bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palate development after fetal tongue removal in cortisone‐treated mice
Authors: Walker Bruce E. , Patterson Anita 
Published: June 2005

AbstractMorphological studies of cortisone‐induced cleft palate have shown retardation in the rotation of palatine shelves from a sagittal to a transverse plane. Cortisone also reduces fetal muscular movements, which may explain why displacement of the tongue from between the palatine shelves is delayed. Previous work with extrauterine development of control fetuses demonstrated that fetal membranes and tongue were major obstacles to shelf rotation. Thus, removal of these obstacles might permit rotation and fusion of palatine shelves in cortisone‐treated fetuses. In the present experiment, fetuses from cortisone‐treated strain CD‐1 mice were released from uterus and membranes and allowed to develop for eight hours in a fluid medium with the umbilical cord left intact. Compared to 4% fusion in utero, there was palatal fusion in 20% of fetuses released from membranes. When the fetal tongue was removed during extrauterine development, the frequency of fusions increased to 61%. Fusion appeared normal by the criteria applicable through light microscopy. Thus, cortisone induces cleft palate primarily through interference with shelf rotation. The palatine shelves of treated fetuses retain their ability to fuse when they can come in contact during the normal time for palate closure.
The craniofacial skeleton in anencephalic human fetuses. II. Calvarium
Authors: Garol James D. , Fields Henry W. , Metzner Louis , Kokich Vincent G. 
Published: June 2005

AbstractA detailed study of the calvarium of twelve anencephalic and four normal human fetuses 26 to 40 weeks gestational age using gross dissection, alizarin red S staining, silver nitrate radiography and histology revealed dramatic alterations in the presence, form, location and relationship of the individual bones. In the larger dorsal cranial defects the interparietal portions of the occipital bone were relocated anteriorly to approximate the frontal bone. The occipital components were rotated anterolaterally and inferiorly with lack of fusion of the chondrocranium posterior to the foramen magnum. The squamae of the frontal bone were collapsed horizontally and reduced in size to lie peripheral to the anterior cranial fossa forming most of the orbital roofs. In anencephaly the bones derived from the chondrocranium were not as severely affected morphologically as those derived from the neurocranium. The sutures were narrow and smooth instead of wide and serrated as in the normally developing calvarium. In general the degree of maldevelopment was proportional to the extent of the dorsal cranial defect in anencephaly.
The craniofacial skeleton in anencephalic human fetuses. III. Facial skeleton
Authors: Metzner Louis , Garol James D. , Fields Henry W. , Kokich Vincent G. 
Published: June 2005

AbstractA sample of 12 anencephalic fetuses with gestational ages ranging from 26 to 40 weeks and exhibiting varying degrees of severity of the dorsal cranial defect was compared to three normal fetuses of comparable gestational ages with regard to the morphology and positional relationships of the maxillofacial skeletal complex. Gross dissection, alizarin red S staining, radiographs, cephalometric tracings, and histologic techniques were utilized. It was found that some facial bones were severely affected in morphology, size, spatial and angular relationships. The manner in which these were altered suggests that their morphogenesis is an adaptation to the primary defect of the neurocranium.
Congenital central nervous system malformations and vinyl chloride monomer exposure: A community study
Authors: Edmonds Larry D. , Anderson Carol E. , Flynt J. William , James Levy M. 
Published: June 2005

AbstractIncidence rates for central nervous system (CNS) malformations in infants born to residents of Kanawha County, West Virginia, 1970‐1974, were significantly higher than comparable United States rates during those years. Since Kanawha County contains a polyvinyl chloride (PVC) polymerization plant, a case‐control study was conducted on the possible relationship between the occurrence of CNS defects and parental occupational or residential exposure to vinyl chloride monomer emissions from this plant. No relationship with parental occupation was found. While a tendency was noted for residences of case families to be located in an area northeast of the plant, this observation did not entirely correlate with existing data on local patterns of wind direction and air pollution.
Teratogenicity of ethylenethiourea and thyroid function in the rat
Authors: Lu M.‐H. , Staples R. E. 
Published: June 2005

