bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incomplete development of the spleen and the deformity in the chimeras between asplenic mutant (Dominant hemimelia) and normal mice
Authors: Suto Jun‐Ichi , Wakayama Teruhiko , Imamura Kenkichi , Goto Saori , Fukuta Katsuhiro 
Published: June 2005

AbstractThe semidominant gene Dh (Dominant hemimelia) induces skeletal and visceral abnormalities of various degrees and failure of the spleen in mice. The homozygous individual (Dh/Dh) seems to be lethal. The present experiment was designed to investigate the ability Dh cells to form a spleen and the genesis of the hind limb malformations by Dh/Dh and Dh/+ cells in chimeric mice. The Dh/Dh and Dh/+ embryos were produced in the F2 progeny of a cross between inbred strains of Dh/+ and DDD mice. They were aggregated with C3H/He or C57BL/6 embryos to make chimeras. Identification of Dh/Dh or Dh/+ embryos was carried out by Pep‐3, and chimerism was analyzed by Gpi‐1. Of 25 chimeras carrying the Dh gene, four mice formed a small spleen, two mice had a vestigial spleen, and the others no spleen. The tissues of the incompletely developed spleens were normal histologically and Dh cells were involved in the tissues of the spleen. In the chimeric mice, hindlimb malformation by the Dh gene was reduced in severity and the lethality of the homozygote (Dh/Dh) was rescued. © 1995 Wiley‐Liss, Inc.
Effects of chloroquine and its enantiomers on the development of rat embryos in vitro
Authors: Tagoe Clifford N. B. , Ofori‐Adjei David 
Published: June 2005

AbstractThe effects of the antimalarial drug chloroquine (CQ) and its enantiomers [(+)]‐CQ and (−)‐CQ on 9½‐day post‐implantation rat conceptuses were studied by the whole‐embryo culture technique over a 48 hr period. At a concentration of 500ng/ml of culture medium (0.97 μM), which falls within serum levels attained during long‐term CQ therapy, the drugs produced varying degrees of growth retardation and dysmorphogenesis in the conceptuses. These effects were most severe with exposure to racemic CQ (100%) and also to equimolar concentrations of the two enantiomers (90%). Dysmorphogenesis was least with (+)‐CQ (30%) and intermediate in severity in those exposed to (−)‐CQ (32%). In the CQ and combined enantiomer groups, there was significant reduction in yolk sac diameter to 81% and 73%, the crown‐rump length to 77% and 71%, the number of somites to 76% and 74%, and the embryonic protein content to 64% and 49%, respectively, of control values. In the (−)‐enantiomer group the only parameter significantly affected was the somite number which was reduced to 83% of control. The growth parameters of (+)‐CQ‐ treated embryos did not differ significantly from controls. The commonest morphological abnormalities observed in all treatment groups were those of axial rotation. Unfused and underdeveloped cranial neural tube, microophthalmia and abnormal otic primordium also occurred frequently, especially in the CQ and enantiomeric combination groups. The results suggest that the commercially available form of chloroquine, CQ, is embryotoxic in doses comparable to serum levels reached during long‐term therapy with the drug. It also appears that although the individual enantiomers show minimal embryotoxicity at the dosage used, they potentiate each other's effects in the racemic mixture. © 1995 Wiley‐Liss, Inc.
Comparative disposition, receptor affinity, and teratogenic activity of sulfon arotinoids
Authors: Willhite Calvin C. , Dubois Antoine , Schindler‐Horvat Janice , Apfel Christian , Eckhoff Christian 
Published: June 2005

