bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some effects of continuous low‐dose congenital exposure to methylmercury on organ growth in the rat fetus
Authors: Chen Wei‐Jen , Bōdy Ralph L. , Mottet N. Karle 
Published: June 2005

AbstractCongenital low‐dose exposure of rat fetuses to methylmercury produced smaller offspring without anatomical abnormalities. The present study explored the mechanisms of the smallness of fetuses. The pregnant rats were given methylmercury water (25 ppm) from day 1 of pregnancy continuously until day 20 of gestation. There was a negative correlation of fetal weight and maternal and fetal mercury burden. The whole organ DNA and protein content of the livers and kidneys in the experiments were significantly lower than the control (P < 0.05) indicating that there were fewer cells per organ in the mercury exposed fetuses. When the data were compared on a per gram of tissue basis, there was no significant difference, indicating that the number and size of the cells of each were not diminished. The incorporation of 3H‐thymidine into fetal tissue DNA was also substantially lower in the experimental group indicating decreased proliferative activity. We conclude from this study that, at least for some major organs, the decreased size in the mercury exposed fetuses is due to fewer cells in the organs due to decreased proliferative activity.
Effects of influenza, mumps, and western equine encephalitis viruses on fetal Rhesus monkeys (Macaca mulatta)
Authors: Moreland A. F. , Gaskin J. M. , Schimpff R. D. , Woodard J. C. , Olson G. A. 
Published: June 2005

AbstractPregnant Rhesus monkeys were infected via instillation of influenza, mumps and western equine encephalomyelitis viruses respectively into the amniotic sacs at approximately 90 days gestation to determine if fetal infections would occur. Virus was recovered from fetal tissues after seven days in 100% of the exposed animals. Thus, the viruses are capable of causing fetal infection.Rhesus monkey fetuses were inoculated with influenza, mumps and WEE viruses by the direct intracerebral route at approximately 90 days gestation to determine possible teratogenicity of the viruses. Influenza virus caused no malformations or measurable fetal effects. Mumps virus resulted in significant fetal mortality. WEE virus resulted in a 100% incidence of encephalitis and hy‐drocephalus. Thus, mumps and WEE viruses are teratogens in primates and are potential teratogens of man.
Fetal mortality and malformations associated with experimental infections of Western equine encephalomyelitis vaccine virus in Rhesus monkeys (Macaca mulatta)
Authors: Moreland A. F. , Schimpff R. D. , Gaskin J. M. 
Published: June 2005

AbstractPregnant Rhesus monkeys were infected via installation of Western Equine Encephalomyelitis (WEE) vaccine virus into the amniotic sacs at 50 and 80 days gestation to determine if the resulting infections would produce fetal mortality or fetal malformations, particularly within the central nervous system.Of those receiving virus at 50 days gestation, 13 of 18 fetuses were aborted or dead in utero at time of Caesarean section; 2 of 18 were malformed (hydrocephalus and polyarthrosis); and 3 of 18 were anatomically normal. Of those receiving virus at 80 days gestation four of eight fetuses were aborted or dead in utero at time of Caesarean section, one of eight was malformed (hydrocephalus) and three of eight were anatomically normal. Three of three controls receiving neutralized virus at each gestational age were anatomically normal. Fetal WEE vaccine virus infection significantly increased fetal mortality and resulted in a significant incidence of fetal malformations.
Cerebral embryopathy in late first trimester: Possible association with swine influenza vaccine
Authors: Sarnat Harvey B. , Rybak Gottfried , Kotagal Suresh , Blair John D. 
Published: June 2005

AbstractAn infant girl was born with cerebral malformations characterized by developmental arrest late in the first trimester of gestation. These features included persistent pontine flexure, cerebellum developed only around the rhombic lip, failure of migration of inferior olive, absence of basis pontis and of corticospinal and corticopontine tracts, and agenesis of olfactory bulbs. The cerebral cortex was thin and poorly laminated, and primary and secondary sulci had failed to form. The choroid plexus contained vascular malformations, hemorrhages, and infarcts. The leptomeninges contained foci of primitive mes‐enchyme. The mother had received an inoculation of swine influenza vaccine six weeks after conception, followed by a 2‐week illness. The temporal relation to the timing of the cerebral malformation suggests a teratogenic effect of the vaccine, but may have been coincidental.
Sensitivity patterns for the induction of homeotic shifts in a favorable strain of mice,
Authors: Russell Liane B. 
Published: June 2005

