Sarah Bachman ’05
Advisor: Giséle Muller-Parker, Ph.D., Western Washington University
Effect of feeding by the leather star Dermasterias
imbricate on the symbiotic algae in the host Anthopleura elegantissima
The effect of predation by the leather star Dermasterias imbricata on
the endosymbiotic zooxanthellae and zoochlorellae of the anemone Anthopleura
elegantissima was examined in flow-through water sea tables at Shannon
Point Marine Center in Puget Sound during the months of July and August
2004. Productivity, photosynthetic pigments, and mitotic index (% cells
dividing) were used as indicators of algal health; fecal algae were compared
with algae freshly isolated from anemones. Two types of waste products
were collected that contained algae, pellets egested from the mouth after
partial digestion (pseudofeces), and fecal streams released from the anus.
All zooxanthellae and zoochlorellae collected from sea stars were photosynthetic
(mean maximum production for zooxanthellae in control = 4.66, pseudofeces
= 1.40, and feces = 3.86; zoochlorellae control = 2.27, pseudofeces =
1.07, feces =0.36), maintained normal chlorophyll levels (mean zooxanthellae
chl a in control=5.06, pseudofeces = 4.11, chl c in control = 1.30, pseudofeces
= 1.41; mean zoochlorellae chl a in control=4.11, pseudofeces = 2.42,
chl b in control = 2.08, pseudofeces = 2.06), and divided at rates not
significantly different from those of freshly isolated control samples
(mean mitotic index in zooxanthellae controls = 1.79, pseudofeces = 2.30,
feces = 1.37; zoochlorellae controls = 6.73, pseudofeces = 5.46, feces
= 5.05). Released algae may represent a source of symbiotic algae for
Anthopleura larvae or other hosts. This study may have important implications
for Western tropical reefs where the predatory crown of thorns starfish
and coral bleaching are concerns.
Kathryn Banahan ’05
Faculty Advisor: Olivia Harriott, Ph.D., Fairfield University
Project Advisor: Jeremy Collie, Ph.D., University of Rhode Island
Resource partitioning between four species of flounder
in Narragansett Bay
In this study, we investigated the diets of four species of flounder in
Narragansett Bay: summer flounder (Paralichthys dentatus), winter flounder
(Pseudopleuronectes americanus), fourspot flounder (Paralichthys oblongus),
and windowpane flounder (Scophthalmus aquosus). These four species are
abundant in Narragansett Bay during the summer months and are therefore
likely to be important components of the benthic food web. Living in the
same region, these flounder share the same resources and may therefore
directly compete. We investigated whether the four flounder species partition
the resources by means of their diets and spatial area. Flounder were
collected at weekly intervals at two stations in the bay from June to
August of 2004. Stomach contents were sorted to the lowest taxonomic level
possible, counted, and weighed. While there was some prey overlap, diet
composition analysis by weight showed that each species of flounder had
a different prey preference. The dominant prey categories in summer flounder
were fish and mantis shrimp, winter flounder preferred worms and amphipods,
fourspot flounder ate squid, and windowpane flounder ate mostly Crangon.
The only significant prey overlap between summer, fourspot, and windowpane
flounder was for Crangon, however, the high abundance of this prey in
the summer makes competition unlikely. The diet of summer flounder varied
between station, reflecting the prey available at each location; in contrast,
the winter flounder diet was the same at both stations. Fourspot and windowpane
flounder were not collected at the mid bay site; therefore their diets
were not analyzed by location.
Michelle Carbuto ’05
Faculty Advisor: Linda Henkel, Ph.D.
The effects of evidence on source memory for actions
Past research on false confessions has shown that people can be convinced
that they have performed actions that they did not perform, even gruesome
murders. In fact, many common interrogation techniques, such as showing
suspects pictures and evidence from the crime scene, can contribute to
false confessions. The main goal of this experiment was to determine under
which circumstances will people think that they performed an action that
they in fact only imagined. With this past research on false confessions
in mind, it was hypothesized that showing a person evidence that an imagined
action was performed will place doubt in the person’s head and cause
more source errors.
