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Results 301 - 350 of 1044
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Willis Craig K R - - 2006
Many mammals save energy during food shortage or harsh weather using controlled reductions in body temperature and metabolism called torpor. However, torpor slows offspring growth, and reproductive individuals are thought to avoid using it because of reduced fitness resulting from delayed offspring development. We tested this hypothesis by investigating torpor ...
Tsunoda Masashi - - 2006
Tributyltin (TBT) compounds have been used as anti-fouling agents and the central nervous system is one of its target organs. TBT-induced modulations of neurotransmitters in the brains of adult mice have been reported. However, little is known about the developmental neurotoxicity of TBT. In this study, we evaluated the effects ...
Ault Patricia - - 2006
PURPOSE: Imatinib has potential teratogenicity in animals, but the effect of exposure to imatinib during conception and pregnancy in humans is not known. PATIENTS AND METHODS: The records of all patients with chronic myeloid leukemia (CML) treated with imatinib were reviewed. We report the experience on 19 pregnancies involving 18 ...
Webb Jonathan K - - 2006
Phylogenetic transitions from oviparity to viviparity in reptiles generally have occurred in cold climates, apparently driven by selective advantages accruing from maternal regulation of incubation temperature. But why, then, are viviparous reptiles so successful in tropical climates? Viviparity might enhance fitness in the tropics via the same pathway as in ...
Pawluski Jodi L - - 2006
Pregnancy and mothering result in a number of hormonal, neurological, and behavioral changes that are necessary to ensure reproductive success. With subsequent reproductive experience (multiparity and mothering), further neurological and behavioral changes may result. Recent research has shown that previous motherhood enhances both hippocampus-dependent learning and memory and long-term potentiation ...
McKenna D S - - 2006
OBJECTIVE: Many expecting parents wish to ascertain fetal gender early in pregnancy. Our goal was to determine whether fetal heart rate (FHR) of males and females during the first trimester is significantly different. MATERIALS AND METHODS: From November 1997 to February 2003 we enrolled pregnant women with singleton gestations who ...
Basolo Alexandra L - - 2006
Maternal investment in offspring is constrained by a variety of trade-offs, and the investment pattern expressed by an individual can have important fitness consequences. The authors investigate two maternal investment tradeoffs in the southern platyfish, Xiphophorus maculatus: investment in offspring size versus number, and investment in sons versus daughters. Variation ...
Dixon Marjorie E - - 2006
OBJECTIVE: Uterine vascular remodeling at mid gestation includes the thinning of the vessel walls and, typically, an increase in lumen diameter. This study aimed to elucidate any differences in structural remodeling in normal murine pregnancies versus those differences that resulted from the crossing of CBA/J female mice by DBA/2 male ...
Larke Amiee - - 2006
Throughout the living world trade-offs between reproductive success and longevity have been observed. In general, two extremes of life history patterning are reported, r- and K-selected species. The latter tend toward larger body sizes, few offspring from any one pregnancy, few offspring over the female reproductive span, longer life spans, ...
Rodríguez M D - - 2006
D-003 is a mixture of long-chain fatty acids isolated and purified from sugar cane wax with cholesterol-lowering and antiplatelet effects. In order to further characterize the developmental toxicity during the treatment period from late gestation up to weaning of the offspring, pregnant females received 0 (control), 500, and 1,000 mg/kg/day ...
Dziminski M A - - 2006
Variable maternal provisioning may evolve when there is variation in the quality of offspring environments. The frog Crinia georgiana has high variability in egg size both within and between clutches, independent of female phenotype. It breeds in ponds with high spatial and temporal variation in habitat quality. Egg size strongly ...
Sinno-Tellier Sandra - - 2006
Male gonadal exposure to ionizing radiation may disrupt spermatogenesis, but its influence on the fecundity of couples has been rarely studied. We aimed to characterize the influence of male gonadal dose of ionizing radiation delivered during radiodiagnostic on the monthly probability of pregnancy. We recruited a random sample of women ...
Hirai Narisato - - 2006
Gonad histological changes were examined in Japanese medaka exposed to 17beta-estradiol (E2) during early-life stages. Two experiments were conducted at different concentrations of E2 (33.5 and 140.6 ng/L, mean value of measurement) and larvae and juveniles were observed for histological changes in the gonad. Differentiation of ovary and testis in ...
