Embryo lethality

Intra-amniotic administration of acrolein in rats induced a significant number of fetal malformations, whereas intravenous administration was embryo lethal. Pregnant rabbits given 4.0 and 6.0mg/kg/day on days 7 through 19 of gestation had high incidences of mater-... 

No evidence of embryo-lethal or teratogenic effect was observed in the offspring of... 

Viability and embryo lethality are recorded for the respective treatment but only viable embryos undergo morphological assessment. The criteria for defining embryo lethality include one or more of the following ... 

Abnormal expansion Ectoplacental cone inside YS Ectoplacental cone—Small Ectoplacental cone—Swollen Tachycardia Bradycardia No heartbeat Arrhythmia Embryo lethal NOT SCORED—Embryo damaged or missing... 

The results of the biological tests carried out on the purified monophosphoryl lipid A fractions are shown in Table XI. The chick embryo lethality test showed that both TLC-1 and -3 were nontoxic, whereas TLC-5 exhibited some toxicity. These results indicate that there might be two levels of toxicity based on structure. The presence or absence of the sugar 1-phosphate group (and possibly some other unknown group) would control the upper... 

Amid an ever clearer picture of auxin action, the auxin receptor remained a conspicuous omission from signaling models. Early biochemical efforts to isolate auxin receptors identified AUXIN-BINDING PROTEIN1 (ABP1).184,185 However, the majority of ABP1 localizes to the endoplasmic reticulum where the pH is too high for auxin binding. Furthermore, embryo-lethal null mutants and the lack of weak mutant alleles complicated detailed analysis. 

Reproductive Toxicity. At a dose range without toxic effects to the maternal oiganism, the following influences could be observed Increase in embryo lethality decrease in ossification of bones tungsten accumulation in the fetus no significant retention in die placenta. 

Figure 8. Plot of observed [log(LC5o) versus calculated embryo lethality data.

Although several sporadic reports on the developmental toxic effects of excess iodine have been found in the literature, systematic study is rare. Developmental toxic effects of excess iodine in animals were mainly indicated by embryo-lethal effects and skeletal variations. Embryo-lethal effects were reported in animals exposed to high doses of iodine, which reached 500-1000 times the required minimal dietary level. Skeletal variations were found in mice exposed to 10 times the adequate iodine intake. No apparent developmental toxic effects has been reported in humans exposed to excess iodine. However, excess iodine ingestion during pregnancy causes maternal thyroid dysfunction, which may result in an adverse pregnancy outcome. The potential developmental toxic effects of excess iodine in humans also need consideration. 

Space environment afreets almost all biological processes, in particular germination and flowering. Embryo lethality and lethal mutation frequency were observed in Arabidopsis thaliana seeds and in other organisms such as Escherichia coli and Bacillus suhtilif while very little is known about the effects of ionising and non-ionising radiation on photosynthetic apparatus. 

Ema M, Harazono A, Miyawaki E, et al. 1997b. Embryo lethality following maternal exposure to dibutyl phthalate during early pregnancy in rats. Bull Environ Contam Toxicol 58 636-643. 

A transient erythema (1-2 h) occurs, but CR does not induce inflammatory cell infiltration, vesication, or contact sensitization, and it does not delay the healing of skin injuries.24,48 The potential for eye damage is also significantly less than it is from CS or CN.24 CR was neither teratogenic nor embryo-lethal in one study49 when given as an aerosol or by gavage. 

Adenoviruses are responsible for approximately 8% of the viral infection worldwide (Rubin, 1993). Avian adenovirus SMAM-1 was discovered during a poultry epidemic in early 1980s (Ajinkya, 1985) and it is serologically related to avian adenovirus Chick Embryo Lethal Orphan virus (CELO). 

Asch, B.B., McCormick, K.J., and Trentin, J.J. 1979. Unusual features of the oncogenicity of chicken embryo lethal orphan (CELO) virus in hamsters. Prog. Exp. Tumor. Res. 23, 56-88. 

In pregnant rats orally administered annatto (28% bixin) on days 6 to 15 of pregnancy at doses of 0 to 500 mg/kg, no increase in embryo lethality and no reduction of fetal body weight were observed among annatto-exposed rats, and annatto did not induce any increase in the incidence of externally visible, visceral, or skeletal anomalies in the exposed offspring. The maternal and fetal no-observed-adverse-effect level (NOAEL) for orally consumed annatto was over 500 mg/kg daily (Paumgartten et al. 2002). 

In a subsequent study, oral doses of synephrine of up to 100 mg/kg body weight (at least 20 times the normal equivalent human dose) given to pregnant rats for 20 days did not produce developmental toxicity. No adverse effects were observed with respect to fetal weight, embryo-lethality, or incidence of gross, visceral or skeletal abnormalities. In this study, administration was either as a natural constituent in a bitter orange extract standardized to 6% synephrine, or as relatively pure 90% synephrine extract (Hansen et al. 2011). 

Teratology studies Rats 300 ppm Maternal and embryo lethality... 

If a molecule targets two different isoforms of a protein, either by design or by the inability to obtain selectivity among closely related isoforms, the most relevant KOs for safety evaluation should be dual KOs of the targeted isoforms. An example that illustrates the complexities of drug target KOs and that incorporates embryo lethal phenotypes, tissue-specific KO, and dual isoform KOs is provided by MEK KOs. 

INDEPENDENT SEED) finger female gametophyte absence of fertilization embryo lethality endosperm cellularization ... 

MEA FIS SET Endosperm, female gametophyte Embryo lethality cellularized endosperm without pollination Grossniklaus Schneitz, 1998 Kiyosue et al., 1999... 

Morulae, as well as blastocysts, can be injected to derive chimeras However, in the former case, contribution by the ES cells is often extremely high. If the injected clone contains some variants, this can result in embryo-lethality... 

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