AbstractIn an effort to develop a prescreening system that is sensitive, is compatible with in‐vivo administration of presumptive teratogens, and utilizes morphological endpoints, we are studying the induction of homeotic shifts in the axial skeleton. Our earlier work had demonstrated the existence of critical periods for certain such shifts, even though the (C57BL × NB)F1 hybrid used was not entirely suitable for this purpose. Using 100 R X‐rays on successive days during the period of major organogenesis, we have now analyzed the sensitivity pattern of the BALB/c, since this strain normally straddles thresholds for the position of axial borders. Mortality, birthweight, and skeletal anomalies were analyzed, in addition to the homeotic shifts. — Day 9 1/4 postconception was clearly the most sensitive stage for the production of posterior shifts at the thoraco‐lumbar border and the lumbo‐sacral border, and for increases in the number of sternebrae and costo‐sternal junctions. Anterior shift could be induced three days later, on day 12 1/4, but this was confined to only one of the four characters, the thoraco‐lumbar border. There are a number of indications that, at given stages during the study period, BALB/c embryos correspond developmentally to chronologically somewhat earlier stages of two strains studied previously. The present results do not support the hypothesis that factors influencing the quantitative skeletal characters act by way of body size. — Since homeotic shifts can be produced by a number of mechanisms and are obvious indications that developmental interference has occurred, and since such shifts are easy to score and convenient to analyze quantitatively, our identification of a highly suitable strain and of stages of maximum sensitivity in this strain should aid in making the system useful in the prescreening for chemical teratogens.
Prune perineum
Authors: Peeden Joseph Noble , Wilroy R. Sidney , Soper Richard G. 
Published: June 2005

AbstractAn infant, horn to unrelated parents, who had a rugated perineal mass which measured 17 cm in diameter is reported. No external genitalia or anal orifice was identified although the infant voided from a 5 mm crevice on the caudal surface of the mass. The patient died at four weeks of age. The perineal mass was made up of two separate sacs. The anterior sac resembled a urinary bladder in which two ureteral and a single vaginal orifice were identified. The posterior sac was continuous with the peritoneal cavity and contained bowel, left ovary, uterus and right kidney. The left kidney was small, polycystic and the right gonad a streak.
The extent of fetal ossification as an index of delayed development in teratogenic studies on the rat
Authors: Aliverti V. , Bonanomi L. , Giavini E. , Leone V. G. , Mariani L. 
Published: June 2005

AbstractIn teratogenic studies toxic effects may manifest themselves in retarded fetal development, such as a reduction in fetal weight. In searching for an additional index, the number of centers of ossification in seven skeletal districts (sternum, metacarpus, metatarsus, cervical and caudal vertebrae, anterior and posterior proximal phalanges) of rat fetuses delivered on days 19, 20 and 21 of gestation were counted and compared. Results showed uneven ossification in day‐19 and ‐20 fetuses, but sufficiently advanced, homogeneous an uniform ossification in day‐21 fetuses to provide a reliable quantitative index for evaluating retarded fetal development. It is therefore proposed that the stage of skeletal ossification in day‐21 fetuses be used in teratogenic studies in the rat to evaluate retarded fetal development.
Cerebellar malformations in prenatally X‐irradiated rats: Quantitative analysis and detailed description
Authors: Inouye Minoru 
Published: June 2005

