Although previous research suggested the treatments may leave patients with mild cognitive impairment, some doctors thought it might be caused by hormonal changes or the anxiety of having cancer.

In the latest study, published in Monday's issue of the journal Cancer, Dr. Masatoshi Inagaki at the National Cancer Centre Hospital East in Chiba and his colleagues used MRIs to compare brain structures in 51 cancer survivors who received chemotherapy to 54 who did not.

The experiment was repeated for 132 cancer survivors who had cancer surgery less than a year earlier. Of this group, 73 received chemo and the rest did not.

Within a year of surgery, sections of the brain involved in cognition - such as concentration, multitasking and memory - were smaller in the women who received chemotherapy than in those who didn't, the researchers said.

The good news is, the differences reversed themselves three years after surgery, the researchers found. The finding shows the brain is resilient and that the fog of chemotherapy eventually lifts.

There were no significant differences in brain structure between cancer survivors and healthy subjects, which suggests the disease itself does not affect brain structure.

Researchers don't know the mechanism behind chemobrain, said Dr. Jeanette Vardy, an oncologist at Toronto's Princess Margaret Hospital. The brain scans Vardy studies also show changes after chemotherapy, but the side-effect is mild, compared with the risk of not getting the treatment.

Doctors are starting to use different chemotherapy drugs that they hope will have less of an effect on the brain, Vardy said.

It's been three years since Judy Mirus, a yoga instructor in Edmonton, finished chemotherapy for her breast cancer. Mirus still has problems with spelling and remembering appointments, but said a little mental fog is not much of a price to pay for being alive.

"People set up their own ways of retraining themselves, and I think I've done that," Mirus said.

They concluded that sitting upright for hours places unnecessary strain on the back, leading to potentially chronic pain problems.

"A 135-degree body-thigh sitting posture was demonstrated to be the best biomechanical sitting position, as opposed to a 90-degree posture, which most people consider normal," said Waseem Bashir, author of the study and a clinical fellow in radiology at the University of Alberta Hospital.

"Sitting in a sound anatomic position is essential, since the strain put on the spine and its associated ligaments over time can lead to pain, deformity and chronic illness."

Bashir presented the study on Monday at the annual meeting of the Radiological Society of North America in Chicago. The team suggested people may prevent back problems by finding a chair that allows them to sit at 135 degrees.

Prevention instead of treatment

"This may be all that is necessary to prevent back pain, rather than trying to cure pain that has occurred over the long term due to bad postures," Bashir said. "Employers could also reduce problems by providing their staff with more appropriate seating, thereby saving on the cost of lost work hours."

Back pain is the most common cause of work-related disability in the United States, according to the National Institute of Neurological Disorders and Stroke.

In a herniated disc, the doughnut-shaped soft tissue cushioning the vertebrae in the back protrudes, putting pressure on the spinal nerves, a condition that can be painful. A herniated disc is most common in the lower back.

People show a natural hollow in their back, but it disappears when seated. That can lead to the pain of a herniated disc.

Seated MRI

By showing disc deformity in people, the MRI study points to a convincing injury mechanism, said Prof. Stuart McGill, a professor of spine biomechanics at the University of Waterloo.

To identify poor seating postures, Bashir and his colleagues used a type of MRI machine that allows people to sit or stand while the images are taken. In traditional scanners, people lie flat, which may mask causes of pain that stem from different movements or postures.

In the experiment, 22 healthy volunteers in Scotland sat in three different positions:

A slouching position with the body hunched forward like in front of a video game console.
An upright 90-degree position.
A relaxed position reclining 135 degrees with feet on the floor.

Seating strategies

Researchers measured spinal angles and spinal disc movement from the different positions. Spinal disc movement occurs when weight-bearing strain is placed on the spine, causing a misalignment in the internal disc material.

The most disc movement was seen in the 90-degree sitting posture, and the least in the 135-degree posture, which suggests less strain is placed on the spinal discs, related muscles and tendons in the more relaxed position.

To prevent the back pain, McGill suggests finding a "sweet spot" that minimizes stress on the disc. Strategies include:

Varying positions, such as standing up when the phone rings.
Tilting the seat pan forward with the seat under the thigh and buttocks and the pelvis at the backrest.
Leaning back in the backrest the way bucket seats in cars tilt back for passengers.
Using a lumbar support.
Following a tailored exercise program.

Sitting at 135 degrees may help. But given the natural variation in the population, some people feel more stress when standing and others from sitting, meaning there is no one-size-fits-all solution, McGill said.

