The data available from measurements at 24 and 48 h generated 36 scatterplots of the types illustrated in Fig. 3, by inclusion of 12 h viable burden data.
By 48 h, neither the C. albicans pixels nor the amount of host infiltrate was as strongly correlated with lesion density or viable burden as at 24 h (Table 2), suggesting that the different 48 h parameters may reflect the outcomes of intra-lesional phagocytic processes.
By 24 h, spleen KC concentrations correlated very strongly with 24 h estimates of lesion density, C. albicans pixels, infiltrate pixels and viable burdens in the kidney (Tables 3, 4).
From the overview of associations provided in Table 4 it can be seen that the earliest strong association between immune effector concentrations and kidney lesion parameters were for KC concentrations in the kidneys at 12 h, which significantly associated with 24 h data for lesion densities, C. albicans pixels, infiltrate pixels and viable burdens.
The virulence rank scores for the 9 strains studied previously (Table 1) showed strong statistical correlations with the 48 h means of these four parameters (Fig. 2): mean viable burdens, r = −0.67 (p = 0.025), mean kidney lesions/mm2, r = −0.74 (p = 0.011), mean PAS-positive pixels in PAS-positive lesions, r = −0.64 (p = 0.031), and mean host infiltrate pixels/mm2, r = −0.52 (p = 0.078).
These data support that blood Gluc activity reflects viable tumor burden.
Here we successfully demonstrate secreted Gluc as a new measure of viable tumor burden in primary and metastatic tumor models.
This was also supported by our mathematical models for tumor growth to compare the total and viable tumor burden in our model.
Viable tumor burden was quantitated by in vivo imaging system (IVIS) of tumor bioluminescence and representative IVIS images, graphs of photon flux over time and at the end of the experiment, and bone metastasis histopathology are shown in Fig. 5a d.
European Association for the Study of the Liver (EASL) guidelines recommended that assessment of tumor response should incorporate the decrease in viable tumor burden and that tumor necrosis should be measured when evaluating therapeutic response in hepatic tumors.
Two of the least virulent strains, HUN96 and pmr1Δ (Table 1) showed a decrease in viable kidney burdens between 24 and 48 h (Fig. 2a), while the highest burdens at 48 h were for AM2003-020, J951361, IHEM16614 and SC5314 (Fig. 2a), which were 4 of the 5 most virulent strains in a previous study (Table 1).
