[Effects of dibenzyltoluene on fetal developments of rats].
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Abnormalities, Drug-Induced↗
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National Institute on Drug Abuse Conference report on placental proteins, drug transport, and fetal development.
The use of illicit and licit drugs during pregnancy is a major public health concern because of potential adverse effects on the fetus and the risk to maternal health. Because the placenta is the primary link between the mother and the conceptus and is essential for the growth and survival of the fetus, abnormalities in placental formation and function resulting from drug use could have a major influence on pregnancy outcome. At present, little information is available on the impact of abused drugs on placental biology alone or in combination with other "host" factors (eg, stress, infections). This prompted the National Institute on Drug Abuse (NIDA) to convene a meeting of experts in placental biology to review cutting-edge research with the mission to translate existing information to new clinical and research initiatives in the drug abuse field. This report summarizes the presentations and research recommendations resulting from the workshop discussions.
Female↗
The effect of viral and other infections of the dam on fetal development in swine. I. Modified live hog cholera viruses; immunological, virological, and gross pathological studies.
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Animals↗
Effects of acute doses of ethanol administered at pre-implantation stages on fetal development in the mouse.
The objective of the present study was to investigate the effects of maternal administration of acute doses of alcohol at preimplantation stages of pregnancy on the fetus and fetal membranes. Single doses of 0.02 ml and 0.03 ml/g body wt. of 25% v/v of absolute alcohol in saline were administered to groups of MF1 mice on one of days 1-6 of gestation. Controls were either pair-fed and pair-watered or saline-treated. Fetuses and placentae were collected on day 15. Resorption and fetal death were increased in most of the alcohol treatment groups. The reduction in fetal body weight was significant in the 0.03 ml group. Compared to the saline controls, most experimental groups exhibited a rise in placental weight. The reduction in cord length was significant in comparison to untreated controls. Craniofacial and systemic abnormalities appeared to correlate with retardation of fetal growth. Hence, following treatment of 0.03 ml/g body wt. of alcohol solution on days 2 and 6, fetuses were collected on days 14, 16 and 18. Most fetuses were found to recover gradually from anomalies associated with growth retardation but the 'catch up' growth was not adequate enough to compensate for the reduction in body weight. These observations indicate that the pre-implantation stage of mouse embryo development is susceptible to the deleterious effects (fetal death and intrauterine growth retardation) of acute doses of alcohol.
Animals↗
Local immune system in the developing fetal larynx.
Using histopathological and immunofluorescent techniques, we investigated the development of the glandular system of the larynx from 12 human fetuses. Glandular buds were first observed at the fourth month of gestation and glandular distribution became evident from the fifth month in the larynx. Ciliated or nonciliated epithelium covered the cavity of the larynx, with the exception of the true vocal cord. Immunofluorescent examination revealed the presence of IgG in the fetal larynx, but there was little fluorescence for IgA, IgM and IgE. Secretory component (SC) synthesis, on the other hand, was found in each serous-type glandular epithelium or acinus from the fourth month on. Our observations suggest that the local immune system by SC, which binds to IgA as SIgA in human laryngeal mucosa, is inherently acquired in the fetal larynx.
Epithelium↗
Hyaluronate metabolism undergoes an ontogenic transition during fetal development: implications for scar-free wound healing.
Wound healing in the fetus occurs by a different process from that in the adult. Instead of healing with scar formation, fetal cutaneous wounds heal by regeneration that results in complete restoration of normal skin architecture. The mechanisms responsible for this remarkable phenomenon involve factors in the fetal environment and properties intrinsic to fetal cells. Hyaluronic acid (HA) is a major component of the fetal extracellular matrix (ECM) and is believed to play an important role in this process. In this study, HA and HA-stimulating activity (HASA) in fetal and adult wound fluid were examined using sensitive, newly developed assays. In an ovine model, higher levels of HA and HASA were observed in fetal as compared with adult wound fluid. This difference was most prominent in wound fluid from fetal lambs at 75 and 100 days gestation (term = 145 days); these samples contained persistently elevated HA and HASA levels for up to 2 weeks after wounding (HA peak levels 145 micrograms/mL and 110 micrograms/mL, respectively). In contrast, wound fluid from 120-day-gestation fetuses had significantly lower levels (P < .001) that were transient and similar to that in the adult (HA peak levels 70 micrograms/mL and 10 micrograms/mL, respectively). These observations confirm an ontogenic transition in wound HA metabolism from a fetal to an adult-like phenotype. Levels of HASA as a function of time after wounding correlated with levels of HA, suggesting a role for HASA in controlling HA deposition during tissue repair. Two patterns of HASA and HA synthesis were noted.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Murine fetal development enhanced by dietary vitamin A, corn oil, and inositol.
