bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in DNA, RNA, and protein content of regions of explanted chicken embryos following insulin treatment
Authors: Hickey Eileen D. , Klein Norman W. 
Published: June 2005

AbstractChick embryos of 11–13 somites, which were cultured 48 hours on insulin‐containing medium, showed deformation of the brain and posterior trunk, and inhibited accumulation of DNA, RNA, and protein contents. These effects became more pronounced with increased insulin dose. Embryos transferred to insulin‐free medium after 2 or 3 hours' exposure to 4 U/ml insulin showed a similar morphological response as embryos continuously exposed to the same dose. Quantitation of DNA, RNA, and protein contents indicated a more severe inhibition in embryos of the continuously exposed group than in those of the briefly exposed group, although embryos of both groups were significantly inhibited relative to their controls. Region‐specific action of insulin was demonstrated in terms of the time at which each region of insulin‐treated embryos first showed reduction in DNA, RNA, or protein content. The brain was the most susceptible region to insulin action; the trunk regions responded later; and the heart and extraembryonic membranes showed no significant effect of insulin treatment. At the molecular level nucleic acid content was most influenced by insulin treatment. Reduction in DNA content of whole embryos, or of specific regions, was the first effect of insulin treatment detected. However, on continuous exposure to a low dose of insulin (0.2 U/ml) the RNA content of the brain was reduced before the DNA content.
Metabolism of β‐aminopropionitrile and its teratogenic activity in rats
Authors: Wilk A. L. , King C. T. G. , Horigan E. A. , Steffek A. J. 
Published: June 2005

AbstractThe administration of β‐aminopropionitrile (BAPN) to pregnant rats induced various fetal anomalies including a high percentage of cleft palate. Following oral administration BAPN was found along with its deaminatedoxidized derivative cyanoacetic acid (CAA) in embryos, placentas, and maternal tissues, serum, and urine. BAPN levels reached a maximum in tissue and serum 6 hours after treatment, were maintained for about 3 hours more, then sharply declined to negligible amounts by 24 hours. CAA levels however gradually rose and high levels were still present at 24 hours. Similar amounts of BAPN were found in tissues after its administration on either day 14. 15, or 16 of gestation; however, only on day 15 was there a positive correlation between embryonic levels of BAPN and cleft‐palate production. Thus 6 hours after BAPN treatment on day 15 embryonic levels of 106, 42, or 16 μg BAPN per g of tissue corresponded to a cleft‐palate incidence of 98, 28, or 0% respectively. Oral administration of CAA produced no cleft palate even though high embryonic levels of CAA were attained. These data indicate that BAPN itself is teratogenic and that it acts within a narrow period of time on day 15 in producing cleft palate.
Teratogenic effects of 5‐fluoro‐2′‐deoxyuridine in pregnant mice
Authors: Ohmori Kazuo 
Published: June 2005

AbstractRadioactive 5‐fluoro‐2′‐deoxyuridine (FUdR) was administered to mice on day 12 of pregnancy, and the resulting radioactivity was measured in embryos, placentas, and maternal liver and spleen. The FUdR was taken up rapidly by the maternal tissues and embryos and was incorporated into nucleic acids within 1 hour of administration. In the maternal tissues the quantity of FUdR incorporated into nucleic acids within 1 hour of administration was greatly increased by increasing the applied dose. In embryos, however, only a slight increase was observed. After 0.14 mg/kg FUdR the quantity incorporated into nucleic acids reached its peak within 1 hour, and increased no further. After a dose ten times larger the quantity of FUdR incorporated into nucleic acids increased steadily in all tissues tested until nearly 8 hours after application. A greater amount of FUdR was incorporated into maternal spleen than into embryos.
Molecular differentiation of several enzymes in early human embryos
Authors: Johnson E. Marshall , Takano Kiichi , Nishimura Hideo 
Published: June 2005

AbstractHomogenates of two human embryos, one each at horizons 16 and 20, were subjected to zone electrophoresis in starch and polyacrylamide gels. The gels were stained to reveal multiple molecular forms of acid and alkaline phosphatase, nonspecific esterase, and lactate, malate, and glucose‐6‐phosphate dehydrogenase. In general there were qualitative and quantitative increases in enzymatic activity with increasing gestational age. The enzymatic ontogeny observed was compared to that previously found prenatally in rats.
Variability of limb malformations induced by 5‐fluoro‐2′‐deoxycytidine in mice
Authors: Kleinebrecht J. , Degenhardt K.‐H. , Fränz J. , Schneider G. 
Published: June 2005

