Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Fetal Resorption”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1998

Defects in embryonic hindbrain development and fetal resorption resulting from vitamin A deficiency in the rat are prevented by feeding pharmacological levels of all-trans-retinoic acid.

Vitamin A is required for reproduction and normal embryonic development. We have determined that all-trans-retinoic acid (atRA) can support development of the mammalian embryo to parturition in vitamin A-deficient (VAD) rats. At embryonic day (E) 0.5, VAD dams were fed purified diets containing either 12 micrograms of atRA per g of diet (230 micrograms per rat per day) or 250 micrograms of atRA per g of diet (4.5 mg per rat per day) or were fed the purified diet supplemented with a source of retinol (100 units of retinyl palmitate per day). An additional group was fed both 250 micrograms of atRA per g of diet in combination with retinyl palmitate. Embryonic survival to E12.5 was similar for all groups. However, embryonic development in the group fed 12 micrograms of atRA per g of diet was grossly abnormal. The most notable defects were in the region of the hindbrain, which included a loss of posterior cranial nerves (IX, X, XI, and XII) and postotic pharyngeal arches as well as the presence of ectopic otic vesicles and a swollen anterior cardinal vein. All embryonic abnormalities at E12.5 were prevented by feeding pharmacological amounts of atRA (250 micrograms/g diet) or by supplementation with retinyl palmitate. Embryos from VAD dams receiving 12 micrograms of atRA per g of diet were resorbed by E18.5, whereas those in the group fed 250 micrograms of atRA per g of diet survived to parturition but died shortly thereafter. Equivalent results were obtained by using commercial grade atRA or atRA that had been purified to eliminate any potential contamination by neutral retinoids, such as retinol. Thus, 250 micrograms of atRA per g of diet fed to VAD dams (approximately 4.5 mg per rat per day) can prevent the death of embryos at midgestation and prevents the early embryonic abnormalities that arise when VAD dams are fed insufficient amounts of atRA.

Animals↗
PubMed1995

In vivo immunosuppressive effects of recombinant ovine interferon-tau (trophoblastin): r.oTP (r.oIFN-tau) inhibits local GVH reaction in mice (PLN assay), prevents fetal resorptions, and favors embryo survival and implantation in the CBA/J x DBA/2 mice combination.

PROBLEM: Ovine trophoblastin protein, be it natural or recombinant (oTP,r.oTP), a member of the tau interferon family (r.oIFN-tau), has been shown to possess immunosuppressive properties in vitro. It acts as a cytostatic agent across species. Indeed, it was immunosuppressive when tested on human and murine lymphocytes in a variety of in vitro immune assays, as it is also on syngenic (ovine) lymphocytes. METHODS: In the present paper, we first verified that this property to act across species also occurred in vivo assays; r.oTP was able to down regulate a local GVH reaction assay (PLN assay) in mice. We then took advantage of these properties of r.oTP to investigate its in vivo effects during murine pregnancy as there is no ovine equivalent of the murine CBA/J x DBA/2 resorption prone mating combination. RESULTS: When given in the postimplantation period, r.oTP drastically boosted resorptions in the CBA/J x DBA/2 matings, as did murine recombinant gamma interferon. However, the same r.oTP treatment in the peri-implantation period resulted in a reduction in resorptions in this spontaneous abortion system. CONCLUSION: The data suggested that r.oTP might have acted more by favouring implantation and embryo survival than by preventing the resorption process itself. The mechanisms possibly underlying these effects, as well as the putative uses of r.oTP evolving from these data, are discussed.

Age Factors↗
PubMed1996

T helper 1 response against Leishmania major in pregnant C57BL/6 mice increases implantation failure and fetal resorptions. Correlation with increased IFN-gamma and TNF and reduced IL-10 production by placental cells.

Maternal immune responses can influence fetal survival and several cytokines have harmful or protective effects on pregnancy. The Th1 cytokines IFN-gamma and IL-2 can cause fetal loss, whereas the Th2 cytokine IL-10 is protective. However, infections such as leishmaniasis show the opposite pattern: resistance is associated with the preferential mounting of a Th1 response, whereas a Th2 response exacerbates the disease. We therefore asked whether the curative Th1 response against Leishmania major in genetically resistant C57BL/6 mice, would compromise concurrent pregnancy. The number of resorptions as assessed by uterine scars was significantly increased in infected C57BL/6 mice and this was associated with a decreased production by placental cells of the Th2 cytokines IL-4 and IL-10 and increased production of IFN-gamma and TNF. Interestingly, the frequency of pregnancy failure before implantation in C57BL/6 mice was also substantially increased. In contrast to C57BL/6 mice, early infection did not reduce implantations in BALB/c mice that mount a Th2 anti-L. major response and succumb to infection. For both resorptions and implantations, there appeared to be a short period early in infection that was detrimental to pregnancy, followed by a period with lesser effects, and a later period that again induced higher resorptions or pre-implantation losses. These results suggest that a beneficial anti-parasite Th1 response can adversely affect pregnancy outcome. Furthermore, Th1 cytokines may be deleterious for not only placental maintenance but also preimplantation events.