Matsuura Ikuo - - 2005
A two-generation reproduction toxicity study in rats adding extra endpoints to detect endocrine disrupting activity was conducted using lindane by dietary administration at 0, 10, 60, and 300 ppm, for investigation of its utility. The extra endpoints included anogenital distance (AGD), nipple development, sexual maturation (vaginal opening and preputial separation), ...
Honeycutt Hunter - - 2005
Infant mice (Mus musculus) born to dams housed in isolation throughout pregnancy (IsoPreg) begin differentially approaching homenest bedding over clean bedding on Postnatal Day 6. Offspring of dams housed with 2 other potentially pregnant conspecifics (SocPreg) display such homing behavior on Day 4. Earlier onset of homing reflects facilitated olfactory ...
Polan H Jonathan - - 2005
Newborn rats seek and attain contact with their mothers by orienting and primitive locomotor behaviors called maternally-directed orienting behaviors (MDOBs). By 2 days of age MDOBs are elicited specifically by maternal features and are heightened by a period of acute separation from the mother. This behavioral regulation by the mother's ...
Blumenstiel Justin P - - 2005
Hybrid dysgenesis in Drosophila is a syndrome of gonadal atrophy, sterility, and male recombination, and it occurs in the progeny of crosses between males that harbor certain transposable elements (TEs) and females that lack them. Known examples of hybrid dysgenesis in Drosophila melanogaster result from mobilization of individual families of ...
Langkilde Tracy - - 2005
Temperature-dependent sex determination (TSD) has evolved independently in at least two lineages of viviparous Australian scincid lizards, but its adaptive significance remains unclear. We studied a montane lizard species (Eulamprus heatwolei) with TSD. Our data suggest that mothers can modify the body sizes of their offspring by selecting specific thermal ...
Becker Christian M - - 2005
OBJECTIVE: To determine whether endometriosis can be treated with the angiogenesis inhibitor endostatin and the effect of this treatment on fertility and reproduction. DESIGN: Pharmacologic intervention in a surgically induced model of endometriosis and in female mice undergoing mating. SETTING: Animal research facility. ANIMAL(S): Eight-week-old, female C57BL/6 and SCID mice. ...
Reebs S G - - 2005
The present study investigated the preference of male and female Syrian hamsters, Mesocricetus auratus, for different types of running wheels. Hamsters were placed individually in sets of multiple cages linked by tunnels, each cage with a different running wheel. The number of wheel revolutions in each cage was tallied daily ...
Good Tatjana C - - 2005
Male and female mammals undergo profound hormonal changes during pregnancy, some of which are sufficiently dramatic to influence offspring survival. In order to understand the proximate mechanisms regulating the variability in reproductive success within and between individuals, we monitored changes in fecal corticosteroid concentrations over the reproductive cycle in male ...
David Clifton Justin - - 2006
Intergeneric androgenetic golden Buenos Aires tetra (BT), Hemigrammus caudovittatus was generated using sperm drawn from post-mortem males preserved at -20 degrees C for 10, 20, 30 and 40 days or fresh sperm to activate the UV-irradiated oocytes of black widow tetra (WT), Gymnocorymbus ternetzi. UV-irradiation (4.2 W/m(2)) of the oocytes ...
Pampiglione S - - 2005
This paper deals with some internal anatomical features observed in histological sections and freshly dissected mounts of Tunga trimamillata, a Siphonaptera recently discovered in Andean regions of Ecuador from several mammals, including man. It was possible to study in males and also non-gravid and gravid females, the location and anatomy ...
Bales Karen L - - 2005
The steroid hormone cortisol has been associated with different levels of "stress" as well as different reproductive conditions in many primates. In callitrichids, cortisol has more often been reflective of female reproductive status than of chronic stress. In this study, we addressed the hypothesis that wild golden lion tamarin (Leontopithecus ...
Chassaing Nicolas - - 2005
We describe a family with an X-linked dominant chondrodysplasia. Four males and six females were affected through four generations. Identification of skeletal abnormalities and hydrocephaly during the pregnancy of three male fetuses led to termination of the pregnancies. A fourth affected male died at 6 days of life. The four ...