AbstractMalformations of limb elements produced in C57BL/10 mice by various dosages of 5‐fluoro‐2′‐deoxycytidine given at day IX or XI were analyzed. This investigation was restricted to the analysis of aplasia, synostosis, synchondrosis, and inhibition of calcification. Teratological patterns were described in detail. Day‐IX treatment induced patterns of ulnar, radial, ulnarradial, and tibial aplasias. Day‐XI treatment produced groups of defects with common characteristics, but no clear teratological patterns. Synostoses, synchondroses, and inhibition of calcification predominated. Dose‐response relations occurred after treatment at both stages.
Distribution and metabolism of triamcinolone acetonide in inbred mice with different cleft palate sensitivities
Authors: Zimmerman Ernest F. , Bowen Donna 
Published: June 2005

AbstractThe distribution and metabolism of labeled triamcinolone acetonide was compared in A/J, C3H, and CBA inbred mice. 3H‐Triamcinolone acetonide (5 mg/kg) administered at day 11.5 of gestation caused 100% cleft palate in A/J, 40% in C3H, and 0% in CBA. A half to 3 h later CBA maternal tissue (skeletal muscle) contained 60% as much radioactivity as did A/J and C3H tissue. CBA mice metabolized the drug faster than A/Js and C3Hs, although levels of unmetabolized drug and metabolites in livers of the three strains were not significantly different. As a consequence of the increased maternal metabolism of the drug in CBAs the level of unmetabolized drug in CBA embryos was 60% of that in A/J and C3H embryos. It is concluded that the cleft palate resistance of CBA embryos derives from the increased maternal metabolism of administered teratogen. However, the greater resistance of C3H than A/J is probably not due to increased metabolism, nor to altered distribution of drug.
Accessory lobe of the liver in Gunn‐derived rats
Authors: Machado Emilio A. , Lozzio Bismarck B. 
Published: June 2005

AbstractCongenital accessory lobe of the liver in rats is described. The defect may be an inherited one, and if so may involve a recessive gene with low penetrance or may be polygenic. No affected individual produced offspring. The accessory lobe consisted of a round intrathoracic mass with vascular connections to the cava or suprahepatic veins. Microscopically, there was disarray of the normal architecture, blood stasis, and severe chronic congestion, which often led to rupture of the dilated vessels and formation of large hemorrhagic areas.
Independent effects of fluorouracil and two mutant genes in mouse embryos
Authors: Dagg C. P. 
Published: June 2005

AbstractPrevious experiments demonstrated that fluorouracil, injected into female mice at day 10 of gestation, reinforced the effects of two limb‐deforming mutant genes, luxoid (lu) and luxate (lx). In the present investigations, male mice heterozygous for lu or lx were mated to + / + females who were injected with fluorouracil at day 11 or 12 of gestation. Some offspring from these matings were mated to + / + mice to determine their genotypes (+ / +, + /lu, or + /lx). Preaxially hyperphalangous hind feet, characteristic of untreated + /lu, and + /lx mice, were found only in the mutation‐bearing offspring. There were no correlations between genotypes and the abnormalities (kinked tail, white belly patch, and small fabella medialis) produced by fluorouracil. It was concluded that under these experimental conditions there were no significant interactions between the teratogen and the mutant genes at 11 and 12 days of development.
The localization of vitamin A in the pregnant rat by means of fluorescence microscopy
Authors: Geelen J. A. G. 
Published: June 2005

AbstractPregnant Wistar rats were administered 50,000 IU of vitamin A palmitate orally on each of the 7th, 8th, and 9th days of gestation. Fluorescence microscopy of serial sections of 10th‐, 11th‐, and 12th day embryos revealed a fading, bright green color indicative of vitamin A. The fluorescence was located in the decidua capsularis, decidua basilaris, Reichert's membrane, parietal yolk‐sac epithelium, giant cells, and uterine musculature but not in the visceral yolk‐sac epithelium or embryo. The thyroid, adrenal, and kidney of experimental pregnant females showed an increase of vitamin A fluorescence.
Sagittal growth trends of the craniofacial complex during formation of the secondary palate in mice
Authors: Hart James C. , Smiley Gary R. , Dixon Andrew D. 
Published: June 2005

