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Results 501 - 550 of 847
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Viswanathan N - - 1993
The role of the fetal circadian pacemaker in the timing of birth was examined in Syrian hamsters (Mesocricetus auratus). Two groups of pregnant hamsters with lesions of the suprachiasmatic nucleus received daily intraperitoneal injections of melatonin (25 micrograms) on Days 9-15 of gestation. One group was injected with melatonin in ...
Zhu L - - 1993
BACKGROUND: The ductus arteriosus (DA) is a fetal vessel in which the elastic laminae fail to assemble normally in late gestation. This feature is associated with the development of intimal cushions, structures that partially occlude the DA lumen and assure that the vessel will close completely when it constricts postnatally. ...
Sandberg J A - - 1993
In vitro N-demethylation of cocaine (COC) was examined in five saline (SAL) and five COC-treated pregnant guinea pigs and their fetuses (60 days, term 69 days). Microsomes from maternal and fetal guinea pigs produced norcocaine (NOR), benzoylnorecgonine (BN), and benzoylecgonine (BE) when incubated with COC. The initial rate of NOR ...
Kleemann D O - - 1993
The effect of nutritional manipulation during mid and late pregnancy on fetal growth and survival in high fecundity (Fec(B) Fec(+)) Merino ewes was examined. A total of 4 treatment groups was utilized in each of 3 years (1987, 1988 and 1989); and 2 groups were given low nutrition during mid ...
Kisker C T - - 1993
Glucocorticoids have been shown to accelerate the development of blood coagulation in the fetal lamb (Kisker, Robillard & Bohlken, 1983). The current studies examine the influence of high levels of triiodothyronine (T3) on the development of blood coagulation in the fetal lamb. Eight twin fetal lambs were studied during the ...
Wallace J M - - 1993
The use of laparoscopic insemination to deposit semen into the tip of the uterine horn ensures fertilization in ewes induced to ovulate at 3-5 weeks post-partum. Acceptable pregnancy rates are achieved if embryos from post-partum donors are transferred to a normal uterine environment yet embryos rarely survive when transferred or ...
Smolen A - - 1993
During pregnancy, mice are more susceptible to flurothyl-induced seizures than are nonpregnant control mice. The potential role of brain GABA in mediating this behavior was examined in the present study. GABA concentrations in the cerebellum, hippocampus, striatum, midbrain, and cortex from individual control, pregnant (days 17-18) and delivery-day Heterogeneous Stock ...
MacLaren L A - - 1993
The objectives of the current study were to determine whether interspecific sheep<==>goat chimaeras exhibited reproductive cycles of their component species and were capable of maintaining ovine and caprine pregnancies to term. All chimaeras had oestrous cycles and several exhibited characteristics of both ewes and does, including short, 6-7-day cycles. Sixteen ...
Smedstad K G - - 1993
This study was designed to test whether there is any difference in the placental transfer of bupivacaine or lidocaine in the early compared to the late preterm maternal/fetal sheep preparation; and whether the premature lamb fetus reacts to a steady state local anaesthetic infusion differently from the same lamb near ...
Pennefather J N - - 1993
Noradrenaline (10-50 nM) and tyramine (0.05-1 mM) enhanced contractile force elicited by field stimulation of strips of myometrium from non-pregnant and pregnant women. In higher concentrations, noradrenaline produced sustained contractions. The EC50 values for noradrenaline were 0.4 microM in tissues from pregnant women and 3.1 microM in tissues from non-pregnant ...
Swords W E - - 1993
The importance of the colonic microflora in health and nutrition is well known, but how they colonize and become established in the colon is not well understood. We therefore characterized the quantitative and qualitative changes of the colonic microflora during the first 120 days of postnatal development. Unlike previous studies, ...
Huysman C N - - 1992
Two outbreaks of porcine parvovirus occurred in a unit of 380 sows, with a subsequent decrease in the size of gilts' litters. Of the 203 gilts and 64 primiparous sows which were seronegative at the time of insemination, 134 gilts and 55 primiparous sows seroconverted during pregnancy. Of the second ...