Subjects were asked to perform or imagine performing a series of 60 actions
(30 performed and 30 imagined), all of which would leave some sort of
evidence that the action had been completed. After performing and imagining
performing the actions, the subjects viewed a slideshow providing evidence
that some of the imagined actions had been completed. For example, the
subject would imagine breaking a toothpick and then later see a broken
toothpick in the slide presentation. Of the 30 imagined actions, 10 were
in the slideshow once, 10 were in the slideshow three times, and 10 were
not in the slide show at all. One week later, the subjects were given
a memory test that included the 60 actions, as well as 15 new actions,
and asked to indicate whether each action was actually performed, imagined,
The main source error of interest in this study was when a subject remembered
performing an action that they only imagined performing. It was hypothesized
that the subjects would be more likely to remember performing the imagined
actions that they saw in the slideshow than the imagined actions not included
in the slideshow. The results thus far support my hypothesis and it seems
only a very small percentage of the time will subjects remember performing
an action they only imagined if they were not exposed to evidence that
they performed the action (that is, if they did not see the item in the
Erin Daly ’05 and Adam Blom ’05
Faculty Advisor: Matt Kubasik, Ph.D.
H/D Exchange Studies of Short Helical Peptides
We have investigated the three-dimensional solution phase structure of
short polypeptides through 1H FT-NMR studies of amide hydrogen/deuterium
exchange kinetics. Hydrogen/deuterium exchange is a mature technique for
the investigation of biomolecular structure. In this technique, the rates
at which amide hydrogen atoms of the biomolecule exchange with deuterons
available from solvent indicate the “solvent accessibility”
of the hydrogen atoms. Amide hydrogen atoms can be protected from exchange
by being buried within a biomolecule or by intramolecular hydrogen bonding,
or both. In our study, octameric and tetrameric peptides of the amino
acid residue alpha-aminoisobutyric acid were interrogated with H/D exchange.
We found significant protection from exchange, indicated stable intramolecular
hydrogen bonds consistent with 310 helical structure for our peptides.
Stacy DeGabriele ’05
Program Advisor: James Udy, PhD., Marine Botany Department, University
of Queensland, Brisbane, Australia
Ecosystem Health Monitoring Program of Queensland,
Australia: Results of a Nitrogen Monitoring Study
Sewage effluent is discharged into many estuarine and coastal waters throughout
Southeast Queensland. It is important to trace the source and extent of
sewage effluent in receiving waters to broadly gauge the contribution
of wastewater to nitrogen pools in the receiving estuaries and Moreton
Bay. This is achieved by Sewage Plume Mapping, which measures the uptake
of the stable nitrogen isotope 15N by the microalga Catenella nipae. In
this experiment, Catenella samples were deployed at the Ecosystem Health
Monitoring Program’s (EHMP) monthly water quality sites. After four
days, the samples were collected, dried, and ground in the laboratory.
They then underwent stable isotope analysis. Based on the knowledge that
within the last six years there have been considerable upgrades of many
of the sewage treatment plants that discharge into Moreton Bay, it was
predicted that lower concentrations of 15N would be found in the Catenella
samples. The results of the stable isotope analysis supported these predictions
and it was found that the release of effluents into the Moreton Bay area,
overall, were lower than previous years.
Melissa DeSantis '05 and Talia Pettini '06
Faculty Advisor: Elizabeth Gardner, Ph.D.
Explicit attitudes of Fairfield University undergraduates
toward homelessness as an investigation of order effect
The present study was designed to measure Fairfield University students’
attitudes toward homelessness and to see whether manipulated empathy had
any significant influence on these measurements. Students completed two
surveys under separate conditions that varied the order of presentation.
