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PubMed2004

Effect of grazing system on fetal development in Nellore cattle.

Intensive grazing systems for beef females, based on abundant availability of high quality forages and supplementary concentrates, may affect fetal development. The objective of this study was to determine the effect of grazing system on length of gestation, fetal development, and characteristics of the calf at birth. Twenty-four pregnant (bred to Nellore bulls) Nellore females were allocated into two groups. The control group (G1) grazed Brachiaria decumbens (signal grass) in a traditional (extensive) grazing system and the second group (G2) were managed on Panicum maximumcv. Tanzania 1 (Tanzania grass) in an intensive grazing system. Fetal development was evaluated by ultrasonography on days 31, 45, 59, 94, 122, 220, and 255 of gestation. The diameter of the amniotic and allantoic cavities, crown-rump length, circumference, and diameter of the head and ocular orbit were determined. At birth, calves were weighed and height, length, thoracic circumference, and ocular orbit and bi-parietal diameters were measured. There were no differences (P > 0.05) in fetal development. The G1 cows had a longer gestation period (4.5 days; P<0.05) and their calves had greater (P<0.05) weight, height, length, and thoracic circumference at birth. In conclusion, Nellore females raised under intensive pasture management conditions, had significantly shorter gestation and smaller calves at birth than those raised under extensive pasture management conditions. Therefore, adoption of new management practices (e.g. intensive pasture management), should take into consideration animal behavior and productivity.

Animal Nutritional Physiological Phenomena↗

PubMed1986

Possible effects of electric blankets and heated waterbeds on fetal development.

Seasonal patterns were seen in fetal growth and in abortion rate for families using electrically heated beds. These patterns could be attributed to the seasonal use of heated beds. The fact that such seasonal patterns were seen only in users, and not in nonusers, of electrically heated beds suggests that electrical bed heating may have a direct effect on fetal development. The effect could be due to excessive heat or to electromagnetic field exposure.

Abortion, Spontaneous↗

PubMed1990

Characterization of human alpha fetoprotein charge microheterogeneity during fetal development.

Aliquotes of human amniotic fluid (AF), fetal serum (FS), and cord blood (CB) were obtained as by-products of routine clinical diagnostic procedures at term or in the second trimester of pregnancy. When samples of CB were applied to a pH 5.5-4 chromatofocusing gradient, three isoforms of AFP could be resolved; a pl 4.57 form (isoform IA, 52% AFP), a pl 4.27 form (isoform IB, 43% AFP), and one species that was bound to the column but could be eluted with 1.0 M NaCl (isoform II, pl less than 4.00, 5% AFP). Term AF displayed a profile similar to that observed in term CB. When samples of 15-20-week gestation AF were chromatofocused, the immunoreactive AFP recovered was distributed between isoform IA and IB (60%) and isoform II (40%). FS and AF obtained from same pregnancy (23-26 weeks) displayed an identical chromatofocusing profile. Aliquotes of AF subjected to conA revealed 83% reactive variants compared with greater than 95% reactive variants for CB. FS displayed a conA profile identical to CB. When individual CB charge isoforms were isolated and subjected to conA analysis, greater than 97% of the AFP bound to conA. In contrast, when AFP isoform IA and IB were isolated from midgestation AF, approximately 22% of the AFP did not bind to the lectin while 100% of isolated AFP isoform II eluted as the reactive variant. These data suggest that human AFP exists as at least three charge and two lectin variants and that the charge profile may change during fetal development.

Amniotic Fluid↗

PubMed2004

Effects of an antisense oligonucleotide inhibitor of human ICAM-1 on fetal development in rabbits.

The potential for reproductive toxicity of an antisense oligonucleotide designed to inhibit ICAM-1 was evaluated as part of the safety assessment for this compound. The human active ICAM-1 inhibitor (ISIS 2302) is not pharmacologically active in rabbits. Female rabbits were treated once daily on Day 6 through 18 of gestation. Rabbits were treated with 0, 1, 3, and 9 mg/kg ISIS 2302 by daily i.v. injection. Reproductive indices evaluated included estrus cycling, litter parameters, fetal development, and fetal body weight. Concentrations of oligonucleotide in plasma following the last dose, and in selected maternal target organs, placenta, and fetal tissues at scheduled necropsy were also measured. Maternal toxicity was evident as a decreased maternal body weight gain, decreased food consumption, and scant feces at doses > or =3 mg/kg. Increased spleen to body weight ratio and increased mononuclear cell infiltrates were indicative of a proinflammatory effect of ISIS 2302 at the 9 mg/kg dose level. Despite the maternal toxicity, there were no changes in litter parameters or fetal development in rabbits treated with ISIS 2302. The only change was a decrease in fetal body weight at the 9 mg/kg dose level, which was attributed to the maternal toxicity observed. Maternal liver and kidney contained dose-dependent concentrations of oligonucleotide, but there was relatively little or no oligonucleotide measured in placenta or fetal tissues. Thus, there was no dose-dependent exposure and maternal toxicity to ISIS 2302, but no reproductive toxicity in rabbits, and exposure of fetus or pups is negligible.

