bluuebunny/crossref_metadata_2025_split huggingface dataset:
The mechanism of glycine betaine regulation in response to hyperosmotic stress in oyster mitochondria: A comparative study of Atlantic and Chesapeake Bay oysters
Authors: Pierce Sidney K. , Rowland‐Faux Laura M. , Crombie Burnette N. 
Published: June 2005

AbstractMitochondria isolated from Crassostrea virginica gill take up14C‐choline and convert it to glycine betaine. Mitochondria from low salinity adapted oysters from both the Chesapeake Bay and Atlantic coast take up choline at similar rates, but the rate of glycine betaine synthesis is up to 4‐fold faster in the Atlantic oyster mitochondria. The choline uptake and glycine betaine synthesis rates are much higher (as much as 5‐fold, depending upon the concentration of choline) in mitochondria from high salinity adapted oysters from both populations compared to the rates found in the low salinity groups. Furthermore, the uptake and synthesis rates in the high salinity adapted mitochondria are similar between Atlantic and Bay oysters up to 5 mM choline. Above that concentration, the uptake and synthesis rates of mitochondria from the Atlantic oysters are greater than the rates in the Bay oysters (2. 5‐fold and 2‐fold, respectively). These results indicate that glycine betaine synthesis is regulated differently both between the two oyster populations and between the two acclimation salinities. © 1995 Wiley‐Liss, Inc.
Effects of exercise on plasma nonesterified fatty acids and free amino acids in Arctic char (Salvelinus alpinus)
Authors: Barton Kimby N. , Gerrits Martin F. , Ballantyne James S. 
Published: June 2005

AbstractThe plasma nonesterified fatty acids (NEFA) and free amino acids (AA) of exercised and rested Artic char (Salvelinus alpinus) were measured. Total nonesterified fatty acids, total saturated fatty acids and total monoenes were significantly elevated in the plasma of the exercised group. Plasma levels of palmitate (16: 0) were also significantly elevated in the exercised fish. No significant changes with exercise were observed in the total polyenes.The total plasma free amino acid and total nonessential amino acid levels were significantly elevated in the exercised group. The concentrations of glutamate, alanine, taurine, and tryptophan increased with exercise. The percent contribution of total essential amino acids to total free amino acids in the exercised fish was lower than that of the rested group.It is suggested that mobilization of specific nonesterified fatty acids and amino acids largely reflect increased oxidation of metabolic substrates by exercising red muscle. © 1995 Wiley‐Liss, Inc.
Regulation of ovarian recrudescence: Effects of social interaction and size on female lizards, Anolis carolinensis
Authors: Summers Cliff H. , Suedkamp Denise A. , Grant Teresa L. 
Published: June 2005

AbstractStressful conditions inhibit reproductive function. For example, ovarian recrudescence is slower in captive and crowded lizards, and the presence of a dominant individual inhibits reproductive activity in subordinate male lizards. However, individuals so not necessarily respond to stressors equally. This study investigated the role of social stresses on reproductive function in female Anolis carolinensis. Groups of five females were placed with a male for 1 month in 25 × 25 × 25 cm aquaria under temperature and light conditions that stimulate reproduction (14L 32°C:10D20°C). Single females sacrificed prior to treatment with simulatory temperature and light regimens, but following acclimation to cages (as initial control, without male present) showed no ovarian recrudescence. Females placed on per cage with individual males (as final control) had significant ovarian growth yielding large yolking follicles when exposed to stimulatory temperature and light. In multi‐female groups two or fewer females per group had significant ovarian recrudescence. These females also had large yolking follicles, significant uterine growth, and always weighed 2. 7 g or more. Any female in a group weighing less than 2.7 g, regardless of the number of actively cycling females in the cage, had quiescent ovaries. Chromatic and behavioral characteristics of reproductively dominant females are not similar to those of dominant males. Dominant males are significantly more often green than brown. Females with cycling ovaries are significantly more often brown. Females which are successful in maintaining ovarian functioning even in crowded conditions acquire this morphological characteristic usually associated with subordinate status in males, which may facilitate courtship behavior. These results suggest that density‐dependent and/or psychosocial stressors inhibit reproductive cycling in this species. © 1995 Wiley‐Liss, Inc.
Immunohistochemical detection of the expression of the α subunit of inhibin, TGF‐β, basic‐FGF and IGF‐II in fetal ovarian grafts grown with fetal testes beneath the kidney capsule of adult castrated male rats
Authors: Koike Satoshi , Noumura Tetsuo 
Published: June 2005