One condition displayed a sympathetic view of the homeless followed by
a general attitude scale, and the second condition provided the general
attitude scale first. Overall scores indicated a slightly sympathetic
attitude toward people who are homeless. Students’ scores were analyzed
under each condition and then compared. No significant differences were
found between the conditions; however the qualitative statistics have
shown an overall indifference on the part of Fairfield University Undergraduates
toward the homeless population.
Kristen Desy ’05 and Bethany Sprung ’05
Faculty Advisor: Olivia Harriott, Ph.D.
Molecular characterization of cyanobacteria populations
in local freshwater bodies
The purpose of this investigation was to determine the diversity of cyanobacteria
in local freshwater ecosystems using amplification and sequence analysis
of phycocyanin genes. This will contribute to the larger goal of determining
the potential for toxin production by these populations. Total DNA extracted
from five freshwater ponds and lakes was used as templates for PCR using
phycocyanin-specific primers. These primers are often used to differentiate
cyanobacterial species in the environment. Thus far, only one phycocyanin
PCR product was obtained. This product was cloned, from which three individual
phycocyanin gene fragments were sequenced. These sequences were analyzed
and compared to DNA sequences in GenBank to determine the genus and species
of cyanobacteria present in the sample. From this analysis it was determined
that the three sequenced gene fragments had statistically significant
similarity to published results for physocyanin genes from Synechocystis
sp. and Microcystis aeruginosa. Both genera are known to have genes for
toxin production. The results confirm from the sequence analysis conflict
with microscopic studies (Dr. Klug and Betsy Sedlack), which suggest an
abundance of other cyanobacterial species. The conflicting results probably
reflect the incomplete sampling of phycocyanin clones in our library.
In future studies, additional clones from the library will be analyzed
to obtain a more complete representation of the cyanobacteria in the sample.
Zachary Freedman ’05
Faculty Advisor: Hugh Lefcort,Ph.D.
Adult Lumnea palustris show preference to heavy
metal pollution at low concentrations
The detrimental effects of heavy metal poisoning on living organisms is
well documented. The goal of our research was to determine if at low amounts
of heavy metal pollution, snails would favor a polluted solution over
a control solution. To test this hypothesis, 2 gravitational flow through
y-maze tubes were used, giving the test organism a choice between two
streams of solution. An adult Lymnea Palustris was placed at the base
of the glass Y-maze and given 25 minutes to make a choice between the
two streams. After 40 trials, the total number of control and heavy metal
solution decisions were counted and the avoidance trends were graphed.
Solutions with trace amounts of zinc and cadmium pollution were favored
by snails. Above a given concentration, snails avoided the heavy metal
Cassandra Godman ’05
Advisor: Glenn Sauer, Ph.D.
Development of RT-PCR Techniques for Metallothionein
Detection in Human Articular Chondrocytes
Metallothioneins (MT) are a family of low molecular weight cysteine-rich
metal binding proteins that can be induced by exposure to metals. Following
metal exposure, they provide tolerance to toxicity by binding to metals
present in the system and reducing their concentrations (Sauer et al.,
1998). Recent studies have shown that MT may also provide resistance to
cellular oxidants and in this way delay the onset of apoptosis. The purpose
of this study was to develop techniques for studying MT gene expression
in apoptotic human chondrocytes. In this study, human articular chondrocytes
were grown in culture and subjected to several varying concentrations
of different inducing agents including Zinc, Cadmium, dexamethason, and
hydrogen peroxide. After treatment, total RNA was extracted and subjected
to reverse-transcriptase PCR (RT-PCR) using primers designed to produce
a 201 bp product from the expressed region of the human MT-II gene. PCR
products were separated on a 1.5% agarose gel and stained with ethidium
bromide. Presence or absence of metallothionein is indicated by the incidence
or lack of bands on the gel. Thus far, only a limited amount of results
are available and further adjustment to the protocols is necessary for
the optimal identification of metallothionein expression.