AbstractPregnant WKAHok rats were exposed to 100 R or 200 R X‐irradiation on one of gestation days 16 through 21. Offspring were killed at 60 days of age and the cerebellum was examined. The cerebellum of animals exposed to 200 R was slightly reduced in weight but not in width. The observed reduction in the dorsoventrai length of the cerebellum was more evident when the X‐irradiation was early in gestation. The anteroposterior length of the hemispheres increased following exposure to X‐ray on days 16 through 19, and that of the vermis and paravermis decreased following treatment on days 17 through 21. Therefore, the anterior portions of hemispheres were situated anterior to the culmen in every 200 R group. Somewhat anteroposteriorly and horizontally directed lobules, as opposed to the normal transverse arrangement, were seen in the cerebellum of rats treated on day 16 or 17. Lobule contortion and fragmentation and an increased number of sublobules were striking in cases treated later. Histologically, ectopic Purkinje cells in the granule cell layer and white matter appeared following X‐irradiation on day 20 or 21, but they were not found following earlier treatment. In the cerebellum of animals exposed to 100 R the reduction in size was mild and the folial abnormalities were rare, but the number of sublobules decreased.
Affinity of intramitochondrial granules for ruthenium red accompanying induced cell death in chick embryos
Authors: Allenspach Allan L. , Rhodenbaugh Timothy C. 
Published: June 2005

AbstractTo test the hypothesis that ruthenium red binding of intramitochondrial granules might reflect an altered or pathological state of membranes associated with degeneration, embryos were treated with 6‐AN to induce cell death in cartilaginous skeletons of chick embryos. Cervical cartilage from normal, 6‐AN‐treated and nicotinamide‐alleviated 6‐AN embryos was examined ultrastructurally for presence of IM RR‐positive granules. Mitochondria of normal cervical chondroblasts which undergo normal phenotypic expression acquire RR‐positive granules, although few mature cells are observed in young embryos. Necrotic chondroblasts, chondroblasts in various stages of degeneration, and proliferating chondrogenic cells of 6‐AN‐treated embryos all demonstrated induced RR‐positive IM granules. Foci of degenerating chondroblasts, with mitochondria demonstrating RR granules, were observed infrequently in teratogen‐alleviated tissue. The cytological features induced by 6‐AN confirm its lethal effect and the degenerative effect on membranes presumably “unmasks” mitochondrial Ca‐affinity sites which then become RR‐positive. Cytochemical observations correspond with the biochemical and structural changes induced by 6‐AN and confirm the hypothesis that RR‐positive sites are the result of pathological changes.
Intersexes in the dog
Authors: Hinsch Gertrude W. 
Published: June 2005

AbstractA litter of five salukis was presented in which all of the individuals were intersexes or hermaphrodites. Anatomical abnormalities were observed. The external genitalia resembled a combination of penile sheath and vulva positioned approximately midway between the anus and umbilicus. At birth structures resembling scrotal sacs were present on either side of the genital structure. These were not apparent in older animals. Internal anatomy consisted of two gonads in a position expected for ovaries, oviducts, uterus and cord‐like structures lateral to the uterus which extended from gonad to inside of the “scrotal sacs.” Histologically. the gonads appeared to be ovaries which contained many dysgenic follicles. Cause of the condition is unknown.
Absorption of methylmercury by the fetal guinea pig during mid to late gestation
Authors: Kelman B. J. , Steinmetz S. E. , Walter B. K. , Sasser L. B. 
Published: June 2005

AbstractPregnant guinea pigs were injected with ∼ 1 μ/kg of CH3 203HgC1 at 22, 40, 47, 59, and 66 days of gestation, and fetal tissues were obtained 24 hours later. Autologous fetal erythrocytes were labeled with 51Cr and used to label the fetal blood pool at each gestational age except 22 days so that tissue‐bound Hg could be calculated. In general, Hg absorbed by the whole fetus increased during gestation, in parallel with increasing tissue mass, while Hg found in whole placentas remained the same. Hg concentrations in the whole fetus and placenta were closely correlated, as were Hg concentrations in brain, liver, and kidney. Liver, kidney, blood, and brain contained the highest Hg concentration early in gestation. While it is difficult to interpret the potential effects of the increased Hg concentrations, particular attention should be paid to the brain, since it is considered a target tissue in MeHg toxicity.
Palate morphogenesis. I. Immunological and ultrastructural analyses of mouse palate
Authors: Kuhn Evelyn Meyer , Babiarz Bruce S. , Lessard James L. , Zimmerman Ernest F. 
Published: June 2005

