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Physiological factors affecting ovine uterine estrogen and progesterone receptor concentrationsPrater, Patrice L. 14 November 1990 (has links)
Two experiments were conducted to determine whether in
ewes uterine concentrations of estrogen and progesterone
receptors are affected by the presence of a conceptus or by
the hormonal milieu associated with extremes in photoperiod
to which ewes are exposed.
In Exp.1, nine mature ewes were unilaterally
ovariectomized by removing an ovary bearing the corpus luteum
(CL). The ipsilateral uterine horn was ligated at the
external bifurcation and a portion of the anterior ipsilateral
uterine horn was removed and assayed for endometrial nuclear
and cytosolic concentrations of estrogen receptor (ER) and
progesterone receptor (PR) by exchange assays. After a
recovery estrous cycle, ewes were bred to a fertile ram. On
day 18 of gestation a 10 ml jugular blood sample was collected
for measurement of serum concentrations of estradiol -17β (E₂)
and progesterone by radioimmunoassay. Ewes were
relaparotomized on day 18 and the remaining uterine tissue was
removed. Endometrium from both the pregnant and nonpregnant
uterine horn was assayed for nuclear and cytosolic ER and PR
concentrations. Nuclear and cytosolic ER concentrations on
day 10 of the cycle were greater than in endometrium of gravid
and nongravid uterine horns on day 18 of gestation (p<.01).
Endometrial nuclear PR levels were also greater on day 10 of
the cycle than in the pregnant (p<.05) and nonpregnant horn
(p<.01) on day 18 of gestation. There were no differences in
nuclear and cytosolic ER and PR concentrations between the
pregnant and nonpregnant uterine horn on day 18. Serum levels
of E₂ and progesterone on day 18 of gestation were 16.56 ±
2.43 pg/ml and 1.74 ± 0.57 ng/ml, respectively. These data
suggest that duration of exposure of the uterus to
progesterone and(or) the presence of the conceptus causes a
reduction in uterine concentrations of ER and PR. Further,
an effect of the conceptus, if any, is exerted via a systemic
route.
In Exp. 2, ten mature ewes were bilaterally
ovariectomized in early October. During the onset of the
winter solstice (late December), a 10 ml blood sample was
collected from five ewes for analysis of serum levels of E₂
and progesterone. Ewes were then laparotomized and
approximately one-third to one-half of a uterine horn was
removed and assayed for endometrial nuclear and cytosolic ER.
The contralateral horn was ligated at the external bifurcation
and 10 μg of E₂ in 3 ml of physiological saline was injected
into the uterine lumen of the ligated horn. After 48 h, a
jugular blood sample was collected for steroid analysis and
a section of the E₂ treated horn was removed and assayed for
endometrial cytosolic and nuclear ER. This procedure was
repeated on the remaining five ewes during the height of the
summer solstice (late June). Endometrial nuclear and
cytosolic concentrations of ER prior to and after exogenous
E₂ stimulation were similar during the winter and summer
solstice (p>.05). However, treatment with E₂ increased
endometrial nuclear and cytosolic concentrations of ER
compared with those of the nonstimulated uterine horn during
the winter and summer solstice (p<.05 for each). Serum levels
of E₂ prior to luminal treatment of ewes with E₂ during the
winter and summer solstice did not differ (16.55 ± 4.05 vs
16.00 ± 3.0 pg/ml, respectively, p>.05). Serum levels of E₂
48 h after administration of E₂ did not differ among ewes at
the winter and summer solstice (18.75 ± 2.4 vs 18.65 ± 1.65
pg/ml, respectively, p>.05). Serum levels of progesterone
were basal (<0.10 ng/ml) and did not differ in ewes prior to
and after E₂ treatment at the winter and summer solstice
(p>.05). These data indicate that physiological factors
and(or) hormones such as prolactin and melatonin secreted in
response to extremes in photoperiod do not appear to influence
uterine concentrations of ER in ovariectomized ewes. / Graduation date: 1991
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The Effect of Progesterone Withdrawal on Molecular and Behavioral Indices after Traumatic Brain InjuryCutler, Sarah Melissa 19 July 2005 (has links)
Systemic injections of the neurosteroid progesterone (P) have been shown to improve cognitive, sensory and motor recovery after traumatic brain injury (TBI). Progesterone withdrawal (PW), however, increases the risk of ischemia, anxiety, seizure, and excitotoxicity. Given these side effects, it is possible that acute PW during recovery from TBI may retard the healing process. In this project, we investigated the effect of acute PW for short and long-term intervals, and optimized post-TBI P treatment through tapered P injections and slow-release implanted capsules. Male Sprague-Dawley rats received either frontal-bilateral cortical contusion injury or sham surgery. P-treated animals displayed increased anxiety in the elevated plus maze at the peak of acute withdrawal compared to tapered P doses or vehicle. Inflammation and apoptosis, as measured by TNF and #61537;, NF and #61547;B, and active caspase-3, among others, were decreased for all P-treated animals; these effects were further reduced with tapered treatment. Three weeks after injury, animals that received tapered P administration displayed fewer sensory deficiencies and increased motor activity. In addition, reducing the effects of acute PW increased the activity of HSP70 and BDNF while decreasing necrotic lesion size and reactive astrocyte staining, indicating increased neuroprotection. Finally, the beneficial effects of P administration after TBI were further enhanced through a steady-state release of P from a subcutaneously implanted silastic capsule. Compared to animals receiving a daily bolus through subcutaneous injections, capsule animals demonstrated decreased anxiety and edema. All P-treated animals, regardless of delivery method, had reduced inflammation and apoptosis compared to vehicle-treated animals. This system also serves as a model of steady-state intravenous P administration used in human clinical trials. In conclusion, all P treatment enhances both short and long term recovery after TBI. Acute PW, however, has a negative effect on both behavior and tissue recovery. At the peak of withdrawal, animals undergoing acute PW exhibit an increase in anxiety, sensory deficits, inflammation and apoptosis, and a decrease in locomotor activity, all of which are further exacerbated by injury. Tapered withdrawal enhances neuroprotection and plasticity, while a steady-steady application of P further decreases edema and the anxiogenic effects of withdrawal.
