Administration of tamoxifen (TAM) (20 mg/kg per day p.o.) for 6 weeks to female lambda/lacI transgenic rats caused a 4-fold increase in mutation frequency (MF) at the lacI gene locus in the livers of dosed animals compared with controls. After cessation of dosing, the MF showed a further increase with time at 2, 12 and 24 weeks, respectively. Phenobarbital promotion of similarly treated animals resulted in no increase in mutation frequency compared with TAM alone. Treatment with phenobarbital or TAM+phenobarbital resulted in time-dependent increases in liver weight compared with the corresponding controls. There was an increase in cell proliferation in the phenobarbital and TAM+phenobarbital groups, and at 24 weeks in the TAM dosed animals compared with controls. There was also a progressive increase in the number of GST-P expressing foci in the livers of TAM and TAM + phenobarbital rats compared with controls. The induction of cell proliferation and GSTP foci in the rat liver by phenobarbital is consistent with its ability to promote tamoxifen-initiated liver tumours in the rat. If the lacI gene is regarded as being representative of the rat genome in general (albeit that the gene is bacterial) the above observations suggest that promotion by tamoxifen confers selective advantage on mutated genes at loci that contribute to the tumour phenotype and that promotion of rat liver tumours by tamoxifen is not dependent simply upon the enhancement of cellular proliferation.

The internet has become a major source of health information for patients. However, there has been little scrutiny of health information available on the internet to the public. Our objectives were to evaluate the quality and readability of information available on the internet regarding clavicle fractures and whether they changed with academic affiliation of the website or with complexity of the search term.Through a prospective evaluation of 3 search engines using 3 different search terms of varying complexity (“broken collarbone,” “collarbone fracture,” and “clavicle fracture”), we evaluated 91 website hits for quality and readability. Websites were specifically analyzed by search term and by website type. Information quality was evaluated on a four-point scale, and information readability was assessed using the Flesch-Kincaid score for reading grade level.The average quality score for our website hits was low, and the average reading grade level was far above the recommended level. Academic websites offered significantly higher quality information, whereas commercial websites offered significantly lower quality information. The use of more complex search terms yielded information of higher reading grade level but not higher quality.Current internet information regarding clavicle fractures is of low quality and low readability. Higher quality information utilizing more accessible language on clavicle fractures is needed on the internet. It is important to be aware of the information accessible to patients prior to their presentation to our clinics. Patients should be advised to visit websites with academic affiliations and to avoid commercial websites.