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Department of Biological Sciences Biology and Environmental
Studies Senior Research 2007 |
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Amy Stoesz Gene expression patterns
of primary BALB/c and C57BL/6 murine peritoneal
macrophages in response to in vitro treatment with lipophosphoglycan
and interferon-gamma. Leishmaniasis, found primarily in
subtropical and tropical regions, is caused by an intracellular protozoan
parasite of the genus Leishmania. Once a host organism is infected, the
immune system undergoes one of two possible responses. A TH2 response, which activates humoral responses, can be fatal to the organism because
it allows the infection to become chronic and progressive due to
inflammation; while a TH1 response, which initiates cell-mediated
defenses, often results in spontaneous recovery. The BALB/c mouse strain characteristically
undergoes a TH2 response, and the C57BL/6 mouse strain typically
exhibits a TH1 response. Lipophosphglycan (LPG), a major cell surface component of
the Leishmania
parasite, was used along with interferon gamma to stimulate primary
peritoneal macrophages from both strains of mice. Their mRNA products were collected and
analyzed via reverse transcriptase-polymerase chain reactions. I found some slight differences in
expression but overall, LPG and INF-gamma alone are not sufficient to show a
consistent difference in the cross-regulation patterns between the two
strains. |
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Daniel Einerson The Effects of Overexpression of Nkx2.1 on
Lung Specific Genes SP-C and SP-B in Xenopus laevis. Lung development is
controlled by many different factors. Among these factors, genes play an
integral role in initiating and coordinating lung development. Specifically,
Nkx2.1 is a transcription factor that has been shown to be integral in the
initiation of lung development. When Nkx2.1 is absent in mice and rats, the
organisms have died at birth. Much research with Nkx2.1 has been done on mice
or rats however; the effects of gene are still largely unknown. This study
attempted to gain further knowledge into the role of Nkx2.1 through the
process of overexpression of the gene in our new
model organism, Xenopus laevis. The
results of the Real-Time Polymerase Chain Reactions (PCR) showed that when
Nkx2.1 was overexpressed in Xenopus embryos the expression
of lung specific genes SP-C and SP-B also increased. This suggests that
Nkx2.1 has an effect on lung development and specifically other genes that
are involved in lung development. It also suggests that when Nkx2.1 is
increased in an organism other genes in that pathway are also increased.
The
uterus is an essential organ for reproduction in mammals. Despite the
importance of the uterus for the fertility and health of women and their
offspring, relatively little is known about the effects of natural remedies
on this tissue. The objective of this study was to investigate the effects of
Red Raspberry Leaf (Rubus idaeus)
extract on isolated uterine tissue of mice (Mus musculus) suspended in a smooth muscle bath. The
isolated tissues were hung under 1g of tension and bathed in DeJalons buffer. Two main questions were addressed in
this project: (1) Does Rubus
extract alone cause a contractile response in isolated mouse uterine tissue?
And if so, is it dose dependent? (2) Does an extract of Rubus potentiate
the contractile response of a) acetylcholine b) electrical field
stimulation? Results indicate that Rubus extract
alone elicited a contractile response however; there is no dependency between
doses given and response elicited. Rubus extract did significantly potentiate
contractile responses evoked from the acetylcholine and electrical field
stimulation suggesting that Rubus may indeed help to facilitate a normal contractile
response in the uterus. This suggests that Rubus, an herbal remedy, can
induce uterine smooth muscle contractions involved in the labor process. |
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Jennifer Hansen The Effect of Carbachol and Electrical
Field Stimulation on Contractile Force of Isolated Diabetic Rat Duodenu. Previous
research has found that diabetes mellitus impairs gastric motility, leading
to a condition called gastroparesis. In order to determine the effect of Type I
diabetes on duodenal motility, isolated strips of proximal small intestine
from 11 control rats and 11 alloxan-induced
diabetic rats were dissected out and placed in a muscle bath. Duodenal strips were subjected to either
increasing doses of carbachol (10-7-10-5M)
or to electrical field stimulation (EFS).
Maximal contractile forces in response to carbachol
were significantly higher in control than in diabetic rats when the baths
were not flushed between each dose.
When the baths were flushed between doses, the mean contractile forces
were slightly higher in control than in diabetic rats, but the differences
were not significant. In response to
EFS, contractile forces were significantly higher in control rats. These findings support my hypothesis that
Type I diabetes hinders duodenal motility.
Although the mechanism behind this change is not known, the decreased
response to carbachol suggests that cholinergic
receptors are altered in the diabetic intestine. The change in response to EFS may suggest
that either the interstitial cells of Cajal (ICC)
or the gap junctions are impaired. |
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Jetter
Robertson Sequencing and expression of
FGF-10 gene in Xenopus Laevis
development During mammalian lung and limb development,
epithelial and mesenchymal interactions govern the
branching of the lung and limb, respectively.