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Investigation of the relationship of body temperature, serum estradiol, and serum progesterone to the onset of parturition in the mareMorgan, Sommer Christine 15 May 2009 (has links)
In cattle and sheep, a significant decrease in temperature has been noted prior to
parturition. In the mare, similar temperature decreases have been documented, although
results have been inconsistent when temperatures were taken rectally. One study
reported a significant temperature decrease when using data from a radio transmitter
inserted into the mare’s flank. The current study utilized nineteen Quarter Horse mares
and one Thoroughbred mare, and was conducted from February to June 2006. Each
mare had been previously implanted in the nuchal ligament with a microchip capable of
reporting body temperatures. Blood collection and temperature recordings began 2 wk
prior to each mare’s expected foaling date. Once the mare was estimated to be within 48
h of parturition, temperature was recorded every 3 h until parturition using both the
microchip and rectal thermometer. Progesterone and estradiol 17-b were evaluated from
daily blood samples from -10 to ± 5 d relative to foaling for determination of the
relationship between these steroids and body temperature, time of foaling, birth weight
and sex of foal. A significant decrease in rectal temperature (P < 0.05) was noted when the last
temperature recorded was taken within 12h of parturition. Microchip data did not
demonstrate any significant differences among readings before parturition. No
significant difference was noted in the mean rectal temperature of all days relative to the
sex of the neonate; however, microchip data showed mares carrying females to have a
significantly (P < 0.05) higher mean rectal temperature of all days. Sex of the foal was
not shown to be related to maternal concentrations of either progesterone or estradiol 17-
b. A direct significant correlation between temperature and maternal plasma
concentrations and progesterone and estradiol 17-b was found.
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Evaluation of the effect of progesterone CIDR Devices on circulating levels of progesterone in cyclic ewesSatterfield, Michael Carey 17 February 2005 (has links)
A homogeneous group of thirty-one crossbred ewes was used to determine the
effect of administering a progesterone Controlled Intravaginal Drug Releasing
Device (CIDR) on circulating levels of progesterone in the subsequent cycle
following CIDR removal. Circulating progesterone levels were determined for each
ewe through daily blood collection via jugular venipuncture. Each ewe underwent a
pretreatment 25 day sampling period (Period 1), a 12 day treatment period
characterized by the presence of the CIDR (Period 2), and another 25 day sampling
period following CIDR removal (Period 3). During the initial period of the study,
progesterone levels in peripheral circulation changed (P < 0.0001, effect of day) in
accordance with stage of the estrous cycle and were elevated during the luteal phase.
In the second period of the study, progesterone levels were elevated (P < 0.0001) in
ewes due to exogenous progesterone from the CIDR device (Period 1 versus Period
2: 1.3 ± 0.1 ng/ml versus 2.4 ± 0.1 ng/ml, respectively). After withdrawal of the
CIDR in the third period of the study, circulating progesterone levels were not (P >
0.10) different from those observed in the initial period of the study (Period 1 versus
Period 3: 1.3 ± 0.1 ng/ml versus 1.4 ± 0.1 ng/ml, respectively). Data collected in
this study revealed that treatment with exogenous progesterone via CIDR for a 12-
day treatment period does not influence circulating levels of progesterone in
subsequent estrous cycles.
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Identification of novel implantation-related genes in the ovine uterusSong, Gwon Hwa 17 September 2007 (has links)
The peri-implantation period in mammals is critical with respect to survival of
the conceptus and establishment of pregnancy. During this period of pregnancy,
reciprocal communication between ovary, conceptus, and endometrium is required for
successful implantation and placentation. Therefore, studies were conducted to indentify
and characterize novel endometrial genes important for implantation and conceptus
development in the ovine uterus.
