Embryo Project Encyclopedia Articles

Leon Chesley published Hypertensive Disorders in Pregnancy in 1978 to outline major and common complications that occur during pregnancy and manifest in abnormally high blood pressures in pregnant women. The book was published by Appleton-Century-Crofts in New York, New York. Chesley compiled his book as a tool for practicing obstetricians and teachers. The book focuses on preeclampsia and eclampsia, but it also describes other common and rare hypertensive diseases and disorders of pregnancy and discusses their histories, diagnoses, management plans, pathologies, and immediate and remote prognoses for mothers and fetuses. Doctors used the book and all subsequent editions to help diagnose and manage complications during pregnancy and to avoid deaths for pregnant women and fetuses.

In the second half of the
twentieth century, scientists learned how to clone organisms in some
species of mammals. Scientists have applied somatic cell nuclear transfer to clone human and
mammalian embryos as a means to produce stem cells for laboratory
and medical use. Somatic cell nuclear transfer (SCNT) is a technology applied in cloning, stem cell
research and regenerative medicine. Somatic cells are cells that
have gone through the differentiation process and are not germ
cells. Somatic cells donate their nuclei, which scientists
transplant into eggs after removing their nucleuses (enucleated eggs).
Therefore, in SCNT, scientists replace the nucleus in an egg cell
with the nucleus from a somatic cell.

In 2004, a team of researchers at Tufts-New England
Medical Center in Boston, Massachusetts, investigated the fetal
cells that remained in the maternal blood stream after pregnancy.
The results were published in Transfer of Fetal Cells with
Multilineage Potential to Maternal Tissue. The team working on that
research included Kiarash Khosrotehrani, Kirby L. Johnson, Dong
Hyun Cha, Robert N. Salomon, and Diana W. Bianchi. The researchers
reported that the fetal cells passed to a pregnant woman during
pregnancy could develop into multiple cell types in her organs. They
studied these differentiated fetal cells in a cohort of women
fighting different diseases. The researchers found that the fetal
cells in the women differentiated into different cell types under
the influence of maternal tissues, and that those differentiated
cells concentrated in the tissue surrounding diseased tissues.
According to the team, this response could be a therapeutic response
to the disease in the once pregnant woman. The research indicated the long
lasting effects of pregnancy in a woman's body.

During the twentieth and twenty-first centuries, Robert Paul Lanza studied embryonic stem cells, tissues,
and endangered species as chief scientific officer of Advanced Cell
Technology, Incorporated in Worcester, Massachusetts. Lanza's team cloned
the endangered species of gaur Bos gaurus.
Although the gaur did not survive long, Lanza successfully cloned
another cow-like creature, called the banteng
(Bos
javanicus). Lanza also worked on cloning human embryos
to harvest stem cells, which could be used to treat dieases. While
previous techniques required the embryo's destruction, Lanza
developed a harvesting technique that does not destroy the embryo,
forestalling many ethical objections to human embryonic
research.

The Southern Gastric-Brooding Frog (Rheobatrachus silus) was an aquatic frog that lived in south-east Australia. In 2002, the International Union for Conservation of Nature Red List declared the frog extinct, although no wild specimens had been reported since 1981. As the common name alludes to, the R.
silus was a gastric-brooder, meaning that the female's eggs developed inside of her stomach. Weeks after ingestion, juvenile frogs escape through the mother's mouth. Because no other observed species performs this reproductive behavior, in the early twenty-first century R. silus became a target of
the de-extinction movement that aims to resurrect extinct species. Researchers studied this frog's reproductive behavior and how the eggs and embryos escape digestion. Some scientists claimed that resurrecting this frog could result in future medical applications related to digestion and to reprogramming organ function, as during pregnancy, R. silus's stomach physiologically functioned as a uterus.