bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavioral teratologic effects of prenatal exposure to continuous‐wave ultrasound in unanesthetized rats
Authors: Vorhees Charles V. , Acuff‐Smith Karen D. , Schilling Mary A. , Fisher J. Edward , Meyer Richard A. , Smith Nadine B. , Ellis D. Scott , O'Brien William D. 
Published: June 2005

AbstractWhile there are no known risks associated with diagnostic ultrasound, uncertainty about the safety of prenatal ultrasound exposure remains. The purpose of the present experiment was to evaluate the behavioral teratogenic potential of continuous‐wave (cw) ultrasound in rats, in the absence of maternal anesthesia or restraint. Pregnant CD rats, trained to remain immobile in a water‐filled ultrasound exposure tank, were scanned with 3 MHz cw ultrasound at levels of 0, 2, 10, 20, or 30 W/cm2|SPTA(spatial peak, temporal average intensity) on gestational days 4–20 for approximately 10 min/day. Offspring were examined postnatally for survival, growth, physical landmarks of development, behavioral development, and the adult functions of locomotor activity, learning and memory, and startle reactivity. No effects of prenatal ultrasound were found on maternal characteristics, offspring survival or growth, physical or behavioral landmarks of development, or adult tests of passive avoidance or startle. Effects at the highest intensity were obtained on corner and side locomotor activity and in a multiple‐T water maze on measures of errors of commission and time spent finding the goal. The results showed that prenatal cw ultrasound in rats can induce effects on some postnatal neurobehavioral functions at high exposure intensities (30 W/cm2), but at lower intensities (2–20 W/cm2) no consistent evidence of neurobehavioral effects was observed. © 1994 Wiley‐Liss, Inc.
Exposure of Drosophila melanogaster embryonic cell cultures to 60‐Hz sinusoidal magnetic fields: Assessment of potential teratogenic effects
Authors: Nguyen Paul , Bournias‐Vardiabasis Nicole , Haggren Wendy , Adey W. R. , Phillips Jerry L. 
Published: June 2005

AbstractThere is considerable concern about potential detrimental health effect associated with exposure to environmentally relevant magnetic fields. One specific concern relates to potential effects of magnetic field (MF) exposure on reproduction and development. Consequently, an in vitro teratogenesis (developmental toxicity) assay employing embryonicDrosophilacells has been used to determine whether exposure to a 60‐Hz MF of 100 μT for 16–18 hr is itself teratogenic and whether such an exposure could potentiate the teratogenic response induced by a chemical teratogen (developmental toxicant). The results demonstrated that (1) MF exposure alone did not induce a teratogenic response, whether the MF was oriented parallel or perpendicular to the plane of the culture dishes; and (2) MF exposure did not alter the teratogenic response induced by optimal or suboptimal concentrations of three chemical teratogens (retinoic acid, hydroxyurea, and cadmium). Furthermore, in additional studies, Drosophilaembryos were exposed to 60‐Hz MFs of 10 and 100 μT for 24 hr or for their entire development time (i.e., until adult ecolsion, about 10 days). Results demonstrated that MF exposure did not produce an increase in developmental abnormalities over those observed in unexposed controls.
Antisense inhibition of Engrailed genes in mouse embryos reveals roles for these genes in craniofacial and neural tube development
Authors: Augustine Karen A. , Liu Edison T. , Sadler T. W. 
Published: June 2005