AbstractEthylenethiourea (ETU) was given by gavage at a dose of 40 mg/kg/day from Days 7 through 15 of gestation to hypothyroid and euthyroid rats, and to rats given exogenous thyroxine, to determine whether ETU teratogenicity occurs through alteration of maternal thyroid function. At sacrifice on Day 20 of gestation 84‐100% of the fetuses in all groups given ETU were malformed regardless of the thyroid status of the dams. Ten percent of the fetuses of dams thyroparathyroidectomized at 75 days of age that were not given ETU were malformed; no malformations were noted among the fetuses of the other groups not given ETU. Hence, ETU was found to induce teratogenicity in rats but not through alteration of maternal thyroid status. In addition, it was determined that ETU lowered serum thyroxine concentration, that hypothyroidism itself increased the background level of malformations in the rat, and that hypothyroidism qualitatively and quantitatively increased the incidence of specific malformations after ETU administration.
Ultrastructural observations on FUdR‐induced cell death and subsequent elimination of cell debris
Authors: Langman Jan , Cardell Emma Lou 
Published: June 2005

AbstractTwelve‐day mouse embryos were treated with fluorodeoxyuri‐dine (FUdR) and sacrificed at various time intervals after treatment. The neu‐roepithelial cells were then examined to determine by electron microscopy the primary site of action of the drug. About two hours after treatment mitotic activity ceased and a number of cells were found with a normal interphase nucleus, but with a cytoplasm in which the ribosomes had lost their normal poly‐somal configuration and were dispersed as single ribosomes. At about the same time cells were seen with an accumulation of chromatin at the nuclear membrane and the segregation of chromatin masses within the somewhat denser karyoplasm. Concurrent with the nuclear changes was the appearance of a condensed cytosome containing monoribosomes. The condensation of the nucleus and cytoplasm was followed by fragmentation of the cell into membrane bound bodies. Since condensed cells always contained monodispersed ribosomes, it seems likely that the dispersal of the ribosomes is the first morphological sign of the action of FUdR.Since about half of the neuroepithelial population underwent cell degeneration, the second goal of this experiment was to study the fate of the dying cells. Some fragments from condensed cells were found within apparently normal neuroepithelial cells, indicating phagocytosis. In addition macrophages were seen containing phagosomes from fragmented cells. Most of the fragments, however, remained free and were not immediately phagocytosed. These un‐phagocytosed fragments lysed and became ghosts, thereby giving the neu‐roepithelium a vacuolated appearance. Hence, cellular debris was eliminated partially by neuroepithelial cells, partially by macrophages and to a great extent by lysis.
Multifactorial contributions to the etiology of spontaneous hemorrhagic necrosis of the central nervous system of fetal hamsters
Authors: Keeler Richard F. , Young Stuart 
Published: June 2005

AbstractExperiments were performed to learn whether males or females of various hamster strains or crosses played a role in the etiology of spontaneous hemorrhagic necrosis (SHN) disease. Disease incidence in fetal hamsters was highly variable in 1,185 observed litters of one hamster strain over a 1‐year period. There was no evidence of Gaussian distribution of incidence among the 177 affected litters to suggest that SHN is a directly transmissible, highly contagious disease. The 177 litters were sired by 39 of 51 males used to breed the 1,185 females; each male sired a total of from 8 to 48 litters. In sequential litter progeny of males that did sire SHN litters, affected litters did not occur at any one period or with any consistent pattern within the males' breeding use. However, direct contact among bred females influenced incidence. Various hamster strains and crosses were examined for susceptibility to SHN disease. In counterpart breedings offspring from the Simonsen, the Lakeview PD4, the Lakeview MHA, and the Lakeview LVG strains all developed SHN, but the Engle strain did not. Among crosses, those involving a Simonsen dam but not those involving an Engle dam were affected with the disease, regardless of the strain of male used. The fact that only certain strains or crosses were free of the disease suggests that genetic factors played an important role in susceptibility.
The induction of axial blisters in the chick embryo by trypan blue
Authors: Nadeau J. H. , Mun A. M. 
Published: June 2005

