BMC Genomics 2008, 9:75.PubMedCrossRef Authors’ contributions All authors participated in the design of the study and data analyses. MH carried out bacterial isolation, resistant and reduction assay, molecular genetic studies and manuscript preparation. XL carried out the genome analysis. SM carried out genomic sequencing and the whole genome shotgun submission. LG performed the electron microscope analysis. CR participated in the design of the experiments
selleck products and helped to draft the manuscript. GW is the principal investigator of the funded project. She coordinated the study and helped to draft the manuscript. All authors read and approved the final manuscript.”
“Background The basic profile of dose-response (DR) relationships is a logical consequence of the population level required by this type of analysis. If the sensitivity of a population to an effector follows a unimodal distribution, then the profile of the corresponding cumulative function (i.e. the DR curve) will necessarily be a sigmoid. In practice,
however, it is possible to find occasional anomalous profiles, far from the simple sigmoid model. Although in such cases formal treatments are generally disregarded, this fact has promoted suspicion about the general validity of the classic DR theory. Before renouncing this conceptual frame, however, it seems more prudent to obey the parsimony principle and to attempt interpretations in accordance with the simple and accepted basis Staurosporine solubility dmso of the theory. A biphasic response is an interesting
anomaly, having two graphical branches with different signs, typically stimulatory at low doses and inhibitory at high doses. This response, which Southam and Ehrlich [1] called ‘hormetic’, has seen a renewed mafosfamide interest in recent years [2–4], which has led to talk of the ‘Compound C nmr rebirth of hormesis as a central pillar of toxicology’ [5] and has even produced a re-launching document, signed by 58 investigators [6]. In this context, it has been pointed out-with good reason-that the dogmatism of classic toxicology has hindered the recognition of the phenomenon [6–8], as well as its generality [9, 10]. Furthermore, it has been suggested that this generality could lead to revision of the environmental protection policies, which are perhaps unnecessarily expensive [4, 11, 12], and it has also been pointed out that hormesis could lend a conceptual basis to the practice of homoeopathy [13]. In a previous work [14] we have discussed some of these viewpoints and presented theoretical and experimental evidence showing that hormetic responses-at least some of them-could be the result of the simultaneous action of two effectors, treated and interpreted under the hypothesis of a single effector.