Dr. David Mininberg, a New York City physician with a degree in Middle Eastern Art is also an expert in ancient Egyptian medicine. He said the scans are proof Tutahkhamun was not the victim of a murder conspiracy.

"They finally lay to rest this rather loosely based conjecture about a murder plot," he explained. "I don't think that anyone who reads the findings as they are written can believe that any longer."

Mininberg was not directly involved in the study but reviewed the paper prior to its presentation Monday at the annual meeting of the Radiological Society of North America, in Chicago.

Tutankhamun remains the most famous of the hundreds of royal mummies buried throughout Egypt because of the spectacular array of objects found in his intact tomb in 1922. Until now, perhaps, the reasons for his early death remained mysterious.

The fact his skull appeared to contain loose bone fragments led to the notion the young leader was bludgeoned to death by his enemies, then quickly entombed to hide the evidence.

A team led by radiologist Dr. Ashraf Selim of Cairo University's Kasr El Aini Teaching Hospital used high-tech CT scans to examine Tutankhamun's corpse in minute detail. The corpse had been cut into several pieces and was in a "critical stage of preservation," they wrote.

According to the researchers, Tutankhamun died at between 18 and 20 years of age and measured about 5-feet, 11-inches in height. They also concluded that the bone fragments found inside the pharaoh's skull came from the first vertebrae in his neck, not his cranium.

Some mishap, perhaps during a modern X-ray examination, probably explains the dislocated fragments, Selim's team concluded. The upper vertebrae may even have made their way into the skull 84 years ago, when a team led by British Egyptologist and Tut discoverer Howard Carter pried off the mummy's golden mask.

"I think this lays to rest the notion that the bone fragments in the head were caused pre-mortem, before his death," said Dr. Joseph Tashjian, a St. Paul, Minn., radiologist and member of the RSNA's public information committee. "It's pretty clear, looking at the images from this study, that they almost certainly came from the removal of the mask from the head. It definitely didn't occur either pre-mortem or even during the embalming period."

"The old theory, which was believed by very few people, has now been completely laid to rest by good scientific work rather than conjecture," Mininberg said.

If he was not bludgeoned to death, how did Tutankhamun die?

The CT scans show evidence of a major fracture to the thigh bone that could have occurred prior to the king's death. According to Selim's team, this wound may have led to a fatal infection.

The wound was still unhealed at the time of the pharaoh's death because "embalming fluid went into the fracture," noted Tashjian, who was not involved in the Tut research but has had prior experience scanning a long-dead mummy.

"I think the femur fracture probably is significant," Tashjian said. "Number one, it's not healed. Number two, femur fractures -- any long-bone fracture -- can have a number of complications, any of which can lead to death, either from infection or an embolism. It's an unusual way to die, from a fracture, but it does happen, even now."

However, a final answer on that score may never emerge, Mininberg said.

"The problem is that the soft tissue is changed by the mummification process, and there is no clear evidence of infection in the bone," he explained. "However, with a fracture as extensive as that was, it wouldn't be unheard of for it to become infected. That's a reasonable conjecture."

Although the why of Tutankhamun's death may have been answered, there's still the question of the curse upon anyone who disturbs his remains.

"While performing the CT scan of King Tut, we had several strange occurrences," Selim noted in a prepared statement. "The electricity suddenly went out, the CT scanner could not be started, and a team member became ill. If we weren't scientists, we might have become believers in the curse of the Pharoahs."

Arkansas and Louisiana passed laws this year forbidding anyone from smoking in cars carrying young children. Courts are ordering smoke-free environments in custody and visitation disputes.

"We are very rapidly moving to protect children from secondhand smoke," John Banzhaf, executive director of Action on Smoking and Health, told the newspaper.

While health experts said that children exposed to secondhand smoke suffer an increased risk of respiratory ailments and sudden infant death syndrome, smokers' rights groups said secondhand smoke is not dangerous.

"If we don't reverse this, they'll be telling us what we can eat and what we can feed our children," said Gary Nolan, spokesman for The Smoker's Club, Inc.

Most smoking bans apply to workplaces and spots like bars and restaurants, but at least six states and some counties prohibit foster parents from smoking when foster children are present, the report said, quoting Kathleen Dachille, director of the Legal Resource Center for Tobacco Regulation, Litigation & Advocacy at the University of Maryland School of Law.

"There are times when it's appropriate to regulate what people can do in their home," Dachille said. "The state is responsible for that child."