When tiny white blood cells known as macrophages run amok in your body, they can cause painful inflammation.
But Harris Perlman, associate professor of medicine at Northwestern University's Feinberg School of Medicine, recently discovered a molecule he describes as "the bouncer" that may help keep macrophages in check and lead to new treatment for people suffering from rheumatoid arthritis, an inflammatory, autoimmune disease.
The bouncer molecule, known by scientists as P21, stops inflammation by preventing the abnormal accumulation of compounds called cytokines. Cytokines are released by macrophages in response to foreign substances like bacteria and viruses in order to recruit more immune cells to the compromised area and fight off the intruders.
Rheumatoid arthritis results when the body attacks the membranes surrounding its own joints. That development leads to the accumulation of cytokines and results in inflammation.
The joints become swollen, hot, stiff and painful. Over time, they wear down and deform. The kidneys, heart, liver and many systems of the body can also be damaged by the persistence of cytokines and other inflammatory compounds.
Why the body activates its immune cells and attacks its own joint tissues is unknown. But Perlman found in an earlier study that patients with rheumatoid arthritis have fewer P21 molecules than people without the disorder.
Perlman and his team of researchers got the idea that perhaps people with rheumatoid arthritis had lost their bouncer molecule, allowing macrophages to produce too many cytokines. Replacing P21 might help prevent the inflammation that causes damage, they thought.
In their recent study, published in the journal Arthritis and Rheumatism, the team looked at rheumatoid arthritis in mice that were lacking P21.
In the mice without P21, the team saw "a very aggressive form of rheumatoid arthritis. ... The bone and cartilage were completely destroyed," Perlman said. "Over time, it never really subsided. It usually goes away over time in mice, but in this case it didn't."
But when they added back a small, active piece of the P21 protein by injecting it in a mouse, a week later "the mice looked great," Perlman said. "There was no more rheumatoid arthritis-like disease. They were cured. We're really excited about that. It opens up a brand-new avenue of research for the field, a brand-new target to look at."
Perlman and his team are now looking to see what happens when the mice receive the P21 protein for a longer period. They are also beginning to look at the role of P21 in other autoimmune diseases such as lupus.
"Thank God we've been very successful. It's a good thing, and we're very humbled by it," he said.
— Kelly April, Special to the Tribune
Colds not tied to cerebral palsy risk
Despite concerns that a mother's infections during pregnancy may raise her baby's risk of cerebral palsy, common colds and stomach flu were not tied to the birth defect in a study.
Other, more serious infections, and factors such as a woman's history of miscarriage or family history of cerebral palsy, were associated with increased risk to babies, said Dr. Michael E. O'Callaghan, one of the study authors. "There's an increased chance but it's still low," he said.
In particular, severe maternal infections in the second half of pregnancy were linked to higher risk for babies. So were preterm birth, growth restrictions inside the uterus and being a twin or part of a larger set of multiples.
Each year about 10,000 babies born in the United States will develop cerebral palsy, according to the Centers for Disease Control and Prevention.
Cerebral palsy describes a number of disorders of the developing brain that affect body movement, posture and balance. It occurs during fetal development, or during or right after birth, and its cause is unknown.
Published in Obstetrics and Gynecology, the study by O'Callaghan and his colleagues looked at 587 people with cerebral palsy and 1,154 without the disorder.
The researchers found that maternal infections like chickenpox and cytomegalovirus — an infection that causes serious symptoms in newborns — were significantly associated with cerebral palsy, especially when they happened in the second half of pregnancy. Those types of infections occurred during pregnancy in the mothers of 41 percent of people with cerebral palsy compared with 31 percent who didn't have the condition.
Smoking prevalence by profession
Miners and people in the hotel and food service industry have the highest smoking rates, while those in education have the lowest, finds a Centers for Disease Control and Prevention report on smoking prevalence.
Data from the National Health Interview Survey found that overall the incidence of smoking was highest among those who didn't graduate from high school, had no health insurance and lived below the federal poverty line. The smoking rate among working adults was 19.6 percent.
When broken into professions, smoking prevalence among miners and people in hotel and food service was 30 percent, followed by people who worked in construction jobs (29.7 percent). Other professions with higher rates included transportation and warehousing (24.3 percent), manufacturing (23.2 percent) and retail (23.1 percent).
In the lower ranks of smoking prevalence were people who worked in education (9.7 percent), business management (10.9 percent) and finance and insurance (13.9 percent).
Among occupation groups, those in construction and extraction had the highest incidence of smoking at 31.4 percent, while those in education, training and library work had the lowest (8.7 percent).
Smoking rates in the U.S. went from 27.8 percent from 1987 to 1994 to 24.5 percent from 1997 to 2004, the report said. But from 2005 to 2010 rates leveled off.
Some workplace interventions have been effective in getting employees to quit, the study authors noted, but more needs to be done. "Although some progress has been made in reducing smoking prevalence among working adults," they wrote, "additional effective employer interventions need to be implemented." They added that those should include health insurance coverage for stop-smoking treatments, user-friendly help for people who want to quit and policies for a smoke-free workplace.
— From Tribune Newspapers, news servicesCopyright © 2015, The Baltimore Sun