Animals↗
PubMed2000

Abnormal development of the sinuatrial venous valve and posterior hindbrain may contribute to late fetal resorption of vitamin A-deficient rat embryos.

BACKGROUND: Normal embryonic development and survival in utero is dependent on an adequate supply of vitamin A. Embryos from vitamin A-deficient (VAD) pregnant rats fed an inadequate amount of all-trans retinoic acid (atRA; 12 microg per g of diet or approximately 230 microg per rat per day) exhibit severe developmental abnormalities of the anterior cardinal vein and hindbrain by embryonic day (E) 12.5 and die shortly thereafter. METHODS: In the present study, we sought to determine whether supplementation of VAD-RA supported (12 microg per g of diet) pregnant rats with retinol (ROL) at the late-gastrula (presomite or rat E9.5) or early somite stages (E10.5), or provision of higher levels of atRA throughout this period could prevent abnormalities in the developing cardiovascular and nervous systems. RESULTS: A newly described defect in the sinuatrial venus valve along with enlarged anterior cardinal veins and nervous system abnormalities and the later death of embryos are prevented by supplementing pregnant animals with ROL on the morning of E9.5. If ROL supplementation is delayed by 1 day (E10.5), most embryos are abnormal and die by E18.5. Supplementation of VAD rats with atRA (250 microg per g of diet) between E8.5 and E10.5 also prevents the cardiovascular and nervous system abnormalities and a significant number of these embryos survive to parturition. Thus, high levels of atRA can obviate the need for ROL between E9.5 and E10.5. CONCLUSIONS: These results support an essential role for retinoid signaling between the late gastrula and early somite stages in the rat embryo for normal morphogenesis of the primitive heart tube and the posterior hindbrain. Further, these results suggest that embryonic death occurring at midgestation in the VAD rat may be linked to the abnormal development of one or both of these embryonic structures.

Abnormalities, Multiple↗
PubMedDate not supplied

Morphometric analysis of the histology of spontaneous fetal resorption in a murine pregnancy.

Immunopathology of the spontaneous resorption phenomenon in the CBA x DBA/J murine model was explored using morphometric analysis. Accompanying the previously reported presence of natural killer (NK) cells in resorptive feto-placental units we find major changes in tissue morphology indicating that early infiltration of the feto-placental unit by maternal leukocytes plays a direct role with NK cells in fetal demise. Total number of cell nuclei per field and total nuclear area per field were significantly elevated in feto-placental units containing abnormally increased NK cell presence before detectable resorption as early as day 7 of gestation. This difference persisted throughout all stages of early gestation up to and including the final resorption event at day 10 to 12. Increases in cell density were also detected in areas of the embryonic unit not associated with NK infiltration. These results demonstrate that the spontaneous resorption phenomenon in this model involves: (i) Early (day 7-8) cellular infiltration of the decidual-ectoplacental cone junction associated with the presence in this area of NK cells. (ii) Late (day 8-9) cellular infiltration of the ectoplacental cone.

Animals↗
PubMed1994

Relationship between decidual leukocyte infiltration and spontaneous abortion in a murine model of early fetal resorption.

The relationship between the early cellular response to embryo implantation and subsequent embryo survival was explored. Immunohistochemistry using the anti-CD11b antibody (Mac-1) was used to localize and quantify maternal inflammatory cells present at the fetoplacental interface. CD 11b is expressed mostly on macrophages, but is also present on natural killer (NK) cells, neutrophils, and B cells. The occurrence of CD11b-positive cells at the fetoplacental interface was quantified in CBA/J females mated by DBA/2 males (20-30% embryo loss) and CBA/J females mated by BALB/c males (5-10% embryo loss) in order to investigate the relationship between infiltration by these types of cells and subsequent embryo loss. CD11b-positive cells were found to infiltrate decidua of each embryo starting at Day 6 of gestation. Their numbers sharply increased on Days 7 and 8, to a plateau on Days 8 to 10, well before any damage to the embryo is macroscopically visible on Days 10 to 12 of gestation. The resorption-prone mating of CBA/J female by DBA/2 male showed a significantly elevated number of CD11b-positive cells in 26% of the embryos on the eighth day of gestation compared to CBA/J female by BALB/c male matings which were taken as the reference mating. Moreover, experimental conditions modulating fetal survival in CBA/J mothers such as poly (I:C) treatment of DBA/2-mated females (lower survival) or mating with BALB/c males (higher survival than with the mating with DBA/2 males), were found to be associated with high or low numbers numbers of CD11b-positive cells at the fetoplacental interface. Furthermore, injection of anti-CD 11b into pregnant mice at Day 6 of gestation significantly reduced the subsequent incidence of resorption in the resorption prone CBA/J x DBA/2 mating. These results suggest that CD11b-positive cells are associated with the etiology of spontaneous abortion in this system.