Previous work on the effects of dietary vitamin A on craniofacial anomalies in mice revealed that 18-day-old fetuses from dams given 200 IU of vitamin A in corn oil daily in their diet weighed approximately 10% more than fetuses from mothers fed the unsupplemented standard mouse diet, Purina 5001. In the experiments reported here, it has been found that water-soluble vitamin A (200 IU/day) and myo-inositol (5 mg/day) added separately to the diets of pregnant mice increased the weight of 11-day gestations by approximately 25% and enhanced development of the eyes by the equivalent of 0.5-1.0 day without significantly affecting development of the liver or hind limbs. Corn oil alone (0.2 ml/day) had a similar effect on weight and eye development of 11-day fetuses and, in addition, growth of the hind limbs was enhanced modestly. The addition to the diet of vitamin A (200 IU/day) dissolved in corn oil (0.2 ml/day) resulted in a 25% increase in the weight of the 11-day fetuses and enhanced development of the eyes and hind limbs by the equivalent of about 1 day of gestation, suggesting that corn oil contains a factor(s) that interacts with vitamin A to accelerate limb development. Corn oil contains very small quantities of beta-carotene or retinol (< 1.0 IU vitamin A/ml); however, it is a rich source of the essential growth factors linoleic and linolenic acids and of inositol esters. The data suggest that the growth-promoting actions of dietary corn oil are due in part to the inositol esters.
Animals↗
[Importance of diets and their effect on fetal development: function and structure of the endocrine pancreas following protein deficiency during intrauterine life].
When an isocaloric low protein diet (8% versus 20%) is administrated to rats during gestation, the fetus or the neonate has a lower body weight and the structure and function of the endocrine pancreas is altered: islet cell proliferation, islet size and islet vascularisation are reduced when compared with a control group. If these fetal islets are cultured during 7 days in vitro, they secrete less insulin than normal islets in response to an AA challenge. When these newborns are fed with a low protein diet until adult age and analyzed at 70 days, the same alterations of the endocrine pancreas persist: the in vitro insulin secretion of the isolated islets in response to AA is dramatically depressed although their response to glucose is normal. However in vivo glucose and insulin levels in response to oral glucose challenge are abnormal. In addition, permanent functional alterations seem to persist when induced in utero. A normal diet (20% protein) given from birth to adulthood does not restore a normal insulin response in vivo to an oral glucose challenge.
Animals↗
Fetal development of the auditory tube and paratubal musculature.
The purpose of this study was to describe the prenatal development of the human auditory tube and paratubal musculature. Twenty prenatal specimens, 8 to 36 weeks of age postconception were embedded in celloidin, sectioned, and stained with hemotoxylin eosin. Qualitative data on the initial appearance and development were obtained using light microscopy (Plates I-VI). Linear and angular measurements were obtained from traced sections. The analysis showed the following: morphological differentiation of this area occurs between 8 and 16 weeks menstrual age; tubal structures develop in anterior-posterior and medial-lateral gradients; the tubal lumen of the perinatal fetus is cylindrical and lacks an isthmus; the allometric growth of the cartilaginous portion of the lumen between 16 and 28 weeks is responsible for the greatest increase in the tubal length during the fetal period.
Cartilage↗
Normal anatomy of the developing fetal brain. Ex vivo anatomical-magnetic resonance imaging correlation.
Fetal brain Magnetic Resonance Imaging (MRI) is a new technique of growing interest, with a high potential to detect prenatal central nervous system abnormalities. This requires an accurate knowledge of the normal morphological sequence of brain development. In this paper we studied the cortical development of post-mortem normal fetal brains, correlating MRI estimations of fetal age with in vitro anatomical and anthropometric measurements. Ten post-mortem fetal heads were submitted to MRI. Maturational state of sulci and gyri and gray-white matter differentiation were analysed in the MRIs and by dissection of the brains. The findings were correlated with the previously estimated ages of the fetuses, which varied between 17 and 38 weeks. Consistency between methods was assessed employing intraclass correlation coefficient and Bland-Altman plots, with a 95% confidence interval. Estimations of fetal age obtained by MRI were very similar to those achieved by anthropometric measurements or by considering anatomical parameters. Gyral development proved to be more precise than gray-white matter differentiation for this purpose. Fetal MRI proved to be as reliable as the macroscopic anatomical examination for depicting normal cortical developmental sequence and age, suggesting that this technique may be a suitable option for achieving precise information about the morphology of human brains along the gestational period.
Aging↗
Fetal development and neuronal/glial cell specificity of cAMP-dependent protein kinase subunit mRNAs in rat brain.