AbstractThe roles ofengrailed‐1 (En‐1) andengrailed‐2 (En‐2) have been investigated during gastrulation and neurulation in mouse embryos. Using antisense oligonucleotides and murine whole embryo culture, early somite embryos were injected with antisense phosphorothioated oligonucleotides directed againstEn‐1 ofEn‐2 transcripts and then grown in vitro for 48 hr. Inhibition ofEn‐1 by antisense targeting during this period resulted in embryos with craniofacial abnormalities, specifically loss of mid‐and hindbrain tissue and hypoplasia in associated neural crest derived areas such as the face and first and second pharyngeal arches. In addition, En‐1 appeared to be essential in early patterning of the neural tube. Embryos removed from culture as 8 hr following injection exhibited undulations in the presumptive spinal cord. Histological analysis of the affected neural tubes at 48 hr showed disrupted cytoarchitecture and in some cases, apparent dorsal‐ventral duplication of the neural tube and underlying notochord. Using S100 beta as a notochord marker, embryos removed from culture at 8 or 12 hr following injection exhibited loss of S100 beta expression in the notochord region subjacent to affected neural tube segments, suggesting that S100 beta, or other notochordal genes, may be downstream components of the En‐1 regulatory cascade. Furthermore, antisense inhibition ofEn‐1 induced caudal dysgenesis, suggesting disruption in primitive streak function. Antisense targeting of En‐2 expression at early somite stages produced few alterations in development, although approximately one third of the embryos exhibited a series of lateral folds in the spinal cord at the level of the forelimb‐bud. Combined injections withEn‐1 andEn‐2 antisense resulted in no novel phenotypes, suggesting that the genes do not possess functional redundancy. © 1995 Wiley‐Liss, Inc.
Aspirin–alcohol interaction in the production of cleft palate and limb malformations in the TO mouse
Authors: Padmanabhan R. , Pallot David J. 
Published: June 2005

AbstractOur objective in the present study was to determine the effects of alcohol on stages when the limb buds and renal primordia develop in the TO mouse and to see if aspirin pretreatment would prevent these organ systems from being malformed as was shown by Randall et al. ('91) in the C57 mice. On one of days 9‐12 of gestation, groups of TO mice were injected intraperitoneally (IP) with a single dose of 200 mg/kg of aspirin, or a proportionate volume of physiological saline. An hour later, half of the aspirin‐treated animals received a single dose of 0. 03 ml/g of freshly prepared 25% (v/v) solution of absolute alcohol and the other half received a proportionate volume of saline. Half of the saline‐treated animals received a single dose of 0.3 ml/g of saline or a proportionate volume of alcohol solution. All animals were killed on day 18 of gestation. Alcohol significantly increased embryonic resorption and caused remarkable intrauterine growth retardation (IUGR). It also induced arched palate, cleft palate and deformities of the digits with haematomas in a modest number of embryos. Aspirin alone did not have teratogenic effects. Pretreatment with aspirin significantly augmented alcohol‐induced resorption, IUGR, cleft palate and digital malformations associated with haematomas. Chronological observations on the development of the treated limbs showed the occurrence of vascular stasis, haematomas, edema and cell death at early stages. Subsequently, digital rays were either destroyed (ectrodactyly) or remained hypoplastic (brachydactyly). It appears that limb development in the aspirin‐ and alcohol‐treated TO mouse embryos is largely affected by vascular disruption. These data provide further evidence to our earlier observation that alcohol and aspirin interact in the production of malformations and that the teratogenic effects of alcohol in the TO mouse are possibly not mediated via treatment related prostaglandin elevation. © 1995 Wiley‐Liss, Inc.
Estimating intracellular pH in developing rodent embryos using a computer imaging technique: Changes in embryonic pH and proliferation rates following maternal treatment with acetazolamide
Authors: Schreiner Claire M. , Collins Michael D. , Scott William J. , Vorhees Charles V. , Colvin Jan , McCandless David 
Published: June 2005

AbstractUsing the transplacental distribution of the weak acid 5,5‐dimethyloxazolidine‐2,4‐dione (DMO), a computer assisted imaging technique has been developed to permit the estimation of intracellular pH (pHi) in very specific areas of the developing rodent embryo. The study reported here demonstrates the heterogeneity of radiolabeled DMO distribution in the developing mouse forelimb. The pattern of pHi distribution shifts from one of high pHi values in the proximal core of the mesoderm on day 10 of gestation to one of higher pHi values in the mesoderm just underlying the ectoderm on day 11. Studies [Scott et al. (1990) Toxicol. Appl. Pharmacol. 103:238‐254] in which DMO concentration was monitored following treatment with acetazolamide or acetazolamide plus amiloride were done in whole embryo homogenates or pooled limb samples which allow for the calculation of an average pHi but may not reflect the pHi in very specific locations of the limb. Two hours after acetazolamide administration, the pHi pattern was not significantly changed from control. Intracellular pH was raised above control levels but was not significant statistically except in the peripheral mesoderm in the ventral third of the forelimb. Fifteen hours after acetazolamide treatment, there was a significant decrease in pHi values with no change in pattern. However, treatment with acetazolamide plus amiloride for 15 hr produced a marked reduction of pHi values throughout the forelimb bud. Changes in bromodeoxyuridine labeling index (an indication of proliferative activity) following treatment with acetazolamide or acetazolamide plus amiloride are reported. The combination treatment reduced the labeling index by approximately 15% below that of control embryos in the limb region where absence of digit(s) will occur. However, we found no overall correlation of proliferative rate and pHi of limb bud mesoderm in treated embryos. Consequently, we were unable to causally associate reduced pHi with decreased proliferative rate. © 1995 Wiley‐Liss, Inc.
Population‐based study of tracheoesophageal fistula and esophageal atresia
Authors: Torfs Claudine P. , Curry Cynthia J. R. , Bateson Thomas F. 
Published: June 2005

