Research Profile - College of Medicine and Health Science - United ...

Department of Physiology
and in vivo. Frondoside A causes apoptosis of the
cancer cells via the mitochondrial pathway.
New studies on the 5-lipoxygenase (5-LOX)
pathway have focused on colonic cancer. 5-LOX
expression was detected in all adenomatous
colonic polyps that were studied but not in
normal colonic mucosa or in hyperplastic polyps.
These adenomas are the precursor lesions for
human colonic cancer. Inhibitors of the 5-LOX
pathway block growth of colonic cancer cells in
vitro and also when transplanted into athymic
mice. These important findings suggest that 5-
LOX inhibitors may be valuable in the
chemoprevention of colonic cancer in humans.
Pathophysiologic mechanisms of
particulate air pollution
The main research topic of Dr Nemmar is related
to the pathophysiologic mechanisms underlying
the respiratory and cardiovascular effects of air
pollution. Within the last two decades,
environmental factors such as air pollution have
been shown to contribute to cardiorespiratory
morbidity and mortality. A growing body of
epidemiological data implicates particulate
matter air pollution (PM) as yet another factor in
the pathogenesis of respiratory and
cardiovascular diseases. PM influences
susceptibility to hard events and may be
particularly harmful to high-risk groups such as
people with diabetes, people with hypertension,
and elderly people. However, the
pathophysiologic mechanisms underlying these
associations are not fully understood. Recently,
through a series of experimental studies, with his
collaborators, Dr Nemmar provided biological
plausibility for the associations between
particulate air pollution and cardiorespiratory
events. In this context, Dr Nemmar has
investigated the translocation of inhaled ultrafine
pollutant particles in humans and hamsters, and
the mechanisms of their acute cardiopulmonary
effects. Dr Nemmar intends to further clarify the
acute and chronic cardiopulmonary effects of
pollutant particles, and to develop
pharmacological approaches capable of
preventing particle-induced cardiorespiratory
complications. Moreover, epidemiological
studies indicate that the effects of air pollution
are more pronounced in“susceptible”subjects,
such as the elderly, diabetics or hypertensive. Dr
Nemmar will verify this hypothesis by extending
his experiments in a relevant animal model of
enhanced susceptibility (spontaneously
hypertensive and diabetic animals).
Diabetic Neuropathy
Professor John Morrison is interested in the
physiology and patho-physiology of the
autonomic nervous system and its various target
organs, particularly those in the lower urinary
tract. He is PI on a grant for Sheikh Hamdan
Medical Awards (together with Professor Wim
Lammers) on the generation of spontaneous
activity in the bladder, and the relative roles of
intramural nerves and spontaneous smooth
muscle activity. These investigations map the
spread of electrical activity in the bladder, the
sites of pacemakers and the effects of distension
on the spread of excitation. Another long-term
interest is in diabetic neuropathy, and the STZ
model of Type I diabetes and the MSG and GK
models of Type II diabetes have been studied.
For the STZ model it takes about 12 weeks for
clear significant changes in peripheral nerve
markers to appear, while in the Type II models,
these changes appear around the time that
glucose tolerance becomes evident, usually
73