Kirkbride C A - - 1992
Sixteen 50 day gestational ewes were fed lasalocid at the rate of 30 g t-1 and were orally inoculated with 100 infective Toxoplasma gondii oocysts 5 days after beginning feeding of lasalocid. Seventeen control ewes were similarly inoculated with T. gondii and were not fed lasalocid. The rate of abortion ...
Burgess K M - - 1992
The effect of RU486, a synthetic progesterone receptor antagonist, on basal uterine prostaglandin (PG) release and release in response to oxytocin injection has been investigated in late-pregnant sheep (days 135-140 of gestation). Fifteen hours after i.m. injection of RU486 (50 mg; n = 5) or vehicle alone (n = 4), ...
Estes J M - - 1992
In utero open surgery can salvage many fetuses with life-threatening anomalies. This approach carries risks, especially from preterm labor induced by the hysterotomy incision. In an effort to decrease uterine injury during hysterotomy, we developed techniques for endoscopic manipulation of the fetus. We developed these methods in fetal lambs. The ...
Symonds M E - - 1992
1. This study examines the effect of chronic cold exposure during pregnancy, induced by winter shearing twin-bearing ewes 4 weeks before predicted lambing date, on O2 consumption and CO2 production during non-rapid-eye-movement (REM) sleep in lambs maintained for at least 1 h at warm (28-18 degrees C) and cold (14-5 ...
Gatenby R M - - 1992
A survey of 101 farmers with sows was conducted in the Koshi Hills of Nepal. Estimates of those reproductive traits which did not differ significantly between local and Pakhribas crossbred sows, are farrowing interval 7.4 months, litter size at birth 8.3, age of piglets at weaning 2.2 months and total ...
Arbeille P - - 1992
Pulsed Doppler ultrasound was used to investigate fetal and maternal ovine circulation in 16 ewes. Resistance index (R) was measured at the following sites: umbilical, fetal cerebral, and uterine arteries. Measurements were performed at days 80, 100, and 130 of gestation, day 0 being the day of mating. Normal ranges ...
Corbel M J - - 1992
A strain of Yersinia enterocolitica of O serogroup 6,30 isolated from the liver of an aborted ovine fetus was inoculated intravenously into a group of pregnant ewes at about 90 days gestation and produced placentitis with abortion or delivery of infected lambs about 50 days later. Y. enterocolitica of the ...
Nephew K P - - 1992
Mechanisms of intrauterine migration were examined in 55 ewes. In the first experiment, corpora lutea were removed from unilaterally ovariectomized ewes on d 4 (d 0 = estrus) and pregnancy was maintained by giving exogenous progesterone. In Exp. 2, the reproductive tract was altered surgically such that embryos initially entered ...
Wrathall J H - - 1992
Thirty adult Mule (Blue-faced Leicester x Swaledale) ewes were actively immunized against a synthetically produced peptide corresponding to the N-terminus of the alpha-subunit of bovine inhibin conjugated to tuberculin purified protein derivative (PPD). Primary immunization in the late anoestrous period was followed by two booster injections at 5 week intervals. ...
Alonso J L - - 1992
Fifteen ewes were inoculated subcutaneously with 2 x 10(6) cells of Corynebacterium pseudotuberculosis seven days before mating, during the embryonic stage of gestation and during the fetal stage of gestation. The clinical signs, antibody response and the consequences of the infection on reproduction were studied. None of the ewes showed ...
Foster J D - - 1992
The technique of embryo transfer was used to investigate the maternal transmission of scrapie in sheep. Embryo donor ewes were experimentally infected with scrapie (all eventually developing the disease) and artificially inseminated six months later with semen from an uninfected scrapie-susceptible ram. Embryos were harvested five and six days after ...
Sadowsky D W - - 1992
Spontaneous, long lasting epochs of myometrial contractility, contractures, occur throughout the majority of pregnancy in sheep. Contractures are temporally related to a switch in fetal electroencephalogram (ECoG) patterns from low to high voltage. In late gestation, fetal ECoG increases in voltage. We have previously suggested that contractures may influence fetal ...
Lévy F - - 1992
Measurement of cerebrospinal concentrations of oxytocin (OT) in intact and peridural-anesthetized ewes showed that central release of OT during parturition is inhibited by this anesthesia. Also, observations of maternal behavior and attraction to amniotic fluid (AF) in inexperienced peridural-anesthetized parturient ewes after intracerebroventricular injections of either OT (2 x 10 ...
