TABLE 2.

Comparison of observed and expected values and statistical analysis of the synergistic inhibition of the synthetic activity of wt HIV-1 RT by the efavirenz-AZTTP combination

Ea (%) and statistics	Mean (nM) ± SDb				Δobs-exp[EFV]	Δobs-exp[AZTTP]
	[EFV]obs for D1	[EFV]exp for D1	[AZTTP]obs for D2	[AZTTP]exp for D2
10	1.4 ± 0.2	0.48 ± 0.01	0.28 ± 0.01	0.094 ± 0.002	0.92	0.18
20	3.1 ± 0.02	2.5 ± 0.01	0.62 ± 0.05	0.5 ± 0.02	0.6	0.12
30	5.36 ± 0.01	7.83 ± 0.01	1.07 ± 0.01	1.56 ± 0.01	−2.47	−0.49
40	8.33 ± 0.01	17.22 ± 0.2	1.67 ± 0.02	3.44 ± 0.02	−8.89	−1.77
50	12.5 ± 0.02	32 ± 0.3	2.5 ± 0.05	6.4 ± 0.02	−19.5	−3.9
60	18.75 ± 0.05	51.6 ± 0.2	3.75 ± 0.01	10.32 ± 0.5	−32.85	−6.57
70	29.1 ± 0.02	80.8 ± 0.1	5.8 ± 0.02	16.16 ± 0.1	−51	−10.36
80	50 ± 0.5	136.5 ± 0.6	10 ± 0.1	27.3 ± 0.2	−86.5	−17.3
90	112.5 ± 0.2	254 ± 0.8	22.5 ± 0.2	50.8 ± 0.6	−141.5	−28.3
Statisticsc	μ1 = 26.78 ± 35.6	μ2 = 64.77 ± 83.6∗	μ1 = 5.35 ± 7.12	μ2 = 12.95 ± 16.7∗	μ = −37.9 ± 48.3	μ = −7.59 ± 8.6∗

^aE, observed inhibition expressed as percent of control activity without drugs (E_con). 

^bEFV, efavirenz; obs, observed effective concentration, calculated according to equation 3; exp, expected effective concentration under the null reference hypothesis I = 1, calculated according to equation 2. Δ_obs-exp, change between observed and expected values. D₁ and D₂, dose of drug 1 and drug 2 giving the indicated percentage of inhibition of RT activity when tested in the combination (D₁ + D₂). 

^cμ, mean value; ∗, P < 0.05 compared to the observed value. This P value indicates that the probability that the observed value differ from the expected ones is ≥95%. Thus, the observed synergy can be considered highly significant. For details see the text.