PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Embryo Loss”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed1979

A possible influence of the bull on the incidence of embryonic mortality in cattle.

Milk progesterone profiles were used to study the high incidence of embryonic mortality between 30 to 80 days after insemination in 91 cows in a single herd. The progesterone levels dropped to basal values at 46.7 +/- 1.37 days after service in 22 per cent of apparently pregnant cows. Embryo loss occurred significantly more frequently following services by one bull (Z). The mortality rates were 14/32 (44 per cent) in cows conceiving to Z compared with 8/73 (11 per cent) in cows conceiving to other bulls. There was no significant effect of the age of the cow or yield on the incidence of embryonic mortality.

Animals↗
PubMed1992

Manipulation of reproduction in sheep.

Active immunization of cyclic ewes against androstenedione (using melatonin, Fecundin) has been shown to increase reproductive output by about 30 extra lambs per 100 ewes put to the ram in UK sheep flocks. However, this technique has not been widely adopted within the industry. One possible reason for this is that it results in an unacceptable incidence of triplet births, even though the litter size distribution is similar to that obtained for untreated flocks with the same overall mean lambing percentage. The use of progestagen sponges plus pregnant mares' serum gonadotrophin (PMSG) for the induction of out-of-season breeding in ewes is associated with a number of recognized shortcomings. A possible reason for the variability in conception rates is the high incidence of complete embryo loss or fertilization failure in ewes that are induced to superovulate after treatment with the doses of PMSG required to promote a high oestrous response. Recent studies have indicated that slow release implants of melatonin (Regulin) can advance the onset of the breeding season of commercial sheep flocks, but only by about 4 weeks. This means that the optimum treatment window varies according to the natural breeding season characteristics for the breed. Nevertheless, this treatment appears to overcome a number of the shortcomings of progestagen sponges plus PMSG. It also produces a modest increase in litter size per ewe pregnant (about 15 extra lambs per 100 ewes) without the wide variation in birth types and birth weights associated with PMSG. The development of a laparoscopic procedure that improves conception rates after intrauterine insemination of frozen semen allows comparisons of genetic merit across flocks. This should promote far greater rates of genetic improvement for traits of high economic importance than those achieved by within-flock selection and in the last two years has allowed the development of sire-referencing schemes within the major terminal sire breeds. Laparoscopic procedures for the collection and transfer of embryos in sheep now have the potential to overcome many of the limitations of more invasive surgical approaches, although the unpredictability of superovulatory responses remains a particular obstacle to full exploitation of multiple ovulation embryo transfer (MOET) for genetic improvement through the female line.

Animals↗
PubMed1975

The embryotoxicity of ytterbium chloride in golden hamsters.

Two experiments were performed to assess the embryotoxicity of intravenously administered ytterbium chloride in golden hamsters: (1) 50, 75, 100, or 150 mg/kg ytterbium chloride were injected early on the 8th gestation day; (2) 100 mg/kg ytterbium chloride were administered at 4 different times during the critical period of organogenesis in this species (7th day, 4 PM; 8th day, 8 AM or 4 PM; 9th day, 8 AM). The pregnant females were killed on the 12th, 14th, or 15th gestation day and the frequency of resorptions was determined, and surviving offspring were studied for the presence of external and internal malformations as well as skeletal damage. Relatively few externally visible malformations and no significant internal malformations were produced. Damage to the skeletal system included fused and supernumerary ribs, and many different sites of poor ossification. Maximal susceptibility to these effects occurred on the 8th day.

Abnormalities, Drug-Induced↗
PubMed1977

The effect of intrauterine position on the radiosensitivity of rat embryos.

Rats were exposed to gamma rays or helium ions on one of days 4-9 of gestation. Embryonic survival was recorded as a function of intrauterine position at autopsy on day 20 of gestation. Embryos located at the ovarian and cervical ends of the uterus experienced higher rates of mortality than did their littermates located at the middle of the uterine horn. This effect was observed in litters exposed to both radiation modalities on all days studied. The influence of intrauterine position on embryonic survival was directly proportional to radiation dose and to the number of fetuses occupying the uterus horn. Under the least advantageous conditions (i.e., a crowded uterine horn exposed to a moderately high radiation dose), the cervical embryo's probability of survival was less than half that of the litter as a whole. A disproportionately high rate of embryonic mortality at the cervical position was also observed in litters irradiated under hypoxic conditions, suggesting that the non-random distribution of radiation effect was not the result of variations in oxygen concentration within the uterus. In contrast, there was no indication that intrauterine position influenced the distribution of gross morphologic abnormalities in irradiated litters.

