bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transplacental passage of label after administration of [3H]retinoic acid (vitamin A acid) to pregnant mice
Authors: Kochhar D. M. 
Published: June 2005

AbstractTo determine whether there is transplacental passage of retinoic acid (vitamin A acid) or its metabolites levels of radioactivity were measured in embryos after administration to 12th‐day pregnant ICR/DUB mice of nonteratogenic or teratogenic quantities of [3H]retinoic acid. After the former treatment radioactivity was demonstrable in embryos, placentas, and visceral yolk sacs (VYS) at 1 h after treatment. Expressed in terms of radioactivity per unit protein content, embryos at 1 h had about one‐third as much radioactivity as maternal livers. The placentas had maximum radioactivity at 2 h, whereas embryos and VYS accumulated maximum levels by 6 h after treatment. At 6 h the level in embryos was twice that in placentas. After teratogenic treatment placentas and embryos attained peak levels of radioactivity at 6 and 12 h later, respectively. Again, embryos at peak level contained 2‐3 times as much radioactivity as placentas or VYS. The amount of retinoic acid, metabolites, or both, in embryos after the teratogenic treatment, calculated on the basis of specific activity of the injected label, was 26 times greater than after nonteratogenic treatment; the amount in maternal liver was 75 times greater. The results support previous evidence that the teratogenic effects of retinoic acid are associated with raised levels of retinoic acid, its metabolites, or both, in embryos.
Cholinomimetic teratogens. IV. Effects of the genotype for muscular dystrophy in chickens
Authors: Landauer Walter , Clark Ellen M. , Larner Melva M. 
Published: June 2005

AbstractEmbryos of a family of chickens homozygous for muscular dystrophy (md/md) reacted with a higher incidence of malformations to treatment with carbachol than did White Leghorn embryos. The same difference in response of embryos from the two stocks occurred after treatment with sulfanilamide. Embryos of reciprocal crosses between these two stocks differed greatly, however, in their response to carbachol, F1 embryos from dystrophic hens producing a much higher incidence of malformations than did those from Leghorn hens. In contrast, both F1 sibs reacted similarly to sulfanilamide, the teratogenic effects being intermediate between those of embryos from the parent stocks.
Graphic reconstructions of craniofacial structures during secondary palate development in rats
Authors: Diewert Virginia M. 
Published: June 2005

AbstractLateral and ventral graphic reconstructions of coronally sectioned rat fetuses at four stages of secondary palate development were made to illustrate the size, form, and spatial relations of craniofacial structures at each stage, and to indicate changes between stages. The results illustrated extensive changes in the nasomaxillary and tongue‐mandibular complexes and spatial relations in the oronasal cavity during this 2‐day period. During closure of the palate the palatine processes and molar dental laminae moved medially, the vertical dimension between the cranial base and Meckel's cartilage increased, and the Meckel's cartilage changed in shape from a “U” to a “V.” During the 2‐day period extensive increases in anteroposterior and vertical dimensions and limited changes in lateral dimensions resulted in a change in shape of the complete orofacial region. More extensive investigations, preferably quantitative, of the changes shown are indicated to identify the relative contribution of various craniofacial components and to establish the role of differential growth in secondary palate closure.
Embryonic development in ectoptic human pregnancy
Authors: Poland B. J. , Dill F. J. , Styblo C. 
Published: June 2005

AbstractEctopic pregnancy in the fallopian tube occurs in about 1 in 50 human pregnancies. Maternal factors in the etiology of this condition have been well documented. There is less information available on the development of the embryo or fetus. To document this information morphological and cytogenetic data were obtained from 76 embryos and fetuses obtained from pregnancies occurring in the fallopian tube. Analysis of the data showed that tubal implantation was associated with a high proportion of severely disorganized embryos. There was also a high incidence of maternal tubal disease. The importance of these factors and the etiology of ectopic pregnancy is discussed.
The “Straight‐jacket” syndrome in chicks. II. Mechanism of development
Authors: Jelínek Richard , Doskočil Milan , Loštický Cyril 
Published: June 2005

