bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced interlitter variability in rats resulting from a restricted mating period, and reassessment of the “Litter effect”
Authors: Holson J. F. , Scott W. J. , Gaylor D. W. , Wilson J. G. 
Published: June 2005

AbstractRats were mated for two or 15 hours and variability of day‐12 embryos in weight, protein content, and [3H]thymidine incorporation was compared in the long mating period (LMP) and short mating period (SMP) groups by a 2‐level nested analysis of variance. Variability in day‐20 fetal weight was similarly compared. In both groups day‐12 embryonic weight was relatively more variable than day‐20 fetal weight, and variability was less in SMP than LMP animals for each comparison made, although statistical significance was attained only for thymidine incorporation. “Litter effects” were noted but not of the magnitude reported by other investigators. It was concluded that inappropriate statistical methods have encouraged the belief that among‐litter variability usually exceeds within‐litter fetal weight variability. The teratological implications of reduced developmental variability and the “litter effect” are discussed.
Studies of teratogenic effects of the dithiocarbamates maneb, mancozeb, and propineb
Authors: Larsson K. Sune , Arnander Claes , Cekanova Eva , Kjellberg Marianne 
Published: June 2005

AbstractOral administration of high dosages of the dithiocarbamate pesticides maneb and mancozeb was teratogenic in rats but not in mice. The malformations, severe limb and craniofacial defects, were pronounced after maneb treatment but less so after mancozeb and propineb, zinc‐containing compounds. The teratogenic effect of maneb was progressively reduced by simultaneously adminstering increasing amounts of zinc acetate. The mechanism of the teratogenic effect may involve the compounds being chelating agents, trapping zinc required for many important enzyme systems.
Craniosynostosis. I. Sagittal synostosis; Its genetics and associated clinical findings in 214 patients who lacked involvement of the coronal suture(s)
Authors: Hunter Alasdair G. W. , Rudd Noreen L. 
Published: June 2005

AbstractThe clinical and genetic findings in 214 patients with sagittal synostosis are described. Seventy‐three per cent of the patients were male. Children with sagittal synostosis were treated earlier than those with coronal synostosis. Major malformations occurred in 22%, and 8.9% were mentally retarded. The retardation was clearly unrelated to the synostosis in almost half the patients. The remaining retarded patients had a significantly lower mean birth weight, higher frequency of malformations, and later age at operation than the control group. We believe the late age at operation was due to bias in the ascertainment of this group of retarded children, and that sagittal synostosis was simply one of a number of malformations that can occur in children with intrinsic retardation. Familial data and the skull measurements of a sample of parents of affected children were compatible with multifactorial inheritance; however there is need for prospective family studies and parental measurements on ethnically uniform groups.
Inhibition of pinocytosis in rat yolk sac by trypan blue
Authors: Williams Kenneth E. , Roberts Graham , Kidston M. Elizabeth , Beck Felix , Lloyd John B. 
Published: June 2005

AbstractDay 17.5 yolk sacs from rats injected with partially denatured 125I‐labeled bovine serum albumin (I‐BSA) were cultured in vitro by a raft technique. The rates of release of [125I] iodotyrosine were similar in control yolk sacs and in yolk sacs from rats preinjected with trypan blue. Day 17.5 rat yolk sacs were also cultured in medium containing I‐BSA. Following pinocytic uptake the substrate was degraded intracellularly and [125I]iodotyrosine released into the medium. Trypan blue, when present in the medium in concentrations above 100 üg/ml, inhibited pinocytosis of I‐BSA and so decreased the rate of [125I]iodotyrosine production. Trypan blue similarly decreased the rate of pinocytic uptake of 125I‐labeled polyvitiylpyrrolidone. Pinocytic uptake of macromolecules was not decreased in yolk sacs from rats pretreated with trypan blue. The relevance of these results to the mechanism of teratogenic action of trypan blue is discussed. It is proposed that if trypan blue in teratogenic doses similarly inhibits pinocytosis by the yolk sac during the organogenetic period teratogenests might result from a transient interruption in the flow of metabolites through the yolk sac to the embryo.
Digital anomalies of mouse limbs induced by treatment with urethan in vitro
Authors: Yasuda Yoshiko 
Published: June 2005

