The clinical trial of injecting stem cell into the brains of three patients as part of treatment of stroke was successful, according to a British biotech company behind the trial.

The trial was done on patients who were disabled by stroke, the company, ReNeuron Group, said. Data from the laboratory safety tests, neurological examinations and neurofunctional tests conducted thus far indicate that the ReN001 treatment is safe and well-tolerated at the initial dose, ReNeuron said in a statement on Thursday.

The treatment has not yet shown any negative impact. The next move is to go ahead with higher doses.

We need to be assured of safety before we can progress to trying to test the effects of this therapy. Because this is the first time this type of cell therapy has been used in humans, it's vitally important that we determine that it's safe to proceed -- so at the present time we have the clearance to proceed to the next higher dose of cells, said Prof Keith Muir of Glasgow University, who led the trial, according to BBC News.

The success of this trial brings back the much-debated topic: Is stem cell research ethical?

Stem cell research is perhaps the most talked and written-about topic in health circles. When the supporters of stem cell research point out the advantages of the research, the ethical questions are raised by the other camp. Using embryonic stem cells for research requires destruction of blastocysts which is formed from laboratory-fertilized human eggs. Many people consider blastocyst as a human life and, therefore, killing that tantamount to abortion or murder, which is immoral, unethical, and thus, unacceptable.

This thought is the most important hurdle that the researchers have to cross to move their research with stem cell further. Not all stem cell however, requires creation, usage and destruction of human embryos. Adult stem cells and pluripotent stem cells are few of the cells which do not require destruction of human embryos and therefore, they are not controversial.

Stem cells help building organisms in human body and research shows they can create blood, tissue and brain cells which can put an end to life-threatening diseases like Alzheimer's and Parkinson's. Although these stem cells are found in adult human body, they are far more effective in a fetus.

After a female egg is fertilized by sperm, embryonic stem cells are developed. The entire process of development takes 4-5 days.

In 2001, former U.S. President George W. Bush announced federal funds should be given to the research of human embryos only if the study meets the following criteria:

  •  The derivation process (which begins with the destruction of the embryo) was initiated prior to 9:00 P.M. EDT on August 9, 2001.
  •  The stem cells must have been derived from an embryo that was created for reproductive purposes and was no longer needed.
  •  Informed consent must have been obtained for the donation of the embryo and that donation must not have involved financial inducements.

However, with the beginning of the Obama administration, the stem cell research took a fresh turn.

In March 2009, President Obama signed an executive order on stem cell research, ending the sluggishness in the process caused by the previous administration's policies.

We will vigorously support scientists who pursue this research, Obama announced at the signing ceremony in the White House. And we will aim for America to lead the world in the discoveries it one day may yield.

The president however, urged the scientists to develop strict guidelines so that the stem cell research never opens the door to the use of cloning for human reproduction.

The Obama initiative opened new avenues for stem cell researchers, but the debate has steam left in it as conservative opinion is still ficused on ethical questions.