AbstractThe hemorrhage, blister formation, and rumplessness observed in the chick embryo following treatment with trypan blue may be due to (1) increased ventricular blood pressure or (2) to necrosis and edema in the caudal region of the embroyo by inhibititing nutrient utilization. To test the role of increased ventricular blood pressure in the induction of caudal blisters, primitive streak to 7‐somite chick embryos were cut in half, separating the upper presumptive heart region from the lower presumptive trunk and tail regions. Each half was then explanted on media containing trypan blue for 24 hours. In intact embryos treated with 0.04 mM trypan blue the frequency of blisters in theposterior region was 80.8%. The blisters usually appeared on both sides of theneural tube, below or in the region of the last few somites. In transected embryos treated with trypan blue, the frequency of blisters in the anterior halves which had beating hearts was 2.6%. Howeverm the frequency of blisters in the posterior halves which were not connected to beating hearts was 47.8%. In some cases the blisters were found in posterior haves in which the rump was not well developed or present at all. Thus, we may conclude that: (1) direct connection beteen the heart and the rump is not necessary for the induction of caudal blisters. (2) The presence of a well‐differentiated rump is also not necessary for blister formation. We suggest that trypan blue acts directly on organs or structures found in the caudal region of the chick embryos.
Myeloschisis in a six weeks embryo of a leukemic woman treated by busulfan
Authors: Abramovici A. , Shaklai M. , Pinkhas J. 
Published: June 2005

AbstractA case of myeloschisis in a six weeks old human embryo is reported. The 39‐year‐old mother was treated by busulfan before and during the early stages of gestation for chronic lymphatic leukemia. Additional histological findings consisted in a decrease of mesenchymal elements together with a somitic disorganisation in the affected area of the embryo. In spite of the well known experience that this drug is well tolerated by leukemic pregnant women, a possible interference of busulfan with the oocyte differentiation in this elderly primipara is proposed.
Use of dose‐response relationships to discriminate between the mechanisms of cleft‐palate induction by different teratogens: An argument for discussion
Authors: Biddle F. G. 
Published: June 2005

AbstractThe examples of 6‐AN‐ and cortisone‐induced cleft palate in the mouse suggest that dose‐response studies can be used to discriminate whether mechanisms of action are different for different teratogens. Evidence for differences in the mechanisms of teratogenic action can be found in terms of the parameters of the response without reliance on other consequences of teratogen treatment. It is argued that the application of established biometrical models or, possibly, the development of new ones is critical to consolidate enumerative data. With practical methods, genetic variation can be sought, interpreted and put to experimental use, structure‐function studies can be made intelligible, and safety evaluation programs might begin to make sense.
Cell ploidy in molar placental disease
Authors: Poland B. J. , Baillie D. L. 
Published: June 2005

AbstractMolar disease of the placenta is associated with cystic change in the villi. The cysts may be from 5–20+ mm in diameter. This disease has been described in association with triploid and diploid cell lines and with and without an accompanying embryo or fetus. It may be followed by malignant change and invasive chorio‐carcinoma. In order to investigate the association between cell ploidy, embryonic development and subsequent malignancy, a detailed study of 30 conceptuses with molar disease was made, with the accompanying maternal history and follow‐up. The cell ploidy was determined by measurement of nuclei by a cytoscan light microscope connected to a computer program as has been previously described. Diploid cell lines were not found with embryonic or fetal development. Triploid cell lines were always associated with an embryo or fetus. Triploidy is not associated with hyperplastic changes in the trophoblast. These results are presented and discussed.
Cyclopia associated with triploidy and hydatidiform mole: A case report
Authors: Deligdisch Liane , Legum Cyril , Peyser M. R. , Toaff R. 
Published: June 2005

AbstractA live 22‐week‐old cyclops fetus with a 69 XYY chromosome pattern and partial hydatidiform mole of the placenta is reported. Although cyclopia and chromosomal triploidy have certain features in common they appear to be two quite distinct entities. As no other 69 XYY fetus has survived to 22 weeks gestation and no other case of cyclopia has been reported with a triploid set of chromosomes, the assumption that the two conditions occurred coincidently in this fetus will have to await the accumulation of additional case reports.
Triploidy in human abortions
Authors: Ornoy A. , Kohn G. , Zur Z. Ben , Weinstein D. , Cohen M. M. 
Published: June 2005