Julie Gryguc ’06 and Kelly Steele ’05
Faculty Advisor: Diane Brousseau, Ph.D.
Bay scallop growout in Holly Pond, Stamford, Connecticut:
A feasibility study
This study was an attempt to grow bay scallops (Argopecten irradians)
in Holly Pond, Stamford, Connecticut over a six-week period from October
to November 2004. Holly Pond is an impounded estuary where salt water
from Long Island Sound meets freshwater from the mouth of the Noroton
River. The null hypothesis that there would be no difference in growth
rate among three locations in the pond was tested. Growth and survival
of scallops suspended in pearl nets were measured weekly. Temperature,
salinity, turbidity and chlorophyll a were determined for each location
during the study period. Scallops located at the site closest to the SoundWaters
Environmental Center had the highest rate of growth (1.05 ? 0.09 mm/wk).
Overall survival of scallops at all sites was 85%. Growth rates in Holly
Pond were lower than those reported by Widman & Rhodes (1991) for
scallops suspended in Long Island Sound, but survival rates were comparable.
Studies to assess growth during the spring-summer, when water temperatures
are more favorable for growth, are needed but this study suggests that
Holly Pond may be a suitable location for the growout of Atlantic Bay
Jessalyn Ierardi ’05
Project Advisor: Sheila Stiles, Ph.D., National Marine Fisheries
Effects of temperature on the larval development
of oyster, Crassostrea virginica
American or Eastern Oyster, Crassostrea virginica, represents the largest
quantity of United States oyster production. Larval development of American
Oysters can last from 10 to 21 days depending on water temperature, salinity,
and food availability. The purpose of this experiment was to observe the
effect of low water temperature (11°C) on the development of oyster
larva, Crassostrea virginica. Hypothesis was that larvae held at room
temperature would grow faster. Growth rates of larvae were determined
every other day. Oyster larvae grew larger and developed faster at room
temperature than at 11°C. Average growth rates for the larvae held
at room temperature after 15 days were 7.28 (+0.716), 7.58 (+1.46), and
7.39 (+0.922) µm/day. Average growth rates for larvae at 11°C
after 7 days were 8.09 (+1.21) and 8.21 (+0.355) µm/day. Temperature
had a significant (p=0.0008) effect on the growth rates of oyster larvae.
Some larvae in the room temperature treatment reached the pre-pediveliger
stage by Day 11, but this stage was not reached in the experimental treatment.
Larvae kept at room temperature grew consistently at a higher average
growth rate. Survival rates were higher for larvae held at room temperature.
The 11°C treatment decreased the growth rate and survival of oyster
Meagan Leduc ’05 and Emily Mis ’05
Faculty Advisor: Phyllis Braun, Ph.D.
Inhibitory effects of green tea extract on biofilm
formation in Candida albicans
During the last decade an increased incidence of biofilm-related infections
have been reported. One of the most prevalent biofilm-forming organisms
is Candida albicans. Biofilm infections have occurred due to the fact
that C. albicans growing in a biofilm formation is resistant to most antifungal
treatments. Currently, green tea extract is being recognized for its ability
to treat and prevent a number of medical problems. In this study, yeast
biofilm formation and cell viability with XTT colorimetric assays were
used to determine the effects of green tea extract on Candida albicans.
Green tea extract promotes metabolic cell activity on cells forming a
biofilm, whereas results indicated that higher levels of green tea extract
inhibit biofilm formation and reduce cell viability.
Shealing Luong ’05
Faculty Advisor: Glenn Sauer, Ph.D.
