bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spontaneous congenital developmental abnormalities observed at necropsy in a large survey of newly born dead lambs
Authors: Hughes Keith L. , Haughey Kevin G. , Hartley William J. 
Published: June 2005

AbstractIn a systematic necropsy study of 4408 newly born dead lambs derived from 79 flocks over two lambing seasons malformation considered sufficient to impair viability was observed in 80 carcasses. Agnathia was observed in 25 carcasses and comprised the major component of congenital lethal malformations. Lambs of both sexes were affected. Its occurrence was often associated with anotia, ear displacement, or ear malformation. Factors thought to be associated with this abnormality are reviewed and attention drawn to the lack of knowledge concerning the embryonic development of the first branchial arch and related structures in sheep. Developmental defects of the muscular and skeletal systems, central nervous system, cardiovascular system (particularly ventricular septal defects), and imperforate intestinal tract were the next most common malformations.
Teratogenic action of heterologous kidney antisera in mice
Authors: McCallion D. J. 
Published: June 2005

AbstractPregnant mice were injected ip with 0.25‐0.5 ml of either an antimouse‐, antirat‐, or antichicken kidney antiserum or a nonimmunized rabbit serum on various days of gestation, but principally days 7‐9. Both antirat‐ and antimouse‐kidney antisera crossreacted with mouse kidney but antichicken kidney antiserum did not. Both antimouse‐ and antirat‐kidney antisera were embryolethal and teratogenic in mice. Both antisera were localized by immuno fluorescence with goat antirabbit gamma globulins in the glomerular basement membrane of maternal kidneys and in Reichert's membrane and yolk‐sac endoderm of embryos. Antichicken‐kidney antiserum was not embryolethal or teratogenic in mice and the antiserum was not fixed in the maternal kidneys or embryonic membranes. The teratogenic agent(s) in rat and mouse nephrotoxic antisera, therefore, seems to be antibodies to class specific kidney antigens.
Effects of a teratogen (9‐methyl pteroylglutamic acid) on oxygen consumption by dispersed embryonic rat cells
Authors: Netzloff M. , Johnson E. M. , Kaplan S. 
Published: June 2005

AbstractPregnant rats were fed 100 mg/kg diet of the folic‐acid antagonist 9‐methyl pteroylglutamic acid on days 10, 11, and 12 of pregnancy. This regimen resulted in a markedly elevated Q02 in dispersed cells from 13‐ and 13.5 day embryos as compared with controls. Cells from embryos taken 1 day after the pregnant females had been returned to a complete ration gave Q02 values similar to those from control embryos. Addition of the antagonist to Warburg flasks containing dispersed cells from day‐13 embryos resulted in an elevated Q02 but not when the antagonist was added to cells from day‐14 embryos.
Cleft palate in rodents after maternal treatment with various lathyrogenic agents
Authors: Steffek A. J. , Verrusio A. C. , Watkins C. A. 
Published: June 2005

AbstractIngestion of diets containing 50% ground sweet pea seeds (Lathyrus odoratus) by pregnant Sprague‐Dawley rats on days 10‐20 of gestation resulted in high frequencies of fetal resorption and surviving young with various degrees of edema, forelimb flexure, angulation of the vertebral column, micrognathia, cleft palate, and other defects. Pregnant A/J mice maintained on such a diet on days 9‐18 of gestation produced offspring with cleft palate and other malformations. The lathyrus factor, β‐aminopropionitrile (BAPN), given in multiple oral doses to pregnant rats at various times during pregnancy also produced high frequencies of resorption and of young with edema, cleft palate, and malformations of vertebrae and limbs. However, when single doses of 500 mg BAPN were administered on day 15 the resorption rate was markedly reduced whereas the frequency of cleft palate was greatly increased. Three other lathyrogenic agents produced high frequencies of cleft palate in rats: 50 mg aminoacetonitrile on day 15, 400 mg D‐penicillamine on days 10‐15, and 50 mg semicarbazide on days 10‐16. The period of greatest cleft palate susceptibility with all the agents tested was day 15.
Chromosome studies in selected spontaneous abortions. IV. Unusual cytogenetic disorders
Authors: Carr D. H. , Law E. M. , Ekins J. G. 
Published: June 2005