Animals↗

PubMed2001

Effects of a 4.7 T static magnetic field on fetal development in ICR mice.

In order to determine the effects of a 4.7 T static magnetic field (SMF) on fetal development in mice, we evaluated fetal teratogenesis and endochondral ossification following exposure in utero. Pregnant ICR mice were exposed to a 4.7 T SMF from day 7.5 to 9.5 of gestation in a whole-body dose, and sacrificed on day 18.5 of gestation. We examined the incidence of prenatal death, external malformations and fetal skeletal malformations. There were no significant differences observed in the incidence of prenatal death and/or malformations between SMF-exposed mice and control mice. Further, we evaluated the immunoreactivity for the vascular endothelial growth factor (VEGF), which is implicated in angiogenesis and osteogenesis, in the sternum of fetal mice following magnetic exposure. Our studies also indicated that on day 16.5 of gestation following SMF exposure, the immunoreactivity for VEGF was increased compared to unexposed controls. However, it was decreased in the exposed group compared to the control group on day 18.5 of gestation. DNA and proteoglycan (PG) synthesis were also measured in rabbit costal growth plate chondrocytes in vitro. No significant differences were observed in DNA synthesis between the SMF exposed chondrocytes and the control chondrocytes; however, PG synthesis in SMF exposed chondrocytes increased compared to the controls. Based on these results, we suggest that while SMF exposure promoted the endochondral ossification of chondrocytes, it did not induce any harmful effects on fetal development in ICR mice.

Abnormalities, Radiation-Induced↗

PubMed2004

Effects of human and murine antisense oligonucleotide inhibitors of ICAM-1 on reproductive performance, fetal development, and post-natal development in mice.

The potential for reproductive toxicity of an antisense oligonucleotide designed to inhibit ICAM-1 was evaluated as part of the safety assessment for this compound. Since antisense compounds are often specific to the species in which they are intended to work, both the human and murine active ICAM-1 inhibitors were tested (ISIS 2302 and ISIS 3082, respectively). Male and female mice were treated prior to cohabitation, through cohabitation, gestation, delivery, and weaning. Mice were treated with 0, 3, 6, and 12 mg/kg ISIS 2302 or ISIS 3082 by daily i.v. injection. Reproductive indices evaluated included estrus cycling, sperm count and motility, fertility, litter parameters, fetal development, delivery, fetal body weight, lactation, and weaning. Behavioral assessment and reproductive capacity of the F1 generation mice was assessed on selected animals. Concentrations of oligonucleotide in selected maternal target organs, placenta, fetal tissues, and expressed milk were also measured. There were no changes in reproductive performance, litter parameters, fetal development, or postnatal development in mice treated with either ISIS 2302 or ISIS 3082. Maternal liver and kidney contained dose-dependent concentrations of oligonucleotide, but there was relatively little or no oligonucleotide measured in placenta, fetal tissues, or expressed milk. Neither the human nor murine-specific antisense inhibitor of ICAM-1 produced any reproductive toxicity in mice, and exposure of fetus or pups was negligible.

Animals↗

PubMed1999

Effects of exposure of a surfactant, polyoxyethylene(10)nonylphenyl ether (NP-10), to sperm on embryonic and fetal development in rabbits.