Animals↗
PubMed2026

Mechanism of Shoutai Wan against recurrent spontaneous abortion: regulation of decidual vascular remodeling via ERβ-ANGPT2 signaling axis.

Shoutai Wan (STW), a classic traditional Chinese medicine formula used to tonify the kidney and prevent miscarriage, has been widely applied in the clinical management of recurrent spontaneous abortion (RSA). Increasing clinical evidence supports its efficacy in reducing miscarriage rates and improving pregnancy outcomes. However, the molecular basis by which STW alleviates defective decidual vascular remodeling in unexplained RSA remains insufficiently understood. Clinically, decidual ERβ and ANGPT2 expression, as well as serum estradiol, ANGPT2 and VEGFA levels were significantly decreased in RSA patients, accompanied by reduced decidual microvascular density. Furthermore, ERβ expression was positively correlated with ANGPT2 and microvascular density. In vivo, STW dose-dependently reduced embryo loss in RSA mice, repaired the damaged decidual-placental interface structure, and improved vascular maturation, structural stability and endothelial-pericyte ultrastructural connections. Mechanistically, STW upregulated ERβ expression. We demonstrated that ERβ binds to the ANGPT2 promoter, suggesting transcriptional upregulation of ANGPT2, thereby activating Tie2 and the downstream PI3K/AKT pathway and increasing NO and VEGFA secretion. In vitro, hypoxia inhibited ERβ nuclear translocation and ANGPT2 secretion in mDSCs, while STW-containing serum reversed these abnormalities. ERβ knockdown impaired the pro-angiogenic capacity of mDSCs, which was partially rescued by exogenous ANGPT2 supplementation. Network pharmacology predicted that STW targets were mainly enriched in PI3K-Akt, estrogen, VEGF and angiogenesis-related pathways. Transcriptomic GSEA further revealed that the gene signatures of angiogenesis and PI3K-Akt signaling were markedly suppressed in the RSA model, and STW treatment significantly normalized these transcriptional signatures.

Female↗
PubMedDate not supplied

Embryonic susceptibility of Microtus ochrogaster (common prairie vole) to phenyl mercuric acetate.

Pregnant M. ochrogaster received single intraperitoneal (i.p.) doses of 0.06, 0.125, 0.25, 0.5, 1,2, or 5 mg phenyl mercuric acetate (PMA/kg of body weight on day 8, 9, or 10 of gestation or 0.5 mg PMA/kg on day 7, 8, 9, 10, 11, or 12 of gestation. No toxicity was exhibited, and no abnormal fetuses were observed in any group. An embryocidal effect that depended on dose and stage of development was determined by increased numbers of resorption sites; resorption sites were dose-dependent, and the embryocidal effect decreased as the embryo matured. A dose of 0.06 mg PMA/kg of body weight produced no resorptions when given on day 8 or day 10 of gestation; 0.125 mg/kg produced no resorptions if given on day 10; 0.5 mg/kg resulted in live fetuses and resorptions in the same uterus when given on days 7 through 11; the same dose on day 12 produced all live fetuses; and 1, 2, or 5 mg PMA/kg given on day 8, 9, or 10 of gestation caused total embryo resorption. The i.p. LD50 of PMA in Microtus ochrogaster adult females was 10 mg/kg of body weight.

Animals↗
PubMed1979

Pinealectomy-induced changes in blood and pituitary luteinizing and prolactin levels during the last phase of pregnancy in rats.