AbstractTo investigate the relationship between sulfon arotinoid biotransformation and teratogenic activity, the potency of the ethyl (Ro 15‐1570) and methyl (Ro 14‐9706) arotinoid sulfones and their in vivo disposition in pregnant hamsters were studied. Administration of Ro 15‐1570 was teratogenic, but Ro 14‐9706 showed no such activity. Total absorbed doses of the ethyl and methyl sulfones (measured as maternal plasma AUC) were very similar. Total delivered dose of Ro 14‐9706 to liver and lung was 120–160% that of Ro 15‐1570, and Ro 14‐9706 was transferred in greater amounts to the embryo as well. Placenta AUC for parent sulfon arotinoids was 160–250% that in the embryo. Plasma analyses by HPLC suggested that the ethyl sulfone was oxidized and appeared in maternal plasma as the corresponding sulfinic (Ro 14‐9572) and sulfonic (Ro 14‐3899) acids, amounting to 10% and 16%, respectively, of the mean maternal ethyl sulfone Cmax value. The concentrations of sulfinic and sulfonic metabolites were always less than the analytical limit of detection in placenta and embryo after maternal ethyl sulfone intubation. Neither the sulfinic nor the sulfonic acid were ever detected in maternal circulation, placenta, or embryo after methyl sulfone intubation. Comparisons of their binding affinities found that neither the ethyl nor the methyl arotinoid sulfone could act as a ligand for cellular retinoic acid‐binding protein (CRABP), nor could these compounds bind retinoid nuclear receptors (RAR). Transcriptional activation of RARs was weak and similar for both compounds. The sulfinic and sulfonic acid arotinoids bind and transactivate RARs, and bind CRABP with efficiencies similar to all‐trans‐retinoic acid. Furthermore, they are active in cultured limb bud chondrocytes. The results suggest that the methyl sulfone (in accord with its lack of activity in cultured limb bud chondrocytes) is of no toxicologic significance in hamster embryo‐even after relatively high delivered dose. Teratogenicity of the ethyl sulfone (which shows marked inhibition of chondrogenesis in cultured limb bud) does not appear to depend on measurable concentrations of these sulfinic/sulfonic acid metabolites in the hamster embryo. © 1995 Wiley‐Liss, Inc.
Formation of protein–glutathione mixed disulfides in the developing rat conceptus following diamide treatment in vitro
Authors: Hiranruengchok Roongrudee , Harris Craig 
Published: June 2005

AbstractProtein‐glutathione mixed disulfide (protein‐S‐SG) formation was investigated in developing rat conceptuses during early organogenesis (gestational day 10, GD 10) using the whole embryo culture system. Low levels of protein‐S‐SG (25.0±6.6 pmoles resolved GSH/conceptus) were found in conceptuses under normal culture conditions. Incubation of the conceptuses with 75‐500 μM diamide (a thiol oxidant) resulted in rapid increases in protein‐S‐SG (to 2‐ to 16‐ fold that of control values) in a dose‐dependent manner during 30 min of the culture period. Approximately 20% of the observed cytosolic glutathione (GSH) depletion following diamide (500 μM) could be accounted for as mixed disulfides of protein sulfhydryls, when determined in whole conceptual tissues after 15 min. The most extensive S‐thiolation of protein sulfhydryls by GSH was observed in visceral yolk sac (VYS) when compared to embryo proper and ectoplacental cone. This result indicates that the most abundant, sensitive, or accessible protein sulfhydryls were found in the VYS. Inhibition of glutathione disulfide reductase activity by pretreatment of the conceptuses with 25 μM BCUN for 2 hr potentiated protein‐S‐SG formation elicited by 75 μM diamide. Reincubation of the conceptuses in fresh media, following the 15‐min treatment with 500 μM diamide, reversed both the GSH depletion and the protein‐S‐SG formation in conceptal tissues. The reduction of the protein‐S‐SG was dependent on adequate intracellular GSH levels and was inhibited when GSH was rapidly depleted by subsequent addition of N‐ethylmaleimide (NEM, 100 μM). Under the same experimental conditions, addition of 1 mM dithiothreitol (DTT) did not significantly enhance the GSH restoration rate nor the protein‐S‐SG reduction rate. The results also indicated that low levels of intracellular cysteine do not play an important role in the reduction of protein‐S‐SG. Protein‐S‐SG formation may be important for cellular regulation and in mediating the embryotoxicity elicited by diamide or other oxidative stresses. © 1995 Wiley‐Liss, Inc.
Phenytoin causes phalangeal hypoplasia in the rabbit fetus at clinically relevant free plasma concentrations
Authors: Danielsson Bengt R. , Danielson Kiki , Tomson Torbjörn 
Published: June 2005