All known actions of cAMP in the brain require cAMP-dependent protein kinase (cAMPdPK), which consists of regulatory (R) and catalytic (C) subunits (R2C2). Using homologous rat cDNAs for all known cAMPdPK subunit isoforms found in the brain (RI alpha, RI beta, RII alpha, RII beta, C alpha, C beta) we observe that, in the fetal rat brain from 12 days of gestation to birth, while alpha subunit (RI alpha, RII alpha, C alpha) mRNA levels are abundant, beta subunit (RI beta, RII beta, C beta) mRNA levels increase from undetectable or very low levels to abundant levels. Furthermore, while alpha subunit mRNA levels are abundant in both primary neuronal and primary glial cultures, beta subunit mRNA levels are very low (C beta) or undetectable (RI beta, RII beta) in primary glial cultures, but are abundant in primary neuronal cultures. Thus, prior to about 12 days of gestation, cAMP in the brain may act only via the alpha cAMPdPK subunits in neuronal and glial precursor cells. After 12 days of gestation, coincident with the onset of final cell division in neurons, beta cAMPdPK subunits may also mediate the effects of cAMP predominantly in neurons.
Animals↗
[Effect of a traditional herbal medicine, tokishakuyakusan, on the fetal development of the spontaneously hypertensive rat].
Forty-three pregnant spontaneously hypertensive rats were administered 1.5% saline and divided into 2 groups: The experimental group of 21 rats and the control group of 22 rats. The animals in the experimental group were administered daily 500 mg/kg of Tokishakuyakusan. No drug was administered to the animals in the control group. Systolic blood pressure measured from 4 to 18 days of pregnancy was similar in both the experimental and control groups. Mean (+/- S.E.) levels of blood viscosity in the experimental group measured on the 19th day of pregnancy were 13.6 +/- 1.6 centipoise (cp) at a shear rate of 0.5/sec and 3.5 +/- 0.1 cp at a shear rate of 230/sec and were significantly lower than those of the control group (19.1 +/- 1.6 cp at 0.5/sec, p less than 0.02; 4.4 +/- 0.2 cp at 230/sec, p less than 0.001). There were observed no significant differences in hematocrit, erythrocyte deformability and fibrinogen levels between two groups. There was observed no significant difference between the mean number in the litter in the 2 groups. The mean weight of the fetuses in the experimental group delivered on the 19th day of pregnancy was 2.4 +/- 0.1 g, being significantly heavier than that of the control group (2.0 +/- 0.0 g) (p less than 0.01). These results indicated that Tokishakuyakusan accelerated development of fetuses of hypertensive rats by utero-placental circulatory improvement which was caused by decreased maternal blood viscosity.
Animals↗
Tenascin: an extracellular matrix protein involved in tissue interactions during fetal development and oncogenesis.
The extracellular matrix protein tenascin (previously described as myotendinous antigen) is selectively present in the mesenchyme surrounding fetal rat mammary glands, hair follicles, and teeth, three organ anlagen where the mesenchyme is essential for development. No tenascin is detectable in the normal adult mammary gland. Carcinogen-induced mammary tumors contained tenascin in their fibrous tissue. As reported for the molecule described as a "hexabrachion," tenascin contaminates so-called "cell-surface fibronectin," where it accounts for most of the detectable hemagglutinating activity. Of the extracellular matrix proteins compared, tenascin is the least effective substrate for attachment of primary mammary tumor cells, but the most effective in promoting cell growth after serum is removed from the culture medium.
Adenocarcinoma↗
The morphology of ciliogenesis in the developing fetal human respiratory epithelium.
Segmental imaging studies of the respiratory epithelium from human embryos and fetuses of normal karyotype have demonstrated that ciliogenesis and ciliation of the respiratory epithelium starts at 7 weeks of gestation. Ciliated cell differentiation follows a pre-determined pattern of distribution. It starts exclusively in the upper segment of the membranous trachea and spreads distally. Ciliation of the carinal angle takes place at 8 weeks of gestation. Three patterns of basal body formation were identified. The various morphological features encountered are described and compared with those observed in cases of Immotile Cilia Syndrome and other pathological conditions. Ciliation of the respiratory epithelium in the cartilaginous trachea does not take place until after the 12th week of gestation. The morphological findings identified in our case material are in agreement with those observed in the developing respiratory epithelium of other higher mammals.
Bronchi↗
Fetal development in cattle with multiple ovulations.