Serum LH levels were higher in pinealectomized than in sham-operated control rats during all 4 of the last days of pregnancy studied, although reaching significance only during the final 2 days, 21 and 22. Prolactin (Prl) levels in the serum on the final day of pregnancy, and its contents in the pituitary throughout the entire study period, were significantly lower in pinealectomized rats. Pituitary weights were lower in pinealectomized than in control animals during days 21 and 22 of pregnancy, but no differences were found between the 2 groups in the average number of living foetuses and resorptions. The results presented would seem to indicate that during the last phase of pregnancy the pineal gland plays a role in the modification of gonadotropin synthesis and release. It appears that with LH the release, and with Prl mainly the synthesis, is being affected by the pineal, although the release of Prl may be influenced as well.

Animals↗
PubMed2026

Therapeutic effect and anti-inflammatory mechanism of modified Shoutai pills against lipopolysaccharide-induced miscarriage in mice.

OBJECTIVE: To elucidate the anti-inflammatory mechanisms of modified Shoutai pills (, MSTP) in miscarriages, we performed transcriptome sequencing on the decidua and placental tissues of pregnancy mice. METHODS: The therapeutic effects and anti-inflammatory mechanisms of MSTP were studied in mice with lipopolysaccharide (LPS)-induced miscarriage. First, the effects of MSTP on pregnancy outcomes and the maternal-fetal interface, in LPS-induced miscarriage mice were examined. RNA sequencing was used to further investigate gene expression changes in LPS-induced miscarriage mice and to assess the effects of MSTP intervention. Finally, the expression levels of inflammation-related genes in the decidua and placental tissues were determined using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: A high dose of MSTP significantly decreased the resorption rate (P < 0.05) and reduced apoptosis of the decidua and placental tissues in mice. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that inflammatory and immune-related signals were enriched. qRT-PCR results confirmed that in decidual and placental tissues, MSTP reduced the gene expression levels of toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-&#x3ba;B), c-Jun N-terminal kinase 1, p38, and tumor necrosis factor-&#x3b1;. CONCLUSIONS: In this study, we demonstrated that MSTP effectively prevented embryo loss with an anti-inflammatory mechanism through downregulation of the TLR4-NF-&#x3ba;B/ MAPK signaling pathway, in LPS-induced miscarriage mice model. To our knowledge, this is the first study to reveal the therapeutic mechanism of MSTP in LPS-induced miscarriage in mice.

Animals↗
PubMed1976

The developmental analysis of an embryonic lethal (C6H) in the mouse.

A development study of the effects of the C6H allele at the albino locus has identified the C6H homozygote as an early postimplantation lethal. Homozygous C6H embryos can first be recognized at 6 1/2-7 days of gestation by abnormalities of the ectoplacental and parietal endodern. At 7 1/2 days, mutant embryos appear severely retarded with obvious abnormalities in all germ layers. All C6H homozygotes are dead and resorbed by 8 days of development. It is proposed that the mutation interferes with the normal differentiation of the parietal endoderm, ectoplacental cone and extra-embryonic ectoderm of the egg cyclinder.

Alleles↗
PubMedDate not supplied

[Study of the embrotoxic properties of the repellent diethyltoluamide].

With application to the skin of an albino female-rat over the whole period of its pregnancy of the repellent diethyltolueneamide (DETA) in doses of 100 and 1000 mg/kg the overall embryonal fatality was found to go up, the size and weight of the rattlings to be down; there was recorded a lagging development of the newborns and a high postnatal death rate. The preparation could easily overcome the placental barrier, it was demonstrable in the placenta, fetuses, as well as in the bodies of newborn rattlings, even 3 months after their birth.

Administration, Topical↗
PubMed1975

[Action of the herbicide Ramrod on the embryogenesis of white rats].

The embryotoxic and teratogenic activity of the acetanilide Ramrod is subjected to experimental testing. Studies are conducted on 103 white unbred female rats, to which the preparation was administered throughout the full gestation period, at doses 1/5, 1/10, 1/30 and 1/40 LD50. Following in reduction of the preparation, an increase in the total embryonal lethality was noted, conditioned entirely by the considerable rise, as compared to controls, of the pre-implantation deaths of embryos. The embryotoxic action of the preparation was furthermore manifested with a decrease in body weight and in the craniocaudal fetal sizes. Upon giving 1/5 and 1/10 LD50 Ramrod, a slight teratogenic effect was recorded. Ramrod at dose 1/40 LD50 exerted no effect whatsoever on embryogenesis.

Acetanilides↗