AbstractAmong 372 spontaneous abortions four had chromosome anomalies that were unique in the series. Each one presented features of interest. There was one example of monosomy‐G and this was associated with apparently normal embryonic development to about the 28‐day stage. In two specimens extra chromosome material was found. In one instance it was added to the long arm of a B‐group chromosome in 44% of cells. In the other the extra material was an abnormal element of unknown origin. The fourth specimen was a 35‐mm fetus with cyclopia and D‐trisomy associated with a D/D translocation. The woman producing this abortus was a carrier of the same translocation. The literature relevant to these four unusual cases was reviewed.
Observation of palatine shelves in living rabbit embryos
Authors: Walker Bruce E. , Ross Lawrence M. 
Published: June 2005

AbstractRabbit embryos were removed from the uterus just prior to the time of palate closure, submerged in saline, and observed for evidence of shelf movement. When the tongue was displaced from between the palatine shelves the latter were not seen to move. After fixation and sectioning, the angle of the shelves to the sagittal plane was measured. This angle progressively approached that of embryos fixed in utero prior to shelf transposition when the tongue, or both tongue and lower jaw, were removed during manipulation in vivo. When the tongue was released it either returned to a position between the shelves or remained ventral to the shelves and forced them into a horizontal position. Thus there was no evidence of a pronounced intrinsic shelf force in rabbit embryos under the conditions of this experiment.
Morphogenesis of malformations in hamsters caused by retinoic acid: Relation to dose and stage at treatment
Authors: Shenefelt Ray E. 
Published: June 2005

AbstractFemale golden hamsters were each given a single administration of retinoic acid sodium saltat one of 20 stages in pregnancy. Retinoic acid is the carboxylic acid derived by oxidation of the hydroxyl group of retinol (vitamin A1 alcohol). It is rapidly excreted and appears to act for a short time. Near‐term fetuses were found to have more than 70 types of malformation. The incidence of each external malformation produced by several oral dosage levels at each of 15 postimplantation treatment times was determined. The incidence of each internal malformation at the fetal LD50 dose was determined. Forty types of malformation whose incidence was 10% or more at the fetal LD50 dose at some time in pregnancy were studied. Embryonic development of various structures was correlated with the critical period for production of each malformation, based on a table of normal development constructed by examining untreated embryos at 48 ages. In many cases the period during which administration of retinoic acid produced a given malformation began well before there was any morphologically identifiable precursor of the structure destined to be affected.
Effects of propranolol on the chick embryo heart
Authors: Jaffee Oscar C. 
Published: June 2005

AbstractPropranolol had a negative chronotropic effect on the preneural chick embryo heart. The specificity of this effect was demonstrated by the finding that propranolol blocked the accelerating effects of isopropylnorepinephrine (Isopr) on the preneural heart. The establishment of threshold doses of both propranolol and Isopr for two preneural stages (50‐55 and 80‐85 hr) of chick embryo development provided evidence that the embryo heart became increasingly sensitive to these agents. A further increase in sensitivity was found when preneural threshold dosages of propranolol and Isopr were administered to 5‐day, presumably innervated, embryos. The finding that beta adrenergic blockers such as propranolol as well as catecholamines influence the preneural heart rate emphasizes the importance of chemical mediators in heart‐rate control during this period; further studies may aid in explaining the large increases in the preneural heart rate usually attributed to the “resetting” of the pacemaker.
Lathyrogen‐induced malformations in baboons: A preliminary report
Authors: Steffek A. J. , Hendrickx A. G. 
Published: June 2005

AbstractFemale baboons maintained on a timed pregnancy program were administered intramuscular, Intravenous, and oral doses of β‐aminopropionitrile (BAPN) and aminoacetonitrile (AAN) during the time of palatogenesis in this species. Resorptions, abortions, and fetuses with skeletal defects resulted. Cleft palate occurred in one set of twins following oral doses of 75 mg/kg/day AAN on days 43‐48 of pregnancy.
Effects of transitory maternal pteroylglutamic acid (PGA) deficiency on respiratory control ratios, phosphorylative capacity, and cytochrome oxidase activities of mitochondria from rat embryos
Authors: Chepenik Kenneth P. , Waite B. Moseley 
Published: June 2005

