host:1167538073=68.162.211.112
author:1167538039=twebster
diff:1167538039:1167537972:=3,4c3,4%0a%3c The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intuitive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a%3c %0a---%0a> The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a> %0a
host:1167538039=68.162.211.112
author:1167537972=twebster
diff:1167537972:1167537919:=3,4c3,4%0a%3c The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' produces a larger effect than the individual effects summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a%3c %0a---%0a> The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a> %0a
host:1167537972=68.162.211.112
author:1167537919=twebster
diff:1167537919:1167537893:=3,4c3,4%0a%3c The intuitive answer, for most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a%3c %0a---%0a> The intuitive answer, foir most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a> %0a
host:1167537919=68.162.211.112
author:1167537893=twebster
diff:1167537893:1167537844:=6,9c6,9%0a%3c ->''fa''[''A''] = dose response curve for ''A''%0a%3c ->''fb''[''B''] = dose response curve for ''B''%0a%3c ->''fab''[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a%3c %0a---%0a> ->''f''a[''A''] = dose response curve for ''A''%0a> ->''f''b[''B''] = dose response curve for ''B''%0a> ->''f''ab[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a> %0a11,12c11,12%0a%3c ->''fab''[''A'',''B''] = ''fa''[''A''] + ''fb''[''B'']%0a%3c %0a---%0a> ->''f''ab[''A'',''B''] = ''f''a[''A''] + ''f''b[''B'']%0a> %0a
host:1167537893=68.162.211.112
author:1167537844=twebster
diff:1167537844:1167537788:=6,9c6,9%0a%3c ->''f''a[''A''] = dose response curve for ''A''%0a%3c ->''f''b[''B''] = dose response curve for ''B''%0a%3c ->''f''ab[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a%3c %0a---%0a> ->fa[''A''] = dose response curve for ''A''%0a> ->fb[''B''] = dose response curve for ''B''%0a> ->fab[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a> %0a11,12c11,12%0a%3c ->''f''ab[''A'',''B''] = ''f''a[''A''] + ''f''b[''B'']%0a%3c %0a---%0a> ->fab[''A'',''B''] = fa[''A''] + fb[''B'']%0a> %0a
host:1167537844=68.162.211.112
author:1167537788=twebster
diff:1167537788:1167537758:=6,9c6,9%0a%3c ->fa[''A''] = dose response curve for ''A''%0a%3c ->fb[''B''] = dose response curve for ''B''%0a%3c ->fab[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a%3c %0a---%0a> ->fA[''A''] = dose response curve for ''A''%0a> ->fB[''B''] = dose response curve for ''B''%0a> ->fAB[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a> %0a11,12c11,12%0a%3c ->fab[''A'',''B''] = fa[''A''] + fb[''B'']%0a%3c %0a---%0a> ->fAB[''A'',''B''] = fA[''A''] + fB[''B'']%0a> %0a
host:1167537788=68.162.211.112
author:1167537758=twebster
diff:1167537758:1167537734:=11,12c11,12%0a%3c ->fAB[''A'',''B''] = fA[''A''] + fB[''B'']%0a%3c %0a---%0a> ->fAB[''A'',''B''] = fA[''A''] + fA[''A'']%0a> %0a
host:1167537758=68.162.211.112
author:1167537734=twebster
diff:1167537734:1167537621:=3,5c3%0a%3c The intuitive answer, foir most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Surprisingly, perhaps, this turns out not to be a very useful way to think about it.%0a%3c %0a%3c Let's examine this idea mathematically. We'll define%0a---%0a> The intuitive answer, foir most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Let's examine this idea mathematically:%0a10,12c8,9%0a%3c Then ''effect summation'' means%0a%3c ->fAB[''A'',''B''] = fA[''A''] + fA[''A'']%0a%3c %0a---%0a> %0a> %0a
host:1167537734=68.162.211.112
author:1167537621=twebster
diff:1167537621:1167537480:=3,9c3,5%0a%3c The intuitive answer, foir most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.'' Let's examine this idea mathematically:%0a%3c ->fA[''A''] = dose response curve for ''A''%0a%3c ->fB[''B''] = dose response curve for ''B''%0a%3c ->fAB[''A'',''B''] = dose response curve for the combination of ''A'' and ''B''%0a%3c %0a%3c %0a%3c %0a---%0a> The intuitive answer, foir most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.''%0a> %0a> %0a
host:1167537621=68.162.211.112
author:1167537480=twebster
diff:1167537480:1167537135:=3,5c3,6%0a%3c The intuitive answer, foir most people, is synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed. The definition of synergistic as greater than additive is correct; the issue lies in what we mean by ''additive''. The intutive answer applies the definition of additivity known as ''effect summation.''%0a%3c %0a%3c %0a---%0a> Suppose you answer: "synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed." Mathematically:%0a> fAB(A,B)%0a> %0a> %0a
host:1167537480=68.162.211.112
author:1167537135=twebster
diff:1167537135:1167537098:=3,6d2%0a%3c Suppose you answer: "synergy, since the combination of ''A'' and ''B'' is greater than the individual results summed." Mathematically:%0a%3c fAB(A,B)%0a%3c %0a%3c %0a
host:1167537135=68.162.211.112
author:1167537098=twebster
diff:1167537098:1167537086:=3c3%0a%3c %25red%25return to [[Interactions|Interactions]]%0a---%0a> %25red%25return to [[Interactions|Interactions]%0a\ No newline at end of file%0a
host:1167537098=68.162.211.112
author:1167537086=twebster
diff:1167537086:1167537012:=3c3%0a%3c %25red%25return to [[Interactions|Interactions]%0a\ No newline at end of file%0a---%0a> return to Interaction%0a\ No newline at end of file%0a
host:1167537086=68.162.211.112
author:1167537012=twebster
diff:1167537012:1167537012:=1,3d0%0a%3c (:Title Answer:)%0a%3c %0a%3c return to Interaction%0a\ No newline at end of file%0a
host:1167537012=68.162.211.112