Scientists Report Early Success in Growing Mini Liver in Lab

SATURDAY, Oct. 30 (HealthDay News) -- Scientists who created functioning miniature livers say their success is an early, but important, advance in the quest to grow replacement human livers in the laboratory.

"We are excited about the possibilities this research represents, but must stress that we're at an early stage and many technical hurdles must be overcome before it could benefit patients," project director Shay Soker, a professor of regenerative medicine at Wake Forest University Baptist Medical Center, said in a facility news release.

In the study, the researchers used mild detergent to remove all the cells from animal livers, leaving only the collagen "skeleton" or support structure. Then, the original cells were replaced with two types of human cells: progenitors, which are immature liver cells, and endothelial cells, which line blood vessels.

The liver skeleton with the new cells was placed in a bioreactor, a piece of equipment that provides a constant flow of nutrients and oxygen to the organ. Within a week, there was progressive formation of human liver tissue and liver-associated function.

According to the scientists, the next step in the research is to find out if these bioengineered livers will continue to function after they're transplanted into an animal.

The research is to be presented Sunday at the annual meeting of the American Association for the Study of Liver Diseases in Boston.

Along with offering a solution to the shortage of donor livers, bioengineered livers could be used to evaluate the safety of drugs, Soker and colleagues pointed out.

More information

The American Liver Foundation explains how to take care of your liver.

Early Humans More Advanced Than Thought

THURSDAY, Oct. 28 (HealthDay News) Early humans were using a highly skilled stone tool sharpening method 75,000 years ago in Africa, more than 50,000 years earlier than previously believed, a new study indicates.

This adds more evidence that modern behavior developed over time during the Middle Stone Age rather than after our ancestors migrated from Africa to Europe, as some scientists have thought.

Researchers from the University of Colorado at Boulder discovered that the delicate technique -- called "pressure flaking" -- was used by anatomically modern humans at Blombos Cave in South Africa during the Middle Stone Age. Previously, the earliest evidence of pressure flaking was from 20,000 years ago in France and Spain.

"This finding is important because it shows that modern humans in South Africa had a sophisticated repertoire of tool-making techniques at a very early time," study co-author Paola Villa, a curator at the University of Colorado Museum of Natural History, said in a university news release.

"This innovation is a clear example of a tendency to develop new functional ideas and techniques widely viewed as symptomatic of advanced, or modern behavior," she added.

Pressure flaking "takes place when implements previously shaped by hard stone hammer strokes followed by softer strikes with wood or bone hammers are carefully trimmed on edges by directly pressing the point of a tool made of bone on the stone artifact," according to background material in the study. Many stones -- with the exception of jasper, obsidian and high-quality flint -- also had to be heated before pressure flaking, researchers noted.

This technique enables better control of the sharpness, thickness and overall shape of two-sided items such as spearheads and stone knives, Villa explained.

The study appears in the Oct. 29 issue of Science.

More information

The Australian Museum has more about tools and human evolution.