Cytotoxicity of Apoptosis-Causing Agents on Cultured
Articular chondrocytes produce and maintain the extracellular matrix of
cartilage in skeletal joints. Recent studies have shown that the breakdown
of cartilage associated with osteoarthritis can be triggered by apoptosis,
or programmed cell death. Apoptosis can be caused by a variety of chemical
agents and by various mechanisms of action. In this study, different concentrations
of six apoptosis-causing agents were incubated at 37ºC for 24 hours
with cultured chondrocytes to determine the effective concentrations causing
cell lysis. Results indicate that sodium nitroprusside (NaNP) and staurosporine
were the most effective at inducing apoptosis. While the calcium ionophore,
A23187, cycloheximide, and actinomycin D concentrations had no significant
effect on cell death. Dimethyl Sulfoxide (DMSO), a carrier for delivery
of several of the compounds to the cells had a modest effect on cell lysis.
These results will be used to design future studies aimed at understanding
the cellular mechanisms of apoptosis in chondrocytes and the role of intracellular
zinc in this process.
Liana Martuccio ’05
Faculty Advisor: Adam King, Ph.D.
An examination of the time left procedure in the
Memory has been shown to be inaccurate in animals and understanding why
this is so has become important for many reasons. We are particularly
interested in discovering why this is true and how it can help us understand
how memory works. The time left procedure gives us insight into the inner
workings of memory in subjects. This procedure, developed by Gibbon and
Church (Time Left: Church & Gibbon, 1981) examines how internal, subjective
time and external, clock-measured time are related. In their analysis
Gibbon and Church trained rats and pigeons to respond to two stimuli referred
to as the comparison and the standard. The comparison primed food after
C sec and the standard primed food after C/2 sec. The standard choice
was offered at a variable time T which was either: T<C/2, T=C/2, or
T>C/2. They found that subjects favored the standard when T<C/2,
were indifferent when T=C/2, and favored the comparison when T>C/2.
This behavior demonstrated that subjects could compute the difference
between two temporal durations! The present experiment mimics the procedure
performed by Gibbon and Church using mice. It modifies the procedure by
introducing a continuous potential time T and the ‘freezing’
of time that forces subjects to make a choice in order for the trial to
proceed. These adaptations are intended to aid in analysis, remove criticisms
related to subjects memorizing specific times, and eliminate the possibility
of subjects not responding.
Kathleen May ’05
Faculty Advisor: Elizabeth Gardner, Ph.D.
Baseline Survey Showed Increased Knowledge of Prejudice
In PY 291 Cognition, culture, race, and identity, students filled out
a Baseline Survey (Plous, 2003) at the beginning and end of the semester.
Scores indicated an increase in knowledge providing evidence of the effectiveness
of classroom learning in increasing understanding of prejudice and discrimination.
Jamie Morley ’06, Jamie Cahill ’06, Kaitlyn
Salem ’05, Lynda Wilmott ’05
Faculty Advisor: Shannon Harding, Ph.D.
The effects of excitotoxic lesions on the restoration
of male rate sociosexual behaviors
Although the ventromedial nucleus of the hypothalamus (VMN) is known to
play a critical role in female rat sexual behavior, its role in male reproductive
behaviors is less clear. The present study was conducted to determine
whether cell bodies contained in the VMN are necessary for sociosexual
behaviors (copulation, partner preference, ultrasonic vocalizations, and
scent marking). Male rats were tested for behaviors before and after castration,
and were subsequently assigned to groups. One group received the excitotoxin
NMDA to selectively destroy cell bodies in the VMN, while a second group
received the non-toxic stereoisomer, NMLA. On the day of stereotaxic surgery,
animals also received two 10-mm Silastic capsules filled with testosterone
to restore hormones to endogenous levels. Restoration of behavior was
assessed in the three weeks that followed. Preliminary data suggest that
NMDA lesions produced some impairments in copulation, ultrasonic vocalizations,
and scent marking. These results imply that the integrity of VMN cell
bodies is critical for the full expression of male rat sociosexual behaviors.
Glenn Newman ’05
Faculty Advisor: Elizabeth Gardner, Ph.D.