Schwarz Aline - - 2005
Solanum lycocarpum St. Hil (Solanaceae) is an invasive and native shrub very common in the Brazilian savanna. It is well known that this plant contain steroidal glycoalkaloids that can be transformed into an intermediate for steroidal drugs production, like oral contraceptives. In this way, it is very possible that these ...
Yan Zhen Z Program in Human Immunogenetics, Fred Hutchinson Cancer Research Center, Seattle, Wash 98109, USA. - - 2005
Fetal microchimerism, derived from fetal cells that persist after pregnancy, is usually evaluated by tests for male microchimerism in women who gave birth to sons. We investigated male microchimerism in women without sons and examined correlation with prior pregnancy history. Immunologic consequences of microchimerism are unknown. We studied healthy women ...
Kinsley Craig H - - 2006
Short-term fluctuations in steroid hormones such as estradiol (E2) and progesterone (P) can affect the concentration of hippocampal dendritic spines in adult, cycling nulliparous female rats. Pregnancy is characterized by a significantly longer duration of substantially elevated E2 and P compared to the estrous cycle. Thus, even greater changes than ...
Reddy Gadi V P - - 2005
Monoterpenoid compounds extracted from wood of Scots pine, Pinus sylvestris L, synergized the attraction of the old-house borer, Hylotrupes bajulus (L), to the male pheromone (3R)-3-hydroxy-2-hexanone ((3R)-ketol) + 1-butanol. Glasshouse experiments using ground traps baited with extracts derived from Scots pine wood or the monoterpenes (+)-alpha-pinene, (-)-verbenone, (-)-trans-pinocarveol and (+)-terpinen-4-ol ...
Guettier Catherine - - 2005
Male microchimerism is frequent in the adult female liver and is attributed to fetal cells originating from previous male offspring. It has never been studied in pregnant women, female children, or fetuses. We examined its frequency and cellular nature in normal and diseased female livers from fetal life to adulthood. ...
Gol Mert - - 2005
OBJECTIVES: Maternal serum human chorionic gonadotropin (MshCG) levels are higher in pregnant women with female fetuses than in pregnant women with male fetuses in the third trimester of pregnancy. Our aim was to examine the effect of fetal sex on MshCG levels throughout the pregnancy. MATERIALS AND METHODS: Twenty-nine uncomplicated ...
Kapoor Amita - - 2005
Prenatal stress can have profound long-term influences on physiological function throughout the course of life. We hypothesized that focused periods of moderate prenatal stress at discrete time points in late gestation have differential effects on hypothalamo-pituitary-adrenal (HPA) axis function in adult guinea pig offspring, and that changes in HPA axis ...
Wada Toshifumi - - 2005
We observed the reproductive behavior of the oval squid Sepioteuthis lessoniana in captivity. The male used three different mating behaviors: male-parallel (MP), male-upturned (MU) and sneaking. Male competition over females frequently occurred before and during the female egg-laying period, and the outcome of most fights depended on male body size. ...
Koketsu Y - - 2005
Of 105 swine herds using a production record system for breeding female pigs, 95 farms were used to analyze nonproductive female days (NPD), the six component intervals of NPD, and related measurements. The NPD was defined as the days when mated gilts and sows were neither gestating nor lactating, and ...
Meylan Sandrine - - 2005
Hormones are an important interface between genome and environment, because of their ability to modify the phenotype. More particularly, glucocorticoids are known to affect both morphological, physiological and behavioral traits. Many studies suggest that prenatal stress (associated with an elevation of corticosterone) has deleterious effects on offspring, an altered physiology ...
Cunha Gerald R - - 2005
Studies were conducted to elucidate the importance of androgen-mediated induction of the extreme masculinization of the external genitalia in female spotted hyenas. Phallic size and shape; androgen receptor (AR) and alpha-actin expression; and sex-specific differences in phallic retractor musculature, erectile tissue, tunica albuginea, and urethra/urogenital sinus were examined in male ...
del Castillo Susan M - - 2005
Gestation and lactation can impose substantial energetic costs on female mammals. We developed a non-invasive means to determine reproductive condition in female giraffe using fecal steroid analysis. Giraffe may be especially challenged during their reproductive cycle because of two characteristics: they are impregnated while lactating and they do not breed ...
