Richard Stuart lifts up his cream polo shirt and points to a small scar just below his left breast. 'That's it,' he said. 'They injected me 30 times, right here, straight into my heart.'
Mr Stuart, 64, a retired textiles manufacturer from Florida, reckons the operation performed on him in December 2005 at Bangkok Hospital has given him a new lease of life. The previous year, a sudden heart failure had left him short of breath, unable to walk up a flight of stairs or drive a car. At that time, doctors installed a pacemaker, gave him a drug prescription and told him there was nothing more they could do for him.
Today Mr Stuart says he's more active than he was before his heart failure. 'After the first month and a half [after the operation], I started to feel I was getting stronger. I started cleaning the pool, the yard, the car. All the normal things that you do,' he said.
The operation Mr Stuart credits with his turnaround is a pioneering stem-cell therapy that claims to rejuvenate damaged hearts.
It works by extracting millions of stem cells from the patient's blood - a 250cc sample is enough - then reintroducing them into the heart or arteries. The hope is that the stem cells will turn into blood vessels or tissue, improving circulation to the heart and its ability to pump blood.
Stem cells, known as the body's 'master cells' that can transform and reproduce, have long been touted as potential miracle cures for chronic diseases and disabilities. But ethical objections to the use of stem cells from human embryos, seen as the most flexible type of cell, has cast a shadow over the field in the US, to the dismay of scientists.
Further controversy was stirred in South Korea in 2005 by the revelation that groundbreaking embryonic stem-cell research credited to scientist Hwang Woo-suk had been falsified.