The effects of exposure of a surfactant, nonoxynol(NP-10), to sperm on embryonic and fetal development were studied using rabbits. In the preliminary test, the concentration of NP-10 at which total sperm immobility was 0.01% and nonfertilizing was 0.008% in vitro. No implantation was observed at the concentration of 0.032% NP-10 in vivo. Based on these results, the rabbit semen was treated either with 0.04, 0.01 or 0.0025% NP-10 solution, and used for artificial insemination to examine if the sperm was fertile as well as to determine the effect of NP-10-treated sperm on embryonic and fetal development. Gestation was not observed after insemination with semen treated with 0.04% NP-10; after insemination with semen treated with 0.01 and 0.0025% NP-10, it occurred without impairing the viability, organogenesis or growth of embryos or fetuses. These results may indicate that gestation may not be possible with sperm severely impaired by exposure to NP-10, but no untoward effect on embryonic or fetal development may be observed when gestation is initiated with exposed semen.

Animals↗

PubMed2005

[Consequences of smoking on fetal development and risk of intra-uterine growth retardation or in utero fetal death].

Active and passive smoking constitutes one of the most serious public health problems due to the deleterious effect on the expected infant and the mother. These effects are dose dependent as illustrated by intra-uterine growth retardation, where the effect worsens with duration of smoking during pregnancy, and also by other conditions such as abrutio placentae or placenta praevia, premature rupture of the membranes and preterm birth, where the risk is multiplied by two (or even three)! In utero death is the ultimate sanction. Studies on the consequences of maternal smoking on fetal development have demonstrated the cardiovascular effect (CO and nicotine) and the respiratory effect (CO) which can be aggravated after birth by passive smoking. Teratogenic and cancerogenic effects have also been clearly demonstrated. Maternal smoking would also affect fetal brain development with negative effects on the major neurotransmitter systems (domaminergic, serotinergic, noradrenergic) and on the development of key structures such as the prefrontal cortex, certain limbic structures including the hippocampus and other structures implicated in motor function such as the ventral striatum. These development anomalies of the brain could give rise, after birth, to psychological, behavioral, attention and cognitive disorders, further arguments in favor of an effective anti-smoking policy including appropriate care for smoking pregnant mothers in both hospital and outpatient settings.

Female↗

PubMed2005

Embryonic and fetal development in a commercial dam-line genotype.

During depopulation of a breeding unit within Swine Graphics Enterprises, extensive data were collected and used to examine relationships among ovulation rate, the pattern of prenatal loss, and placental and fetal development. Groups of Large White x Landrace females (n=447) were slaughtered between day 20-30, 50-55 or 85-90 of gestation, with approximately equal numbers of animals representing gilts and parity 1 (G/P1), parity 2-3 (P2/3), and parity >4 (P4+). Ovulation rate and embryo number were recorded for all animals. With the exception of the G/P1 animals, embryonic and placental weight were recorded for four conceptuses per sow on day 20-30; on day 85-90 two conceptuses per sow were dissected to determine placental and fetal development. Ovulation rate (22.7 +/- 0.2 overall) was higher (P <0.05) in P2/3 (23.6 +/- 0.4) and P4+ (24.7 +/- 0.4) than in G/P1 (20.2 +/- 0.5). Embryonic/fetal survival was 61.8 +/- 2.1% at day 20-30, 50.2 +/- 2.2% at day 50-55 and 48.7 +/- 1.9% at day 85-90 and the number of surviving conceptuses was higher (P <0.05) in the P2/3 sows than in other parity groups. There was no relationship between ovulation rate and number of live embryos at day 20-30 or 85-90. At day 20-30 and 85-90, embryo weight was positively correlated with placental weight, but neither placental weight nor embryonic/fetal weight was correlated with number of viable embryos. A parity by gestation day interaction existed; placental weight for P4+ (3.42 +/- 0.43 g) was less than for P2/3 (7.55 +/- 0.40 g) at day 20-30 (P <0.0001), whereas at day 85-90, placental weight of P2/3 (209.5 +/- 8.5 g) was less (P=0.05) than both G/P1 (235.7 +/- 7.3g) and P4+ (235.4 +/- 7.1 g). At day 85-90, fetal brain weight, relative to body weight (R2=0.61, P <0.0001), and fetal brain:liver weight ratio (R2=0.35; P <0.0001) were negatively related to mean fetal weight, and brain:liver weight ratio showed a trend towards a relationship with number of viable fetuses (P=0.08). Parity also affected brain:liver weight ratio (P=0.01). Clearly, high ovulation rates in the higher parity sows have the potential to cause excessive in utero crowding of conceptuses in the post-implantation period. Even with moderate crowding, increased brain:liver weight ratios in smaller fetuses in late gestation indicate that uterine capacity impacts fetal development as well as the number of surviving fetuses.