AbstractCytochrome oxidase activities and protein contents of homogenates and mitochondrial fractions of embryos from untreated and 9‐methyl PGA treated pregnant rats were determined on various days of gestation. Rates of respiration, ADP:O, and respiratory control ratios were determined with the mitochondrial fractions. The cytochrome oxidase specific activities of homogenates or mitochondrial fractions of treated embryos were similar to those of controls of the same age. However, total mitochondrial protein and cytochrome oxidase activities of the treated embryos were similar to those of controls even though the treated embryos were smaller than controls. The amount of oxygen consumed by the treated embryos was not significantly different from that consumed by controls and the ADP:O and respiratory control ratios calculated for mitochondrial fractions of treated and control embryos were not significantly different.
Skeletogenesis in insulin‐treated chick embryos. I. Anatomical and histological observations, with particular reference to the tibiotarsus
Authors: Rabinovitch A. L. , Gibson M. A. 
Published: June 2005

AbstractChick embryos were exposed to insulin early in development, and the gross and microscopic effects on endochondral ossification of the tibiotarsus were studied throughout the incubation period. The major anatomical effects were a generalized reduction in embryonic size, micromelia, and angulation of the tibiotarsus. There was a significant reduction in the growth rate of the tibiotarsus with some evidence of recovery toward the end of the incubation period. Histologically, the most striking feature of the tibiotarsus was degenerative necrosis of the epiphyseal cartilage. This involved all cartilage zones and was usually more pronounced in the proximal epiphyseal plate. The proliferative zone was compressed and poorly demarcated, and the usual arrangement of parallel rows of hypertrophic chondrocytes never resulted. Periosteal ossification, cartilage resorption, and marrow‐cavity formation were initially delayed but later progressed more rapidly than in the control tibiotarsi. Joint formation was impaired by the extension of necrotic areas and fibrous material across the joint space.
Generalized growth retardation in rats induced by prenatal exposure to methylazoxymethyl acetate
Authors: Fischer Milton H. , Welker Carol , Waisman Harry A. 
Published: June 2005

AbstractSingle injections to rats of methylazoxymethyl acetate on days 13 to 18 of gestation retarded the general postnatal development of the offspring and resulted in micrencephaly. The effects were most severe when the compound was administered on day 14 or 15 of gestation. At 35 days of age, body, brain, kidney, liver, spleen, and testis weights were significantly reduced, whereas at 14 days of age only the brain weights were significantly less than controls. The brain was the only organ that showed macroscopic malformations, characterized by greatly reduced cerebral hemispheres and defects in the cortical mantle. In addition, nuclear groups and fiber tracts throughout the telencephalon, diencephalon, midbrain, and cerebellum were reduced in size.
The etiology of human malformations: Insights from epidemiology
Authors: Leck Ian 
Published: June 2005

AbstractThe epidemiological evidence that led to the incrimination of thalidomide as a teratogen was obtained by a combination of descriptive, correlative, analytic, and experimental studies. Most surveys of the common malformations have however been purely descriptive. Their main value has been to clarify the relative importance of the parts that genotype and environment in general play in causation. For example, it now seems that liability to neural tube defects is influenced much more by environment and less by genotype than is the case for cleft lip; that whether genetic or environmental, the influences that produce most cases of these and other common defects are multiple; and that if even one of these influences could be identified and controlled, incidence might fall substantially. The future for epidemiological research in this field seems to lie mainly in developing hypotheses about these influences from the knowledge already gained in descriptive studies, and in testing these hypotheses by correlative, analytic, and experimental methods.
Viral antibodies in mothers of defective children
Authors: Lapinleimu Kaisa , Koskimies Olli , Cantell Kari , Saxén Lauri 
Published: June 2005

