bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ectopia cordis cervicalis: A case report
Authors: Müller G. , Schaller A. 
Published: June 2005

AbstractA case of ectopia cordis cervicalis is reported; it seems to be the seventh one in the available literature. It concerns a completely ectopic cor biloculare with a truncus arteriosus persistens, located above the apertura thoracis superior, being covered by soft tissue. A survey of the cases cited in the available literature since 1712 is given.
An epidemiologic study of neural tube defects in Los Angeles County II. Etiologic factors in an area with low prevalence at birth
Authors: Sever Lowell E. 
Published: June 2005

AbstractEpidemiologic characteristics of neural tube defect (NTD) births occurring in Los Angeles County, California, residents during the period 1966–1972 are presented. The prevalence at birth was 0.52/1000 births for anencephalus, 0.51/1000 for spina bifida, and 0.08/1000 for encephalocele, rates considered to be low for a predominantly white population.We hypothesized that environmental (nongenetic) factors are of less etiologic importance in a low‐prevalence population than in areas or time periods with high prevalence. We tested that hypothesis by examining epidemiologic characteristics of NTDs in Los Angeles County and comparing them with high‐prevalence populations. The data did not support a major etiologic role for environmental factors: (1) no significant differences between rates by month of birth or conception; (2) no significant association with maternal age or parity for anencephalus; for spina bifida a significant maternal age effect (P < 0.01) and for encephalocele a parity effect (P < 0.02); and (3) no significant relationship with father's occupational class for either anencephalus or encephalocele but a marginally significant (P < 0.05) inverse association for spina bifida when a statistic based on ordinal relationships was used.Findings supporting the importance of genetic factors in etiology included: (1) a high percentage of males; (2) a higher twin concordance rate than in high‐prevalence populations; and (3) an anencephalus rate among blacks comparable with rates for blacks in other United States populations. Our findings in conjunction with those from other areas and times of low prevalence suggest environmental factors play a relatively insignificant role in the etiology of NTDs in such populations.
Differences in frequency of cleft lip among the a strains of mice
Authors: Juriloff D. M. 
Published: June 2005

AbstractThe frequency of spontaneous cleft lip on Day 14 of gestation was examined in the A/J, A/HeJ, A/WySn, A.BY/Sn, A.SW/Sn, Bl0.A/SgSn, and B10.A(2R)/SgSn inbred strains of mice. A/WySn was found to have a higher frequency of cleft lip (20–30%) than A/J or A/HeJ (10%). Differences among strains in laterality of clefting and in rates of differential mortality of affected embryos were also found. Results of crosses between A/WySn and A/HeJ suggested that the difference in rate of clefting may be due to a genetic maternal effect. The results for A.BY/Sn, A.SW/Sn, Bl0.A/SgSn and B10.A(2R)/SgSn indicated that no association of cleft lip liability and the H‐2 complex was detectable.
The teratogenicity of cocaine
Authors: Fantel Alan G. , MacPhail Bonita J. 
Published: June 2005

AbstractPregnant rats and mice received high doses of cocaine hydrochloride by intraperitoneal injection. Despite treatment periods which included most of organogenesis, no increase in congenital abnormalities was observed. Rats showed significant reductions in maternal and fetal weights as well as increased resorption frequencies. Fetal edema was also found. Mice showed only decreased fetal weights with no increase in malformations.
In vitro effects of the teratogen and folic acid antagonist, 9‐methyl pteroylglutamic acid, on glycosaminoglycan accumulation in fetal rat limbs
Authors: Schmidt Richard R. , Abbott Patricia K. , Cotler Jerome M. 
Published: June 2005

AbstractFetal rat limbs were obtained from pregnant females on the 14th day of gestation. Forelimbs and hindlimbs were pooled separately and preincubated for 22 hours at 37°C in Eagle's MEM containing the teratogen and folic acid antagonist, 9‐methyl pteroylglutamic acid (9‐mePGA). Following removal of old medium, fresh medium together with the teratogen were added at the same concentration as before. Tritiated glucosamine (10 μCi) was added to each vial and the incubation continued for 4 hours at 37°C. Tissues were homogenized, digested with pronase, and glycosaminoglycans (GAG) selectively precipitated with cetylpyridinium chloride. In vitro exposure of fetal limbs to various doses of 9‐mePGA resulted in a significant increase in the accumulation of labeled GAG by fetal forelimbs at the high and intermediate dosage levels. No effect was observed at the lowest dose. Accumulation of labeled GAG by fetal hindlimbs although similar to fetal forelimbs in control incubations, was unaffected by in vitro exposure to 9‐mePGA at any of the dosage levels studied.
Trisomy 13 in the mouse
Authors: Hongell Karin , Gropp A. 
Published: June 2005

