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Biomedical subjects

Timothy Chambers

Publications and source records attributed to Timothy Chambers.

2 recordsLinked to original sources

The relationship between paediatricians and commerce.

The interaction between doctors and commerce, particularly the pharmaceutical industry, has recently been subject to increasing scrutiny. Doctors are now exposed to mounting influence from industry as it spends large amounts of money on marketing, is heavily involved with continuing medical education and sponsors a major proportion of research. Conflicts of interest may exist on both sides of the relationship: doctors can be manipulated and companies need to be profitable. Paediatricians are just as open to this influence as are other members of the medical profession. There is evidence that clinical practice is altered by interaction with industry, although doctors appear to deny the likelihood of being influenced. There are significant concerns over the increasing involvement of the pharmaceutical industry with research, although the regulation of the industry continues to be strengthened and the process of research is becoming more transparent. Disclosure of conflicts of interest involving authorship is now common practice and should extend to all facets of the relationship. However, collaboration continues to be necessary in order to develop new therapies, maximise research and particularly in paediatrics, to test medications in children. Paediatricians need to be aware of the sources of influence and understand current guidelines so that interactions with industry continue to be appropriate.

Commerce↗

Thioredoxin-1 mediates osteoclast stimulation by reactive oxygen species.

We found that the antioxidant protein thioredoxin-1 (Trx) is more highly expressed in osteoclasts than in macrophages. Moreover, transfection of RAW 264.7 (RAW) cells with a Trx-expression construct resulted in a dramatic increase in their capacity for osteoclast formation. In contrast, Trx-expression was suppressed and osteoclast formation was abrogated by transfection with the antioxidant proteins glutathione peroxidase-1 (Gpx) or peroxiredoxin-1 (Prx). These divergent effects suggest that Trx augments osteoclast formation through some special function. It is known that Trx enhances the binding of several transcription factors to DNA. We found that AP-1, NFkappaB, and NFAT-reporter gene expression was enhanced more greatly by RANKL in RAW cells transfected with the Trx-expression construct. Thus, oxidants stimulate osteoclastic differentiation by induction of Trx-expression, which augments the DNA binding of transcription factors essential for osteoclastic differentiation. Conversely, antioxidants, including Gpx and Prx, suppress Trx-expression and thereby osteoclastic differentiation.

Animals↗