Reinemeyer C R - - 1992
A sample of 126 sheep producers in Tennessee was randomly selected from the members of a statewide organization of sheep producers. Data about the participants' farms, sheep, parasite control practices and sources of information regarding ovine parasite control were obtained by a telephone survey. The response rate was 99%. The ...
Mieusset R - - 1992
Fertilization rate and embryonic mortality were assessed in 636 ewes inseminated in each uterine horn with 50 x 10(6) frozen spermatozoa from four control rams and from four rams submitted to a moderate (1.4-2.2 degrees C), but repeated, intermittent (16 h/day for 21 consecutive days) increase in their subcutaneous scrotal ...
Lotgering F K - - 1992
This study was designed to determine the accuracy of estimated values of maximal heart rate (HRmax) and oxygen consumption (VO2) during pregnancy. We measured HR and maximal VO2 (VO2max) at rest and during cycle (CE) and treadmill exercise (TE) tests with rapidly increasing exercise intensities during gestation and after delivery. ...
Winter A C - - 1992
Genital tracts were collected from non-pregnant cull ewes in early April and examined for macroscopic abnormalities. An assessment was made of the possible effect of any abnormality on the ability of the animal to become pregnant. It was found that 23.2 per cent of the tracts had abnormalities and it ...
Kendrick K M - - 1992
Microdialysis sampling was used to measure the release of oxytocin (OXY) and monoamine and amino acid transmitters from the region of the medial preoptic area (MPOA) and the bed nucleus of the stria terminalis (BNST) during parturition and suckling in sheep. Results showed that OXY and gamma-aminobutyric acid release increased ...
Nawaz M - - 1992
Six ewe genotypes, generated by mating Coopworth (C), Polypay (P), and Suffolk (S) rams to P and Coopworth-type (Ct) ewes, were exposed to Hampshire rams for spring lambing from 1987 through 1990. Data from 1,013 exposures and 973 resultant lambings were used to analyze reproductive traits and cumulative ewe productivity ...
Wallace J M - - 1992
Induction of ovulation post partum is associated with a high incidence of prematurely regressing corpora lutea. However, inadequate luteal function is not the sole reason for pregnancy failure, because ewes with normal corpus luteum function and successful fertilization also fail to establish pregnancies. The effects of suckling status and the ...
Oukessou M - - 1992
The influence of the state of pregnancy (mid- and end of pregnancy) on the kinetic disposition of gentamicin was determined in the ewe. Kinetic parameters were determined after a single intravenous bolus administration (4 mg/kg). It was shown that the steady state volume of distribution was significantly increased from mid ...
Walker D - - 1992
Pregnant ewes and their fetuses were chronically catheterized using aseptic procedures under general anaesthesia, and the ewes were then fed either lucerne chaff alone, or lucerne mixed with dried plant material obtained from one of three forb species, Tribulus terrestris (caltrop), Abelmoschus ficulneus (native rosella) or Ipomoea lonchophylla (cowvine), from ...
MacLaren L A - - 1992
Three models were used to test the hypothesis that interspecific pregnancy failure between the sheep and goat is due to a species-specific, maternal antibody response. Interspecific pregnancies were established in ewes and does, sheep in equilibrium goat chimeric conceptuses produced by injection of ovine blastocysts were transferred to ovine recipients, ...
Stafford K J - - 1991
The frequency of primary cycle ruminoreticular movements was measured in ten ewes during pregnancy and lactation, in three ewes during pregnancy and in two non-pregnant ewes. The frequency, of one movement every 76 seconds during non-pregnancy and up to months 2 of pregnancy increased during later pregnancy and lactation to ...
Kellerman T S - - 1991
During 1987 when cob rot was rife, perinatal losses were reported in flocks and herds that had been exposed to diplodiosis. The affected lambs or calves were either stillborn or died soon after birth. Dosing trials at the Onderstepoort Veterinary Research Institute involving 82 ewes revealed that 66% of the ...
Anderson J C - - 1991
Culture of cervical tissue with radiolabelled precursors showed that, in pregnant ewes, net hyaluronate synthesis increased between days 120-140 but that the marked polydispersity of hyaluronate remained unchanged. In the less sulphated of two proteoglycan populations, the proportion of heparan sulphate increased and that of dermatan sulphate decreased, while the ...