AbstractNew Zealand White robbits were treated orally with 0 (controls), 50, 100, or 150 mg/kg phenytoin on days 14‐16 of pregnacy. Total and free plasma concentrations of phenytoin were determined in maternal plasma 2, 6, and 24 hr after the final dose in all aimals. In addition, after administration of 150 mg/kg maternal plasma concentrations were also determined after 12 and 48 hr, the concentrations in amniotic fluid after 6 hr and those in fetal tissue 6 and 24 hr after the final treatment. A high degree of plasma protein binding was observed in maternal blood. Treatment with 50 mg/kg resulted in free plasma concentrations of up to 5.0 μmol/1 during the 24 hr period following the final dose. Significantly higher free plasma concentrations were observed at the two higher dose levels; up to 9.7 μmol/1 at 100 mg/kg and 12.7 μmol/1 at 150 mg/kg. Digital hypoplasia was not seen in the control group or the animals treated with 50 mg/kg. However, treatment with 100 mg/kg resulted in hypoplasia in a single or a few digits in approximately 50% of the fetuses, and 150 mg/kg provoked hypoplasia in almost all digits in all fetuses. These results show that even though the doses which caused digital defects in rabbits are much higher than those used therapeutically, the resulting free concentrations of phenytoin are similar to those which are associated wth the some type of defects in humans. These data indicate that the pharmacologically induced fetal hypoxia/ischemia and vascular disruption preceding malformations of this type, which were observed in a previous study in rabbits, may be of human relevance. © 1995 Wiley‐Liss, Inc.
Glycoconjugates in normal and abnormal secondary neurulation
Authors: Griffith C. May , Hsieh Tauyee , Smith Catherine , Sanders Esmond J. 
Published: June 2005

AbstractIn chick embrayos, the anterior greater portion of the neural tube develops by the folding, apposition, and fusion of the neuroectoderm. The smaller caudal portion that forms the secondary neural tube (lumbosacral and coccygeal regions) is derived from the tail bud, an aggregate of mesenchymal cells located at the caudal limit of the body. Tail bud mesenchyme, arranged in a solid cord, undergoes mesenchymal‐ epithelial transformation to form the secondary neural tube. Previous evidence suggests that this transformation is accompanied by modulation of cell surface glycoconjugates in the differentiating tissues. In this study, we show by lectin histochemistry and lectin blotting of proteins isolated by SDS‐PAGE, that Datura stramonium agglutinin (DSA) binds preferentially to differentiating tail bud cells. This lectin is specific for β1‐4‐linked N‐acetylglucosamine oligomers, such as the oligosaccharides of the poly‐N‐acetyllactosamine series that have been previously implicated in cell differentiation. Ultrastructural lectin cytochemistry indicates that at least some of the proteins binding DSA are localized extracellularly. The use of DSA as a teratogen resulted in embryos showing a variety of neural tube and notochord defects. We have also examined the binding of DSA to embryos that were treated with teratogenic doses of retinoic acid by sub‐blastodermal injection, and find that the DSA‐ binding patterns are perturbed. Analysis of DSA‐ treated embryos using the TUNEL technique indicated that cell death was not a factor in DSA teratogenesis. This strongly suggests that the glycoconjugates of the cell surface have a role in the normal differentiation of tail bud mesenchyme into the neuroepithelium of the secondary neural tube. Perturbations of glycoconjugate activity results in defects of the secondary neural tube and associated tail bud derivatives. © 1995 Wiley‐Liss, Inc.
Population dynamics of pedigree leopards, Panthera pardus ssp, in captivity
Authors: Shoemaker Alan H. 
Published: June 2005

AbstractThe demographic history of 4 races or subspecies of leopard, Panthera pardus, was reviewed from international studbook records dating back to 1953. The Chinese leopard has been the most common pedigree race maintained in captivity, a factor linked to the length of time (29 years) this subspecies has been in captivity. The relative youth of the wild‐born founders also helped them to adjust to captivity as well as live long reproductive lives. Today, however, this race is suffering from the ill effects of inbreeding due to the small founder size. This condition appears to be correctable now that additional specimens have been located.Persian leopards have a larger founder size than the former race, but some of their ancestors were older animals at the time of acquisition. Because of this, their potential fecundity was probably depressed from psychological problems related to adjustment and a shorter life span in captivity. Two founding females experienced pelvic deformities while young, and few of their cubs survived because they all had to be delivered via caesarian section. This procedure also shortened the reproductive life of the females involved because the owning zoos refrained from breeding the animals in the leopards' later years.Captive leopards appear to live longer than their wild counterparts, although precise data on wild populations is not available. In captivity many reach 12–15 years old, and exceptional individuals of several races have lived 20 years. Most captive‐born leopards begin breeding when they are 3 years old and continue until they are 8–10 years old. Reproduction in females usually ceases at 12–14 years, although males have a longer reproductive life, with several successfully breeding when 19–20 years old.
Behavioral development in okapis and giraffes
Authors: Horwich Robert H. , Kitchen Craig , Wangel Mark , Ruthe Richard 
Published: June 2005