AbstractIn the years 1964‐66, 338 newborns with a total of 379 gross malformations of the central nervous system and matched‐pair controls were reported to the Finnish Register of Congenital Malformations. Blood samples and detailed maternal histories were obtained from 162 mothers of defective children and their respective controls during the first 2, postpartum months. In the analysis of maternal antibodies the experimental group did not differ in most cases from the controls. However, antibodies against ECHO 7 occurred with significantly (P < 0.005) higher frequency in the experimental group, and when high titers against ECHO 7 were compared this difference was even greater (P < 0.001). On the other hand, antibodies against Coxsackie B1 and high titers against B5 occurred more frequently (P < 0.05) in the control group.
Ethionine as a depressant of synthesis of and source of label for DNA in chick embryos
Authors: Ruddick Joseph A. , Runner Meredith N. 
Published: June 2005

AbstractFour milligrams of ethionine containing 14C‐ethyl ethionine was injected into the chick yolk sac on day 4. The resulting embryos were reduced in size but without gross malformation. Studies of growth and of disposition of label showed that ethionine reduced the DNA increment and increased the specific activity of DNA during the first 24 h. During days 5‐12 the DNA content continued to fall behind that of controls while its specific activity of label from ethionine progressively increased. Elution of TCA supernates from Sephadex columns indicated that ethionine was available to the embryos during this time. Since the specific activity of the label in the protein and RNA fractions remained at relatively constant levels, label reached these fractions throughout the experimental period. The increasing specific activity of DNA indicated labeling at a rate exceeding the rate of net accumulation, and thus there was selective labeling of DNA from ethionine.
A new in vitro culture technique for rat embryos
Authors: Robkin Maurice A. , Shepard Thomas H. , Tanimura Takashi 
Published: June 2005

AbstractA new technique for culturing embryos, which permits detailed observation and manipulation, is described. The method has been applied to rat embryos on day 10, 11, or 12 of gestation. Twenty‐four‐hour culture of day‐11 rat embryos resulted in nearly normal increases in somite number, and embryo length and protein increment of about half that occurring in vivo. After 24 h of culture the embryos generally were translucent and showed no apparent areas of gross tissue necrosis. Sections from representative embryos are presented. The apparatus is extremely compact and requires only about 9 ml of medium which is sufficient to support three embryos. The small volume allows the measurement of metabolites consumed or liberated with reasonable accuracy. The method permits a detailed and continuous record to be made of the heart rate and the addition of drugs to and sampling of the culture medium. The apparatus, named the PLASMOM, was used to measure the effect of changes in the ambient temperature on the heart rate of day‐11 rat embryos. The results showed a linear dependence of heart rate on temperature between 30 and 40° C.
Yearly and seasonal incidence of mongolism in Quebec
Authors: McDonald Alison D. 
Published: June 2005

Abstract2398 births of children with mongolism between 1958 and 1967 in the Province of Quebec were registered—a rate of 1.86/1000 live births. This is somewhat higher than the rates of 1.6 recorded in Britain and 1.5 in Australia. Between 1948 and 1957 the total number of mongoloid births recorded was 1063 (0.9/1000 live births). Underascertainment, especially of mongols who died, was evidently the reason for this low rate. In neither 10‐year period were annual fluctuations in rate found comparable to those observed in Victoria, Australia. There was no evidence of seasonal variation in incidence nor of any increase following epidemics of infectious hepatitis in 1961–63. The findings support those of other surveys in the United States, Britain, and Italy and suggest that the Australian findings were either a chance occurrence or the result of a local phenomenon.
Iniencephaly and anencephaly with spinal retroflexion. A comparative study of eight human specimens
Authors: Lemire Ronald J. , Beckwith J. Bruce , Shepard Thomas H. 
Published: June 2005

AbstractTwo major groups of malformed human fetuses exhibit retro‐flexion of the cervical spine, one called “iniencephaly” and the other “anencephalfy with spinal retroflexion.” In the former there is a cranial cavity as well as uninterrupted skin covering the retroflexed region and the head. The latter has partial or complete absence of the neurocranium, and the affected region of nervous tissue is not covered with skin. This difference clearly suggests different times of onset of these two classes of malformation, although the frequent occurrence of caudal myeloschisis in iniercephaly suggests that the difference is very small. Despite this important difference these conditions have numerous morphological features in common which justify discussing them together. The present paper reviews these morphological details, based upon six specimens with anencephaly with spinal retroflexion and two with iniencephaly.
The effect of hydrocortisone on the closure of the palatal shelves in two inbred strains of mice in vivo and in vitro
Authors: Lahti Aito , Antila Erkki , Saxen Lauri 
Published: June 2005