West K S - - 1991
Ewes in two trials were given either a high (H) or a low (L) level of premating nutrition for 19 wk followed by 6 wk of either H or L postmating nutrition to examine effects on reproductive performance. Trial 1 ewes were 5- to 8-yr-old Polypays and Trial 2 ewes ...
Woudstra B R - - 1991
Low amplitude, long-lasting epochs of myometrial activity, contractures, occur throughout the majority of pregnancy in all species studied to date. Contractures are associated with a fall in fetal oxygenation and changes in fetal behavioral state. In the present study we observed that contractures produced by the administration of 70 mU ...
Ogunbameru B O - - 1991
Two experiments were conducted to evaluate systems of providing supplemental heat to newborn pigs during and after farrowing. In Exp. 1, 35 sows were randomly allotted to farrowing crates with two supplemental heat treatments: 1) two lateral 250-watt heat lamps; and 2) two lateral heat lamps, plus a 250-watt heat ...
Mutiga E R - - 1991
One to three embryos were transferred to three groups each of 12 Kenya Merino ewes to establish if uterine capacity is a limiting factor to reproductive performance in this breed of sheep, in a tropical environment. A fourth group of 12 ewes received three embryos following superovulation. Multiple transfers increased ...
Wood G N - - 1991
The reliability of some behavioral and physiological indices used for the recognition and assessment of acute pain in lambs after castration and tail docking has been examined. Changes in the indices were measured after blocking neural activity with local anaesthetic (lignocaine) and after an opioid antagonist (naloxone) was administered. Six ...
Czlonkowska M - - 1991
Control ovine oocytes matured and fertilized in vitro were transferred to intermediate recipient ewes. After 5 days, 59% of eggs were recovered. Thirty-one (38%) reached morula/blastocyst stage. Twenty-one embryos at the morula or blastocyst stage were transferred to six recipient ewes, resulting in five pregnancies, of which four were maintained. ...
Crosse B A - - 1991
A woman in the first trimester of pregnancy presented with pneumonia and hilar lymphadenopathy after exposure to lambing ewes. She subsequently aborted. Infection with Chlamydia psittaci of ovine origin was confirmed. Pregnant women are susceptible to this infection, which may cause life threatening disease. The patient also had features of ...
MacIsaac R J - - 1991
PTH-related protein (PTHrP) has been implicated in calcium regulation during fetal life. In this study the ontogeny of PTHrP was examined in ovine parathyroid glands. Immunohistochemical techniques, Western blot analysis, and a RIA with antisera raised against synthetic fragments of human (h) PTHrP (i.e. 1-34, 1-40, 50-69, and 107-141) were ...
Løken T - - 1991
Fifty pregnant goats, inoculated intramuscularly at different gestational stages with a non-cytopathic ovine pestivirus or a cytopathic bovine pestivirus, all developed pestivirus-neutralizing antibodies within 5 weeks of inoculation. The incidence of reproductive failure was similar for the two agents. Parturition at term with only healthy kids occurred in 13 (26 ...
Santos A C - - 1991
Ropivacaine is a new amide local anesthetic structurally related to bupivacaine and mepivacaine. Its potency and duration of action are similar to those of bupivacaine but its therapeutic index may be greater. Since pregnancy enhances the cardiotoxicity of bupivacaine, the current study was devised to compare the toxicity of ropivacaine ...
Owiny J R - - 1991
Although cocaine use during pregnancy is an important cause of perinatal morbidity and mortality, there are no reports of its effect on maternal and fetal carbohydrate metabolism. Six pregnant ewes and their fetuses were instrumented under halothane general anesthesia at 113-119 days' gestation. Between 124-135 days' gestation, the ewes received ...
Vatnick I - - 1991
Twin-pregnant ewes underwent unilateral fetectomy (Fetx) at 50 days of gestation and were studied at 136 days. Aspects of conceptus growth and placental cellularity and metabolism in vitro were compared to those of unoperated control groups of twin-pregnant or single-pregnant ewes. Mean fetal weight in Fetx ewes tended to be ...
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