bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incorporation and utilization of radioglucose in the fish embryo Oryzias latipes during teratogenesis
Authors: Smithberg Morris , Dixit Padmakar K. 
Published: June 2005

AbstractMalformations have been produced in fish embryos of Oryzias latipes following exposure to the sulfonylurea sodium tolbutamide during day 1 of development (Smithberg '62).Our present objectives were to determine (1) whether glucose 1‐14C would be differentially incorporated by embryos after drug treatment; and (2) whether the incorporated radioglucose would be converted to glycogen and lipid following drug treatment Total glycogen and total lipid were also measured in a normal and teratogenic environment.We confirmed the results of others that total glycogen decreased during the first three days of normal development and then slowly regained its initial level. During treatment with tolbutamide significantly more glycogen was utilized during the first three days. Total lipid tended to be lower in embryos after 48 hours of treatment compared to corresponding control embryos.Incorporation of radioglucose was inhibited by the drug, and the degree of inhibition varied with its concentration, although the conversion of glucose (or its products) into glycogen and lipid was not different in control and experimental embryos. It is suggested that tolbutamide may affect the permeability of the fish embryo membrane.
Teratogenic effects of aminopterin in sheep
Authors: James Lynn F. , Keeler Richard F. 
Published: June 2005

AbstractSheep were given subcutaneous injections of aminopterin at different times and for different intervals during gestation. Congenital malformations occurred after treatment at all periods. The principal malformations observed were rotational and flexing deformities of the appendicular skeleton, kyphosis, scoliosis, torticollis, aplasia of the mandible, overflexion of the carpal joint, hypermobility and dorsiflexion of the hock and stifle joints, and relaxation of the fetlock joints. Aplastic ears were also noted.
Abnormal development of eyes in mice homozygous for the fidget gene
Authors: Konyukhov B. V. , Vakhrusheva M. P. 
Published: June 2005

AbstractThe eyes of 17‐, 24‐, 28‐, and 31‐somite and 10‐ to 16‐day prenatal, newborn, and 6‐month‐old fidget (fi/fi) mice were studied. The present study showed that the eye abnormalities in fi/fi mice are due to growth retardation of the optic vesicle. In fi/fi embryos the volume of the optic vesicle and its mitotic index were considerably below normal. The reduced growth rate of the optic vesicle led to its delayed contact with the ectoderm and prevented normal lens induction. The lens often did not bud off from the surface ectoderm. In some cases the greatly reduced growth rate of the optic vesicle prevented its contact with the ectoderm and resulted in aphakia. Anophthalmia was also observed, which was caused by the arrest of eye development at the early optic‐vesicle stage. The mitotic index in the wall of myelencephalon and the ventral half of prosencephalon wall was considerably lower than normal. This suggests that the anomalies of the eye and the labyrinth in fi/fi mice are evidently due to an antecedent developmental abnormality of the brain.
Changing body wall and rib defects after local application of nitrogen mustard to different mediolateral portions of rib‐forming levels of two‐day chick embryos
Authors: Sweeney Robert M. , Watterson Ray L. 
Published: June 2005

AbstractMethylbis(beta‐chloroethyl)amine hydrochloride was applied for 1 minute to the slit vitelline membrane over different mediolateral portions of ribforming levels of 22‐ to 27‐somite chick embryos by uniformly prepared agar discs of uniform dimensions. Gross effects on rib patterns and external features (body wall, feather tracts, wings) were recorded after 10 to 11 days of incubation.Rib patterns were essentially normal in most specimens with agar discs placed over the right lateral plate only; modifications of external features other than right wings were minimal under these circumstances. Placement of agar discs close to or over any portions of the somites and also over the lateral plate resulted in modifications both of rib patterns and external features. Related modifications occurred in vertebral and sternal components of ribs 3–7. Vertebral components were reduced in size, otherwise modified, or absent. Sternal components were either modified correspondingly, usually to greater degrees, or absent. Sternal components never formed in the absence of corresponding vertebral components. Similar modifications of vertebral and sternal components sometimes occurred on the left side when agar discs were applied to the right side. Modified external features (transverse grooves or depressions, body foreshortening, dorsal displacement and other modifications of breast and ventral feather tracts) appeared to be due to reduction of body musculature.These results are compatible with the classical hypothesis that vertebral and sternal rib components and ventrolateral muscles originate exclusively from somites.
A gene producing symmelia in the mouse
Authors: Hoornbeek Frank K. 
Published: June 2005