AbstractThe effects of urethan on ICR/JCL mouse limbs were examined in forelimbs of day‐11 embryos cultured in concentrations of 0, 50, and 100 μg/ml for one to four days, and in forelimbs of day‐12 embryos and in fore‐ and hind limbs of day‐13 embryos in 0, 10, 50, and 100 μg/ml for one to four days. Urethan did not cause digital malformations in day‐11 limbs but induced syndactyly in day‐12 forelimbs and polydactyly in day‐12 forelimbs and day‐13 fore‐ and hind limbs. The polydactyly may have been due to effects on mesenchymal cells producing localized cell proliferation, whereas syndactyly may have been due to effects on precartilage cells, resulting in excess migration of mesenchymal cells toward the digits, leaving the connective tissue at the interdigital space to develop inadequately.
An analysis of the age and size of 483 human embryos
Authors: Skidmore F. D. 
Published: June 2005

AbstractThe crown‐rump length of 483 fixed human embryos of Carnegie stages 6–23 was analyzed and median and predicted mean lengths were calculated. The results were compared with those of other series and confirmed that early human growth rates are different from those of macaques with which human embryo growth has previously been compared. The study indicated that it is possible to predict: 1. the median size of an embryo of given Streeter horizon or Carnegie stage; 2. the age of a fresh embryo, or one of undisputed Streeter staging, by comparison with mean figures of other authorities; and 3. the corrected age of an embryo of known length or known Streeter staging or both in terms of postovulation age. Since teratogens may reduce the embryonic growth rate this information is relevant in the analysis of teratogenic factors in human development.
Craniomyeloschisis: A spontaneous mutation of the rat
Authors: Layton W. M. , Smith J. M. 
Published: June 2005

AbstractCraniomyeloschisis (proposed gene symbol cms) was a spontaneous mutation of the rat inherited as an autosomal recessive trait with complete penetrance. Homozygous offspring died at birth with failure of closure of the neural tube caudal to the midbrain. Neural crest derivatives were relatively normal. There were associated severe malformations of the axial skeleton including skull, vertebral column, and ribs. The pattern of malformations was quite uniform. Heterozygotes were anatomically normal. The mutation is extinct.
Biochemical basis of skeletal defects induced by hydralazine: Inhibition of collagen synthesis and secretion in embryonic chicken cartilage in vitro
Authors: Rapaka Rao S. , Parr Robert W. , Liu Tsan‐Zon , Bhatnagar Rajendra S. 
Published: June 2005

AbstractHydralazine (1‐hydrazinophthalazine) produces skeletal defects resembling those observed in experimentally induced manganese deficiencies. Since glycosylation of collagen, a step preceding its secretion, requires Mn2+, the effect of hydralazine on collagen secretion and the formation of hydroxylysine glycosides was examined in explants of embryonic chicken long‐bone rudiments. Auto‐radiographic studies showed that hydralazine blocked collagen secretion. Secretion was restored by Fe2+ alone or Fe2+ + Mn2+ but not by Mn2+ alone, suggesting that a Fe2+ ‐requiring step was involved. Biochemical analyses showed that hydralazine inhibited the formation of hydroxylysine, a step requiring Fe2+, but it did not inhibit the formation of hydroxylysine‐glycosides by Mn2+ ‐requiring steps, although the reaction was inhibited in vitro. Hydralazine also failed to inhibit intracellular mucopolysaccharide synthesis which involves several Mn2+ ‐requiring enzymes. These observations suggest that the deleterious effects of hydralazine on bones are caused by its inhibition of hydroxylation steps in collagen synthesis.
Potentiation by the injection vehicle of the teratological action of acetazolamide in rats
Authors: Muther Thomas F. , Jones Jeff C. , Smoak Nancy S. 
Published: June 2005

AbstractThe high alkalinity of the injection vehicle of certain parenteral solutions of acetazolamide produces necrosis of the skin upon sc injection. The possible modification of this effect on the teratogenicity of acetazolamide was examined. Acetazolamide in a vehicle of pH 10.5 produced 36.6% fetal malforma tions, in a vehicle of pH 8.7, 6.1%, and in neutral suspension, 11.8%. Adrenal medullectomy or phentolamine plus the high pH acetazolamide reduced the fre quency to 23.2 and 24.4%, respectively. The teratogenicity of the low pH acet azolamide was increased by epinephrine to 64.2%. The frequency of hemimelia and micromelia, and of bilateral involvement, was greater in litters exposed to the high pH acetazolamide or the epinephrine‐acetazolamide combination, and was reduced by phentolamine or adrenal medullectomy. Neither the high pH vehicle nor epinephrine produced fetal defects in the absence of acetazolamide. The biological disposition of acetazolamide was not altered by any of the treat ments. Reduction of uterine blood flow may be responsible for the potentiation of teratogenicity by the high pH vehicle.
Asbestos and embryonic development
Authors: Schneider U. , Maurer R. R. 
Published: June 2005