Abortion, Spontaneous↗
PubMed1984

Effect of simultaneous prenatal exposure to ochratoxin A and citrinin in the rat.

Ochratoxin A (OA) and citrinin (CT) are food-borne mycotoxins produced by several fungal species of the genera Aspergillus and Penicillium. Both are teratogenic in the rat. To determine the prenatal effects of simultaneous exposure to these toxins, pregnant Sprague-Dawley rats were injected either with a single individual subthreshold teratogenic dose of OA (1 mg/kg) or CT (30 mg/kg) or with both toxins. Toxins were dissolved in 5% sodium bicarbonate and administered subcutaneously on one of gestation d 5, 6, 7, 8, 10, 11, or 14. Maternal body weight gain of animals in the combination group was similar to other treatment groups and the control. Approximately 22-40% mortality in dams occurred on gestation d 5, 6, 7, and 14. Other than d 7, there was no significant effect on the number of implants. Treatment on d 5 or 7 resulted in increased fetal resorptions. Fetal body weights were not decreased significantly. OA and CT in combination resulted in a significant increase in gross malformations on d 6 and 7, visceral anomalies on d 5, 7, 8, and 10, and skeletal defects on d 5, 6, 7, 8, 10, and 14. When administered individually, OA and CT resulted in very few fetal resorptions. Fetal body weights were not significantly different except on d 8 of gestation following CT treatment. Individual toxin treatment resulted in minimal malformations on all gestation days. These results suggest that OA and CT, when administered concurrently, may interact to enhance prenatal toxicity and teratogenicity, and these results have focussed attention on the public health hazards of contamination of food with these mycotoxins.

Abnormalities, Drug-Induced↗
PubMed1994

Effects of sensory stimuli on the incidence of fetal resorption in a murine model of spontaneous abortion: the presence of an alien male and postimplantation embryo survival.

Pregnancy outcome may be altered by both genetic and environmental factors. The mating of CBA/J female mice with DBA/2 males normally results in pregnancies characterized by a relatively high incidence of early embryo compared with most other syngeneic or allogeneic matings. This study addressed the role of normal laboratory stress in the induction of early embryo loss. The previously studied 'Bruce effect' describes the total loss of preimplantation embryos (pregnancy block) that is apparently caused by the stress induced by the presence of an alien male and mediated by neuroimmunological effects on prolactin activity. To determine whether this effect could be responsible for the high incidence of postimplantation embryo losses in the CBA/J x DBA/2 model, the original DBA/2 male was replaced on day 6 of gestation by another DBA/2 male, a CBA/J, a C57Bl/6 or a BALB/c male. The relatively high incidence of embryo loss was not affected by removing the original DBA/2 male or introducing another DBA/2 or a CBA/J male, indicating that stress induced by an alien male did not increase the postimplantation losses in this model. Furthermore, the introduction of a DBA/2 male to a CBA/J female that had been mated with a BALB/c male did not elicit early embryo loss. However, the replacement of the original DBA/2 male by a BALB/c male dramatically reduced the incidence of early embryo loss in pregnant CBA/J female mice. The introduction of a C57Bl/6 male also reduced embryo loss but to a lesser extent.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗
PubMed1990

The influence of dietary folate supplementation on the incidence of teratogenesis in zinc-deficient rats.