Quiz and Team Learning with Feedback Comparable
Absorb and Relate papers (A/R) were compared with a quiz with team-based
learning and immediate feedback (Q+TBL+IFAT), both, or neither as preparations
for essay test questions. Results suggested A/R and Q+TBL+IFAT are equally
effective in helping student’s master material. When A/R and Q+TBL+IFAT
were combined as preparation, test performance was significantly higher
when compared with neither as preparation.
Lauren Puma ’05
Faculty Advisor: Linda Henkel
Age differentiation in source maturity for naturally
Studies show that older adults make more errors than do young adults on
source monitoring tests in which they indicate the source or origin of
their memories (e.g., was it imagined or perceived? Was it seen or heard?
Did person A say it or person B?) Such declines in source memory are due
in part to age related difficulties with inhibitory control and the ability
to focus their attention. Research has shown that focusing on perceptual
details (i.e. voice and physical attributes) while experiencing events
helps bind the information to its source and leads to improved source
memory. However, older adults generally focus more on their own feelings
while experiencing events. Some studies show that when older adults are
told to focus on external emotional aspects (i.e., other people’s
feelings), it helps them to focus less on their own reactions and more
on perceptual characteristics, which improves their source monitoring
This study was designed to further address whether an external emotional
focus improves source performance for older adults. In addition, it examines
several different components of source memory that have not been previously
studied in this manner.
Subjects were instructed to either focus on people’s perceptual
features or emotional responses while watching two videotaped scenes consisting
of four individuals having natural conversations. In the scenes, each
individual makes positive, negative, and neutral statements. Later they
were presented with a list of statements and were to indicate (1) if the
statements were said or not said and (2) the source of the statements,
including who said them, and in which scene they were said.
Subjects also completed the Memory Self Efficacy Questionnaire in which
they rated how confident they are in their ability to remember details
in various natural settings, and they rated how well they thought they
did on the source memory test as well.
It was hypothesized that overall younger adults would perform better on
the source monitoring test than older adults. It was expected that older
adults in the emotional focus condition would perform better on the source
monitoring test than older adults in the perceptual focus condition, but
that younger adults in the perceptual focus condition would perform better
than younger adults in the emotional focus condition. In addition, it
was expected that older adults would overestimate how accurate their source
performance actually is, whereas younger adults were expected to be more
accurate in their self-assessments.
Data analyses are currently underway and will be presented in the poster.
Support for these hypotheses is expected.
Betsy Sedlack ’05
Faculty Advisor: Jen Klug, Ph.D.
Occurrence of potentially toxic cyanobacteria in
western Connecticut aquatic systems
Cyanobacteria, photosynthetic bacteria that are members of the phytoplankton
community, are capable of producing toxins that are potentially harmful
to animals, including humans. High concentrations of cyanobacteria increase
the likelihood of high toxin levels. Cyanobacteria blooms are more common
in bodies of water with high temperatures and low nitrogen to phosphorous
ratio but high nutrients over all. This study surveyed a number of bodies
of water in the area to look for the presence of potentially toxic species.
Water quality, including temperature, conductivity, dissolved oxygen,
as well as total nitrogen and phosphorus, was measured at each site. In
addition, phytoplankton community composition was determined by microscopic
analysis. Correlation analysis suggests that cyanobacteria abundance is
not dependent on a single environmental factor. We did see a positive
relationship between temperature results and cyanobacteria concentration.
Because nuisance blooms are difficult to predict, monitoring bodies of
water that are prime areas for cyanobacteria will lead to a better understanding
of these communities. Alerting ecologists and individuals in contact with
the water of dangerous densities of cyanobacteria is important so that
high density areas can be avoided and controlled.
Carolyn S. Stankiewicz ’05
Advisor: Shelley Phelan, Ph.D.