AbstractChrysotile asbestos was administered to pregnant CD‐I mice in their drinking water and to Day 4 blastocysts during culture. Administration to pregnant mice did not affect embryo survival. In vitro administration of asbestos did not interfere with embryo implantation upon transfer of blastocysts to recipient females but did result in a decrease in postimplantation survival. These studies did not demonstrate asbestos to be teratogenic whether administered to the dam or to the blastocyst in vitro.
The effect of practolol and butoxamine on aortic arch malformation in beta adrenoreceptor stimulated chick embryos
Authors: Gilbert Enid F. , Bruyere Harold J. , Ishikawa Shizen , Cheung Matthias O. , Hodach Richard J. 
Published: June 2005

AbstractAn equimolar dose of the beta‐1 ndrenorocoptor antagonist practolol administered to embryonic chicks prevents the induction of aortic arch malformations by isoproterenol. Whereas 3.75 × 109 mole isoproterenol in 5 μ1 saline solution induced aortic arch anomalies in 39% of embryos injected at Hamburger‐Hamilton developmental stage 26, pretreatment with practolol one to two minutes before catecholamine administration reduced the anomaly rate to 4%. Practolol when injected alone did not influence survival rate nor did it cause cardiovascular malformations. Probably the most significant result of this study involves the prevention by practolol of aortic hypoplasia and interrupted aortic arch complexes, anomalies frequently induced by isoproterenol when administered at this stage of embryonic chick development. Butoxamine, a beta‐2 adrenoreceptor antagonist, did not block the overall effect of isoproterenol nearly as effectively as did practolol. Results from the present study suggest that aortic arch anomalies may be induced in embryonic chicks via beta‐1 adrenoreceptor stimulation. Beta‐2 receptor stimulation does not appear to be as significantly involved.
Effect of intraamniotic administration of vitamin A on rat fetuses
Authors: Nanda Ravindra , Romeo David 
Published: June 2005

AbstractThe present study examines the effect of intraamniotic (i/a) administration of vitamin A to rat fetuses. Vitamin A aquasol in concentrations of 50 I.U., 100 I.U., and 300 I.U., was mixed in 5 μl of saline. On day 13 of gestation, each of the three experimental subgroups were injected i/a with varying doses of vitamin A. The four control subgroups consisted of: (1) i/a injection of 5 μl of saline only, (2) amniotic puncture only, (3) laparotomy or (4) i/a injection of sorethytan oleate. The fetuses were recovered on day 18 of gestation, and were weighed and examined for gross malformations. The viable fetuses from the experimental groups showed various malformations such as cleft palate, micrognathia and limb defects. The percentage of resorbed fetuses was significantly high. The control fetuses showed a moderate number of resorptions; however the percentage of malformations was small. The results show that the i/a method can be used effectively to study the direct teratogenic effect of vitamin A on the fetuses.
The effects of methylxanthines on catecholamine‐stimulated and normal chick embryos
Authors: Gilbert Enid F. , Bruyere Harold J. , Ishikawa Shizen , Cheung Matthias O. , Hodach Richard J. 
Published: June 2005

AbstractDoses of theophylline and caffeine which do not produce aortic arch anomalies in embryonic chicks have been shown to potentiate catecholamine‐induced aortic arch malformations in that experimental animal. Theophylline (2.1 × 10−5 mole per milliliter isotonic saline solution) potentiated the effective dose of norepinephrine more than 100 times. The greatest potentiation observed with epinephrine (2.5 ×) was induced by 2.6 × 10−5 mole caffeine. This study also demonstrated that both methylxanthines specifically induce aneurysms of the ascending aorta and complete absence (or nearly complete constriction) of the right ductus arteriosus. The incidences of these types of cardiovascular malformations proved to be dose dependent with theophylline a more potent teratogen than caffeine. The mobilization of calcium and/or cyclic nucleotide phosphodiesterase inhibition by the methylxanthines are suggested as significant actions in the potentiation of catecholamine‐induced aortic arch anomalies.
Toxicity studies with dieldrin: Teratological studies in mice dosed orally with HEOD
Authors: Dix K. M. , Van Der Pauw C. L. , McCarthy W. V. 
Published: June 2005

