Children with autism have deifcits in their mitochondrial DNA

Research showed that children with autism have deficits in their mitochondrial DNA. These deficits can make it harder for the body to fight off infection.

Children with autism experience deficits in a type of immune cell that protects the body from infection. Called granulocytes, the cells exhibit one-third the capacity to fight infection and protect the body from invasion compared with the same cells in children who are developing normally.

The cells, which circulate in the bloodstream, are less able to deliver crucial infection-fighting oxidative responses to combat invading pathogens because of dysfunction in their tiny energy-generating organelles, the mitochondria.

The study is published online in the journalPediatrics.

"Granulocytes fight cellular invaders like bacteria and viruses by producing highly reactive oxidants, toxic chemicals that kill microorganisms. Our findings show that in children with severe autism the level of that response was both lower and slower," said Eleonora Napoli, lead study author and project scientist in the Department of Molecular Biosciences in the UC Davis School of Veterinary Medicine. "The granulocytes generated less highly reactive oxidants and took longer to produce them."

The researchers also found that the mitochondria in the granulocytes of children with autism consumed far less oxygen than those of the typically developing children -- another sign of decreased mitochondrial function.

Mitochondria are the main intracellular source of oxygen free radicals, which are very reactive and can harm cellular structures and DNA. Cells can repair typical levels of oxidative damage. However, in the children with autism the cells produced more free radicals and were less able to repair the damage, and as a result experienced more oxidative stress. The free radical levels in the blood cells of children with autism were 1 ½ times greater than those without the disorder.

The study was conducted using blood samples of children enrolled in the Childhood Risk of Autism and the Environment (CHARGE) Study and included 10 children with severe autism age 2 to 5 and 10 age-, race- and sex-matched children who were developing typically.

In an earlier study the research team found decreased mitochondrial fortitude in another type of immune cell, the lymphocytes. Together, the findings suggest that deficiencies in the cells' ability to fuel brain neurons might lead to some of the cognitive impairments associated with autism. Higher levels of free radicals also might contribute to autism severity.

"The response found among granulocytes mirrors earlier results obtained with lymphocytes from children with severe autism, underscoring the cross-talk between energy metabolism and response to oxidative damage," said Cecilia Giulivi, professor in the Department of Molecular Biosciences in the UC Davis School of Veterinary Medicine and the study's senior author.

"It also suggests that the immune response seems to be modulated by a nuclear factor named NRF2," that controls antioxidant response to environmental factors and may hold clues to the gene-environment interaction in autism, Giulivi said.

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Study: Maternal infections increase child's autism risk

A study found that a pregnant woman with a bacterial infections diagnosed in the hospital had a higher risk of the child being diagnosed with autism.

Hospital-diagnosed maternal bacterial infections during pregnancy were associated with an increased risk of autism spectrum disorders in children, according to a Kaiser Permanente study published Dec. 23 in the Journal of Autism and Developmental Disorders.

The research contributes new evidence to a body of scientific literature on the role of infection in autism risk and points to areas for further examination.

The study included 407 children with autism and 2,075 matched children who did not have autism. The study included infants born between January 1995 and June 1999 who remained members of the Kaiser Permanente health plan for at least two years following birth.

"Though infections in pregnant women are fairly common, in this study most were not associated with an increased risk of autism," said Lisa A. Croen, PhD, research scientist with the Kaiser Permanente Division of Research and senior author of the study. "Only bacterial infections diagnosed in the hospital were associated with an increased risk."

"Infections diagnosed in a hospital setting were more common among mothers of children who developed an ASD compared with mothers of children who did not develop an ASD," Croen further explained.

Women with bacterial infections diagnosed during a hospitalization (including of the genitals, urinary tract and amniotic fluid) had a 58 percent greater risk of having a child with an ASD. While not very common in any of the mothers studied (1.5 percent of mothers of a child with ASD vs. 0.5 percent of mothers of a child without ASD), infections diagnosed during a hospitalization in the second trimester were associated with children having more than a three-fold increased risk of developing ASD.

"Infections diagnosed in an inpatient setting may represent more severe infections, and these were associated with increased risk of ASD," said Ousseny Zerbo, PhD, research fellow with the Kaiser Permanente Division of Research and the study's lead author.

While the mechanism for how maternal infections may influence autism risk has not been firmly established, Zerbo said animal tests have shown that immune-system responses to infections during pregnancy may influence the neurological development of the fetus.

"Our findings indicate that although most infections during pregnancy were not associated with autism in the child, there appears to be some increased risk for autism," Zerbo said. "It would be prudent for pregnant women to contact their doctor if they suspect an infection."

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Dissolvable brain sutures may treat brain infections

A new theory claims that dissolvable brain sutures that are already used can be modified to contain antibiotics and treat brain infections thus reducing hospital stay length.

A plastic material already used in absorbable surgical sutures and other medical devices shows promise for continuous administration of antibiotics to patients with brain infections, scientists are reporting in a new study. Use of the material, placed directly on the brain's surface, could reduce the need for weeks of costly hospital stays now required for such treatment, they say in the journal ACS Chemical Neuroscience.

Shih-Jung Liu and colleagues explain that infections are life-threatening complications that occur in about 5-10 percent of patients who have brain surgery. Current treatment involves intravenous antibiotics for up to eight weeks and extended, costly hospital stays. Previous studies showed that drug-delivering plastics could release antibiotics directly into the brain. However, additional surgery was needed to remove the plastic when treatment finished. Liu's team sought to develop a biodegradable version using a dissolvable plastic called PLGA.

They describe development of PLGA fibers that release vancomycin, a powerful antibiotic that kills many microbes, including the infamous "MRSA," which shrugs off most other known antibiotics. They tested the fibers in rats, which are stand-ins for humans in these types of studies. The fibers successfully released vancomycin for more than eight weeks in the brain and did so without apparent side effects.

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Sleep disorders 'can weaken the immune system'

Patients suffering with sleep disorders are more likely to develop infections this winter.

This is the opinion of Dr Ellie Cannon, a GP who specialises in general health. She stated that getting enough rest each night is one of the most effective ways a person can boost their immune system, which would subsequently make them more resistant to diseases.

Other changes a person could make include adopting a healthier diet and participating in more exercise.

"Exercise boosts your circulation and your immune system. That is a great two-fold motivation to keep up the exercise," Dr Cannon added.

She also advised that proteins such as lean meats and fish can also help to improve a person's immune system.

The Royal College of Psychiatrists states that sleep disorders such as insomnia can be caused by emotional problems or depression and advises that people could seek cognitive therapy and stimulus control to help alleviate some of these issues.

Read more: http://www.privatehealth.co.uk/news/december-2011/sleep-disorders-can-weaken-immune-system-36285/