Animals↗

PubMed1988

Application of high-performance liquid chromatography for the study of the microheterogeneity changes of mouse alpha-fetoprotein in fetal development.

Changes in the microheterogeneity of mouse alpha-fetoprotein (MAFP) during fetal development were investigated by high-performance liquid chromatography (HPLC). A total of six distinct isoforms (Iso-1, Iso-2, Iso-3, Iso-4, Iso-5, Iso-6) of the heterogeneous MAFP were resolved from mouse amniotic fluid (MAF). Analysis of MAF collected at various times revealed that these isoforms were accumulated at different stages of the fetal development.

Animals↗

PubMed1981

Changes of sulfated mucopolysaccharides and mucopolysaccharidases during fetal development.

The changes of sulfated mucopolysaccharides and mucopolysaccharidases during bovine fetal development were analyzed. It is shown that chondroitin sulfate C increases in concentration up to the 50th day of fetal development and then decreases progressively until its complete disappearance in most adult tissues. Likewise, hyaluronidase also reaches a peak on the 50th day and decreases in activity until its disappearance in adult tissues. On the other hand, heparitin sulfate and chondroitin sulfate B as well as beta-glucuronidase and beta-N-acetylglucosaminidase remain without significant changes during the whole period. The fetal chondroitin sulfate C is tissue specific with different molecular weights depending on the tissue of origin. Some properties of fetal muscle and brain hyaluronidase are also described. The possible role of chondroitin sulfate C and hyaluronidase in the processes of differentiation and division is discussed in view of the present findings.

Acetylglucosaminidase↗

PubMed2005

Fetal development of striated and smooth muscle sphincters of the male urethra from a common primordium and modifications due to the development of the prostate: an anatomic and histologic study.

BACKGROUND: The aim of the study was to investigate the development of the human urethral sphincter complex during fetal development. METHODS: 23 human male fetal specimens were investigated. The histological sections were processed according to the epoxy resin-based plastination technology. RESULTS: At 9th week of gestation, a combined sphincteric primordium of the rhabdosphincter and the lissosphincter is situated at the anterior and lateral aspects of the membranous and prostatic urethra. Both muscular components assume an omega-shaped configuration due to the presence of a constant connective tissue raphe posterior to the urethra that anchors the rhabdosphincter in the perineal body. Development of the prostate laterally and posteriorly does not modify the growth of the urethral sphincter complex anteriorly but inhibits its development laterally and posteriorly. CONCLUSIONS: The important morphological characteristics of the male adult rhabdosphincter and lissosphincter can be seen very early in fetal development.

Fetal Development↗

PubMed1978

Specific binding of estrogens in different fetal tissues of guinea pig during fetal development.

Cytosol and nuclear specific estradiol binding was evaluated in the fetal uterus, kidney, lung, and brain of guinea pig during fetal development and after birth. The quantity of specific binding sites increases during fetal development and decreases after birth, particularly that of the nuclei. An exception is the binding in the cytosol fraction of lung in which the number of available binding sites continues to increase in newborn animals. In the fetal uterus the amount of specific binding of estradiol and estrone is similar. The selective uptake of radioactivity and its localization by autoradiography in cell nuclei are in accordance with the high levels of estrogen receptors, particularly at the end of gestation.

Animals↗

PubMed1990

Parathyroid hormone-related peptide in normal human fetal development.

Parathyroid hormone-related peptide (PTHrP) has been detected in fetal serum and amniotic fluid. Using a combination of immunocytochemistry and molecular biology we have detected the peptide and its mRNA in a variety of fetal tissues throughout gestation. Tissue-specific mRNA isoforms were observed, the pattern of hybridization of which changed throughout gestation. In addition, the intensity and pattern of immunocytochemical localization of the peptide was found to vary over the time-period studied (8-30 weeks). PTHrP is expressed by a variety of tumours associated with the syndrome of humoral hypercalcaemia of malignancy and probably accounts for the hypercalcaemia by virtue of its limited amino acid homology with parathyroid hormone. These data demonstrate for the first time that PTHrP, a tumour-related peptide, is expressed during normal human fetal development, and suggest the possibility that it may function to regulate fetal calcium balance and growth in utero.

Amniotic Fluid↗

PubMed1989

Epithelial proliferation in thymic hyperplasia. An immunohistochemical study and correlation with the developing fetal thymus.