AbstractThe fetal development of mice trisomic for chromosome 13 (Ts 13) was investigated. Trisomic fetuses were obtained from the progeny of male mice heterozygous for the two Robertsonian translocation chromosomes Rb (11.13)4Bnr and Rb (6.13)3Rma mated to “all acrocentric” NMRI females. Trisomic fetuses were found at all stages between days 12 and 19 of gestation (vaginal plug day counted as day 1). The frequency of trisomy was 24.8% of all surviving implants. The frequency of Ts decreased slightly but not significantly with progressing pregnancy. In eight newborn litters, two dead and four living trisomic newborns (13.6%) were found. The latter died within a few hours after birth. The most conspicuous features of Ts 13 fetuses were their small size and a marked hypoplasia as compared with their normal euploid in utero mates. The weight of the the trisomic fetuses and that of their placentas was significantly lower than of the normal controls at all stages studied. The general developmental delay and the delay of the ossification of Ts 13 fetuses were about 1 to 1 1/2 days. Cleft palate was observed in 86% of the Ts 13 fetuses. Edema developed in the neck and back of the trisomic fetuses from day 14 on; this disappeared after day 17. It is suggested that the hypoplasia and general retardation of growth found in trisomy 13 and in other autosomal trisomies, as well as the more or less specific palatal and cardiovascular malformations in this disorder, may be caused by impaired proliferation of trisomic cells. This postulated impairment of cell growth may also affect the fetal part of the placenta.
Teratogenic and clastogenic effects of BUdR in mice
Authors: Fränz J. , Kleinebrecht J. 
Published: June 2005

AbstractPregnant mice (C57B1/6JFfm) were treated with BUdR on day 9 of gestation. For doses ranging from 300 to 1,200 mg/kg b.w. of BUdR the teratogenic effect in near‐term fetuses was analyzed. The findings confirm the phase and dose dependency of the induced malformations found by other authors. They also demonstrate, however, a BUdR‐specific induction of special malformations. For a dose of 1,200 mg/kg of BUdR the effect on mitotic rates and the induction of chromosomal aberrations were investigated. Mitotic rates were counted in single organs as well as in total homogenized embryos. The methods are equally useful. The embryos were analyzed 3, 6, 12, and 24 hours after BUdR treatment either after homogenization or in serial sections. Decrease of mitotic rates has been found to be most remarkable at 3 and 12 hours after treatment. At 24 hours only the neural tissue showed a slight decrease of the mitotic rate. Chromosomal aberrations are induced at all times, but the highest rates are seen at 3 and 12 hours after treatment. The aberrations are of the chromatid type.
Teratogenic effects of 27.12 MHz radiofrequency radiation in rats
Authors: Lary Joseph M. , Conover David L. , Foley Edward D. , Hanser Peggy L. 
Published: June 2005

AbstractHigh‐intensity 27.12 MHz radiofrequency (RF) radiation was determined to be teratogenic in rats during most of the gestation period. Eight groups of pregnant rats were exposed to a magnetic field strength of 55 amps/meter and an electric field strength of 300 volts/meter on gestation days 1, 3, 5, 7, 9, 11, 13, or 15. Exposures ceased once the dam's colonic temperature reached 43.0°C (about 20–40 minutes' duration). Eight matching control groups were sham‐irradiated for 30 minutes at 0 amps/meter and 0 volts/meter. An additional group of pregnant rats received no treatment. With one exception, no significant differences occurred between sham‐irradiated and untreated control groups. RF exposure, however, caused a significant incidence of fetal malformations throughout the postimplantation period (days 7 through 15). It also caused a low but significant incidence of preimplantation malformations. Fetal weight and crownrump length were reduced in all postimplantation exposure groups but were not affected by preimplantation exposure. The incidence of dead or resorbed fetuses was significantly increased in rats irradiated on days 7 or 9. The effects observed appeared to be caused by RF‐induced hyperthermia in the treated dams. Since a number of industrial, scientific, and medical devices operating at or near 27.12 MHz can cause hyperthermia in humans, women of childbearing age should avoid exposure to RF‐radiation levels that exceed current US occupational standards.
The use of early chick embryos in experimental embryology and teratology: Improvements in standard procedures
Authors: Fisher Marilyn , Schoenwolf Gary C. 
Published: June 2005