AbstractObservations on the behavioral development of two okapi calves and one giraffe calf were made at Brookfield Zoo. The following behaviors were monitored for 4 to 6 mo after birth; nursing duration and nursing attempts, mother‐infant distance, bunting the mother's udder, lying, moving, maternal grooming, mother and infant autogrooming, object licking, tail chewing, and contact by others in the herd. Behaviors in both species showed oscillating patterns with high levels of mother‐infant contact behaviors at 3–4 wk, 9–11 wk, and 14–15 wk in okapis. Giraffe infants showed similar oscillations with high periods of contact about 2–5 wk later than those in okapis. Other behaviors oscillated in concert with these, with specific correlations occurring between nursing behaviors and grooming behaviors.A main difference between okapi and giraffe development centered around maternal motivation during the high contact (regressive) periods. In okapis, after 10–12 wk there was a low rate of nursing success, whereas in giraffes the percentage of success in nursing rose with later behavioral oscillations. The regressive periods became conflict periods in okapis, whereas in the giraffe, the mother initiated the periods. This difference was in accordance with the unique strategy of infant rearing in wild giraffes in which there is an extended “hider” period when older calves are left together in shaded areas with an adult sentry. Field studies also indicated probable oscillations of mother‐infant contact and a prolonged period of the mother initiating contact with her calf.
The physiological effects of psychological stress
Authors: Stoskopf Michael K. 
Published: June 2005

AbstractThe study of behavior is a powerful tool in the captive management of wild animals. It can, if properly applied, provide insight into a wide variety of problems. The interpretation of behavioral observations requires a firm understanding and characterization of the environmental parameters that can induce the physiological state of stress through neurological means in the study subjects. These factors include, but are not limited to, territorial factors, including social and physical accommodations, photo factors, and acoustical factors. Proper interpretation of behavioral observations also requires a basic understanding of the biochemical and physiological impacts of neuroendocrine‐mediated stress. These include alterations in an individual's ability to metabolize toxic substances, resist infections, and reproduce. Confounding effects of these alterations must be considered in the examination of behavioral data. The most powerful experimental designs in comparative behavior are those that concurrently examine environmental stressors, physiological status, and behavior.
Reproductive studies of the Oryx
Authors: Durrant Barbara S. 
Published: June 2005

AbstractThe genus Oryx comprises one species already extinct in the wild and others that are rapidly disappearing. It is important to understand the reproductive physiology of these species in order to ensure their successful captive propagation.It was determined behaviorally and hormonally that the scimitar‐horned oryx's 21–22 d estrous cycle very closely resembled that of the domestic cow.Four females of three species (Arabian, scimitar‐horned, and fringe‐eared oryx) were treated with prostaglandin (PG) and pregnant mares serum gonadotropin (PMSG) or follicle‐stimulating hormone (FSH). All animals responded to prostaglandin treatment with shortened cycles and behavioral estrus. Ovulation occurred in all females but only one responded to gonadotrophin treatment with a mild superovulation.An embryo recovered from an Arabian oryx was frozen in liquid nitrogen for 6 months. Upon thawing, the normal‐appearing morula was surgically transferred to a scimitar‐horned oryx. The recipient failed to carry the embryo and returned to estrus within three weeks of the transfer.It was demonstrated that induction of ovulation and synchronization of estrus can be achieved in the three Oryx species with PMSG or FSH combined with prostaglandin treatment.
Problems and experiences in performing artificial insemination in bonobos (Pan paniscus)
Authors: Matern Bernd 
Published: June 2005

AbstractA report is given on the problems and the procedure of artificial insemination in the bonobo (Pan paniscus). In addition, the different possibilities and methods of the process of collecting sperm, its conservation, and determining the time of ovulation are discussed, as well as the various insemination techniques and their usage under practical conditions in zoological gardens.
Activity budgets and use of exhibit space by South American tapir (Tapirus terrestris) in a Zoological Park setting
Authors: Mahler Anne E. 
Published: June 2005