Thymic hyperplasia is a B-cell lymphoid proliferation in which an epithelial component has not, to our knowledge, been previously described. We present a case of thymic hyperplasia in which numerous lymphoid follicles with germinal centers were partially surrounded by small sheets of spindle and epithelioid cells. Electron microscopy confirmed the epithelial nature of these cells. Immunostaining was performed using antibodies to keratins, S100 protein, and two B-cell markers, LN1 and MB2. The proliferated epithelium stained only for high-molecular-weight keratin, whereas the lymphoid tissue stained positively for both B-cell markers. To determine the origin of the proliferated epithelium, the staining was compared with that of the developing fetal and normal adult thymus. We have shown that during fetal development, the keratin composition of thymic epithelium changes from staining predominantly with low- to high-molecular-weight keratin. The immunostaining characteristics of the epithelium in this case of thymic hyperplasia suggest an origin from adult-type epithelium. Furthermore, the association of S100-positive interdigitating reticulum cells with the proliferated epithelium suggests that it is of medullary origin. Our results indicate that epithelial proliferation can be an important component of thymic hyperplasia.

Aged↗

PubMed1994

Effects of prenatal exposure to 50 Hz magnetic fields on development in mice: I. Implantation rate and fetal development.

Pregnant CD1 mice were exposed or sham-exposed from day 0 to day 17 of gestation to a 50 Hz sinusoidal magnetic field at 20 mT (rms). Preimplantation and postimplantation survival were assessed and fetuses examined for the presence of gross external, internal, and skeletal abnormalities. There were no statistically significant field-dependent effects on preimplantation or postimplantation survival, sex ratio, or the incidence of fetuses with internal or skeletal abnormalities. Magnetic field exposure was, however, associated with longer and heavier fetuses at term, with fewer external abnormalities. The results lend no support to suggestions of increased rates of spontaneous abortion or congenital malformation following prenatal exposure to power frequency magnetic fields.

Abnormalities, Radiation-Induced↗

PubMed1988

Placental and fetal development in straightbred and reciprocal crosses of Yorkshire and Ossabaw swine.

Placental and fetal development were compared in 7 Yorkshire (Y) and 12 feral, Ossabaw (F) gilts mated to Y and F boars to produce straightbred and reciprocal cross litters (YY, YF, FY and FF, sire listed first). Gilts were slaughtered at d 75 +/- 2 of gestation. Ovulatory rate and litter size were higher in Y than in F gilts; however, rates of embyonal survival were similar in all groups. Groups differed in fetal body weight, metabolic body weight, crown-to-rump length, placental weight, metabolic placental weight and placental surface area, respectively. The YY group had highest values and the FF group smallest values for all variables except placental surface area. Pearson product-moment correlation coefficients of placental development with fetal length and weight across breeding groups were significant (e.g., placental surface area: fetal length, r = .67; placental surface area: fetal metabolic body weight, r = .76). It is concluded that the relationship between placental and fetal development observed in domestic swine is present in feral swine and crosses between domestic and feral swine at this gestational stage. These developmental measures are significantly influenced by fetal genotype and uterine environment but also by the breed of sire.

Animals↗

PubMed1987

Fetomodulin: marker surface protein of fetal development which is modulatable by cyclic AMP.

A novel cell surface marker of fetal development was identified in both in vivo and in vitro systems of the mouse using monoclonal antibodies against a glycoprotein of an apparent size of 133,000 Da. Two independent clones of hybridomas were isolated by fusing murine myeloma cells, NS-1, with spleen cells of a rat which was immunized with murine 3T3 fibroblast. The analysis of molecular size and tryptic peptides of the immunoprecipitate indicated that fibroblast and putative parietal endoderm cells, which were derived by induced differentiation of F9 embryonal carcinoma cells with retinoic acid and cyclic AMP, expressed apparently the same protein. Undifferentiated F9 cells and F9 cells which were treated with retinoic acid or cyclic AMP alone had little or no immunoprecipitable proteins. Analogously, parietal endoderm of in vivo embryos tested positive for this protein but visceral endoderm and embryonic ectoderm did not. The amount of this surface protein was increased in fibroblast and differentiated F9 cells by elevation of intracellular cyclic AMP concentrations. These results are consonant with a hypothesis that this surface protein plays a role in fetal development via a quantitative modulation by cyclic AMP.

Animals↗