The first and second studies defined the uterine expression of seven members of
the cathepsin (CTS) family of lysosomal proteases, and a secreted inhibitor of CTSL
called cystatin C (CST3) during the peri-implantation period. In addition, regulation of
CTS and CST3 by progesterone (P4) and interferon tau (IFNT) was evaluated. CTSL
was the most abundant CTS in the ovine ovine uterus and was also coordinately
expressed with CST3 in the endometrial epithelia and conceptus trophectoderm. CTSL
and CST3 were found to be novel P4-induced and IFNT-stimulated genes in the luminal
epithelial cells of the ovine endometrium.
The third study identified radical S-adenosyl methionine domain containing 2
(RSAD2) and interferon-induced with helicase C domain 1 (IFIH1) in the ovine uterus.
Results of this study indicated that IFNT induces RSAD2 and IFIH1 in a P4-independent
manner in the stroma, immune cells, and glands of the ovine endometrium. These two
genes are proposed to have biological roles in the establishment of uterine receptivity to
the conceptus during implantation.
The fourth study characterized endometrial expression of stanniocalcins (STC)
during pregnancy. STC1 appeared in the endometrial glands on Day 18 of pregnancy, increased from Days 18 to 80, and remained abundant through Day 120 of gestation. In
addition, this study demonstrated that STC1 is induced by P4 and increased by placental
hormones, such as placental lactogen (CSH1) and growth hormone (GH), in the ovine
endometrial glands.
Collectively, these studies identified genes that are expected to be critical to
unraveling the mechanism(s) of reciprocal fetal-maternal interactions required for
successful implantation and pregnancy. A more complete understanding of these genes
will be important for developing therapeutic strategies to prevent, treat and/or diagnose
infertility in domestic animals and humans, because they are biomarkers of P4 and/or
IFN effects.
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Characterisation of diabetes mellitus in dogsFall, Tove, January 2009 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2009. / Härtill 4 uppsatser.
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Induction of fertile estrus during seasonal anestrus in ewes and fall born ewe lambsKnights, Marlon, January 2001 (has links)
Thesis (Ph. D.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains viii, 160 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 132-159).
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Effects of dexamethasone and progesterone treatment on experimental brain injury induced by surgical electrocauteryUn, Ka-chun., 阮嘉駿. January 2012 (has links)
Haemostasis is an important aspect in neurosurgical operations for the achievement of good outcome. Bipolar coagulation is an extensively used haemostatic technique in modern neurosurgery but it may also cause iatrogenic brain trauma due to thermal injury. Published studies on coagulation-induced brain injury on a histological level are, however, limited. The present study aimed at investigating the extent of inflammatory and glial responses caused by different settings of bipolar coagulation using an animal model. It also investigated whether and how pre-operative treatment with dexamethasone or progesterone, both known to have neuro-protective effects, would modulate gliosis and macrophage infiltration induced by bipolar coagulation.
The study consisted of two parts. The first part investigated the astrocytic and macrophage responses after bipolar coagulation at different power settings. 45 Sprague-Dawley rats received craniotomy, followed by bipolar coagulation at different power output settings (mock operation as control, 20W and 40W) over the rat cortex for a standardized duration of two seconds. On day 3, day 7 and day 28, brain sections were assessed by immunohistochemical staining for GFAP (astrocytes) and ED1 (macrophages). Quantification of outcome by random field cell counting under light microscopy was performed.
The second part of the study used another 45 male Sprague-Dawley rats, divided into three treatment groups: Group 1 received the vehicle agents only (Control); Group 2 received progesterone 20mg/kg; Group 3 received dexamethasone 1 mg/kg. All treatments were given intraperitoneally two hours before craniotomy. The animals received bipolar coagulation at 40W for a standardized duration of two seconds. On day 1, 3 and 7, brain sections were assessed by immunohistochemical staining for GFAP and ED1. Quantification of outcome by random field cell counting under light microscopy was performed. T2-weighted magnetic resonance imaging for the animals on day 3 was also performed.
The results showed that bipolar coagulation was associated with significant glial and inflammatory responses that correlated with power output. Progesterone and dexamethasone were both effective in reducing the glial hypertrophy and macrophage infiltration associated with bipolar coagulation. Dexamethasone had an additional advantage of reducing brain oedema and cavity formation. The findings suggested that progesterone and dexamethasone could be further explored as potential protective and/or remedial agents for bipolar coagulation-induced brain trauma sustained during neurosurgical procedures. / published_or_final_version / Surgery / Master / Master of Research in Medicine
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The role of progesterone in attenuating mitochondrial injury in neural cells in an in vitro model of traumatic brain injuryMalcolm, Shannon Gail 12 1900 (has links)
No description available.
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Priming effect of glycodelin-A on zona pellucida induced acrosome reaction in human spermatozoaWong, Siu-tak. January 2008 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 115-146) Also available in print.
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