AbstractThe inheritance and description of a lethal condition involving sireniform abnormalities in mice are reported. Symmelia was produced by homozygosity for an incomplete recessive gene provisionally called siren (symbol srn). Sirens were apodal, monopodal, or dipodal. with the ischia present as a vestigial structure or missing. Femora, when present, were medially placed and usually fused. Pubes and tibiae were abnormal in some cases, and fibulae usually were. Visceral defects included absent or abnormal kidneys and adrenals, and blind or undeveloped intestines.
A mechanism for closure of the secondary palate
Authors: Verrusio A. Carl 
Published: June 2005

AbstractBefore the palate begins to close in mouse and rat embryos the cranial base in flexed in the area of the craniopharyngeal canal. As the process of palate closure progresses there is a gradual reduction in the flexure of the cranial base until finally, when the palatine processes are horizontal, the cranial base is almost straight. Rapid growth and straightening of the cranial base might play a role in palate closure by providing the “internal shelf force.” This hypothesis can be demonstrated by means of a mechanical model. The model consists of a thin sheet of plastic cut in the shape of a sagittal view of a vertical shelf and a piece of string attached to the convex border of the model shelf to represent the cranial base (in its flexed position). When the string is pulled, and the angulation of the “cranial base” is reduced to a straight line, the distal part of the model palatine process rotates to a position perpendicular to the proximal or attached part of the shelf, in a manner similar to that of the palatine processes in the embryo.
The closure of the neural tube in the golden hamster
Authors: Marin‐padilla Miguel 
Published: June 2005

AbstractThe sequence of events leading to the closure of the neural tube has been investigated in hamster embryos. This consisted of: (1) approach and fusion of the neural folds at the level of the presumptive neural‐crest cells; (2) active proliferation of the neural‐crest cells at the area of fusion and formation of a distinct wedge by them; (3) fusion and closure of the surface ectoderm; (4) reduction of the number of neural‐crest wedge cells due to their active migration from it; (5) fusion of the neurectoderm beginning at the ependymal surface, progressing dorsally until the neural tube was completely closed; and (6) fusion and closure of the mesoderm between the surface ectoderm and the closed neural tube. The time required to complete this sequence of events, the amount of embryonic tissue involved in it at a given time, and the number of neural‐crest cells formed at the area of fusion varied from one region of the embryo to another. It is postulated that the mesoderm appeared to play a double role in the process of closure—a direct one late in the closure process (see 6) and an indirect one, perhaps as a buttress supporting the other cellular elements during the entire closure process.
Effect of actinomycin D and urethan on successive litters and generations of mice
Authors: DiPaolo J. A. , Elis J. 
Published: June 2005

AbstractSequential litters and generations of A/He mice were given repeated injections of actinomycin D or urethan to study effects on fertility, embryotoxicity, teratogenicity, and carcinogenicity. The drugs were given every other day throughout pregnancy. Seven weeks separated each mating and course of treatment. Both drugs had a deleterious effect on fetal development dependent on dosage and litter series. The largest dosages blocked development completely; the effect of 50 μg/kg actinomycin D lasted through the second mating period. The number of offspring relative to controls was also decreased with smaller dosages. Drug toxicity increased with successive matings. In three consecutive generations commencing with females obtained from the lowest treatment regimen a response was observed similar to that seen in offspring obtained by repeated treatment of the same females. Actinomycin D was less carcinogenic than urethan; an increase in the number of lung tumors was found only in the females used for breeding. Compared to the control group, both breeders and offspring exposed transplacentally had an increased incidence of tumors following urethan administration. Malformations occurred only after urethan treatment.
The role of sulfated mucopolysaccharides in cleft palate production
Authors: Nanda Ravindra 
Published: June 2005

