Immune response protein linked to Alzheimer's - San Francisco Chronicle

ALZHEIMER'S DISEASE

Protein linked to brain disorders

Stanford scientists have identified a possible new culprit in the development of Alzheimer's disease and other brain disorders, and the finding may create new avenues for understanding, and maybe preventing, cognitive decline in old age.

The protein called C1q is part of the body's natural immune response. When an immune reaction is triggered, C1q is one of the first molecules to be released, attaching itself to cells targeted for destruction. Once C1q is bound to those cells, other molecules follow its lead, eventually guiding immune cells to the site to destroy the intruder.

The Stanford scientists found that in both mouse and human tissue, C1q accumulated in the brain - in particular, near the synapses that connect brain cells - at much higher levels in older tissue than in younger tissue. In some cases, the scientists found a 300-fold increase.

The scientists believe that the C1q on its own doesn't cause much damage. Instead, it becomes a sort of time bomb waiting for something else - a minor brain injury, an infection or a small stroke, for example - to trigger an immune response that will destroy the synapses where C1q has built up.

For decades, scientists have been focusing on other proteins - most commonly, two called beta amyloid and tau - as the main targets for defeating Alzheimer's and other neurodegenerative conditions. C1q may turn out to be another such target, the scientists say.

Their work was published Aug. 13 in the Journal of Neuroscience.

- Erin Allday ^[1]

TYPHOID MARY

Salmonella hides in immune cells

Researchers at Stanford have discovered that salmonella can hide out in the very immune cells sent to defend against it, hacking the cells' metabolisms and camping out for the long haul.

The research provides a clue to a long-standing mystery: How Typhoid Mary, an asymptomatic carrier of the typhoid fever-causing salmonella typhi, managed to spread the salmonella strain to countless others in the early 1900s while remaining perfectly healthy herself.

The bacterium's ability to hang out, dormant, in immune cells can turn infected people into chronic asymptomatic carriers, who, like Typhoid Mary, unknowingly spread the infectious organism to others.

Between 1 and 6 percent of those infected with salmonella typhi are chronic, asymptomatic carriers. Typhoid fever affects millions in developing nations each year.

Researchers examined a closely related salmonella strain in mice. The mice were able to harbor the infection for an entire lifetime, as long as two years.

Previous work found that the bacteria are able to reside inside attack cells called macrophages, a frontline defense against invading microbes. The new study found that salmonella that survived an initial assault against them were then able to manipulate macrophages to their favor.

The study was published Aug. 14 in Cell Host & Microbe ^[2] .

- Kristen V. Brown ^[3]

PSORIASIS

Insurance limits treatment

A UC Davis study found that many patients with psoriasis or psoriatic arthritis are not receiving treatment or can't get access to newer, expensive drugs known as biologics due to insurance company restrictions.

Analyzing surveys of 5,600 patients conducted by the National Psoriasis Foundation ^[4] between 2003 and 2011, the researchers found as high as 49 percent of those with mild psoriasis, 36 percent with moderate disease and 30 percent with the most severe forms were not receiving any treatment for the painful and disfiguring condition.

Psoriasis, which afflicts about 7.5 million Americans, often appears as thick, red, flaky silver-white patches on the skin. But it's far more than a cosmetic condition and can lead to joint inflammation and arthritis, diabetes, cardiovascular disease and even premature death.

The survey found that 22 percent of patients with severe psoriasis were being treated with topical creams and ointments alone. The researchers said systemic biologics are more effective at curbing the excessive inflammation that can damage the joints, heart and liver.

The study was published last week online in JAMA Dermatology.

- Victoria Colliver ^[5]

MENTAL HEALTH AND SMOKING

Quitting helps patients

Psychiatric patients are among the most prolific smokers, but a new Stanford-led study found they were more likely to quit and less likely to be hospitalized again for their mental health condition if they receive help to stop smoking during in-patient psychiatric care.

The research counters long-held thinking that encouraging mental health patients to quit smoking would be detrimental to their emotional recovery because cigarettes are perceived as a crutch for coping with stress.

The flipside is smoking significantly contributes to the early deaths of people with mental health conditions, a group that lives an average of 25 years less than the general population. Researchers noted the daily cycle of nicotine withdrawal that a smoker experiences can exacerbate stress.

Nearly half the cigarettes sold in this country are to people with psychiatric or addictive disorders, according to the Centers for Disease Control and Prevention.

Stanford researchers, in collaboration with their counterparts at UCSF, found that a simple smoking-cessation program that included periodic meetings with a counselor, written and computerized materials as well as the use of nicotine patches supported, rather than harmed, patients' mental health.

The study was published online Aug. 15 in the American Journal of Public Health ^[6] .

- Victoria Colliver

AUTISM

Clues found to strong math skills

Autistic children with average IQs demonstrated much stronger math skills than non-autistic children in a recent study, and researchers believe they have identified the part of the brain responsible for this advantage.

The finding came out of a study conducted by Stanford University School of Medicine and Lucile Packard Children's Hospital ^[7] . It involved 36 children ages 7 to 12, half of whom were diagnosed with autism.

All participants had IQs in the normal range and showed normal verbal skills on standardized tests. But when it came to math, the autistic children outperformed the control group.

Those children reported that they tended to use analytic strategies, rather than rely on rote memory, when cracking problems. As they solved problems, an MRI scanner revealed unusual activity in the ventral temporal occipital cortex - an area specialized for processing faces and visual objects. This area, researchers said, may hold clues for why autistic children can develop specialized skills in number-crunching.

That said, researchers stressed, not all autistic children have superior math abilities.

The study was published last week online in Biological Psychiatry.

- Stephanie M. Lee

BOVINE BRAIN DISEASE

New virus' genome sequenced

A team of scientists led by researchers at UC Davis has identified and sequenced the genome of a new virus thought to cause brain disease in cows.

The findings are important because they will allow veterinarians to easily determine whether a sick cow is infected by the new virus or by the virus that causes mad cow disease - a rare but disturbing infection that can cause neurological damage in humans, too.

The new pathogen is part of a family called astroviruses, which can infect mammals and birds, and most commonly cause intestinal infections in humans. Scientists gave the new virus a mouthful of a name: BoAstV-NeuroS1.

In addition to sequencing the virus' genome, the scientists also looked at tissue samples from sick cows known to have been infected with the pathogen. In all of those cows, the researchers found similar patterns of infection - the virus typically was found in the animals' spinal cords, and it caused particular tissue abnormalities.

Its unique pattern of infection should make it easier for veterinarians to determine whether neurologically sick cows are suffering from the new virus or from mad cow disease, the UC Davis scientists said.

Their work was published online in the September issue of the journal Emerging Infectious Diseases, which is put out by the U.S. Centers for Disease Control and Prevention ^[8] .

- Erin Allday