AbstractThe chick embryo is a convenient experimental system for embryologic and teratologic studies. However, windowing eggs during the first day of incubation, a procedure that is required to expose embryos in ovo, frequently results in dysmorphogenesis. The frequency and severity of the particular anomalies caused by windowing are greater the younger the embryo at the time this procedure is done. At all stages examined, dysraphic defects of the neural tube are the most common anomaly present following windowing. Defects of the neural tube are virtually eliminated if the air space introduced over the embryo by windowing is filled with albumen or saline, and the egg (with its window sealed with tape) rotated 180°, so that the embryo rests subjacent to an undisturbed area of the shell. Subblastodermic injection of saline, a vehicle often used for teratogenic agents, has no adverse effects when eggs are subsequently filled with albumen or saline and rotated. Furthermore, known teratogens (e.g., colchicine, hyaluronidase) injected subblastodermically after windowing are active in eggs that are then filled with albumen or saline and rotated. Finally, the addition of albumen or saline, followed by rotation, may be delayed up to 3 hours without reducing the restorative effects of these two procedures. Our modified procedures for the handling of windowed eggs significantly increase the value of young chick embryos for studies of early developmental events.
Relationship of developmental stage to effects of vinblastine on the artificial “embryo” of hydra
Authors: Chun Yong H. , Johnson E. Marshall , Gabel Bradley E. G. 
Published: June 2005

AbstractThree milligrams of vinblastine sulfate per liter of culture medium prevented normal development of all reaggregated artificial hydra “embryos” at the 66‐hour stage of regeneration. One milligram of vinblastine per liter of medium had no effect on development, and 100 mg did not markedly accelerate the developmental disruption beyond the pace of the 2 mg/liter concentration which was the lowest effective concentration. Treatment with vinblastine through the first few hours of development was sufficient to produce the toxic endpoint at 66 hours of incubation, but effects were delayed in appearance when treatment was initiated later in development. Early development of exposed preparations proceeded normally even in the presence of rather high concentrations of the test substance, and the pellet was resistant to the effects of vinblastine treatment begun after 24 hours of development. From these results, it would appear that interference with cell division is not the primary means by which vinblastine perturbs this developing system.
Embryotoxicity of Norlestrin, a combined synthetic oral contraceptive, in rhesus macaques (Macaca mulatta)
Authors: Prahalada S. , Hendrickx A. G. 
Published: June 2005

AbstractThirty timed‐mated pregnant rhesus monkeys received Norlestrin (Norethindrone acetate, 2.5 mg, and ethinyl estradiol, 0.05 mg pertablet, Parke‐Davis) orally at four different dose levels. The dose levels were 5, 10, 25 and 50 mg/day/monkey and the doses were administered during early (days 21–35), late (days 33–46), and throughout (days 21–46) organogenesis, except for the 50‐mg‐dose‐group animals, which were treated only during early organogenesis (days 21–35). All except the animals in the 50‐mg‐dose group were allowed to go to term (165 days gestation). Pregnancy for the animals in the 50‐mg‐dose group was terminated by eesarean section on day 50 of gestation and the fetuses were fixed, serially sectioned, and examined histologically. No teratogenicity was observed. However, the prenatal mortality rate (38.5%) was higher for the Norlestrin‐treated animals than in the control colony (21%). Eight animals aborted between days 40 and 78 of gestation and two other cases resulted in stillbirths at 139 and 165 days of gestation. There was a higher incidence of abortion (44.4%) in the 25‐mg‐dose group. Norlestrin treatment during early organogenesis also resulted in a higher abortion rate (37.5%) compared to treatment during late organogenesis (22.2% abortions). No morphological abnormalities were found in infants observed at birth or in juvenile monkeys which died of natural causes or in those that were sacrificed over a period of two years. No histopathology was observed in the 50‐day‐old fetuses examined by serial section. Examination of endogenous maternal serum estrogen and progesterone levels in Norlestrin‐treated monkeys (25 mg/day, days 21–35) suggested that placental steroidogenesis was not affected; however, the lower levels of estrogen in maternal serum suggested that the ovarian steroidogenesis was affected. Although the precise pathogenesis of this selective embryolethality is not known, several observations in this study suggest a direct generalized embryotoxic effect. Thus, this study for the first time has demonstrated that, while Norlestrin may be embryolethal at 100 times the human contraceptive dose equivalent (25 mg/day) in the rhesus monkey, nevertheless it does not affect the offspring which survive the exposure.
Some teratogenic properties of ethanol and acetaldehyde in C57BL/6J mice: Implications for the study of the fetal alcohol syndrome
Authors: Webster W. S. , Walsh D. A. , McEwen S. E. , Lipson A. H. 
Published: June 2005