AbstractOffspring of rats treated with vitamin A, cortisone, or both drugs were studied with the aid of 35S‐sulfate to investigate whether sulfated‐mucopolysaccharides have a role in cleft palate production. Vitamin A alone or combined with cortisone produced a high frequency of cleft palate. Cortisone alone produced no cleft palates. Autoradiographic results showed that 35S‐sulfate incorporation in palatal tissue of control fetuses and those from rats treated with both drugs was almost similar, whereas isotope incorporation was several times higher than this in the vitamin A‐treated group and slightly less than this in the cortisone‐treated group. The results appear to indicate that there is no relation between disturbed sulfate mucopolysaccharide metabolism and the production of cleft palate.
The relation of the uterine vasculature to fetal growth and the intrauterine position effect in rats
Authors: Barr Mason , Brent Robert L. 
Published: June 2005

AbstractLigation of the uterine vasculature was performed on the 10th or 18th day of gestation in 114 Wistar rats. In each rat the blood vessels of one uterine horn were ligated at the level of the oviduct, midhorn, or the cervix; the opposite horn served as a control. Fetal weight and mortality data were analysed for the effect of the vascular interruption and the effect of intrauterine position. It was found that patency of the ovarian artery was not essential for normal fetal growth and that the loop‐artery configuration of the vessels to the uterine horn was not a determinant of the position effect. The time in gestation at which the ligation was performed had a decided effect on ultimate fetal weight: the later in gestation, the greater the fetal growth retardation. Various factors that could be responsible for the position effect are discussed. It is suggested that the association between fetal weight and intrauterine position is species dependent and is determined by unknown factors, not singly by hemodynamics, myometrial pressure, or time of implantation.
The embryolethal and teratogenic effects of cyclophosphamide on mouse embryos
Authors: Gebhardt D. O. E. 
Published: June 2005

AbstractPregnant mice were injected once with 10 or 20 mg/kg cyclophosphamide. A large embryolethal effect was induced by treatment on the 3rd and on the 8th and 9th days of pregnancy. Mortality was probably due to a direct effect of cyclophosphamide on the embryos. Limb malformations were induced at a later stage; therefore it appears that embryolethality and teratogenicity are separable processes. The anomalies consisted of synostoses, retardation of ossification, and poly‐ and oligodactyly. Polydactyly was induced at an earlier stage than oligodactyly.
Malformations caused in mouse embryos by a red dye contained in commercial trypan blue
Authors: Bertini Francisco , Sacerdote Fabio 
Published: June 2005

AbstractA red impurity (dye C, absorption maximum 560 mμ) was separated from two commercial samples of trypan blue by dialysis against double‐distilled water and ethanol extraction. Paper and Sephadex G‐25 chromatography proved that the nondiffusable trypan blue (TBC) was made up of 85% blue dye (dye TB, absorption maximum 590 mμ) and of residual dye C (15%). Swiss mice were injected ip on day 8 of pregnancy with 2–3 mg of TBC or with dye C in an amount representing 15% of the absorbance units (at 590 mμ) of the whole dose of TBC. All were killed on day 16 of pregnancy. The conceptuses of females treated with dye TBC were 62% resorbed, and 29% of the survivors were malformed. Those of the dye C group were 4% resorbed and 17% malformed. Only one of the 73 control implants was resorbed. The mean weight of both experimental groups was significantly lower than that of controls. The malformations were, in order of frequency: omphalocele, encephalocele, exencephaly, monophthalmus and anophthalmus. The types and distribution of malformations obtained with dye C were similar to those caused by the nondiffusable dye.
Effect of actinomycin D on early axial development in chick embryos
Authors: Wolkowski Rochelle M. 
Published: June 2005