AbstractDoses of 1.5 and 4.0 mg/kg/day of HEOD in corn oil and 0.25, 0.5 and 1.0 mg/kg/day of HEOD in dimethyl sulphoxide (DMSO) were administered to pregnant CF1 mice on days 6 to 14 (inclusive) of gestation. Some maternal and foetal toxicity was seen in the HEOD in DMSO and DMSO control groups compared with the untreated controls, such as reduced body weight gains, some maternal deaths, lower foetal body weights and increased incidence of delayed ossification of the foetal bones. No maternal or foetal toxicity was seen in the HEOD in corn oil or the corn oil control groups. No compound‐related teratogenic effects were observed.
Cytosine arabinoside‐induced transplacental dysgenetic hydrocephalus in mice
Authors: Kasubuchi Yasuo , Wakaizumi Satoru , Shimada Morimi , Kusunoki Tomoichi 
Published: June 2005

AbstractPregnant mice were injected with 30 mg of cytosine arabinoside/kg body weight on 13‐1/3 and 14 days of gestation. Within six hours after the first injection, pyknotic nuclei and nuclear debris were found at the matrix layer surrounding the lateral ventricles of the embryonic brain. Autoradiographic studies using tritiated thymidine revealed that most of the matrix cells exposed to cytosine arabinoside during DNA synthesis were killed by this dose of the drug. Twenty‐four hours after the second injection, most of the matrix cells had disappeared. When experimental animals were examined after birth, they showed marked dilatation of the lateral ventricles. The dilatation of the lateral ventricles was more pronounced in the parieto‐occipital region. The young showed rapid enlargement of the cranial vault and subsequently died by 35 days of age.
Holoprosencephaly in human embryos: Epidemiologic studies of 150 cases
Authors: Matsunaga Ei , Shiota Kohei 
Published: June 2005

AbstractOne hundred fifty embryos with holoprosencephaly were found among the total of 36,380 conceptuses obtained through induced abortion in the period from 1962 to 1974, giving an overall incidence of 0.4%. The occurrence was largely at random through time, and no “epidemic” was noted in particular years or months, but there appeared more cases derived from conceptions in winter than in summer months. The mean maternal age did not differ significantly from that of the general embryonic population, indicating that, although none of our cases were karyotyped, chromosome aberrations such as trisomies 13 and 18 that are closely associated with maternal age may not constitute a major part as causes of holoprosencephaly in human embryos. Maternal age did not differ by the presence or absence of associated external anomalies. No association was found with paternal age, parental consanguinity nor with maternal medical history, including irregularity of menstrual cycles, and smoking and drinking habits. There was an indication that the mothers were prone to have repeated miscarriages, supporting the view that some kind of maternal predisposition is responsible for the causation of holoprosencephaly. Argument was made that, apart from various chromosome aberrations well documented as causes of this malformation, polygenic mechanism probably accounts for the majority of the cases with normal karyotype.
Congenital cerebral and ocular malformations induced in rhesus monkeys by Venezuelan Equine Encephalitis virus
Authors: London W. T. , Levitt Neil H. , Kent Stephen G. , Wong Vernon G. , Sever John L. 
Published: June 2005

AbstractRhesus monkey fetuses were inoculated with Venezuelan Equine Encephalitis (VEE) vaccine virus by the direct intracerebral route at approximately 100 days gestation to determine possible teratogenicity of the virus. Congenital micrencephaly, hydrocephalus and cataracts were found in all animals and porencephaly in 67% of the cases. The virus replicated in the brain and other organs of the fetus. VEE vaccine virus is teratogenic for non‐human primates and must be considered a potential teratogen of man.
Effect of 6‐aminonicotinamide in teratogenic doses on the DNA‐ and RNA‐concentration in rabbit embryos
Authors: Scheil H.‐G. , Claussen U. , Grote W. 
Published: June 2005

AbstractPregnant rabbits were injected ip with 5 mg/kg 6‐ANA at day 10, 11, 12 or 12.5 respectively of gestation. Embryos removed at day 13 of gestation had reduced DNA and RNA concentrations. The differences (DNA: 14%; RNA: 22.4%) were significant in the group treated on the twelfth day. Some possible mechanisms are discussed.
A lethal neonatal dwarfing condition with short ribs, polysyndactyly, cranial synostosis, cleft palate cardiovascular and urogenital anomalies and severe ossification defect
Authors: Piepkorn Michael , Karp Lawrence E. , Hickok Durlin , Wiegenstein Louise , Hall Judith G. 
Published: June 2005

