2011 Postgraduate Research Competition - UNSW Science - The ...

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Running Puts Stem Cells on Track!
Joyce Siette and Fred Westbrook
School of Psychology
Abstract
Memory impairments in later life are extraordinarily common, ranging from almost universal
self-reported mild memory complaints, to the more severe memory problems associated with
dementia and neurodegenerative diseases. It is thus critical to develop preventative
strategies for combating the effects of brain ageing. To date, studies of cell therapy and
exercise individually offer remedial strategies for decreasing impaired function and
behaviour. The current experiment aimed to identify the additive effects of these two
approaches. Aged rats were assessed on the object recognition (perihrinal-dependent) and
place recognition (hippocampal-dependent) memory tasks prior to receiving a cell
transplant or sham transplant, and were allowed to exercise for 6 weeks. We found that
aged animals were impaired on the place task only. Groups that received either running, cell
transplant, or both, dramatically reversed this impairment. Additionally, histological results
show that transplanted cells migrate successfully to areas critical for memory formation and
retention. Exercise may further improve this migration and promote cell survival.
Epidemiological and clinical studies already suggest that physical exercise may be an
effective preventative strategy against dementia. By contrast, cell therapy remains an
experimental approach in animals, where control of cell fate is a major obstacle to clinical
translation. Here, in a naturalistic animal model of memory dysfunction, our exciting findings
indicate that exercise plus cell therapy leads to better memory outcomes than cell therapy
alone.
Naturally-inspired antimicrobial peptide:
Panacea for bacterial infections on biomaterials
Abstract
Ren Chen and Naresh Kumar
School of Chemistry
Biomaterials are used in a variety of medical devices and implants, such as catheters,
prosthetic implants and contact lenses. The use of biomaterial implants and medical devices
is an increasingly common and often life-saving procedure. However bacterial infections on
biomaterials have emerged as a major problem, accounting for approximately 45% of all
hospital-acquired infections.
Consequently there is an urgent need to develop surfaces which resist bacterial adhesion
and colonisation. Our research group and collaborators have developed a cationic peptide
“Melimine”, with excellent broad-spectrum antimicrobial activity. In this study we explored
the ability of Melimine to prevent bacterial adhesion in vitro and in vivo when covalently
tethered on biomaterial surfaces. Melimine-coated surfaces showed a significant reduction
in bacterial adhesion when observed under confocal microscopy. Furthermore a half log
reduction in viable bacteria was observed in the test group compared with the control
group in a subcutaneous mouse model after 5 days. Coating of biomaterial surfaces with
Melimine represents a promising strategy for the prevention of device-related infections.
|living well + ageing well