AbstractNormal C57BL and A/J mice and A/Js with spontaneous bilateral cleft lip and palate were obtained at 13–16 days of gestation and the heads were prepared for serial sectioning in the sagittal plane. The midsagittal sections were photographically enlarged and measurements made to assess the amount and rate of growth. The C57BL fetuses outgrew the A/Js. in all parameters. A mandibular growth spurt was not observed, but an increase in mandibular growth relative to that of the maxilla was found. Maxillary growth was less in malformed A/Js but the mandible was not micrognathic. The cranial base angle was not significantly different in normal and malformed A/J fetuses, but the vertical dimension was significantly greater in the former than the latter at days 15 and 16. The increase in the angle made by the mandible and the posterior cranial base before and during palatal closure appeared to have the greatest influence on the vertical dimension.
The in vivo biosynthesis of DNA, RNA, and proteins by mouse embryos after a teratogenic dose of cyclophosphamide
Authors: Short Robert D. , Rao K. S. , Gibson James E. 
Published: June 2005

AbstractPregnant Swiss‐Webster mice received 20 mg/kg cyclophosphamide ip on day 11 of gestation and 100–125 μCi/kg 14C‐labeled thymidine, orotic acid, uridine, or leucine at various times afterwards. DNA synthesis in embryos, as measured by 14C‐thymidine incorporation, was significantly reduced at 12 h but not 3, 6, 24, 48, or 72 h after treatment, and embryonic DNA was reduced at 12, 24, 48, and 72 h. 14C‐thymidine incorporation and DNA content were also reduced in placentas and maternal livers after a delay of at least 6 h. Embryonic protein synthesis, as measured by 14C‐leucine incorporation, was significantly reduced at 72 and 96 h after treatment. Embryonic RNA synthesis or content was not significantly affected. It was concluded that a teratogenic dose of cyclophosphamide quantitatively affects the synthesis of DNA and protein in the mouse embryo. The temporal aspects of the changes indicated that the effects on DNA synthesis may be the cause of induced developmental defects but effects on protein synthesis appear to be the result rather than the cause of the defects.
Early and late effects of in vitro exposure of preimplantation mouse embryos to trypan blue
Authors: Fisher D. L. , Smithberg M. 
Published: June 2005

AbstractPreimplantation 129/SvSl mouse embryos obtained by induced superovulation and cultured from the 4‐cell to blastocyst stage were exposed to various concentrations of trypan blue for 48 h or to the LD50 (0.16%) and LD99 (0.35%) concentrations for various lengths of time. At least 2 ½ h exposure to the latter concentrations was required before significant reduction in blastulation rates (80% in controls) occurred. Embryos that blastulated after 48 h of culture were transplanted to adult nulliparous 2‐day‐pseudopregnant 129/SvSl females and fetuses were examined 15 days later. Approximately 70% of implanting control blastocysts developed into fetuses. Significantly fewer fetuses developed after 48 h preimplantation exposure to concentrations of 0.08 % or more of trypan blue. The percentage of resorptions increased with exposure to increasing concentrations of trypan blue during the preimplantation period. The only abnormality found in treated fetuses was subdermal hematoma.
Experimental first‐trimester amniocentesis in nonhuman primates
Authors: Poswillo D. 
Published: June 2005

AbstractThe effects of amniocentesis prior to palate closure were investigated in Macaca irus embryos. Nine embryos were used as operated controls, being obtained by hysterotomy on consecutive days from 39 to 47 of development; nine animals composed the experimental group, in which amniocentesis was carried out via a laparotomy approach from day 39 to 47, and the fluid used for cytological investigations; nine unoperated pregnant animals, chosen at random from consecutive births in the colony, provided a further control group. Radiographs of experimental fetuses at regular intervals after amniocentesis revealed one instance of postural moulding which assumed a normal position within 2 months. Histological examination of the operated control embryos confirmed that experimental amniocentesis covered the 9 days immediately preceding palate closure. All nine of the animals in the amniocentesis group were delivered by Cesarean section at term, and found free of gross abnormalities. From birth until 6 months these were compared with the normal controls. Birth weights and sizes fell within the normal range, and at 6 months there were no features to distinguish between the experimental and control groups in any aspect of growth or development.
The influence of the fetal genome on trypan blue‐induced cardiovascular defects
Authors: Fox Marjorie H. 
Published: June 2005