AbstractA case of severe lethal neonatal dwarfism is reported. It appears to be a new variety of short rib‐polydactyly dwarfism. It is characterized by severe lack of ossification of all bones except the clavicle and the presence of cleft palate, as well as genitourinary, central nervous system and cardiovascular anomalies. Electronmicroscopy revealed accumulations of granular material in the chondrocytes.
Congenital kyphoscoliosis and spinal cord lesion produced in the rat by β‐aminopropionitrile
Authors: Nogami H. , Terashima Y. , Tamaki K. , Oohira A. 
Published: June 2005

AbstractPregnant rats received the lathyrogen β‐aminopropionitrile (1,500 mg/kg) intraperitoneally on day 16 (plug day = 0 day). Kyphoscoliosis was produced in a high incidence in the fetuses at the level of the upper thoracic spine as early as 24 hours after treatment. Although most of the affected newborns died within two weeks, survivors were studied until 20 weeks after birth. Survivors developed paraplegia in consequence of kyphoscoliosis. Both spinal deformity and motor disturbance were progressive. Biochemical and electron microscopic observations suggested that β‐aminopropionitrile treatment resulted in an inhibition of collagen formation in the spinal column and surrounding longitudinal ligaments of the fetuses six hours after the treatment. In addition, electron micrographs of vertebral bodies showed a decrease of proteoglycan granules in the extracellular matrix. Therefore, rupture and collapse of weakened ligaments and vertebral bodies might result in severe spinal deformity and spinal cord lesion.
The association of sex ratio anomalies with pyloric stenosis
Authors: Bear J. C. 
Published: June 2005

AbstractPublished family data were examined for evidence of aberrant sex ratios in relatives of pyloric stenosis index cases. An excess of males over females was found among unaffected members of sibships in which there occurred more than one case of pyloric stenosis. The male excess among affected members of these sibships did not differ from that among index cases without affected sibs. An unusual frequency of spontaneous abortions in these sibships, which might account for the observed excess of males, was not observed. No evidence was found of sex ratio anomalies in other classes of relative of pyloric stenosis index cases, whether or not the index cases had affected sibs.
Effects in mice of simultaneous prenatal exposure to ochratoxin A and T‐2 toxin,
Authors: Hood Ronald D. , Kuczuk Maureen H. , Szczech George M. 
Published: June 2005

AbstractAspergillus ochraceus and Fusarium tricinctum are food contaminating molds whose toxic metabolites, ochratoxin A and T‐2 toxin, are known mammalian teratogens. In order to determine the possible effects of simultaneous exposure to such environmental agents, ochratoxin A (2 or 4 mg/kg) and T‐2 toxin (0.5 mg/kg) were injected ip, either together or individually, in CD‐1 mice on gestation days 8 or 10. Ochratoxin induced craniofacial malformations when given alone on day 8, but not on day 10. T‐2 toxin induced tail and limb anomalies particularly when given on day 10. When the two toxins were given together on day 10, ochratoxin exacerbated the incidence of T‐2 induced gross malformations. An increase in fetocidal effects was also noted in groups treated at the high dose combination on either day, and effects on fetal growth of the high dose combination given on day 10 were greater than those of the other treatments. Few skeletal or visceral malformations were noted. These results indicated that two teratogens with presumably differing mechanisms of teratogenesis may have additive effects when administered concurrently to the same animal. Such results could be due to generalized toxic effects on the fetus or to more specific mechanisms, but further information is needed to differentiate between the two possibilities.
Teratogenicity testing in humans: A method demonstrating safety of Bendectin
Authors: Smithells Richard W. , Sheppard Sheila 
Published: June 2005

AbstractWe investigated the incidence of birth defects in the offspring of women who took Bendectin during pregnancy. Copies of all prescriptions issued for Bendectin in two Cities, Leeds and Liverpool, over periods of 12 and 14 months, respectively, were scanned and a record initiated for each patient. Birth notifications were later searched for matching with indexed patients. Births were traced for 2,298 patients and the incidence of major defects compared with those in the relevant populations. We found no evidence to suggest that Bendectin is teratogenic in humans.