AbstractSix individuals of Tapirus terrestris (two adult males, one juvenile male, and three adult females) were observed the first three months of 1982 at Audubon Park and Zoological Garden. Data for fourteen behavioral states were collected by scan sampling at ten‐minute intervals throughout the day and twice throughout the night in an open air, mixed‐species exhibit. The data were analyzed to calculate activity budgets and space use. Sleeping, eating, foraging, walking, and standing made up the major portions of the activity budgets. “Natural” activity patterns, as in the wild for browsing ungulates, were displayed under captivity in variously modified form. The characteristics of an individual, especially the reproductive state, affected both activity budget and space use. Zoo regimen significantly modified activity budgets and space use by the animals.
Integration of hand‐reared gorilla infants in a group
Authors: Meder Angela 
Published: June 2005

AbstractThough many zoo‐born gorilla infants still have to be hand‐reared and sooner or later associated with conspecifics, preferably a group, neither the managing procedures nor the process of social integration has been recorded in detail thus far. The present study, conducted at the Frankfurt Zoo, deals with a simultaneous introduction of two hand‐reared infants, a male and a female, into a group. The procedure of the introduction was documented. Behavioral observations were made during 1.5 years of integration by using ad libitum and focal‐animal sampling methods. The findings were compared with some data collected during a previous introduction conducted by a different procedure. The results show that both introductions were successful insofar as the infants were able to live within the group after a given time. But social integration by the new introduction procedure took much longer than previous attempts.
Stress‐induced adrenal changes and their relation to reproductive failure in captive nine‐banded armadillos (Dasypus novemcinctus)
Authors: Rideout Bruce A. , Gause Gerald E. , Benirschke Kurt , Lasley Bill L. 
Published: June 2005

AbstractHistological features of adrenal glands from captive and unstressed free‐ranging nine‐banded armadillos were compared to determine if undefined stress factors associated with captivity were capable of causing changes in adrenal morphology. Animals in captivity less than 3 mo showed histological features identical to unstressed free‐ranging animals. Animals in captivity 6 mo or longer, however, showed adrenal changes like those previously described in other mammals exposed to various types of stress, except that there was no accompanying increase in adrenal weight. Similar adrenal changes were found in free‐ranging animals exposed to extremely harsh winter weather. Females from both the chronic captive population and this stressed free‐ranging population were seen to suffer reproductive failure. Reproductive function in males was not affected. There was no detectable sex difference in gross or histological adrenal changes; however, previous reports indicate there is a sex difference in the secretory product from the adrenals of captive nine‐banded armadillos. A possible relationship between reproductive failure in the female and the sex difference in adrenal secretory products is discussed.
Meat eating and predation in captive‐born semi‐free‐ranging Lemur fulvus and caged Lemur macaco
Authors: Glander Kenneth E. , Freed Benjamin Z. , Ganzhorn Jörg U. 
Published: June 2005

AbstractA group of brown lemurs, Lemur fulvus, and a group of black lemurs, Lemur macaco, at the Duke University Center for the Study of Primate Biology and History have been observed to capture and eat birds and lizards. Although vertebrate prey are not unusual for many carnivorous prosimians, folivorous prosimians never have been observed to take vertebrates in the wild and rarely even insects.
Wolf scent marking with raised‐leg urination
Authors: Mertl‐Millhollen Anne S. , Goodmann Patricia A. , Klinghammer Erich 
Published: June 2005

AbstractRaised‐leg urinations were performed almost exclusively by dominant male and female wolves (Canis lupus). The alpha male and female in two captive groups showed full raised‐leg urinations (RLUs) throughout the year. Each alpha male and female sniffed and marked on one another's marks frequently; however, the pair that bred did more marking and more double marking. They increased their marking frequency prior to and during the breeding season, decreased it at the time of parturition, while the female was in the den, and then increased to a moderate level when the female took part in pack activities again. Because the alpha pair was the principal sender and receiver of the message within the group, it is likely that double marks function to maintain and advertise the pair bond. Because the group that did not breed also did not double mark frequently, the presence of double marking in a captive group may be diagnostic of the viability of the group as a pack.
An Artificial “gum‐tree” for marmosets (Callithrix j. jacchus)
Authors: McGrew W. C. , Brennan J. A. , Russell J. 
Published: June 2005

AbstractMarmosets (Callithrix, Cebuella) in the wild gouge wells in trees and eat the exudates that accumulate there. An artificial gum‐tree was made of wooden dowel and filled with Acacia Senegal exudate (gum arabic) dissolved in water. Three families of marmosets avidly gouged and consumed gum from this device, showing all of the behavioral patterns described in nature. The gum‐tree cost little and was easy to make.