The role of protein kinase C and MAP kinase in
regulating Peroxiredoxin 6 expression
Reactive oxygen species (ROS) are typically found within cells as a byproduct
of normal metabolic activity. Cells may also be exposed to ROS from their
environment. Antioxidant proteins such as Peroxiredoxin 6 (Prdx 6) are
part of the cell’s defense system that helps to control levels of
ROS and protect the cell from ROS-associated damage. We have discovered
that expression of the Prdx 6 gene is down-regulated in liver cells that
have been deprived of serum, and strongly induced with subsequent treatment
of growth factors, cytokines or hormones. However, the pathways that mediate
this induction remain unknown. Therefore, this study was done in order
to elucidate the signal transduction pathways and regulatory sequences
that play a role in the expression and induction of Prdx 6 in response
to the known inducers keratinocyte growth factor (KGF), tumor necrosis
factor-? (TNF-?), and dexamethasone (dex). Since protein kinase C (PKC)
and MAP kinase (MAPK) pathways have been found to mediate the effects
of numerous ligands implicated in cell growth and differentiation, it
was hypothesized that either one of both of these pathways may play a
role in the induction of Prdx 6. Mouse epithelial cells from the H2.35
cell line were grown to subconfluence and then serum deprived. Chemical
inhibitors were used to inactivate the PKC or MAPK pathway, and then cells
were induced with either KGF or TNF-? for 8 hours. RNA was analyzed by
Northern Blot to evaluate levels of Prdx 6. It was found that the inhibition
of PKC lowered both basal and TNF-?-induced expression of Prdx 6 suggesting
that PKC plays a role in TNF-? induction. Currently, we are investigating
the involvement of MAPK, as well as the effects of these inducers on peroxide
accumulation and H2O2 toxicity. Our studies implicate a role in these
pathways in both basal and induced Prdx 6 expression and support the involvement
of Prdx 6 in the oxidative stress response associated with growth and
Michael Vendetti ’05
Faculty Advisor: Susan Rakowitz, Ph.D.
Diminishing the Effects of the Framing Effect:
Need for Cognition and Processing
The framing effect is when respondents provide different decisions for
objectively equivalent situations. Previous studies have found the Need
for Cognition (NC) and higher amounts of situational processing to be
able to lessen the framing effects in subjects. Thirty-five participants
were presented with 4 situations, which were randomly assigned so each
had 2 positive frames. Half of the participants were in a processing condition
where they were asked to make a choice and provide a justification for
their choices; the others had to provide a choice. Finally, Participants
completed the NC scale, and had a median-split to determine high vs. low
NC scores. The current study delves further into the investigation of
possible negating effects on the framing effect.
David Wilson ’05
Faculty Advisor: Glenn Sauer, Ph.D.
The effects of four different apoptosis inducing
agents on the Caspase activity of articular chondrocytes
The effects of four different apoptosis inducing agents were measured
through spectroflourometric quantification of the specific activity of
cellular caspases. The Caspase family of proteases has been shown to play
a role in the cascade of cleavage events which lead to the systematic
disassembly of dying cells. Etoposide a DNA NaNP were used to treat the
articular chondrocytes and induce apoptosis. Four different time periods
were used to measure Caspase activity over time, as T-0 cells were exposed
only momentarily and T-1, T-2 and T-3 cells were exposed to each apoptosis
u inducer for 1, 2 and 3 hours respectively. The CaspACE™ Assay
System used flourochrome 7-amino-4-methyl coumarin (AMC) to label the
Caspase substrates provided by the assay kit. The levels of AMC released
as a result of cleavage by Caspase enzymes were recorded and understood
to represent a proportional amount of Caspase activity present in the
sample. As was expected, the activity due to Caspase among T-0 cells with
only momentary exposure to inducing agents was minimal. With exception
to some inconsistencies with those cells treated by etoposide and staurosporin
the cells demonstrated increased Caspase activity as the treatment time
increased. The most noticeable activities came from T-3 cells, which demonstrated
significant Caspase activity in all treatments except staurosporin. In
general, the data tends to suggest glucose oxidase as the most effective
inducer of apoptosis which compared to the other three treatments.