AbstractSeven triploid embryos and fetuses, six spontaneously aborted and one resulting from pregnancy interruption are described. A wide range of malformations, from amorphous, nodular embryos, to apparently normal phenotypes were observed. The degree of hydatid degeneration in the placentae ranged from minimal to severe. In several cases large, atypical cells were present in the villous stroma. There was no apparent correlation between the degree of placental lesion and fetal malformations. It is suggested that termination of triploid pregnancies is determined more by the degree of placental damage rather than the severity and type of fetal anomalies.
The differentiation of the columella in avian embryos treated with hadacidin with some observations on other skeletal abnormalities
Authors: Jaskoll T. F. , Maderson P. F. A. , Weiner B. E. 
Published: June 2005

AbstractSingle doses of N‐formyl hydroxyaminoacetic acid (hadacidin) were injected into chick embryos HH stages 5–30. Embryos surviving for 8 + days total incubation time were recovered and examined for gross and microscopically observable defects. Particular attention was paid to the development of the columella. Survival was only 20%, but a high incidence of cranio‐facial and hind limb defects was observed in most age groups. While three categories of columella defect were observed, reflecting some degree of age dependency, this chondrogenic tissue is less susceptible to teratogenic action than other skeletal tissues. The types of columella defect observed are interpreted in the light of a model of cellular interactions in fenestra vestibularis differentiation presented previously. It is concluded that hadacidin produces abnormalities of skeletal differentiation by disrupting morphogenetic, rather than the initiative phases of development of particular elements.
Effect of maternally administered sodium nitrite on hepatic erythropoiesis in fetal CD‐1 mice
Authors: Globus Morton , Samuel Daisy 
Published: June 2005

AbstractA commonly used food preservative, sodium nitrite, was administered to pregnant CD‐1 mice at a concentration of 0.5 mg/mouse/day. Embryotoxic and teratogenic effects on the hemopoietic tissues and skeletons of their offspring, were evaluated. Fetal mortality, resorptions, the mean number of offspring per litter, the mean weight per embryo and the incidence of skeletal malformations, were not significantly different from controls.Hemopoietic cell suspensions, prepared from the livers of treated and control 14‐, 16‐ and 18‐day embryos, were cytocentrifuged onto microscope slides and differential counts were performed after staining with benzidine and Wright‐Giemsa stain. The results indicate that maternally administered Na nitrite, stimulates fetal hepatic erythropoiesis. This was manifested in a statistically significant increase in the percentage of polychromatophilic erythroblasts and mature erythrocytes at 14 and 16 days of gestation, respectively. The possibility that Na nitrite may induce fetal methemoglobinemia is discussed and mechanisms responsbile for the observed erythroid stimulation, are considered.
Teratogenic effects of hyperthermia in the bonnet monkey (Macaca radiata)
Authors: Hendrickx Andrew G. , Stone Gary W. , Henrickson Roy V. , Matayoshi Kunio 
Published: June 2005

AbstractSeventeen timed‐mated bonnet monkeys (Macaca radiata) were exposed to hyperthermia in a forced‐draft incubator for a duration of one, three, four or eight days between 21 and 46 days of gestation. On each day of exposure the core temperature of the pregnant animal was elevated 2.4 to 5.4°C above the reference temperature recorded before heat exposure. Malformations occurred following a one‐hour daily elevation of the core temperature above the reference temperature under the following exposure conditions: 3.8°C, days 23 to 26; 3.9°C, days 24 to 27; 2.4°C, days 27, 28 and 30; and 4.1°C, day 26 of gestation. Five resorptions occurred following exposure for one, three or four days between days 24 and 29 of gestation after core temperature elevation of 3.7 to 4.4°C and three abortions occurred following exposure for four days between days 24 and 35 of gestation after core temperature elevation of 2.6 to 3.9°C. The results clearly indicate that the teratogenic sensitive period is from 23 to 30 days gestation following elevations of the core temperature from 2.4 to 4.1°C. No distinct pattern of malformations was observed although skeletal and umbilical cord malformations were the most common. Pathological changes in placental structure, expecially maternal surface infarctions and intervillous thrombi, were associated with three of the four abnormal fetuses, suggesting a relationship between pathological placental characteristics and fetal malformations in this study. The degree of core temperature elevation which resulted in malformations in the present study are similar to those applied to other mammalian species, and the specific anomalies observed in the bonnet monkey resemble those observed in other mammalian species, including man.
Light microscopic and ultrastructural observations in advanced stages of induced exencephaly and spinal bifida
Authors: Peters P. W. J. , Dormans J. A. M. A. , Geelen J. A. G. 
Published: June 2005