AbstractIn a longitudinal study including measurement of the pressure in the amniotic cavity, amniotomy, and planimetric evaluation of the size of the amniotic sac, we investigated the development of the “strait jacket” syndrome in White Leghorn chicken embryos injected intraamniotically (ia) or paraamniotically on the fourth day of incubation with histone or embryotoxic serum, with the following results. Hyperlordosis and eventration developed as an outcome of tonic contraction of the amnion, which was observed only three hours after ia administration. Contraction of the amnion caused elevation of the intraamniotic pressure, which, 12 hours after ia injection, attained a mean value of 22,4 Pa (2.3 mm H2O). This value was not only significantly higher than the mean for control embryos (3.9 Pa), but it was critically close to the mean fluid pressure in thehrain vesicles. Loss of the latter overpressure caused the vesicles to collapse, and the walls shriveled and exencephaly developed, Paraamniotic injection was not followed by either contraction of the amnion, or significant increase in intraamniotic pressure. This did not prevent, heart malformations and cranioschisis of various extent. The majority of cardiovascular malformations were probably the hemodynamic consequence of overfilling of the intraembryonic vascular bed, which was one of the early signs of the effect in question. Cranial‐vault defects can be causally associated with the formation of amnionic adhesion and fusion with the epidermal ectoderm. This observation stresses the significance of the embryonic membranes and the fluid pressures within them for the development of certain congenital deformities and concentrates attention on teratological study of substances that induce protracted contraction of smooth muscle.
Embryotoxicity of the folate antagonist methotrexate in rats and rabbits
Authors: Jordan Robert L. , Wilson James G. , Schumacher Herbert J. 
Published: June 2005

AbstractThe prenatal effects of methotrexate (MTX) in rats and rabbits were assessed. It was found highly embryotoxic in postimplantation rat embryos; 0.3 mg/kg ip or less caused nearly total embryolethality with slight teratogenicity. Rabbit embryos were far more resistant to small doses of MTX than rats, but 19.2 mg/kg iv, when given during days 10 to 15 of gestation, produced little death and a constant spectrum of malformation in a high percentage of offspring. Cleft palate, skull defects, and severe fore‐and hindlimb dysplasias, occurred with a high degree of regularity and were strongly dose and developmental‐stage specific.
Epithelial breakdown in the palatal processes of mouse fetuses with spontaneous cleft lip and palate
Authors: Tsai H. M. , Carl Verrusio A. 
Published: June 2005

AbstractContact and fusion of the palatal processes are prevented by mechanical obstruction in A/J mice with spontaneous cleft lip and palate. Histological examination of cleft‐lip fetuses revealed a very thin epithelial covering on the tip of the palatal process at day 15 1/2 of gestation, when the palate normnlly undergoes fusion, but at day 16 the palatal epithelium was completely disrupted, exposing the underlying mesenchyme. This epithelial discontinuity lasted only one day — by day 17 epithelial continuity was reestablished. These findings support the hypothesis that contact between the palatal shelves is not a prerequisite for epithelial degeneration.
Simultaneous prevention of blood abnormalities and hereditary congenital amputations in a brachydactylous rabbit stock
Authors: Petter Claude , Bourbon Jacques , Maltier Jean‐Paul , Jost Alfred 
Published: June 2005

AbstractHematological and histological studies of the rabbit brachydactyly mutant were made to clarify the question of the blood abnormality that had previously been implicated in the teratogenic process leading to congenital amputation. The hemoglobin of fetal and adult br/br rabbits, studied by electrophoresis and cyanmethemoglobin assay, exhibited no differences from that of controls. The br/br fetuses were polycythemic and severely macrocytic. Fetal limb vessels showed thrombosis leading to hemorrhages in the extremities. The hepatic tissue was abnormal, being particularly poor in hematopoietic cells; blood cell macrocytosis was attributed to impaired erthropoiesis. Treatment of pregnant rabbits with folic acid plus vitamin B12 or with folinic acid was able simultaneously to prevent the fetal blood cell macrocytosis and the congenital abnormalities.
Descriptive system for congenital limb anomalies
Authors: Frias Maria Luisa Martinez , Castilla Eduardo Enrique , Paz Joaquin Eugenio 
Published: June 2005