AbstractIn order to characterize the participation of growth factors in gonadal differentiation and development, we examined patterns of expression of the α subunit of inhibin, transforming growth factor‐β (TGF‐β), basic fibroblast growth factor (basic FGF) and insulin‐like growth factor‐II (IGF‐II) immunohistochemically in experimentally induced ovotestes. Ovotestes were derived from ovaries of fetal rats on gestational day (GD) 13 that had been co‐grafted with fetal testes (GD 17) beneath the kidney capsule of adult castrated males and examined on the 7th, 14th and 21st days after transplantation (TD). Reactivity with antibodies against the α subunit of inhibin and basic FGF was observed in the Sertoli cells in both ovotestes and testes on TD 14 and on TD7, 14 and 21, respectively. Expression of IGF‐II was also recognized in the Leydig/interstitial cells in both types of graft on TD 14 and 21. Therefore, the gonadal somatic cells in the testicular region of the ovotestes had immunohistochemical properties similar to those in the co‐grafted testes. However, the somatic cells in the ovarian region of the ovotestes had immunohistochemical profiles different from those in solitary grafted ovaries. The germ cells in the ovotestes showed some differences in patterns of expression when compared with those in co‐grafted testes and solitary grafted ovaries: expression of basic FGF was recognized in the germ cells in ovotestes on TD 21 but not in co‐grafted testes; expression of IGF‐II was recognized in the germ cells in ovotestes on TD 21 but not in solitary grafted ovaries. These results indicate that the immunohistochemical properties that reflect expression of growth factors in female gonadal somatic cells were changed to properties that resemble those of male gonads by the co‐grafted fetal testes. © 1995 Wiley‐Liss, Inc.
Wool growth rate in vitro is independent of host animal nutrition, season, and the potential mediators of photoperiod, melatonin and prolactin
Authors: Winder L. M. , Scobie D. R. , Bray A. R. , Bickerstaffe R. 
Published: June 2005

AbstractIn most sheep breeds, wool growth varies seasonally and is correlated with changes in photoperiod, temperature, and nutrition. Wool growth regulation by these factors may result from systemic changes, or to a response localized at the wool follicle. Possible roles of systemic and local factors have been examined here by comparison of wool growth responses in vivo and in vitro.Wool follicles were isolated and maintained under conditions facilitating fibre growth for at least 4 days. The wool growth rate by follicles isolated regularly over a 10 month period was invariate (P > 0.10), in contrast to a seasonally varying wool growth rate by follicles from the same animals in vivo (P < 0.001). Although a high energy, high protein diet increased wool growth in vivo (P < 0.05), cultured follicles isolated from these animals showed no change in growth rate (P > 0.10). These observations suggest that the regulation of wool growth by environmental factors is extrafollicular and that there is no carryover of the in vivo growth rate when follicles are isolated and systemic signals are therefore removed.Additional work discussed here examined the regulation of pelage by prolactin and melatonin, potential endocrine mediators of photoperiod. The fibre production rate by isolated follicles maintained in control media was not different to that of prolactin or melatonin supplemented follicles (P > 0.10). It is concluded that selective breeding of domesticated sheep has suppressed the response of follicles to regulation by prolactin and melatonin. Studies currently underway using in situ RT‐PCR will provide further characterization of this conclusion. © 1995 Wiley‐Liss, Inc.
Manipulating melatonin in red deer (Cervus elaphus): Differences in the response to food restriction and lactation on the timing of the breeding season and prolactin‐dependent pelage changes
Authors: Heydon M. J. , Milne J. A. , Brinklow B. R. , Loudon A. S. I. 
Published: June 2005

