Finally, the recent study by Zhang et al. (2010b) is hampered by potential confounding, a small study group, sampling artifacts, and lacks reporting of critical information, such that the reported chromosome changes in this study are impossible to interpret.
In addition, replication of the study is impossible as the individual neuropsychological tests employed were not reported.
This type of study is impossible in humans due to obvious ethical considerations and the cost and complexity in working with primate models has precluded their use for extensive studies of the exoerythrocytic stage.
The study is impossible to evaluate properly without that information – and how those claims were ranked – and it should have appeared as an appendix in the original paper.
Although the one-to-one comparability of these studies is impossible (see "Methods" section), some preliminary interpretations can be drawn on criteria in decision-making.
In the absence of a population of E. helvum known to be uninfected, formal investigation of specificity in our study is impossible.
Due to differences in methodology, a full comparison with our study is impossible.
However, all of these sick mice died soon after transplantation, and generation of transgenic offspring to carry on the follow-up study is impossible.
However, the contribution of insulin aspart to effects on weight observed in these studies is impossible to separate from that of insulin detemir.
However, demonstrating the approach to the posterior epidural space in this cadaveric study was impossible because the epidural space was congested with the needle and endoscope, and limited space was available for J-turning the endoscope to visualise the posterior epidural space.