Snook R R - - 2005
Courtship song serves as a sexual signal and may contribute to reproductive isolation between closely related species. Using lines of Drosophila pseudoobscura experimentally selected under different sexual selection regimes, we tested whether increased promiscuity and enforced monogamy led to evolutionary changes in courtship song elements. In D. pseudoobscura, males produce ...
Cocco Pierluigi - - 2005
OBJECTIVES: To explore reproductive outcomes in relation to occupational exposure to DDT. METHODS: We inquired into the reproductive history, including total number of children, sex distribution in the offspring, time-to-pregnancy, and number of spontaneous abortions and stillbirths, of the spouses of 105 men first exposed to DDT in a 1946-1950 ...
Cohen-Bendahan Celina C C - - 2005
Increased prenatal exposure to testosterone (T) in females of an opposite-sex (OS) twin pair may have an effect on the development of sex-typical cognitive and behavioral patterns. The prenatal exposure to T due to hormone transfer in OS twin females may occur in two ways, one directly via the feto-fetal ...
Kanazawa Satoshi - - 2005
This paper proposes the generalized Trivers-Willard hypothesis (gTWH), which suggests that parents who possess any heritable trait which increases male reproductive success at a greater rate than female reproductive success in a given environment will have a higher-than-expected offspring sex ratio, and parents who possess any heritable trait which increases ...
Fernández-Fernández R - - 2005
Ghrelin, the endogenous ligand of the GH secretagogue receptor, has been recently involved in a wide array of biological functions, including signaling of energy insufficiency and energy homeostasis. On the basis of the proven reproductive effects of other regulators of energy balance, such as the adipocyte-derived hormone leptin, we hypothesized ...
Naguib Marc - - 2005
The nutritional and social conditions that individuals experience during early development can have profound effects on their morphology, physiology, behaviour and life history. Experimental increases in brood size in birds can result in reduced offspring condition and survival, indicating that developmental deficits in enlarged broods have negative fitness consequences within ...
Wewers Dirk - - 2005
The present study was conducted to test the hypothesis that an application of an antiandrogen during pregnancy causes an infantilization of the male offsprings' behaviour later in life. The subjects studied were male guinea pigs whose mothers were either treated with an antiandrogen (flutamide and carrier) or a placebo (carrier ...
Krakauer Alan H - - 2005
In the few species of birds in which males form display partnerships to attract females, one male secures most or all of the copulations. This leads to the question of why subordinate males help in the absence of observable reproductive benefits. Hamilton's concept of kin selection, whereby individuals can benefit ...
Al Atawi F - - 2005
BACKGROUND: Adult females have significantly more leptin than males. We investigated the effect of fetal sex on levels of leptin and other pregnancy hormones (progesterone, estradiol, FSH, LH and beta hCG) in pregnant females during different stages of pregnancy. PATIENTS AND METHODS: Serum leptin levels in pregnant females followed at ...
Arthuri Mariana Trevisani - - 2005
The effect of sex hormones on orofacial pain modulation is poorly understood. Therefore, this study aimed to investigate the effect of hormonal changes as a result of pregnancy, as well as that of the kappa (kappa) opioid receptor antagonist on female rats' sensitivity to the temporomandibular joint (TMJ) formalin test. ...
Heifetz Yael Y Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, - - 2005
Proteins and peptides in Drosophila melanogaster seminal fluid induce mated females to increase their rates of egg deposition. One seminal-fluid protein, ovulin (Acp26Aa), stimulates an early step in the egg-laying process, the release of oocytes by the ovary. Ovulin, upon transfer to females, is cleaved sequentially within the mated female's ...
Menon Balakrishnan - - 2005
A young female patient of 30 years of age previously asymptomatic presented with complaints of exertional dyspnoea and hemoptysis with a normal chest roentgenogram. She was eventually diagnosed to have lymphangioleiomyomatosis, a rare pulmonary disorder. In this patient it occurred without any history of current pregnancy or estrogen consumption, as ...
Luke Barbara - - 2005
This study evaluated the effect of gender mix (the gender combinations of twin pairs) on fetal growth and length of gestation, and reviewed the literature on the long-term effects of this altered fetal milieu on cancer risk. In singletons, it is well established that females weigh less than males at ...
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