AbstractFrom a multiracial population of 1,035,384 births monitored by the California Birth Defects Monitoring Program (CBDMP) from 1983 to 1988, we ascertained 34 cases of esophageal atresia (EA), 204 cases of tracheoesophageal fistula (TEF) with an EA (TEF/EA), and 54 cases of TEF without EA. The total prevalence rate was 2.82 per 10,000 live births and stillbirths and showed no secular trend nor marked seasonal variation. Rates of multiple birth were high for each defect (TEF 3.7%, TEF/EA 4.9%, EA 8.8%; population 1.1%). Non‐Hispanic whites were overrepresented for TEF and TEF/EA, but not for EA. EXcluding trisomies, mean maternal age was above the population mean (26.8 years) for TEF (27.9 years) and TEF/EA (28.0 years), but not for EA (26.2 years). The proportion of trisomies was significantly higher for EA (23.5%) than for TEF (9.3%; p<0.02) or for TEF/EA (7.4%, p<0.003). We subdivided each defect into five mutually exclusive types: isolated, multiple, syndromic, chromosomal, and trisomic. Male‐to‐female (M/F) ratios varied considerably between types, both within and between defects. The highest M/F ratios within each defect were for the multiple type (TEF 2.29, TEF/EA 1.44, EA 1.33; population 1.05), and the lowest for trisomies (TEF 0.25; TEF/EA 0.25, and EA 0.60). All types excepttrisomies were significantly associated with a single umbilical artery. We found an association of EA and TEF/EA with dextrocardia (3.1% of cases), and confirmed the association of primary hydrocephalus with TEF and TEF/EA (2.7% of cases). The proportion of cases with additional midline defects or VATER or VACTERL type anomalies was similar for all three defects, suggesting a common developmental pathogenesis. Epidemiologic differences between defects, and between types within defects, may reflect differences in timing of the pathological process or differences in susceptibilities (e.g., by sex or aneuploidy) and emphasize the need to evaluate each defect and its types separately in epidemiologic studies. © 1995 Wiley‐Liss, Inc.
Effect of supplemental folic acid on valproic acid‐induced embryotoxicity and tissue zinc levels in vivo
Authors: Hansen Deborah K. , Grafton Thomas F. , Dial Stacey L. , Gehring Theresa A. , Siitonen Paul H. 
Published: June 2005

AbstractValproic acid (VPA) is an anticonvulsant drug known to cause spina bifida in humans. Administration of the vitamin, folic acid has been reported to decrease the frequency of VPA‐induced exencephaly in mice treated with the drug in vivo. A protective effect by folinic acid has not been observed in vitro. The purpose of this investigation was to reexamine the ability of folinic acid to decrease the incidence of VPA‐induced neural tube defects in vivo. We also examined the effect of increased intake of folic acid on zinc levels in various maternal and embryonic tissues. Folinic acid, whether administered by intraperitoneal injection or in osmotic mini‐pumps, did not decrease the number of mouse fetuses with VPA‐induced exencephaly. Dietary supplementation with 10–20 times the daily required intake of folic acid in rodents also failed to decrease the embryotoxicity of VPA. Such dietary supplementation had no effect on zinc levels in maternal liver, brain, or kidney, nor in embryonic tissues. These results indicate that folic acid is not able to reverse the embryotoxicity induced by the anticonvulsant, that there is no apparent effect of high dietary folate intake on maternal or embryonic zinc levels and suggest that folate is probably not involved in the mechanism of VPA‐induced embryotoxicity. © 1995 Wiley‐Liss, Inc.
Urinary steroid evaluations to monitor ovarian function in exotic ungulates: I. Pregnanediol‐3‐glucuronide immunoreactivity in the okapi (Okapia johnstoni)
Authors: Loskutoff N. M. , Ott J. E. , Lasley B. L. 
Published: June 2005

