BRIEFLY
- TRIAL
SET TO LAUNCH FOR TRABECULECTOMY ANTI-SCARRING AGENT. Cambridge
Antibody Technology (CAT), based near Cambridge, Great Britain, recently
announced the completion of a Phase II/III European clinical trial
of Trabio, a human monoclonal antibody under development as an anti-scarring
agent to improve the outcome of glaucoma filtration surgery. (Six
other CAT-derived human therapeutic antibodies are at various stages
of clinical trials; Humira, the leading CAT-derived antibody, isolated
and optimized in collaboration with Abbott, has been approved by the
FDA for marketing in the United States as a treatment for rheumatoid
arthritis.) The current trial includes 344 patients undergoing first-time
trabeculectomy, enrolled at major eye hospitals in six European countries.
Data from the trial is expected to be available at the end of 2004.
- THREE CELL TYPES RESPONSIBLE FOR LIGHT
DETECTION IN THE EYE. A team of researchers from Johns
Hopkins has put to rest a long-standing controversy over how many
cell types are responsible for detecting light in the eye. The answer:
three. In the June 15 advance online publication of Nature,
researchers announced that rods, cones and special retinal cells that
produce a protein called melanopsin account for the entirety of a
mouses reaction to light levels. They discount the idea that
cells that produce proteins called cryptochromes are somehow connected
to light detection. Along with producing visual images, detecting
and reacting to light is among one of the eyes most important
functions, helping to regulate the bodys internal clock, the
pupils ability to react to light, and the motivation toward
activity at appropriate times of the day. The Johns Hopkins team removed
the genes for three key proteins that help pass light information
from rods, cones and melanopsin-producing cells. Offspring from these
cross-bred knockout mice were missing all three proteins, had a "half-dose"
of the three proteins or had various combinations of protein levels.
None of the so-called triple-knockout mice could adjust their pupils
in response to light; nor did they adjust activity levels when exposed
to light, although the mice with a half-dose of each of the three
proteins reacted normally. Additional tests showed that mice without
rods and cones were able to reset their internal clocks when exposed
to the same color of light favored by melanopsin-producing cells--but
not by cryptochromes.
SOURCE:
Hattar S, Lucas RJ, Mrosovsky N, et al. Melanopsin and rod-cone photoreceptive
systems account for all major accessory visual functions in mice.
Nature AOP, published online June 15, 2003;doi:10.1038/nature01761.
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