AbstractThe mean litter incidence of genetically determined, congenital patencies of the interventricular cardiac septum was found to differ significantly and consistently in control neonates produced by matings within and between two Long‐Evans lines of rats (O/O>C/O>O/C>C/C). When dams carrying siblings of control neonates were injected with a standardized dose of trypan blue on day 8 of pregnancy, there occurred significant increases in the incidence of cardiovascular malformations in litters of all genotypes. Although neither the magnitude of the increases nor the severity of the induced malformations was directly correlated with line or sibship differentials with respect to the incidence of spontaneous septal, patencies some unidentified aspect of the fetal genome significantly influenced the nature of the induced defects. Both O/O and hybrid litters were characterized by a high incidence of severe transposition syndromes, consistently associated with highly specific, unilateral cephalic malformations or extensive spina bifida. The incidence of comparable associated head and heart malformations was significantly lower in C/C litters, in many of which the dye exposure merely increased the incidence of isolated interventricular septal patencies over that found in control siblings or induced noncardiovascular malformations at the caudal end of the body axis. In general, the collective data afford little support for the concept that a familial or subline predisposition towards spontaneously occurring cardiac malformation renders the fetal cardiovascular system particularly susceptible to the teratogenic activity of trypan blue.
Hydrocortisone‐induced cleft palate in hamsters
Authors: Shah Ravindra M. , Chaudhry A. P. 
Published: June 2005

AbstractSingle im doses of 25–30 mg hydrocortisone on day 11 of gestation produced 100% cleft palate in hamsters without undue fetal resorption; 75 mg produced a significantly larger resorption rate. The cleft palates varied in morphology, some being complete and others incomplete; the latter were relatively more common with smaller doses. The fetal birth weight of experimental offspring was greatly decreased.
Teratogenic effects of intrauterine injection of acetazolamide and amiloride in hamsters
Authors: Storch T. G. , Layton W. M. 
Published: June 2005

AbstractTo learn if acetazolamide acts at an intrauterine site when it produces limb deformities in the hamster, acetazolamide was injected into one horn of the pregnant uterus and an inactive analogue into the opposite horn. Significantly more forelimb malformations occurred in the acetazolamide‐injected horns, but hindlimb malformations occurred with equal frequency in both horns. These results suggest that acetazolamide acts at an intrauterine site when it produces forelimb malformations, but may not do so when it produces hindlimb malformations. In other experiments, acetazolamide was given intraperitoneally, and a dose of amiloride, too small to affect the acetazolamide‐induced extrauterine potassium alterations, was also injected into one uterine horn and a control solution into the opposite. Significantly fewer forelimb malformations occurred in the amiloride‐injected horns, suggesting that amiloride can act at an intrauterine site to reduce the incidence of forelimb malformations without affecting the extrauterine potassium changes.
Relationship of temporal patterns of cell death and development to malformations in the rat limb. Possible mechanisms of teratogenesis with inhibitors of DNA synthesis
Authors: Ritter E. J. , Scott W. J. , Wilson J. G. 
Published: June 2005

AbstractCytosine arabinoside palmitate (ara‐CP) is a sustained‐action form of the DNA‐synthesis‐inhibitor cytosine arabinoside (ara‐C). When given at day 12 of rat gestation ara‐CP caused moderate but prolonged depression of DNA synthesis, killed embryonic cells after 2–3 days, and led to severe limb and other defects and extreme growth retardation. The results were compared with those obtained in earlier studies with hydroxyurea and with ara‐C, both of which also caused depression of DNA synthesis, cell death, and limb defects, but at different times in relation to treatment. There was a relation between the time of maximal cell death in the limbs after treatment and the specific limb malformations seen at day 20. The relation of cell death to teratogenesis seen with these chemical agents is similar to that previously reported for X irradiation.
Induction of a cytoplasmic factor increasing resistance to the teratogenic effect of 6‐aminonicotinamide in mice
Authors: Pollard D. R. , Fraser F. C. 
Published: June 2005