AbstractImmunoreactive pregnanediol‐3‐glucuronide was assessed in daily urine samples from five female okapis. Indexed by creatinine (CR), the resultant profiles accurately reflect ovulation and pregnancy in this species. The infertile cycle was approximately 14.5 days by this method with the preovulatory levels averaging less than 1 ng/mg CR (N = 88) for approximately eight days (N = 28). Postovulatory levels averaged 24 ng/mg CR (N = 55) in one female and 12 ng/mg CR (N = 27) in another for approximately six days (N = 26). Pregnancy is confidently detected by three weeks postcoition by elevated pregnanediol levels that remain significantly higher that luteal phase levels until weeks before parturition.
Noninvasive assessment of seasonal hormone profile in captive bald eagles (Haliaeetus leucocephalus)
Authors: Bercovitz Arden Bryan , Collins Jan , Price Paul , Tuttle Dale 
Published: June 2005

AbstractThe hypothesis was to test whether a ratio of estrogen:androgen in eagle feces would reflect gonadal activity, and whether our procedure for noninvasive hormone analysis of fecal steroids could be applied to assess seasonal reproductive function in four captive bald eagles (Haliaeetus leucocephalus). Total immunoreactive excretory estrogens (E) and testosterone (T) were analyzed and compared as an E/T ratio from ad libitum monthly stool collections during the 1980–81 breeding season of birds maintained in an artificial insemination (AI) project. Since active male gonads are known to secrete a preponderance of androgens into the peripheral circulation and that renal clearance filters steroid metabolites into the urine, it was reasonable to assume that a lowered excretory E/T profile would mimic major changes in male seasonal steroidogenesis; analogously, active female gonads would result in an increased excretion of urinary estrogens, in turn reflected by a seasonal elevation of E/T ratios. A serial profile of excretory E/T ratio data for two male bald eagles approximated unity values except for a midseason low (x < 0.4) in February, one month prior to semen collections, followed by a significant end‐of‐breeding season rise in E/T values (x > 2.5, P < 0.01). The average E/T profile from data of two female eagles were two‐ to sixfold higher than males except for a significant mid‐breeding season peak in E/T values during March (x > 13.5, P < 0.01). Despite the absence of nest building or egg production by either female, these preliminary observational data indicated seasonal patterns of gonadal activity in both female eagles that were synchronous with semen availability from adjacent males.
Evaluation of secondary infertility in the gorilla
Authors: O'Grady John Patrick , Esra Gerald N. , Yeager Caroline H. , Thomas Warren D. 
Published: June 2005

AbstractReproductive failure in two female gorillas in the Los Angeles Zoo led to evaluation for secondary infertility. Male factor was excluded by noting routine conceptions in other individuals in the same group, and by behavioral observations of coital activity with the infertile females. Biochemical evidence of ovarian function was obtained by urinary sex steroid analysis. Continuity of the reproductive tract of the infertile apes was then studied by hysterosalpingography and laparoscopy while their general health was evaluated by ultrasonography and physical examination. Progressive, multiorgan involvement with Echinococcus vogeli was documented and mebendazole therapy begun. The investigation of secondary infertility in great apes by combined methods is safe and accurate, but requires special equipment and experienced personnel.
Environmental influences on the activity of captive apes
Authors: Wilson Susan F. 
Published: June 2005

AbstractForty‐one zoological gardens in seven European countries were visited to investigate activity level in captive environments for great apes. Forty‐three groups of gorillas and 68 groups of orangutans were observed. The seven factors quantified for each of the environments were size of the enclosure, usable surface area, frequency of feeding, number of animals, and number of objects (stationary, temporary, and movable). Activity level of each group was measured by instantaneous scan sampling for one hour on two consecutive days. For both species, the factors most highly related to activity level were number of animals, and stationary, temporary, and movable objects. The usefulness of these variables for predicting group activity level was different for the two species, however. Factors important for gorillas were stationary and temporary objects, while stationary and movable objects were significant for orangutans. These findings suggest that objects within environments may be more important for captive apes than the size or construction of the enclosure. Also, the types of objects that need to be included in environments may be related to the natural behavior of the individual species.
A note on the structure of tail hairs from a pygmy hippopotamus (Choeropsis liberiensis)
Authors: Kranz Karl R. 
Published: June 2005