AbstractThe effect of hydrocortisone on the development of the palatal processes of a resistant (CBA) and a susceptible (A) mouse strain was tested in vitro. In both strains hydrocortisone caused retardation of the fusion process, but never prevented it (as in vivo in the susceptible strain). It is concluded that the results lend further support to Fraser's hypothesis.
Skeletogenesis in insulin‐treated chick embryos. II. Histochemical observations, with particular reference to the tibiotarsus
Authors: Rabinovitch Albert L. , Gibson M. A. 
Published: June 2005

AbstractChick embryos were exposed to a teratogenic dose of insulin at 5‐½ days of incubation, and the effects on the histochemistry of the developing tibiotarsus were studied until hatching. Tests for mucopolysaccharides, glycogen, calcium, and alkaline phosphatase were used. The matrices of intact cartilage revealed no changes in mucopolysaccharide staining. The major staining differences occurred in areas of cartilage necrosis and suggested loss of sulfate from the ground substance. Chondrocytes exhibited no consistent changes in glycogen content. However, in the premature secondary ossification centers that developed in proximal and distal epiphyses the chondrocytes showed an accumulation of glycogen just before full hypertrophy. Calcification, although initially delayed, was extensive and dystrophic calcification occurred in the necrotic areas. Alkaline phosphatase as usual was associated with ossification and in experimental tissues was associated with necrotic areas and the secondary ossification sites.
LSD: No chromosomal breakage in mother and embryos during rat pregnancy
Authors: Emerit I. , Roux C. , Feingold J. 
Published: June 2005

AbstractLSD (500 μg/kg/day ip) given to pregnant rats from the 7th–13th days of pregnancy produced no in vivo chromosome damage, either in maternal bone marrow or in the embryos. These negative cytogenetic results parallel the lack of teratogenicity observed under these conditions.
Does LSD induce chromosomal damage and malformations? A review of the literature
Authors: Long Sally Y. 
Published: June 2005

AbstractAlthough there are reports of five children with limbs defects among 161 children from parents who took LSD (lysergic acid diethylamide) this review of the literature indicates that LSD does not cause chromosome breakage and that there is no strong evidence of teratogenicity in animals.
Embryotoxicity of methyl mercuric chloride in golden hamsters
Authors: Harris Stephen B. , Wilson James G. , Printz Richard H. 
Published: June 2005

AbstractInjection of 8 mg/kg methyl mercuric chloride ip in hamsters on day 5, 8, or 9 of pregnancy caused some maternal deaths, a high incidence of fetal resorption, decreased fetal weight, and moderate to high rates of malformation among surviving newborns. The most common malformations were clubfoot and hydrocephalus. When 4 mg/kg of methyl mercury was injected on day 8 maternal animals and their offspring did not differ from controls. A dose of 2 mg/kg daily from days 1 through 14 of pregnancy caused increases in maternal deaths, fetal resorptions, and malformations, but fetal weight was not affected.
Postnatal effects of maternal hypercortisonism on skeletal development in newborn rats
Authors: Ornoy Asher , Horowitz Ada 
Published: June 2005

AbstractPregnant rats were treated daily by im injections of 10 mg cortisone acetate, on days 8–20 of gestation. Experimental term offspring were smaller than controls. Their long bones were smaller, but contained a higher per cent of ash, calcium, and phosphorus. Sections of the long bones revealed a thinner layer of maturing and calcifying cartilage in the epiphyses, and persistence of bone trabeculae and islets of cartilage, with reduced volume of bone marrow, in the diaphyses. During the first 2 postnatal weeks the experimental offspring gradually reached the control weight. Concomitantly there was a complete disappearance of the bone injuries, and a decrease of the ash and mineral concentration to control levels. It thus appears that cortisone acetate, after passing through the placenta, does not cause true congenital skeletal anomalies, but produces only a transient direct effect on the fetal skeleton.