AbstractMidpalate was analyzed for the presence of nonmuscle contractile systems. The results indicate that increased amounts of actin and myosin are present in cells of regions 2 and 3. A localization of the contractile proteins in cellular projections directed against smooth muscle myosin and against skeletal muscle actin. Specificity of the immunofluorescence reactions was ascertained by immunoabsorption studies using purified myosin and actin. Electron microscopic observations of the mesenchymal cells in region 2 revealed 70Å microfilaments along the cell periphery and packed in fliopodia‐like projections which course between the cells. These cells, which surround a small ossification center, show no orientation, but extend up to the cranial base perichondrium and down into the shelf between the tongue side epithelium and the ossification center. The cells and projections are attached to each other by adherens and tight‐like junctions, forming a putative cohesive contractile network. Putative contractile cells in region 3 are strikingly aligned perpendicular to the oral epithelium and extend one‐third of the distance into the shelf. Projections from region 3 cells are contiguous with basement membrane material of the oral epithelium. Axonal bundles and single axons were commonly observed coursing through regions 2 and 3, often seen in close association with the mesenchymal cells. Both clear and dense‐core vesicles were found in the axons and cells of these regions. The possible role of these putative nonmuscle contractile cells in palate morphogenesis is discussed.
Maternal hormone therapy and congenital heart disease
Authors: Ferencz C. , Matanoski G. M. , Wilson P. D. , Rubin J. D. , Neill C. A. , Gutberlet R. 
Published: June 2005

AbstractExogenous female sex hormone exposure was studied in the mothers of 110 infants with conotruncal malformations of the heart, born in the years 1972–75. Cases were ascertained throughout the referral area of the Maryland State Intensive Care Neonatal Program. For each case, three normal controls were chosen from the birth popoulation: Two matched on eight characteristics related to the likelihood of hormone‐taking (race, maternal age, parity, fetal losses, gestational age, delivery mode, time of prenatal registration, private/service), and one also on the infant's sex and birthweight; the third control was chosen at random.In personal interviews, information was obtained on the mother's general health, family history, reproductive characteristics, pregnancy health, and environmental exposures. Identification of hormonal products was aided by a display of pills and packages. Maternal recall was examined in comparison to the responses of a group of mothers of infants with hypoplastic left heart (“disease controls”). Regression analysis on time elapsed since the infant's birth revealed no difference in recall between the mothers of cases and of controls.Multilogistic regression analysis, controlling for confounding variables and for scores constructed for reproductive, malformation, and exposure risks, showed no increase in relative risk for cases when compared with matched controls. When compared to random controls, the analysis suggested a possible increase in relative risk with increased environmental exposure scores; components of the risk score were excess smoking and alcohol intake, exposure to X‐ray, drugs, paints, insecticides, and chemicals. The possible significance of this finding needs to be further investigated.
Search for maternal factors associated with malformed human embryos: A prospective study
Authors: Matsunaga Ei , Shiota Kohei 
Published: June 2005

AbstractUsing data from 3,474 human embryos derived form induced abortion, various maternal factors ascertained prior to morphologic examination of the specimens were analyzed in association with the frequency of malformed embryos. The overall frequency of malformed embryos was 3.3%; polydactyly, holoprosencephaly, exencephaly with or without myeloschisis, and cleft lip accounted for 88% of the total malformations. Mothers of low parity showed an increased frequency of malformed embryos. There were nine embryos form mothers with thyroid disorders, of which one was affected with exencephaly and myeloschisis and another with holoprosencephaly and polydactyly; this finding may support the relation of maternal hyperthyroidism with anencephaly suggested by previoius case reports. The frequency of malformed embryos from mothers who drank alcohol was significantly lower than from those who did not. Several possibilities were suggested to interpret this unexpected finding. No association was verified with maternal age, irregular menstrual cycles, irradiation, contraceptive methods, maternal occupation, and a smoking habit, or with parental consanguinity. The limitation of this study is discussed in relation to both negative and positive results.
Effects of maternal diabetes on early embryogenesis: II. Hyperglycemia‐induced exencephaly
Authors: Sadler T. W. 
Published: June 2005