Two studies were conducted to investigate the possibility that pteroylmonoglutamic acid supplementation would alleviate teratogenesis in zinc-deficient rats. Pregnant rats of the Wistar strain were fed on Zn-deficient (less than 0.5 mg Zn/kg) or Zn-supplemented (75 or 95 mg Zn/kg) diets from mating until day 18.5 of gestation. The basal level of pteroylmonoglutamic acid added to all diets (0.56 mg/kg) was supplemented with 30-200 mg/kg in selected diets. Dietary Zn deprivation resulted in fetal resorption, fetal growth retardation and reduced concentrations of Zn in fetuses and maternal plasma and tibia. Low maternal body-weight at conception emerged as an important determinant of risk of resorption in Zn-deficient rats. Dietary Zn deficiency resulted in reduced maternal plasma folate concentrations and these values were inversely correlated with litter size or weight in Zn-deficient rats. Pteroylmonoglutamic acid supplementation increased maternal plasma folate concentrations, but did not reduce the high incidence of teratogenesis which occurred in Zn-deficient rats. Supplementation of Zn-deficient rats with pteroylmonoglutamic acid significantly increased the incidence of clubbed foot and tended to increase the incidence of brain or meningeal abnormalities, or both, and cleft palate, but did not reduce maternal or fetal Zn status. Pteroylmonoglutamic acid supplementation also increased the weights of Zn-supplemented control fetuses.

Animals↗
PubMed1986

Immunogenetic studies of spontaneous abortion in mice. II. Antiabortive effects are independent of systemic regulatory mechanisms.

CBA/J females (H-2k) mated with DBA2/J males (H-2d) exhibit a high rate of fetal resorption. Fetal survival has been improved by pretreatment of CBA/J females with spleen cells from BALB/c J (H-2d) (but not from CBA/J or DBA/2/J) males. Similarly, three out of nine recombinant inbred strains (recombining BALB/c and DBA2 genomes at the homozygous state) possess antiabortive effects like the BALB/c parent. Previous studies showed that BALB/c pretreatment triggers the appearance of suppressor cells in the spleen and of IgG1 anti-H-2d antibodies in the serum of CBA/J females. Studies of these two immunological parameters after CBA/J preimmunization by the different recombinant strains suggest that local intrauterine immunoregulation is the determinant of success or failure of allopregnancy.

Abortion, Veterinary↗
PubMed1982

Maintenance of pregnancy in ovariectomized rats with steroid analogs and the reproductive ability of the progeny.

The quantity of and the temporal requirements for natural steroids and steroid analogs were studied over the course of pregnancy after ovariectomy. A series of experiments determined that progesterone (3 mg/day) maintains the free blastocyst and when subsequently combined with estradiol supports implantation, and pregnancy through Day 20. The amount of estradiol (100 ng/day) that adequately induces blastocyst implantation and supports pregnancy through Day 13 had to be continued throughout pregnancy to prevent fetal resorption. Fetal survival was benefited if the estradiol dose was doubled from Day 13 to termination. During this study a within strain difference appeared which reduced the number of blastocysts that implanted. This problem was resolved by ovariectomizing the pregnant rats on Day 4 before 1000 h rather than on Day 3. Substitution of dydrogesterone (9 beta, 10 alpha-pregna-4, 6-diene-3, 20-dione) for progesterone on an equal weight basis and diethylstilbestrol (DES) for estradiol (2 for 1) proved adequate to maintain pregnancy to term. The pups were delivered by cesarean section and raised by surrogate mothers. As the females matured they experienced normal first estrus and subsequent estrous cycles. When bred they had litters of normal numbers. The males were fecund and sired litters of normal numbers. The cross-reactivity of dydrogesterone in estrogen, testosterone, corticosterone, progesterone and 20 alpha-hydroxy-pregn-4-one-3-one radioimmunoassays was nil. Thus, steroid analogs can adequately support the entire course of pregnancy after fertilization in ovariectomized rats.

Animals↗
PubMed1992

Sodium nitroprusside increases cyclic GMP in fetal rat bone cells and inhibits resorption of fetal rat limb bones.

To elucidate the role of cGMP in bone resorption, the nucleotide was measured in bone and bone cells in response to several agents including stimulators of bone resorption. In other experiments, sodium nitroprusside (SNP), which elevates bone cGMP, was tested for effects on resorption. In cells from 20-day fetal rat calvaria, cGMP was 52.4 +/- 8.4 fmol/10(6) cells; cAMP was 5.3 +/- 0.3 pmol/10(6) cells. SNP, 0.1 mM, in the presence of IBMX, increased cGMP 74% with no significant effect on cAMP. Parathyroid hormone (PTH), 0.5 microM, did not significantly affect cGMP, but increased cAMP 711%. Calcitriol did not affect either nucleotide. In bone resorption studies, 0.1 mM SNP inhibited the effects of PTH and calcitriol. Lower concentrations of SNP (0.001, 0.01 mM) had no effects on hormone-stimulated resorption. Unstimulated control bones were not affected by 1 nM-1 mM SNP. The results suggest that elevated cGMP could result in inhibition of bone resorption.

1-Methyl-3-isobutylxanthine↗