AbstractIn this study, we investigated the influence of food availability and lactation upon seasonality in red deer. This was examined by testing the hypothesis that advancing the timing of breeding and autumn moult using the hormone melatonin will be prevented when the food availability of lactating hinds is severely restricted. This hypothesis was rejected. Implanting 1 g of melatonin between June 22 and November 30 resulted in advances in the timing of the onset of ovarian activity and winter coat growth of 18 and 35 days, respectively. Whilst the onset of ovarian activity was unaffected by lactation and restricted food availability, these factors significantly delayed the winter coat growth by 20 days. The date of onset of winter primary fibre growth was negatively correlated to plasma concentrations of the hormone prolactin in July. We suggest that seasonal changes in the growth of primary hair fibres are modified by two mechanisms: the increasing duration of melatonin secretion, as day lengths decline, which depresses prolactin secretion, and low nutrition, which elevates prolactin secretion in lactating deer.To conclude, we have demonstrated that the sensitivity of red deer to photoperiodic influences is preserved in lactating animals at low levels of nutrition, and that the timing of the onset of the breeding season and winter coat growth differ detectably in their sensitivity to nutrition and lactation. © 1995 Wiley‐Liss, Inc.
Descriptive kinetics of the seminiferous epithelium cycle and genome size in the mole Talpa occidentalis (Insectivora)
Authors: Sánchez A. , Stamatopoulos C. , Redi C. A. 
Published: June 2005

AbstractThe male germ cell cytodifferentiative process of the mole Talpa occidentalis is described. Cytochemical procedures were used 1) to follow acrosome formation and spermatid differentiation, dividing the seminiferous epithelium cycle into ten stages, each characterized by typical germ cell‐to‐cell associations, and recognizing 13 steps in spermatid differentiation; 2) to monitor, in situ, histones replacement by protamines at step 11 of the spermiogenic process.The seminiferous epithelium cycle of the mole has the basic histological features present in all mammals and appears rather similar to that of the common shrew (Sorex araneus), the only one so far known among Insectivora. The metabolism of the DNA‐associated proteins reveals that protamines replace histones during the late steps (11–13) of spermiogenesis, mRNA for protamines having been synthesized at an earlier step (assuming that in the mole this occurs at the first spermiogenic steps, as in the house mouse).In addition the genome size (5.0 pg) and the AT/GC ratio (1.3) were evaluated. © 1995 Wiley‐Liss, Inc.
Characterization of the chemiluminescence measured in hemocytes of the eastern oyster,Crassostrea virginica
Authors: Austin Kellie A. , Paynter Kennedy T. 
Published: June 2005

AbstractHemocytes of the Eastern oysters,Crassostrea virginica, produce reactive oxygen intermediates (ROIs) during phagocytosis to destroy foreign cells. Although evidence suggests that oyster hemocytes generate superoxide anions (O2−) following phagocytic stimulation, the production of other ROI species such as hydrogen peroxide (H2O2), singlet oxygen (1O2), hydroxyl radical (·OH), and hypochlorous acid (HOCl) has not been directly investigated. In this study, ROI production by oyster hemocytes was measured by quantifying the production of chemiluminescence (CL) amplified with different luminescent probes. The ROIs involved in CL production were identified by testing the effects of scavengers and inhibitors of particular ROI species on CL. Taurine completely inhibited luminol‐dependent CL, indicating that HOCl production was primarily responsible for the CL generated by hemocytes during phagocytosis of yeast granules. In addition, azide strongly inhibited luminol CL, implicating the involvement of myeloperoxidase in the production of HOCl and the resulting CL. Superoxide dismutase partially inhibited CL, indicating that superoxide ions were also produced and contributed to CL. Luminol CL was significantly higher in hemocytes from oysters heavily infected with the parasitePerkinsus marinusand remained completely inhibitable by taurine suggesting that HOCl production was enhanced by infection. Last, the concentration of taurine measured in oyster hemolymph was sufficient to quench a significant amount of the HOCl generated by the hemocytes and may reduce the effectiveness of the oyster's defense response to infections. © 1995 Wiley‐Liss, Inc.
Self‐fertilization of hermaphrodites of the teleostClarias lazereaafter oral administration of 17‐α‐methyltestosterone and their offspring
Authors: Liu Shaojun , Yao Zhanzhou 
Published: June 2005