AbstractA study was made of the uptake of actinomycin D, 3H‐thymidine, and 3H‐uridine in the axial regions of 11‐ to 13‐somite chick embryos cultured in vitro. Actinomycin D was taken up into all regions of embryos, with significantly more actinomycin D per cell in the axial region, including the node and unsegmented axial mesoderm (the lower axis). Demonstrable effects on RNA synthesis were restricted to tissue in the lower axial region. However, inhibition of DNA synthesis was seen in tissues of the upper axis already segmented, as well as in the lower axis. The differential response of the embryonic axis to actinomycin D is considered to be based on a greater demand for cells in the unsegmented and nodal region. Actinomycin D inhibited RNA synthesis, thereby inhibited DNA synthesis and cell division, and reduced availability of cells for growth and development. The paucity of cells in the node and unsegmented axial mesoderm restricted the formation of new somites and the laying down of new nerve cord and notochordal tissue. The upper axial region was not permanently affected.
The production of congenital malformations using tissue antisera. VII. Yolk‐sac antiserum
Authors: Brent Robert L. , Johnson Albert J. , Jensen Marcela 
Published: June 2005

AbstractHeterologous antisera against rat yolk sac made in rabbits and sheep produced congenital malformation, fetal growth retardation, and embryonic death when injected into pregnant rats. Antigens present in the cellular or acellular portions of the yolk sac were capable of producing teratogenic antibodies. Fluorescence‐labeling techniques revealed that yolk‐sac antiserum contained antibodies that reacted strongly with the nonserum‐protein antigens of maternal adrenal, ovary, and kidney; fetal yolk sac; and chorioallantoic placenta. Teratogenic yolk‐sac antiserum localized in the noncellular and intracellular portions of the parietal and visceral yolk sac including Reichert's membrane. It is postulated that yolk‐sac dysfunction is produced by the localization of these antibodies in the yolk sac. The localization of yolk‐sac antiserum in the yolk sac was observed at term regardless of whether the antiserum was injected on the 11th or 20th day of gestation, although the time of injection affected the localization at term qualitatively and quantitatively. These results suggest that further studies of the functions of the yolk sac at various periods of gestation are indicated not only in rodents but in humans since the yolk sac may play a role in human teratogenesis. The unanswered questions concerning yolk‐sac function and dysfunction in rodents and the importance of the yolk sac in humans add another aspect to the problem of transferring the results of teratogenic studies in rodents to the human situation.
The distribution of cortisone‐14C in pregnant mice
Authors: Waddell William J. 
Published: June 2005

AbstractThe distribution of the teratogenic steroid cortisone was studied in pregnant A/J mice by whole‐body autoradiography to ascertain whether sites of localization in the pregnant females or embryos might suggest a mechanism of teratogenic action. A high concentration of radioactivity was found in maternal kidney, liver, bile, and intestinal contents and uterine cavity fluid. Maternal ovary and adrenal had much less activity but nevertheless a slightly higher activity than blood. There was no other prominent accumulation in either mothers or off spring. The concentration in the embryonic palatal buds was no higher than that in any other embryonic area, and the concentrations in embryonic tissues were less than those in maternal tissues. The remarkable accumulation in the uterine luminal fluid appeared to result from active secretion by the yolk sac. Addition of carrier cortisone or pretreatment of the pregnant mice with ouabain or mercuhydrin did not significantly alter the pattern and intensity of distribution. Pretreatment with cobaltous chloride decreased the concentration of radioactivity in the fetuses.
Symmelia in one of monozygotic twins
Authors: Davies Jack , Chazen Eric , Nance Walter E. 
Published: June 2005

AbstractPostmortem dissection of a liveborn infant with symmelia who was one of a pair of monozygotic female twins revealed fusion of the preaxial halves of the hindlimbs to form a single hip joint, a femur with two medial and no lateral condyles, and knee and ankle joints that flexed backwards. The kidneys, bladder, uterus, and rectum were absent. Twenty‐three instances of twinning were found among 327 cases of symmelia reported in the medical literature. Only two pairs were definitely concordant, but whenever data were given they supported monozygosity. There appears to be more than a 100‐fold increase in the incidence of symmelia in monozygotic twin births as compared with single births. The high frequency of discordance could result from unequal expression of a cytoplasmic abnormality. Alternately, the developmental arrest of the primitive streak that leads to symmelia may also initiate the formation of a second primitive streak, thereby giving rise to twin embryos.
The effects of maternal hypercortisonism and hypervitaminosis D2 on fetal osteogenesis and ossification in rats
Authors: Ornoy A. 
Published: June 2005