AbstractTo investigate the teratogenic effect of acute alcohol exposure, pregnant C57BL/6J mice were exposed to 25% ethanol (either two doses of 2.9g/kg or one dose 5.8g/kg) during the organogenic period either by intraperitoneal injections or by intubation. The incidence of malformations varied according to (1) the stage of embryonic development at the time of exposure, (2) the route of administration of the alcohol, and (3) the amount of alcohol given and the time period over which it was administered. Oral doses of alcohol were teratogenic although less so than the same dose given intraperitoneally, and two intraperitoneal doses four hours apart produced significantly more malformations than the same two doses six hours apart. The primary metabolite of alcohol, acetaldehyde, was also investigated for its teratogenicity. It was found that one or two doses of four percent acetaldehyde (0.32g/kg), administered intraperitoneally were teratogenic. A further attempt was made to raise blood acetaldehyde levels by exposing mice to disulfiram, an inhibitor of acetaldehyde dehydrogenase, prior to administration of alcohol. The disulfiram pretreatment did not increase the malformation rate. Treatment with alcohol on day 7 or 8 caused a variety of facial abnormalities, some of which were comparable to those seen in children with fetal alcohol syndrome. Exposure on day 9 or 10 resulted in limb defects. The results suggest that one or more episodes of heavy maternal drinking at critical periods in pregnancy may severly damage the embryo and may produce many features of the fetal alcohol syndrome.
Evaluation of the association between birth defects and exposure to ambient vinyl chloride
Authors: Thériault Gilles , Iturra Hilda , Gingras Suzanne 
Published: June 2005

AbstractBirth defects incidence for infants born to residents of Shawinigan, Canada in 1966–1979 were significantly higher than in three comparison communities. Since there has been a vinyl chloride polymerization plant in this town since 1943 from which ten cases of angiosarcoma of the liver have been identified, this study explores the possible association between exposure to vinyl chloride monomer (VCM) in ambient air and the occurrence of birth defects in the community. The excess of birth defects fluctuated seasonally in a way that corresponded to changes in VCM concentration in the environment. Mothers who gave birth to malformed children were younger on average in Shawinigan than in the comparison communities. However, there was no excess of still‐births in Shawinigan. The excess in birth defects involved most organ systems, and variation in birth‐defect rates among school districts could not be accounted for by estimates of VCM in the atmosphere. The occupational and residential histories of parents who gave birth to malformed infants were compared with those of parents of normal infants. The two groups did not differ in occupational exposure or closeness of residence to the vinyl chloride polymerization plant. Some descriptive data from this study raised the hypothesis of an association between VCM in the air and birth defects in the exposed community, but as a whole, within the sample size available, such an association could not be substantiated.
Altered postnatal mitogenic responsiveness of adult rat splenic lymphocytes following in utero exposure to corn oil
Authors: Schmidt Richard R. , Abbott Patricia K. 
Published: June 2005