Treatment of lactating and nonlactating parous cows (n = 379) with 12 mg of FSH-P to evaluate development of multiple bovine fetuses resulted in ovulation rates ranging from 1 to 27 corpora lutea (CL). Fertilization rate (i.e., ova fertilized at 6 to 8 d postmating, 80.0%) was not affected by ovulation rate. The percentage of fetuses developing normally at 51 to 53 d postmating decreased (P less than .01) as ovulation rate increased; 1 CL, 100.0%; 2 CL, 100.0%; 3 CL, 66.7%; 4 CL, 45.8%; 5 CL, 33.3%; 6 to 10 CL, 13.6%; and greater than 10 CL, 8.9%. Of the 86 cows permitted to calve, 47 produced singles, 22 twins, 9 triplets, 7 quadruplets, and 1 quintuplets. Calf birth weight and gestational length decreased (P less than .01) as the number of calves born increased from one to two to three. Smaller decreases (P less than .05) in birth weight occurred among triplets, quadruplets, and quintuplets, whereas gestational length did not differ (P greater than .1) among these groups. Systemic progesterone concentrations in the dam were proportional (P less than .01) to the number of fetuses in utero between d 126 and 266 for dams gestating one, two, or three or more fetuses; estrone sulfate was lower (P less than .01) in dams with one than in those with two or more fetuses. Placental weight (i.e., cotyledons plus intercotyledonary membranes) per fetus at 52 +/- 1 d of gestation and at term decreased as the number of fetuses increased. The chorioallantoic membranes were often fused among multiple fetuses and contained either all viable or all dead fetuses, but not both, within the same anastomosed placental unit. These results suggest that ovulation rate is the first limiting factor to increasing cow productivity for beef cattle because some bovine females had the capacity to gestate up to three fetuses per uterine horn, or a total of five fetuses, above which pregnancy was terminated.
Abortion, Veterinary↗
Lipid peroxidation in developing fetal guinea pig brain during normoxia and hypoxia.
Lipid peroxidation in the fetal guinea pig brain was studied at 30, 35, 40, 45, 50, and 60 days of gestation. Conjugated dienes and fluorescent compounds, indices of lipid peroxidation, peaked at 35 days of gestation, decreased by 45 days, and remained at that level until birth. The higher levels of peroxidation products in early gestational periods (30-40 days) suggest that either the anti-oxidant mechanisms for scavenging oxygen free-radicals and further metabolizing oxidation products are underdeveloped, or the rate of peroxidation is higher than periods near term. Prenatal hypoxia increased the levels of conjugated dienes and fluorescent products in the brains of preterm (50 days) and term (60 days) fetuses. Brain homogenates incubated in air at 37 degrees C underwent rapid lipid peroxidation as measured by the level of thiobarbituric acid (TBA)-reactive substances. However, term brain showed a higher rate of peroxidation and attained higher steady state levels of TBA-reactive substances than preterm brain. This may be due to the higher levels and degrees of unsaturation in fatty acids in term brain. Following hypoxia, term brain showed 5 times the rate of lipid peroxidation and a 3-fold increase in total TBA-reactive substances over controls. These studies show that a significant degree of lipid peroxidation is occurring in the fetal brain during gestation and that the developing brain is more susceptible to lipid peroxidation near term. Furthermore, prenatal hypoxic stress further increases the susceptibility of the brain to peroxidative reactions.
Animals↗
[Effect of fenibut and seduxen on fetal development in the second half of pregnancy].
In experiments on rats it was found that fenibut (50 mg/kg, 1/20 of LD50) during a single and repeated administration in the fetus period of pregnancy does not exert any negative effect on the maternal organism, the growth and development of the fetus. Seduxen administered in a dose of 50 mg/kg (1/80 of LD50) alone and in combination with fenibut was shown to decrease the female body weight gain and to disturb the fetus development. Following a single administration on the 17th day of pregnancy, the effect was poorly pronounced.
Animals↗
Fetal development and regulation of pituitary cell types.
The ontogenesis of the pituitary gland is considered from anatomical and functional points of view. Embryogenesis of the hypothalamo-pituitary unit involving development of the hypothalamo-hypophyseal portal system is complete during early life as shown in several mammalian species. The ultrastructural characteristics of the different cell types during development are described according to observations made by using immunochemical techniques. The patterns of differentiation of the cell types are reviewed according to studies of pituitary glands from human anencephalic fetuses and encephalectomized rat fetuses as well as in vitro studies of cultured pituitary primordia in synthetic media. The maturation of the neuroendocrine mechanisms controlling the secretion of fetal hormones is also analyzed. During fetal life, the factors implicated in the regulation of pituitary hormone secretion are generally the same as in adults, but the intensity of the response of pituitary cells to their action is variable according to the species, thus reflecting an immaturity in the functioning of certain cell types.
Animals↗