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D A New

Publications and source records attributed to D A New.

35 records · Page 2Linked to original sources
PubMed1976

Techniques for assessment of teratologic effects: embryo culture.

A simple method is described for growing rat embryos in vitro for 48 hr from head-fold to early limb-bud stages at rates of development and protein synthesis indistinguishable from those in vivo. Culture of the embryos can be continued for longer periods but at a reduced growth rate. Preheating the culture serum to 56 degrees C for 30 min improves embryonic development, but raising the culture temperature 2-3 degrees C or exposing the presomite embryos to 20% O2 (160 mm Hg) causes malformations, particularly of the brain and spinal cord. The value of such culture methods for teratology is briefly discussed.

Abnormalities, Drug-Induced↗
PubMed1972

Opossum fetuses grown in culture.

Opossum fetuses explanted at limb bud stages have been successfully grown in culture for periods up to 20 hours. Blood circulation was maintained, and organogenesis continued at about the same rate as in vivo.

Animals↗
PubMedDate not supplied

Effects of fibroblast growth factor 2 and insulin-like growth factor II on the development of parthenogenetic mouse embryos in vitro.

Most parthenogenetic embryos (PEs) in mammals die shortly after implantation, and this failure to develop is associated with genomic imprinting. We have examined the influence of human recombinant basic fibroblast growth factor 2 (FGF-2) and human recombinant insulin-like growth factor II (ICF-II) on the development of (CBA x C57BL/6)F1 parthenogenetic mouse embryos. Embryos were treated in vitro at the morula stage with different doses of FGF-2 and, after their development to blastocysts, transferred to pseudopregnant recipients. The optimal doses of FGF-2 did not affect the number of forming and implanting blastocysts, but increased, from 20 to 42%, the number of embryos developing to somite stages. PEs (18-21 somites) treated with an optimal dose of FGF-2 were explanted for further development in culture by treatment with the second growth factor, IGF-II. Eighty-three percent of those embryos cultured with IGF-II (2.5 microg/ml) developed to 35 or more somites, as compared with 36% of embryos cultured without any growth factors (P < 0.01). Also, a significantly higher proportion of PEs developed to 40-50 somites in this case. These results show that the in vitro treatment of PEs with FGF-2 at the morula stage increases the number of somite embryos, and the second treatment of somite PEs with IGF-II in culture medium prolongs their development significantly.

Animals↗
PubMedDate not supplied

[Effects of growth factors FGF2 and IGF2 on the development of parthenogenetic mouse embryos in utero and in vitro].

We studied the effects of fibroblast growth factor 2 (FGF2) and insulin-like growth factor 2 (IGF2) on the development of parthenogenetic mouse embryos (CBA x C57BK/6)F1. The parthenogenetic embryos were treated in vitro during the preimplantation period and, at the blastocyst stage, transplanted into the uterus of pseudopregnant females. The addition of FGF2 at an optimal dose (2.5 ng/ml) to the culture medium increased twofold the number of embryos developed in utero to the somite stages as compared to the control: 18 and 43%, respectively. The parthenogenetic embryos (18-21 somites), treated and nontreated with FGF2 during the preimplantation period, were explanted for further development in vitro and treated with IGF2 at 2.5 micrograms/ml. As a result, many more parthenogenetic embryos (> 87%) of both groups developed in vitro to the stage of 30 or more somites as compared to the control (59%). The treatment of the parthenogenetic embryos with FGF2 alone at the preimplantation stages did not improve their development in vitro at the postimplantation stages. The results we obtained suggest that the treatment of parthenogenetic embryos in vitro with FGF2 during the preimplantation period increased twofold the number of somite embryos in utero, while their subsequent treatment in vitro with IGF2 leads to a significant prolongation of their development, as compared to the control.

Animals↗