AbstractIt was previously shown that maternal treatment with 6‐aminonicotinamide (6‐AN) produces a higher frequency of cleft palate (CP) in A/J than C57BL/6J mice. C57BL mice are more resistant to 6‐AN when fed a high niacin diet (Purina Lab Chow) than a low niacin diet (Purina Breeder Chow). This component of the strain difference appears to be cytoplasmically transmitted. The present study showed that when C57BL mice were transferred from the low niacin to the high niacin diet for 1 h before 6‐AN treatment the CP frequency dropped to the value in offspring of females raised on the high niacin diet and remained at this low level when the time on this diet before treatment was increased to as much as 1 month. In A mice the response was not as immediate as in C57BLs, and as the time the females were on the high niacin diet before treatment was increased the CP frequency rose again. It is suggested that niacin in the diet functions as an inducer for an enzyme system controlled by a cytoplasmic factor that increases the resistance of the organism to the CP‐producing effect of 6‐AN.
The further epidemiological differentiation of cleft lip and palate: A population study of clefts in King County, Washington, 1956–1965
Authors: Emanuel Irvin , Culvers Bruce H. , Erickson J. David , Guthrie Ben , Schuldberg David 
Published: June 2005

AbstractA retrospective epidemiological study of cleft lip and palate in King County, Washington, between 1956 and 1965 is reported. Multiple sources of ascertainment were employed, and particular attention was given to obtaining information concerning other associated malformations. Occurrences of cleft lip (CL), cleft lip and palate (CL + P), and cleft palate (CP) were analyzed by sepa rate categories, depending on the presence or absence of associated major or minor malformations. The results strongly indicated that clefts with associated malformations are different epidemiological entities from pure clefts. Sex‐ratio reversals occurred for some categories with associated malformations. In contrast to the usual male excess of CL ± P, there was a female excess of CL ± P with major associated malformations. In contrast to the usual female excess of CP, 49% of children with CP with associated malformations were male. No maternal‐age effect was observed for any “pure” cleft category, but significant “U‐shaped” maternal‐age distributions were seen for CL + P with associated major malformations, CP with associated major malformations, and CP with all associated malformations. Increased frequency of low birth weight and infant mortality were confined to categories with associated malformations. No significant birth order, season, secular change, or time–space clustering effects were observed. The incidence rate for all clefts was 1.84/1000 live births.
Further data on the slit‐lid mutant in mice and the effect of cortisone and doca on its development
Authors: Stein Kathryn F. , Kettyle Cynthia Nichols 
Published: June 2005

AbstractThe development of a mutant with eyelids open at birth that appeared in our laboratory was described previously (Stein et al., '67). It differed from similar mutants described in the literature and was called slit‐lids. Later Ricardo and Miller ('67) reported that complementarity tests between our mutant and another, called lid‐gap, indicated they were identical or allelic. They found that cortisone injected prenatally reduced the frequency of the lid‐gap phenotype (also reported by Watney and Miller, '64), but not of the slit‐lid mutants supplied by us. In our hands, however, cortisone did correct the defect in a large proportion of the slit‐lid progeny of injected pregnant females (Stein and Nichols, '68). Further experiments, reported here, confirmed our earlier results, and data from both series are combined in this paper. Injections of a mineralocorticoid, deoxycorticosterone, magnified the defects characterizing the untreated slit‐lid mutant. Histological data have been reviewed and supplemented for comparison with those of Harris and Fraser ('68) who reported no evidence in lid‐gap of the excessive vacuolation of the lens described by us in our mutant, but noted evidence of injurious adhesion of eyelids to cornea. In both respects the slit‐lid mutant appears to differ from lip‐gap.
Dilatation of the urinary tract in fetal rabbits following postcesarean incubation
Authors: Springman Frank R. , Roell Michael G. , Doerr Bruce I. 
Published: June 2005

AbstractAccording to the revised guidelines of 1966 of the Food and Drug Administration for reproductie studies in rabbits, Cesarean‐delivered fetuses might be incubated for 24 h as a test of survival. The present experiment indicated that this procedure, followed by fixation of fetuses in Benin's solution, results in apparent dilatation of the urinary tract. Most of the incubated fetuses showed distended bladders (71%) with occasional dilatation of ureters (9.3%) and renal pelves (8.5%) as compared to none in the nonincubated fetuses. An awareness of these induced changes in the urinary tract is important for the investigator, who may construe the observations as a teratogenic effect of a test compound.