AbstractAfter culture for 28 months, six specimens of Clarias lazera, which had received 17‐α‐methyltestosterone (MT) orally at a concentration of 30 m̈g per gram of diet for 60 days after hatching, reached sexual maturity and performed self‐fertilization in the absence of males. Under the light microscope, scanning electron microscope, and electron microscope, we examined the ova and moving sperm stripped from each of the six hermaphrodites. Testes and ovaries, which reached maturity synchronously, were found in one individual after self‐fertilization. The testes, which consisted of many lobules in which there were numerous sperm, were basically similar to the mature normal testes. However, the testes had unusual characteristics, such as the absence of spermatogonia on the walls of the lobules, looser junctions between adjacent lobules, a less dense distribution of sperm, and a few abnormal sperm (two‐headed sperm). All offspring produced by the six hermaphrodites were female. The all‐female offspring of the hermaphrodites provide evidence that the female ofClarias lazerais homogametic. © 1995 Wiley‐Liss, Inc.
Biological setting events for self‐injury
Authors: Carr Edward G. , Smith Christopher E. 
Published: June 2005

AbstractSelf‐injurious behavior typically occurs in response to specific antecedent stimuli that predict the occurrence of such desirable consequences of the behavior as obtaining attention from others, escaping aversive situations, and securing preferred foods, objects, and activities. Setting events constitute an additional controlling variable, altering the probability that a specific antecedent stimulus will evoke self‐injury. We discuss the influence of several biological factors, including menses, otitis media, fatigue, allergies, and constipation, that may serve as setting events. We also present a model which suggests that these events alter the functional properties of the antecedent stimuli that control self‐injurious behavior, thereby strengthening the specific consequences that maintain the behavior. One implication of this model is the likelihood that effective intervention will have to have multiple components, addressing both the biological and environmental variables that control the behavior. A second implication is that greater collaboration between medical and psychological or educational practitioners will be necessary in order to address the multiple factors that affect self‐injury. © 1995 Wiley‐Liss, Inc.
A theoretical analysis of the role of hyperarousal in the learning and behavior of fragile X males
Authors: Cohen Ira L. 
Published: June 2005

AbstractFragile X syndrome, the most common form of inherited mental retardation, is associated with a broad spectrum of cognitive and behavioral impairments. Researchers have noted a characteristic behavioral profile consisting of social avoidance, as well as verbal and motor repetitive behaviors, in a subgroup of males with fragile X syndrome. Although these behaviors are evident in their most extreme form in males having both fragile X syndrome and autism, milder variants are evident in nonautistic males as well. Clinical data we have collected suggest that the severity of these agitated behaviors starts increasing during adolescence. These data suggest fragile X males have problems with arousal modulation. It is hypothesized that these arousal problems have an impact on both the acquisition and display of cognitive and adaptive skills. Neurocomputational issues that may be relevant to understanding these cognitive and emotional phenomena are discussed. © 1995 Wiley‐Liss, Inc.
Studies of the development of congenital anomalies in embryos of riboflavin‐deficient, galactoflavin fed rats. II. Role of the terminal electron transport systems
Authors: Aksu Oguz , Mackler Bruce , Shepard Thomas H. , Lemire Ronald J. 
Published: June 2005

AbstractStudies of the tissues of embryos and fetuses of rats treated with a riboflavin‐deficient, galactoflavin‐augmented diet during pregnancy were performed, and demonstrated that the activities of the succinic and DPNH oxidase systems (the terminal electron transport systems) were markedly reduced from control values during the critical period of development (days 12 thru 16 of gestation). The activities of the electron transport systems of placental tissue and maternal heart tissue were unaffected during the same period, suggesting that fetal tissue is particularly susceptible to the effects of riboflavin deficiency.
Morphogenesis of cleft palate induced by exogenous factors. III. Intraamniotic application of hydrocortisone in mice
Authors: Dostál M. 
Published: June 2005

AbstractIn analyzing the morphogenesis of an experimentally induced congenital defect, estimation of the direct effect of the teratogen on offspring is of a great importance. In order to avoid the probable modification of the terato‐genic action of a given substance caused by the placental barrier and maternal metabolism, it is useful to apply the teratogen directly into the anmiotic sac of the embryo or fetus. However, it has been claimed that puncture of the amniotic sac both in mice and rats may itself induce cleft palate. An intraamnioticinjection method worked out in our laboratory diminishes the occurrence of cleft palate caused by nonspecific factors to a uniform and fairly negligible level. The application is performed by means of a glass micropipette provided with sharp, beveled tip. Using this method hydrocortisone was injected into the amniotic sacs of embryos and fetuses of randombred H‐Velaz mice, and it was shown that administration on day 12, 13, or 14 of gestation induced cleft palate. The direct action of corticoids upon the morphogenetic system of the palatine shelves is therefore supposed.
Teratogenic effects of rotenone on the early development of chick embryos in vitro
Authors: Rao K. Vasudeva , Chauhan S. P. S. 
Published: June 2005