AbstractPregnant rats were administered 160,000 USP units of retinol acetate in 0.5 ml corn oil by gavage on the 15th–19th days of gestation. In addition to untreated pregnant controls, another group of pregnant animals received 0.5 ml corn oil only over the same gestational interval. Mitogenic responsiveness of splenic lymphocytes obtained from adult offspring was evaluated using an in vitro lymphocyte transformation assay. Splenic lymphocytes (5 ± 105/well) were cultured for either 48, 72, or 96 h in the presence of either concanavalin A (Con A), phytohemagglutinin (PHA), or pokeweed mitogen (PWM). Lymphocyte responsiveness to the T‐cell mitogens, Con A and PHA, was significantly reduced by 48 h of culture in the offspring of the corn oil control and retinol‐acetate‐treated groups and remained constant from 48 h to 72 h. Lymphocytes from the offspring of the untreated controls displayed a decreased mitogenic responsiveness to all three mitogens from 48 h to 72 h of culture. Responsiveness to the B‐cell mitogen, PWM, was similar for splenic lymphocytes of all three groups. Furthermore, a significant increase in cellularity was observed in spleens obtained from the mature offspring of the corn oil control and retinol‐acetate‐treated groups. No differences were observed between lymphocytes obtained from offspring of corn oil control and retinol‐acetate‐treated animals in any of the parameters studied. Results of the present study permit us to suggest that monitoring postnatal immune function subsequent to prenatal insult is an area that should be especially considered by teratologists.
Teratogenic action of hypolipidemic agents: An in vitro study with postimplantation rat embryos
Authors: Steele C. E. , New D. A. T. , Ashford A. , Copping G. P. 
Published: June 2005

AbstractTwo hypolipidemic agents known to be embryotoxic and teratogenic in vivo were found also to cause developmental abnormalities when added to the culture serum of rat embryos growing in vitro. However, development was normal when the embryos were grown in hypolipidemic serum (low in cholesterol and triglycerides) prepared from rats dosed with the hypolipidemic agents. The results indicated that it is a direct action of the agents on the embryos, and not the hypolidemia, which is harmful to embryonic development.
Retained developmental capacity of blastocysts transferred from lead‐intoxicated mice
Authors: Wide Mariann 
Published: June 2005

AbstractBlastocysts from mice injected with an implantation‐inhibiting dose of lead were transferred nonsurgically to pregnant foster mothers. This was done to obtain information about the ability of these blastocysts to implant and to develop into late fetal stages. There was no difference in the ability of lead‐treated blastocysts to implant as compared with the transferred nontreated blastocysts. Nor was there any effect of the exposure to lead before implantation upon the development of the blastocysts into normal fetuses. The results indicate that the preimplantation blastocysts are protected from possible harmful influences from the lead treatment of the mothers, and that the implantation failure in lead‐treated mice is not due to the inability of the blastocysts to implant. A significant increase in the frequency of exencephaly was observed in fetuses derived from transplanted blastocysts as compared with those from normal pregnant mice.
The pathogenesis of retinoic acid‐induced vertebral abnormalities in golden Syrian hamster fetuses
Authors: Wiley M. J. 
Published: June 2005

AbstractAdministration of single doses of retinoic acid to hamsters on days 7, 8, and 9 of pregnancy resulted in missing, irregular, and abnormally fused centers of ossification in the vertebrae of fetuses recovered near term. A study of early events in embryonic tissues following maternal treatment with 60 mg/kg of the teratogen on day 8 revealed a variety of changes which could be linked to the development of the bony defects. By 12 hours following treatment, the mean number of somites in teratogen‐exposed embryos was significantly reduced in comparison to controls. Within 24 hours of maternal treatment lesions were observed in the aortae of the retinoic acid‐exposed embryos. The vessels were consistently damaged caudally with dissection of aortic contents into the adjacent unsegmented mesoderm. Kinking of the neural tube, notochordal irregularities, and a loss of intercellular relationships in the paraxial mesoderm accompanied the vascular lesions. By 36 hours following treatment, abnormalities were evident in the appearance of the caudal somites, and at later stages these appeared to translate into defects in the sclerotomes and subsequently, the vertebrae. The observations suggest that vascular damage plays a significant role in the induction of the vertebral defects by disrupting somitogenesis. Moreover, the results support the hypothesis that retinoic acid produces abnormalities in the vertebral skeleton by a mechanism different from that which has been suggested to operate in the induction of defects in the limb skeleton.