Study: Bacteria may limit space travel
LORRAINE, France, Nov. 2 (UPI) -- French scientists say the prolific virulence and growth of bacteria in space, coupled with reduced production of antibodies, might limit future space travel.
The researchers from Nancy-University in Lorraine, France, said long-term space flights might compromised by microbial hitchhikers, such as bacteria. That's because space travel appears to weaken the human immune system, while increasing the virulence and growth of microbes, they said.
"When people think of space travel, often the vast distances are what come to mind first," said Jean-Pol Frippiat, one of the report's co-authors. "But even after we figure out a way to cover these distances in a reasonable amount of time, we still need to figure out how astronauts are going to overcome disease and sickness."
Frippiat and colleagues said they based their conclusions on studies showing that immune systems of both people and animals in space flight conditions are significantly weaker than their grounded counterparts. They also reviewed studies that examined the effects of space flight conditions and altered gravity on virulence and growth of common pathogens such as Salmonella, E.coli and Staphylococcus. Those studies, they said, show such bacteria reproduce more rapidly in space flight conditions, leading to increased risk of contamination, colonization and serious infection.
The research appears in The Journal of Leukocyte Biology.
Whooping cough immunity may last 30 years
ANN ARBOR, Mich., Nov. 2 (UPI) -- U.S. medical researchers suggest whooping cough -- pertussis -- immunity may last at least 30 years on average.
The study, published in the journal PLoS Pathogens, used mathematical models to test the theory whooping cough has been on the rise due to waning immunity in vaccinated or previously exposed people.
Pejman Rohani of the University of Michigan in Ann Arbor, but based at the University of Georgia during completion of the study, and Helen Wearing of the University of New Mexico in Albuquerque constructed two different mathematical models based on immunity "extinctions."
They compared predictions to incidence data from England and Wales from both the pre-vaccine era -- 1945-1957 -- and the vaccine era --1958-1972 and found, on average, whooping cough immunity lasts at least 30 years and perhaps as long as 70 years after natural infection.
"This is surprising because clinical epidemiologists currently believe the duration of pertussis immunity is somewhere between 4-20 years," Rohani says in a statement.
However, Rohani points out that in the past 20 years or so, vaccines have quite fundamentally changed and stimulate a different part of the immune system -- especially in North America.
Cruise ship restroom cleanliness studied
BOSTON, Nov. 2 (UPI) -- U.S. researchers say they have found a link between poorly cleaned cruise ship restrooms and the likelihood of a norovirus infection outbreak.
The study by scientists from Boston University School of Medicine, Carney Hospital, the Cambridge Health Alliance and Tufts University School of Medicine is said to be the first of environmental hygiene aboard cruise ships.
The researchers inspected 273 randomly selected public restrooms aboard various ships and found only 37 percent were cleaned daily. Although some objects in most restrooms were cleaned at least daily, the scientists found on 275 occasions no objects in a restroom were cleaned for at least 24 hours.
The least thoroughly cleaned object was baby changing tables.
The researchers said they found the thoroughness of cleaning did not differ by cruise line and did not correlate with Center for Disease Control and Prevention Vessel Sanitation Program inspection scores that averaged 97 out of a possible 100 points for the study vessels.
The research appears in the journal Clinical Infectious Diseases.
Statins may have different brain effects
SEATTLE, Nov. 2 (UPI) -- A U.S. medical researcher says he has determined two commonly used statins have different drug and cell dependent effects in the brain.
Professor John Albers and colleagues at the University of Washington's Northwest Lipid Metabolism and Diabetes Research Laboratories at the University of Washington compared the effects of two statins -- simvastatin (Zocor) and pravastatin (Pravachol) on two different types of brain cells -- neurons and astrocytes, which are support cells that help repair damage.
The scientists said although statins are of great value in treating high cholesterol and lowering the risk of heart disease, studies suggest similar statin drugs can have profoundly different effects on brain cells -- both beneficial and detrimental.
By directly applying the drugs to cells as opposed to administering them to animals, the scientists said they could eliminate differences in the drugs' ability to cross the blood-brain barrier as a reason for any differing effects.
Albers and his team said they looked at the expression of genes related to neurodegeneration, and found, despite using biologically equivalent drug concentrations, differences between both cells and drugs.
For example, the scientists said simvastatin reduced the expression of the cholesterol transporter ABCA1 by approximately 80 percent in astrocytes while pravastatin lowered expression by only around 50 percent. Another difference was that while both statins decreased expression of the Tau protein -- associated with Alzheimer's disease -- in astrocytes, they increased Tau expression in neurons. Pravastatin also increased the expression of another Alzheimer's hallmark, amyloid precursor protein.
While increased levels of these two proteins may account for potential risks of disease, Albers said large decreases in cholesterol proteins like ABCA1 should be considered. Brain cholesterol levels tend to be reduced in elderly people, and in such individuals the long-term effects of statin therapy could lead to transient or permanent cognitive impairment.
The researchers said their findings reinforce the idea that great care should be taken in deciding the dosage and type of statin given to individuals, particularly elderly people.
The study is reported in The Journal of Lipid Research.