AbstractChick embryos at five developmental stages ranging from full primitive streak to six pairs of somites were exposed in vitro to the action of 1 μg/ml rotenone for 15 minutes. The syndrome of defects caused by this treatment was described. Protection experiments using various chemicals applied to the rotenone‐treated embryos indicated that the biochemical lesion caused by rotenone is an inhibition of the respiratory chain. Rotenone did not seem to interfere with the primary organizer of the embryo as shown by grafting experiments. The general similarity of the rotenone syndrome and that caused by other teratogens was discussed and it was suggested that different biochemical lesions caused by a variety of teratogens may lead to apparently similar syndromes.
Comparative teratogenicity of pyrimethamine in rats and hamsters
Authors: Sullivan George E. , Takacs Eva 
Published: June 2005

AbstractPyrimethamine, a drug used in the treatment of toxoplasmosis, was much less teratogenic in golden hamsters than in Wistar rats. About 70% of rat fetuses were killed or malformed by administration of single oral doses of 5 mg to pregnant females. Less than 10% of hamster fetuses died or were malformed following single doses to the mother of 20 mg, which on a mg/kg basis was eight to nine times greater than that given to rats. In the rats repeated daily doses of 0.5 mg per female were severely teratogenic. The incidence of dead and abnormal fetuses in rats treated with 5 mg pyrimethamine was markedly reduced, from about 70 to 10%, by single intraperitoneal injections of 6 mg folinic acid; this result suggests that folinic acid might be potentially of value in lessening the teratogenic risk that may exist when pyrimethamine is employed in toxoplasmosis therapy during early pregnancy.
A meiotic cytogenetic study in mice of a commonly used tranquilizer reported to concentrate in mammalian follicular fluid
Authors: Jagiello Georgiana , Ducayen Mercedes B. , Lin J. S. 
Published: June 2005

AbstractThe ability of meprobamate, a commonly used tranquilizer, to be concentrated in human ovarian follicular fluid and to block superovulation in the mouse prompted an examination of its potential as a meiotic mutagen. Examination of in vitro meiotic behavior of mouse ova in a medium containing 1–10,000 μg/ml of meprobamate revealed that at 500 μg/ml abnormal second metaphase configurations were induced and that at a concentration of 750 μg/ml the progression of meiosis was essentially stopped. Superovulation was blocked in young mice each treated with 5 mg meprobamate and examination of intrafollicular oocytes principally revealed normal second metaphase configurations with first polar bodies. A single iv or chronic treatment throughout the time required for total maturation of a mouse follicle did not affect subsequent meiotic maturation of ova. The data suggest that the in vitro effects of the tranquilizer on mouse ova are prevented in vivo by an unknown barrier or mechanism within the ovarian follicle, and that at relatively high doses no detectable chromosome change in ova would be expected.
Skullbase malformations in rat fetuses with hypervitaminosis A‐induced exencephaly
Authors: Geelen J. A. G. 
Published: June 2005

AbstractExencephalic fetuses (16th–20th day), offspring of female Wistar rats treated with vitamin A palmitate orally during pregnancy, were studied in serial sections. The median part of the skullbase of the rat is formed by the basioccipital, basisphenoid, and presphenoid. In exencephalic fetuses the basioccipital had a normal shape; the hypophyseal fossa in the basisphenoid was too deep; the presphenoid was malformed. The angle between the cervical vertebral column and basioccipital was increased and those between the basioccipital and basisphenoid, and the basisphenoid and presphenoid were reduced. As a result the longitudinal axis of the skullbase was shortened. In all exencephalic fetuses the pontine and cervical flexures were less well marked than in controls. No anomalies of the rostral part of the notochord were observed. It is concluded that there is a relation between abnormal flexures of the neural tube and the malformation of the skullbase. The resemblance of the skullbase in human anencephaly and rat exencephaly is emphasized.