AbstractThis investigation was performed to demonstrate the morphologic basis of the elevation of fetal proteins in the amniotic fluid of fetuses with neural tube defects. Pregnant rats were treated with hypervitaminosis A to induce exencephaly or with trypan blue to produce spina bifida aperta. The malformations were studied on days 15ndash;20.On day 15 of gestation, edema developed in the primitive nervous tissue. This was followed by the appearance of quickly expanding hemorrhages throughout the ventricular and intermediate zones. Some capillaries did not rupture but collapsed and showed degenerative changes of the endothelium, probably due to lack of blood perfusion. The ventricular layer in exencephaly and spina bifida aperta was exposed to the amniotic cavity due to non closure of the neural tube. On day 17, this superficial lining of the primitive nervous tissue was disrupted by the expanding hemorrhages and subsequent necrosis. As a result vast amounts of fetal blood and cell debris were extruded into the amniotic fluid. During days 18 to 20, the degeneration of the nervous tissue proceeded rapidly. This process showed the same features in the ventricular cells, the primitive neurons and the neurons. Initially it was characterized by condensation of the nuclear chromatin and the cytoplasm, irregular outlines and breakdown of the plasma membrane. Only part of the cell debris was phagocytozed by macrophages.It is concluded that the leakage of fetal serum and cell debris causes the elevation of fetal protein levels in the amniotic fluid of fetuses with open neural tube defects.
Plastic casts of embryonic respiratory and cardiovascular system: A technique
Authors: Clark Edward B. , Rooney Patrick R. , Martini D. Richard , Rosenquist Glenn C. 
Published: June 2005

AbstractThis report describes a technique for producing plastic casts of the cardiovascular and respiratory systems of the chick embryo at Stage 36 or older. For casts of the cardiovascular system, polymerization compound is injected in the right ventricle filling the heart, venous, and arterial system. A two stage injection produced more detailed casts of the pulmonary vasculature. For respiratory system casts, the compound is injected in the trachea filling the bronchi and air sacs. Casts are prepared by tissue corrosion in 10% potassium hydroxide. This technique is an alternative to serial section reconstruction in the study of developing cardiovascular and respiratory system.
Effect of the brachypod mutation on early stages of chondrogenesis in mouse embryonic hind limbs: An ultrastructural analysis
Authors: Duke Jackie , Elmer William A. 
Published: June 2005

AbstractThis paper is an ultrastructural investigation of the early chondrogenic events which occur in the tibia and fibula blastemata of normal and brachypod embryos during 12‐; and 13‐days of development. Transverse sections taken within the central core of the 12‐day normal fibular blastema revealed a characteristic morphology consisting of elongated cells with long cytoplasmic filopodia separated by matrix which contained granules and fibers. In 12‐day brachypod embryos the cells within the fibular blastema portrayed an atypical morphology. The cells were more closely associated, exhibited small spiky microvilli rather than long cytoplasmic filopodia, had more extensive intercellular contacts and were deficient in matrix. The brachypod tibial blastema in embryos of the same age displayed a quasi normal appearance. More matrix was present, filopodia were apparent but shorter than normal and numerous sections of filopodial processes were observed in the intercellular spaces.Fibular regions of 13‐day normal limbs exhibited spacing and morphology similar to 12‐day limbs, but had more matrix material. Cells in the fibular region of 13‐day brachypod limbs presented a normal morphology and arrangement, but matrix granules were still scarce and aggregation of collagen was abnormal. An explanation of how these differences may contribute to the expression of the brachypod phenotype is offered.