AbstractA descriptive system for the nomenclature, notation and classification of congenital limb malformations, suitable for clinical, epidemiological and experimental use is presented. Every developmental limb anomaly is described by stating the type of anomaly and the affected anatomic structure. All anomalies are classified into three basic types: excess, deficiency and fusion. The anatomic structure of the affected limb is defined within a two dimensional order.This system was used to describe 652 cases with isolated developmental limb anomalies obtained from two series of observations. The observed data are presented in a progressively expanded classification ranging from 4 to 497 diagnostic categories. Observed incidence rates for the four main types of anomaly from a sample of 297,299 consecutive livebirths, are: excess: 1.22; deficiency: 0.17; fusion: 0.20; combined: 0.24 per thousand.
Trypan blue accumulation in the embryonic gut of rats and mice during the teratogenic phase
Authors: Dencker Lennart 
Published: June 2005

AbstractFour to 48 hours after iv and sc administration of teratogenic doses of trypan blue to rats and mice the uterus was removed and rapidly frozen, after having been placed in a horizontal plane, and frozen sections were attached to tape and dried at a low temperature. By this procedure embryos and placental structures were present in the same sections and loss or redistribution of the dye was minimized. The dye was found in the yolk‐sac cavity and to be accumulated in the visceral (proximal) endoderm. It was also accumulated in the embryonic endoderm—forming the embryonic gut. This accumulation occurred after the administration of the trypan blue up to the time of closure of the vitelline duct, which occurs at 11 days postconception in rats and 9.5 days in mice. None was found when injection was made after this closure. No dye was detected in the ecto‐ and mesodermal layers. The period of embryonic uptake of trypan blue largely corresponds with the period of teratogenic sensitivity in these species as reported by others.
Spina bifida and so‐called asplenia syndrome occurring separately in sibs
Authors: van Went Johan J. , van Went Greta F. , Willem Delleman J. , Becker Anton G. 
Published: June 2005

AbstractAttention is drawn to the possibility that neural‐tube defects may sometimes be associated with the so‐called asplenia syndrome (Ivemark syndrome). This hypothesis is based upon a family in which one child had spina bifida and hydrocephaly and another had cardiovascular and other fissural anomalies, similar to Ivemark syndrome. The family history, moreover, revealed several cases of anencephaly and/or spina bifida, both on the paternal and maternal sides.
Cleft palate following prenatal food restriction in mice: Association with elevated maternal corticosteroids
Authors: Hemm Roger D. , Arslanoglou Leontios , Pollock John J. 
Published: June 2005

AbstractFollowing food restriction of pregnant CD‐1 mice, the maternal serum corticosteroid levels and incidence of skeletal and visceral abnormalities of the progeny were determined. Dams from the groups receiving restricted food on gestation days 6 to 15 had increased resorptions, and the progeny had delayed ossification of the skeleton with cleft palate accompanied by delayed ossification of the presphenoid bone. The incidence and intensity of these changes was correlated with the level of food restriction. The incidence of cleft palate for progeny from dams receiving 4.0 to 2.5 g of feed per day ranged from 6.3% to 100.0%, respectively. Serum corticosteroid levels of pregnant control and food restricted dams were similar on gestation day 10, but the levels of food restricted dams were 6 to 10 times greater than controls on gestation day 15. Thus cleft palate, delayed skeletal ossification, and increased resorptions are predictably produced by food restriction of CD‐1 mice and were highly correlated with the elevated endogenous serum corticosteroid levels.
Influence of cyclophosphamide and 4‐ketocyclophosphamide on mouse limb development
Authors: Manson Jeanne M. , Smith Carl C. 
Published: June 2005