AbstractTeratogenic effects of hyperglycemia on early stages of embryogenesis were investigated using the whole embryo culture technique. Young (0–1 and 2–3 somites) and old (4–6 somites) mouse embryos were exposed for 24 h to diabetic levels of excess glucose equal to 5× and 8× the normal blood glucose levels. A high frequency of neural tube defects (exencephaly) was observed in embryos maintained at either concentration, and this effect was dose‐ and age‐dependent. Thus, younger embryos (0–3 somites) were more frequently affected than older ones, and more embryos were affected at the higher dose than the lower one. Although malformations were observed, amounts of total protein were similar between control and treated cultures except for the youngest (0–1 somite) embryos, which had significantly lower amounts of protein than controls. Histological analysis of embryos maintained in 8× glucose for 4, 8, and 24 h after initiation of culture showed only a slight amount of pyknotic debris in the neuroepithelium and revealed no other causes for the abnormality. Inhibition of neural tube closure observed in this study is similar to that occasionally described in infants of diabetic mothers, and suggests that hyperglycemia may play a role in production of the malformation.
The Down syndrome in the fetus
Authors: Stephens Trent D. , Shepard Thomas H. 
Published: June 2005

AbstractA significant number of fetuses with the Down syndrome are spontaneously lost before birth; however, very few such fetuses have been described. In the present study, 13 fetuses of 127–180 mm in crown‐rump length were examined following amniocentesis diagnosis of trisomy 21 and therapeutic abortion. Four features, i.e., simian crease, clinodactyly, septal heart defects, and decreased size, were found to be relatively common in trisomy 21 fetuses as compared to controls. Other features were found to be less useful in identification. We conclude that the presence of two of the four features noted above is suggestive of trisomy 21 in the fetus.
A study of fetal growth retardation in teratological tests: An examination of the relationship between body weight and ossification of coccygeal vertebrae in mouse and rat fetuses
Authors: Ariyuki Fumio , Higaki Koh , Yasuda Mineo 
Published: June 2005

AbstractWe examined the relationship between body weight and ossification of coccygeal vertebrae in normal full‐term fetuses of mice and rats to reliably evaluate fetal growth retardation in teratological tests. Correlation coefficients between body weight and number of ossified coccygeal vertebrae were positive in mice and rats. However, the coefficients were variable between groups and were not statistically significant in some groups. Averages of body weight and ossified coccygeal vertebrae were variable in the normal fetuses. However, the coefficient of variation in each group was nearly constant, and the component of variance between groups (\documentclass{article}\pagestyle{empty}\begin{document}$ \hat\sigma $\end{document}12) was small as compared with that within groups (\documentclass{article}\pagestyle{empty}\begin{document}$ \hat\sigma $\end{document}02). Therefore, the relationship between low body weight and retardation of ossification observed in teratological experiments may be evaluated by measuring relative differences of body weight and ossification between the treated group and the control group with the variance within groups (\documentclass{article}\pagestyle{empty}\begin{document}$ \hat\sigma $\end{document}0) as a scale.
An electrocardiographic study of cardiovascular problems in mirex‐fed rat fetuses
Authors: Grabowski Casimer T. , Payne Doris B. 
Published: June 2005

AbstractSperm‐positive female rats were intubated with pesticide, Mirex, in oil (5 to 10 mg/kg) on days 8½ to 15½. Controls were untreated or oil‐fed. Testing was done on day 18½. Fetuses were sequentially exposed and ECGs obtained with the fetus attached to the placenta and uterus. Counterparts of standard leads, I, II and III were used. Fetuses were weighed and examined afterwards. Swollen fetuses were rated on a scale of 1 (slight edema under chin) to 5 (3 mm edema across back). ECGs from 81 controls and 205 Mirex fetuses were obtained. They were evaluated for rate of heart beat, regularity of beat, PR intervals, and other features. One control exhibited an abnormality, a transitory period of premature atrial contractions. Mirex‐fed fetuses frequently exhibited tachycardia, closely correlated with degree of edema. The heart rate increased from 150/minute in controls to 180 in slightly swollen to 224 in swollen fetuses. Mean PR intervals increased with degree of swelling and with dose. The frequency of first degree heart‐block was also dose‐related, ranging from 20% in the 5 mg/kg group to 77% in the 10 mg/kg group. Second‐degree heart‐blocks were found in 8%, 3% showed arrhythmias, and one had atrial flutter/fibrillation. These cardiovascular problems seem primarily related to the Mirex‐induced edema and demonstrate that fetal edema is not innocuous. These data demonstrate the usefulness of fetal electrocardiography to detect functional teratology.