The Fibroblast Growth Factor (FGF) gene family has been shown to play
an intricate role in regulating these interactions. The FGF-10 gene, in
particular, has been shown to play an essential role in these communications
and its deficiency results in the inability for the lung to branch out from
its initial bud in mice. The FGF-10 gene was isolated from Xenopus laevis and
its entire open reading frame sequence was obtained using fragments of the
sequence from previous studies in our lab. In addition, expression patterns
of the FGF-10 gene were analyzed in various stages of X. laevis development. |
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Jessica
Swanson Finding
The Optimum Environment of Crayfish (Orconectes immunis) For
Long-term Survival and Use In High School Biology Classrooms. Maintaining live organisms in biology classrooms
can be beneficial in helping students learn about life sciences. The purpose of this experiment was to
determine the optimal artificial environments for crayfish (Orconectes immunis), a
common experimental material for long-term use in high school biology
classrooms. Due to budget cuts in
schools, supplies for labs in classrooms have been greatly reduced, therefore
keeping organisms alive is important.
It was found that in artificial conditions, crayfish that were fed
with tuna and pellet food lived longer than those fed with plants and worms
as well as those crayfish that had more than one hiding spot in their tank. |
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Michelle Y.
Perry Quantification and Comparison of Trabeculae in Human, Canine, and Swine. Differing
degrees of trabeculation exist in large mammalian
heart. Yet, this will be important information to know for it will affect the
choice of a given animal model for cardiac device testing, but may also relate
to physiological functions as well (i.e. cardiovascular disease). This study
was aimed at determining the relationship between the trabecular
width and density to ventricular volume in human, canine, and swine heart
models. A total of 30 hearts (10 human, canine, and swine) were used in the
study. A 6 mm endoscope and a 2.45 mm catheter were inserted in the apex,
free wall, and outflow tracts of both the right and left ventricles in
isolated hearts. Image analysis was used enumerate trabecular
width and density. Trabecular density in the free
wall of the right ventricle (RV) was significantly correlated (p < 0.05)
with RV volume in human and swine hearts. In humans more prominent, yet fine trabeculae were observed in the left ventricle while
swine and canine hearts showed a more coarse
arrangement of trabeculae. |
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Caryn Daas Heritable Disorders of the
Connective Tissue: the Overlapping Significance of Marfan,
Loeys-Dietz, and Vascular Type IV Ehlers-Danlos Syndromes. At least three genetic diseases with vascular
involvement are severe enough to be potentially fatal, often without
forewarning. Marfan, Loeys-Dietz,
and Vascular Type IV Ehlers-Danlos syndromes, are three conditions whose overlapping symptoms
are numerous. These inherited connective tissue disorders can leave patients
with aortas so delicate that they can rupture in pregnancy or in even lesser
activities. Certain genetic mutations galvanize patients to aggressive and
widespread vascular disease. The severity of the clinical presentation is
predictive of the end result, and precise diagnostic distinctions are
critical. This investigation reviews the literature surrounding the three
syndromes, and sets out to paint a clearer picture for diagnosis of the most
severe of these disorders: Vascular Type IV Ehlers-Danlos
syndrome. |
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Jessica Patton The Effects of the Hormone Leptin on
Obesity, Metabolism, Body Temperature, and Feeding Behaviors, Using Normal,
ob/ob, and db/db Mutant Mice. Why is obesity or being overweight such a battle
for some people and not others? A way
to address this question is to look at how the body utilizes the hormone leptin, which is derived primarily from adipocytes. Leptin, the product of the obese (ob/ob) gene
plays a major role in maintaining the balance between the regulation of food
intake, hunger, satiety and metabolism.
The purpose of this experiment was to determine if the lack of leptin or the leptin receptor
(as found in mutant mice, Mus musculus) affects normal metabolism, body
temperature, and feeding behaviors.
Eighteen mice were used in this experiment: 6 controls, 6 mutant ob/ob,
and 6 mutant db/db. The ob/ob
mice had a defective leptin gene and db/db mice had a defective leptin receptor gene. The variables that were tested in these
mice were basal metabolic rate, body temperature, food intake, water intake,
and cage waste. Results demonstrated
that normal mice had a statistically higher metabolic rate and body
temperature than the ob/ob and db/db mice. Although the normal mice ate more than the
others, the effect was insignificant. The water intake was statistically
higher in the db/db mice compared
to the ob/ob and control mice. The cage waste was statistically higher in
the db/db mice (from high urine
output) and in the control mice (they had large amount of food debris) when
compared to the ob/ob mice. These results suggest that mutations in the
genetic expression of leptin or the leptin receptor may contribute to obesity and lower
metabolic rates in the mouse model. |
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