AbstractThe pygmy hippopotamus (Choeropsis liberiensis), like the Nile hippopotamus (Hippopotamus amphibius), defecates by backing into vertical objects while making a series of rapid, propellerlike tail movements that spread a mixture of urine and feces in a wide swath. Split hairs from the distal ventral surface of the pygmy hippopotamus tail were studied with the scanning electron microscope to determine whether the splitting was a normal character of the hair or was due to damage. The results suggest that splitting is a normal feature of the hair that may facilitate the dispersal of urine and feces.
Strike‐induced chemosensory searching in old world vipers and new world pit vipers at San Diego Zoo
Authors: O'Connell Barbara , Greenlee Robin , Bacon James , Chiszar David 
Published: June 2005

AbstractRattlesnakes (Crotalus unicolor, C vegrandis) and Russell's vipers (Vipera russelli) at San Diego Zoo exhibited sustained high rates of tongue flicking after striking mice (Mus musculus) but not after seeing, smelling, and/or detecting thermal cues arising from mice. Called strike‐induced chemosensory searching (SICS), this phenomenon contributes to poststrike trailing of envenomated prey. Because these zoo‐raised snakes had always been offered dead rodents, and because these prey were usually ingested without first being struck, the present snakes had rarely exercised their innate predatory repertoire (ie, ambush tactics including striking, releasing, and trailing). Indeed, most specimens had never before struck a mouse and, hence, had never exhibited SICS. The occurrence of SICS in the present study clearly indicates that this important aspect of the predatory repertoire had not been degraded as a consequence of long‐term captive husbandry.
Application of noninvasive techniques to monitor reproductive function in a brown hyena(Hyena brunnea)
Authors: Ensley P. K. , Wing A. E. , Gosink B. B. , Lasley B. L. , Durrant B. 
Published: June 2005

AbstractEstrus in a 10‐yr‐old brown hyena was described by monitoring urinary steroid metabolites. These studies were repeated the succeeding year and combined with ultrasonography, vaginal cytology, and laparoscopy to further aid in identifying natural and induced estrus. Collection of semen from a 14‐yr‐old male brown hyena was accomplished by electroejaculation. Use of frozen semen once during natural estrus and again during estrus induced with follicle stimulating hormone (FSH) did not result in pregnancy. Further studies with this animal indicate that stimulation with gonadotropin releasing hormone (GNRH), rather than FSH, may be the more appropriate treatment for stimulating ovulation in canids or related species.While this study did not result in conception, a significant step toward that end was realized by utilizing urinary estrogen to monitor the estrus cycle.
Early functional maturity of captive male northern elephant seals (Mirounga angustirostris)
Authors: Spotte Stephen , Schneider Jack 
Published: June 2005

AbstractA male northern elephant seal (Mirounga angustirostris) that was conceived in captivity was stillborn February 14, 1981, at Mystic Marinelife Aquarium in Mystic, Connecticut. Either of two males in the exhibit could have sired the pup. Both were only 3 yr at the time of conception.
Urine‐marking during agonistic encounters in the bush dog (Speothos venaticus)
Authors: Biben Maxeen 
Published: June 2005

AbstractDuring staged encounters, bush dogs of the same sex showed a high level of aggressive‐defensive behaviors and a higher than normal frequency of urine‐marking. Where dominance was established during encounters, dominant individuals marked more than subordinates. Where dominance was not clearly established, both participants remained aggressive and showed higher than normal levels of marking. Urine‐marking appears to communicate aggressiveness and may be used to compensate for the otherwise relatively inconspicuous aggressive and dominance displays of this species.
Preliminary observations on reproduction in the Central American agouti, Dasyprocta punctata
Authors: Meritt Dennis A. 
Published: June 2005

AbstractTwo adult male and three adult female agoutis have been reproducing at the Lincoln Park Zoo since 1978. Agoutis of the species D. punctata and D. fuliginosa are capable of breeding and producing offspring in every month of the year in captivity. The minimum interbirth interval of captive punctata is 127 days, and its gestation period is apparently less than 127 calendar days. In captivity, agoutis are likely to produce multiple offspring.