John R. Trevithick, PhD, A Canadian Vision Research Pioneer Leaves Us at Age 82.

It is my sad task to note the passing of John Trevithick, PhD, at age 82, at his home in London Ontario. (2/20/2018)

John is well known to many ARVO (Association for Research in Vision and Ophthalmology) and ISER (International Society for Eye Research) members, since the early 70’s as one of the first researchers who took up the lens as a model for cell differentiation. A pioneer in the explorations of cAMP in N. Crassa, he sought to explore this signaling molecule in mammalian cell differentiation. The lens epithelial to fiber cell transition continues during the entire life of the mammalian lens.

            Along the way John explored cataract mechanisms of course but as a biochemist he always was interested in the fundamental knowledge of cell physiology and biochemistry that could be revealed. His lab was one of the first groups to optimize culture media conditions to permit the study of whole living lenses in tissue culture. This permitted the precise manipulation of external and internal chemistry and was used to correlate research done with diabetic rat models and the RCS model. Interesting effects on the RCS lens posterior opacity caught his attention in this model, where degeneration was occurring in the retina. Along with diabetic cataract models his group explored the contribution of antioxidant biochemistry to degenerative processes in the lens and retina. Some surprising findings, of dramatically slowing cataract formation and other degenerations by supplementing endogenous antioxidants resulted in a couple Nature publications. I joined his lab in 1988 as a PhD student, at the University of Western Ontario.

            John took me, and other students, to many meetings around the world and he spent a lot of care teaching us to repeat work and make sure we published reproducible data. He let us write papers early and we tended to graduate with a few publications already completed. With John, I enjoyed discovering that the diabetic rat lens was iso-osmolar for several weeks by dumping Taurine and free amino acids to perfectly balance the increase in sorbitol. Then this amino acid deficiency led to the loss of GSH, ATP production, ion transport capacity, and finally the loss of fluid regulation. This was a lesson John taught many of us, that if you delve into the biochemistry of even an old model system, you will likely find some new knowledge. Do not assume that a decade of literature on a topic has documented everything important.

            John was Emeritus professor of Biochemistry and had continued also as a professor in Kinesiology, working to explore the effects of exercise on the eye in normal and diabetic rats, working with Tom Dzialoszynski and Earl Nobel. Most recently they spent the last several years on space radiation effects upon the lens. That work, funded by the Canadian Space Agency, involves trips to UBC and the use of their busy cyclotron facility. John, always curious to the very end and finding ways to fund vision research in Canada, which does not have a vision-focused funding category as we have in the USA.

If any members of the vision research community have a memory of John Trevithick they would like to share, please email to me at 

Mitton@oakland.edu

Tom and I are planning to write a short memorial paper about John and his contributions to vision science in Canada and internationally. Many of us owe our thanks to John for the time he devoted to ARVO, ISER, vision science and teaching the next generation of scientists.

A mostly complete list of John Trevithick’s publications in PubMed are found here:

John Trevithick Papers in PubMed

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Different Effects of Valproic Acid on Photoreceptor Loss in Rd1 and Rd10 Retinal Degeneration Mice.

Different Effects of Valproic Acid on Photoreceptor Loss in Rd1 and Rd10 Retinal Degeneration Mice. in Molecular Vision.  http://www.molvis.org/molvis/v20/1527/

Using retinal degeneration mouse strains, this paper’s data demonstrate that the underlying etiology of the photoreceptor degeneration is important to determining the effects of Valproic Acid (VPA) on the rate of photoreceptor loss. Our results are very important, because off-label VPA clinical trials with Human RP patients are underway in the USA and South Korea. Thus, VPA might help some families, but not others, depending on the exact genetic mutation, and thus disease etiology, involved in their RP. Our study with mice would indicate that any clinical trials should make comparisons of VPA to placebo within RP patients who have the same disease etiology (same genetic mutation). Patients should also be monitored very closely to evaluate changes in the rate of visual field loss and visual acuity loss while taking VPA in such trials. Continue reading