Sometimes, it takes one angry accountant to get things done.

Doctors have been aware of anosmia - the inability to smell - "as far as I know, forever," says Gary Beauchamp, director of the Monell Chemical Senses Center in West Philadelphia. But they've never been able to do much about it.

Monell scientists are working to change that.

In February, they began a campaign to find a treatment for anosmia. And the campaign was spurred, in large part, by a letter Beauchamp received from one fed-up, anosmic accountant about a year ago.

"He had lost his sense of smell. And he writes us kind of an angry letter," Beauchamp recalls. "And the letter is: 'This is a terrible thing. Nobody pays any attention to it, and why aren't you?' And it was a pretty eye-opening letter, because he was really right."

He gave Monell a six-figure sum to jump-start the campaign, called A Sense of Hope. Further efforts to raise $1.5 million over three years are underway.

Thought to affect about 6 million Americans, anosmia has many causes. For some, it's a head injury; for others, including the accountant, it's an upper-respiratory infection.

The consequences can be profound.

Because taste and smell are so closely linked, "you no longer can tell the difference between, say, apples and potatoes, or between cherry and strawberry and banana, or between white wine and red wine," Beauchamp says. Nor can you discern the scent of smoke or a gas leak.

Those scents are all detected by nerve cells in the nose called neurons, which send information about odor to the brain.

Neurons are destroyed every day by dirt, toxins, and other particles we inhale.

But these particular neurons are built for the harsh conditions of the nasal cavity; they're our only nerve cells known to perpetually regenerate. So we keep on smelling.

That is, unless you're missing the neurons in the first place.

All the cells in the nose involved in smelling, including the neurons, develop from specialized stem cells. If you can't produce the stem cells, you can't make the neurons. And if you can't produce the neurons, you can't smell.

That's the problem facing many anosmics; injury or illness has destroyed their olfactory stem cells and, in turn, their ability to generate these crucial neurons.

Monell researcher Mridula Vinjamuri wants to solve that problem by growing the stem cells in a lab. "And the idea is to transplant them back into the nasal cavity of the humans who have lost their smell and see if they can recuperate from this loss," she says. "It's a huge initiative." A successful transplant could be five or 10 years away.

She's growing the stem cells from mouse tissue. In about a month, she'll start growing them from human tissue.

Other labs have already done that. But they haven't been able to reliably turn the stem cells into neurons, she says.

"We want to make the stem cells grow into neurons. That's the big step that we are taking."

"It happens within the body, but we don't know how," she says. And we don't know what outside factors, chemical or otherwise, could induce the process, she says.

She'll be poring over petri dishes in a lab on Market Street to find out.

And if she does, it will be due, in part, to one angry accountant.