AbstractPregnant rats were treated daily with intramuscular injections of 5 or 10 mg cortisone acetate dissolved in 0.5 ml normal saline, or orally with 20,000 IU vitamin D2 dissolved in 0.5 ml olive oil, or both. Controls received olive oil and normal saline, or vitamin D2. Treatment was from day 8 or 10 of gestation until the animals were killed on day 18, 20, or 22. The higher dose of cortisone shortened the diaphyses and epiphyses of long bones. Concomitant administration of vitamin D2 caused further bone shortening and hypomineralization. The main microscopic alterations in the fetal bones of cortisone‐treated rats were changes in cartilaginous intercellular substance, narrowing of the hypertrophic and calcifying cartilage cell layer, and inhibition of endochondral ossification. Bone trabeculae were very wide and irregular. The bone matrix had abnormal staining properties. Bone marrow spaces were obliterated and contained a very large number of fibroblasts, preosteoblasts, and osteoclasts. The number of osteoclasts was further increased by treatment with vitamin D2. It is presumed that cortisone passed through the placenta and affected fetal bones, causing the microscopic changes. Concomitant administration of vitamin D2 potentiated the effects of cortisone on bone, and also produced certain specific changes.
A morphological and histochemical study of thalidomide‐induced upper limb malformations in rabbit fetuses
Authors: Nudleman K. L. , Travill A. A. 
Published: June 2005

AbstractThe upper limbs of 21‐day‐old thalidomide‐treated rabbit fetuses were studied macroscopically, histologically, and histochemically. The deformed limbs were arthrogrypotic, twisted, or medially rotated and inverted. Often these malformations were coupled with anomalies of the thumb. One or more of the preaxial bones or their primordia were either anomalous or missing. The degree of the induced dysmelia could be recognized by the graded severity of the histology. The least severely affected limbs exhibited defects of ossification and/or chondrification, whereas more severely affected ones contained atrophic chondrocytes, undifferentiated mesenchyme, or absence of primordia. In the deformed limbs glycogen was retained in the hypertrophic and calcified chondrocytes and glycogen granules were dispersed in reduced thenar structures, but alkaline phosphatase activity was reduced or absent in the same areas. There were no detectable differences in the amount or distribution of acid mucopolysaccharides between abnormal and control limbs. However calcium deposition in the cartilaginous matrices was reduced or absent in the abnormal limbs. In limbs with reduced amounts of osseous tissue there was no evidence of histochemical aberration in the deposited bone. It would appear, therefore, that thalidomide affected mesenchymal derivatives at various stages of development; that it was associated directly or indirectly with the utilization of glycogen and the production of alkaline phosphatase; and that its influence was expressed by aberrations in the chondrification and calcification processes during later fetal development.
Embryonic abnormalities in hamsters following intrauterine injection of 6‐aminonicotinamide
Authors: Turbow M. M. , Clark W. H. , Dipaolo J. A. 
Published: June 2005

AbstractHamster embryos were injected intraamniotically (ia) with 6‐aminonicotinamide (6‐AN) on gestation day 7, 8, or 9 and examined near term. Control treated embryos received 5 μl of water, a needle puncture without injection, or no treatment, and had low rates of resorption and malformation. 6‐AN injected ia produced offspring with multiple defects including exencephaly, cleft palate, anophthalmia, micrognathia, and hydrocephalus. In contrast to day‐8 and ‐9 embryos, which responded to 5‐μg doses of 6‐AN, day‐7 embryos required 50–100 μg before exhibiting abnormalities.