AbstractMany studies have been performed on the in vivo teratogenicity of cyclophosphamide, and there is uncertainty whether the parent compound or P‐450 generated alkylating metabolite(s) is the proximal teratogen(s). We have examined the influence of cyclophosphamide and a metabolite, 4‐ketocyclophosphamide, on mouse limb development. Pregnant mice were injected with 10, 15 or 20 mg/kg of cyclophosphamide on days 9 to 11 of gestation. Hindlimb buds were maximally sensitive to 20 mg/kg of cyclophosphamide at 9 A. M. on day 11, and the predominant malformations formed were preaxial ectrodactyly and hemimelia. Hindlimb buds of the same gestational age exposed to cyclophosphamide in vitro responded identically to controls in morphology and uptake of 3H‐thymidine and 35SO4. Exposure to 4‐ketocyclophosphamide in culture, however, resulted in the formation of limbs with a “hemimelic” appearance and distal limb reduction, and with reduced uptake of 3H‐thymidine and 35SO4. These findings support the position that the P‐450 generated metabolite (s), and not the parent compound, is the proximal teratogen(s).
Evaluation of the teratogenic potential of tertiary butylhydroquinone (TBHQ) in the rat
Authors: Krasavage Walter J. 
Published: June 2005

AbstractTertiary butylhydroquinone (TBHQ), an approved antioxidant used alone or in combination with other antioxidants produced no teratogenic effects after administration via the diet to pregnant rats at concentrations of 0.125, 0.25 and 0.50% during the sensitive period of gestation. The mean body weight and feed consumption of the dams were unaffected. The average number of corpora lutea, implantation sites, viable fetuses, resorptions and fetal body weights and mortality did not differ between the control and treated groups. A significant number of rudimentary ribs were seen in all groups. However, the incidence of this variation was two times greater in the control group than in any treatment group. It is concluded that TBHQ is not teratogenic in rats at 62.5, 125 and 250 times the approved use level for humans.
Incidence rates for cleft lip and palate in British Columbia 1952‐71 for North American Indian, Japanese, Chinese and total populations: Secular trends over twenty years
Authors: Lowry R. B. , Trimble B. K. 
Published: June 2005

AbstractThe incidence of cleft lip and/or cleft palate was examined for the 1952‐71 period for the Province of British Columbia. Although there were some fluctuations, some of which were significant, there was no general trend which indicated that the rates were either increasing or decreasing. These rates are important for a background calculation when investigating new environmental teratogens. The total rate of 1.97 per 1,000 live births is comparable with other Caucasian populations where there is good ascertainment and adequate follow‐up period. This study also confirmed the previously reported high rate for North American Indians in British Columbia (3.74 per 1,000 live births) and established rates for the Japanese (3.36 per 1,000 live births) and Chinese (1.76 per 1,000 live births) of British Columbia. Since these three sub‐populations are relatively small in relation to the total population, they do not influence the overall total rate to any great extent.
The effect on fetal development and utero‐placental blood flow of ligating a uterine artery in the rat near term
Authors: Bruce Neville W. 
Published: June 2005

AbstractThe uterine artery of one horn of 13 rats was ligated on day 18 of gestation; the remaining horn was used as a control. The effect, four days later, on blood flow to the reproductive tract, was measured with radioactive microspheres and compared to the effect on fetal and placental weights. Fetal survival in the ligated horns, 41%, was significantly lower (P < 0.05) than that in the control horns, 98%. Fetal and placental weights of the survivors in the ligated horns, 3.159 ± 0.133 g (SE) and 450 ± 18 mg respectively, were similarly lower than those in the control horns, 3.814 ± 0.111 g and 529 ± 27 mg respectively. Maternal placental blood flow closely reflected the weight of tissue being supplied and was similar in the ligated and control horns, 129 ± 21 and 130 ± 18 ml.min−1. 100g−1, respectively. Myometrial blood flow was again similar in the ligated and control horns, 34 ± 5 and 37 ± 4 ml.min−1. 100 g−1, respectively, and in the ovarian, middle and cervical sections of each horn. These results are compatible with the view that ligation causes only a temporary reduction in uterine blood flow which permanently checks placental and fetal, or placental thus fetal, growth. Blood flow then returns to normal levels compatible with the reduced weights of tissues being supplied.
Non‐confirmation of thalidomide induced teratogenesis in rats and mice
Authors: Scott W. J. , Fradkin R. , Wilson J. G. 
Published: June 2005

AbstractIt has been reported that thalidomide, dissolved in a 1:3 mixture of Tween 20 and physiological saline and administered intraperitoneally to pregnant mice and rats induces a variety of malformations, including limb deformities, characteristic of the primate syndrome. The studies reported herein attempted to confirm these findings without success although the rodent strains used were not the same. A low level of non‐specific malformations was observed in the fetuses of both species at dose levels reported to cause a 47% and 92% rate of malformation in mice and rats respectively. One possible source of difference was Tween 20 which was toxic to the point of lethality in these studies at dose levels reported to be non‐toxic in the earlier studies.
Chronotropism and blood flow patterns following teratogenic doses of catecholamines in 5‐day‐old chick embryos
Authors: Cheung Matthias O. , Gilbert Enid F. , Bruyere Harold J. , Ishikawa Shizen , Hodach Richard J. 
Published: June 2005

AbstractIn vivo heart rates of 5‐day‐old chick embryos were recorded from electrodes placed in close proximity to the heart. L‐epinephrine (4 × 10−10 mole), 1‐norepinephrine (1 × 10−9 mole) and 1‐isoproterenol (1.6 × 10−10 mole) in 5 μl of isotonic saline transiently accelerated the mean heart rate by almost 9%. L‐phenylephrine (2 × 10−9 mole/5μl) and the experimental procedure produced no appreciable effect. The positive chronotropic effect of the catecholamines was found to be highly significant (P < 0.0005) as computed by Student's t test. However, no direct relationship could be established between the chronotropic response and the aortic arch anomalies produced. A prolonged reduction of blood flow in the primitive heart tube and the sixth aortic arch after administration of epinephrine and isoproterenol is apparently related to the induction of hypoplastic right pulmonary artery with absent or hypoplastic right ductus arteriosus.
Teratogenic effects of ribavirin on hamster and rat embryos
Authors: Ferm Vergil H. , Willhite Calvin , Kilham Lawrence 
Published: June 2005

AbstractRibavirin, a synthetic nucleoside with marked antiviral activity, induced developmental malformations when administered to pregnant hamsters by oral, intraperitoneal or intravenous routes. Abnormalities of the limbs, eyes and brain were the most common defects found in the hamster. Higher doses (about 10 ×) were required to induce anomalies in rat embryos and the malformations were generally restricted to the head region. In both rats and hamsters oral administration of the drug seemed to be more teratogenic than administration by other routes suggesting that metabolism of ribavirin in the maternal gastro‐intestinal tract and/or liver may change it into its active form.
Cranio‐dirachischisis totalis in cephalothoracopagus twins
Authors: Ferm Vergil H. 
Published: June 2005

AbstractA set of conjoined 13‐day‐old male hamster twins is described. The twins were joined at the head and thorax. The brain was exencephalic and the neural plate was completely open throughout its length. The notochord was duplicated throughout its entire length. Partial twinning of the neural plate as indicated by histologic reconstruction is suggested with fusion or non‐separation of the neural plates in the medial alar wing area. There was complete separation of the neural plates together with duplication of the lower extremities and tails in the caudal region of this specimen.
Cholinomimetic teratogens. VI. The interaction of cholinomimetic teratogens with the antimalarial drugs chloroquine and chlorguanide
Authors: Landauer Walter 
Published: June 2005

AbstractA typical syndrome of short and crooked neck together with muscular hypoplasia of the legs occurs with low incidence in chicken embryos following injection into the egg at 24 hours of incubation of the antimalarial drug chloroquine; but treatment at later stages does not have similar effects. When, however, chloroquine was used in addition to carbachol or neostigmine at 96 hours of incubation the malformations caused by the two cholinomimetic compounds, i.e., carbachol and neostigmine, occurred with greatly increased frequency and tended also to be exaggerated in expression. Chlorguanide, another antimalarial drug, when used as additive, reduced the teratogenic effects of such compounds as decamethonium and neostigmine. It appears that the neuromuscular pathways to teratogenicity are for carbachol and neostigmine and for chloroquine clearly related, if at different levels of expressivity.