Gut bacteria reveals human migration

From ABC Science, News in Science, 23 January 2009:
A bacterial parasite known to cause stomach ulcers is shedding new light on ancient patterns of human migration across the Pacific region, according to an international study.
In the latest edition of Science, researchers report that their study of the distribution of Helicobacter pylori genotypes has given further weight to the theory that Australia was first populated around 30,000 years ago.
H. pylori is particularly useful for studying the movement of human populations because it is extremely widespread, and is transmitted from mother to child.
Co-author Professor Barry Marshall, a microbiologist at the University of Western Australia, says H. pylori is a lot like mitochondrial DNA, which is also used to investigate human migration patterns.
"You catch [H. pylori] off your mother," says Marshall. "All of us carry our mothers' mitochondrial DNA and that goes all the way back through the generations."
H. pylori has a further advantage in that it contains thousands of genes, compared to just 37 genes in mDNA, and differs between populations.
"It was found over [the] last few years that each human racial group carried a Helicobacter that was relatively unique in that group," Marshall says. Read more.

The vaccine revolution

From Pathway magazine, the Royal College of Pathologists of Australasia, Winter 2008:
Being a baby one hundred years ago was a pretty dicey affair. Up to one in three would not live to see their first birthday, instead falling victim to any one of a long list of diseases including smallpox, diphtheria, measles, tetanus and whooping cough. Even if they did successfully run the gauntlet of these killers, they still had a lifetime of fighting ahead of them. Something as simple as a scratch could lead to an untreatable and possibly fatal infection.
All that changed in 1796. A rural English doctor called Edward Jenner discovered that inoculating a person with material from a cowpox lesion protected them against subsequent smallpox infection, and the first vaccine was born.
Since then, widespread immunisation has lead to the complete eradication of smallpox and, in the developed world, almost relegated infectious diseases such as polio, diphtheria, tetanus and measles to the pages of medical history. Read more (pdf file, page 22).

This sound barrier can be broken

From The Australian, 10 January 2009:
At age two years and seven months, William Long is already an unstoppable chatterbox. “People say ‘oh my goodness, he really doesn’t stop talking’,” says his mother Sandra. Not that this would normally be considered that unusual, except for the fact that William is profoundly deaf, and has been since birth.
The discovery when their son was just three days old that he could not hear a sound came as a huge shock to Sandra and her husband. Neither had any family history of hearing problems, and no apparent cause could be found for William’s condition.
“I had this baby and I thought I can’t talk to him and he can’t hear me so I sort of shut down,” Sandra recalls. “I didn’t develop that loving bond.”
Thankfully, a chance meeting at an early intervention centre brought the Long family into contact with Dimity Dornan, founder of the Hear and Say Centre—a not-for-profit organisation that specialises in teaching hearing-impaired children to listen and speak through a program called auditory-verbal therapy.
As a result of that meeting, and receiving cochlear implants, William is now a consummate conversationalist who is scoring well above his age in auditory comprehension—what he understands—and expressive communication. He embodies the results of a recent study showing auditory-verbal therapy effectively levels the playing field for deaf children with cochlear implants in terms of speech, listening and language development. Read more in newspaper.

Sleep longer for healthier arteries

From 6minutes.com.au, 5 January 2009:
A single extra hour of sleep can reduce the five-year risk of coronary artery calcification by 33%, according to research published in the Journal of the American Medical Association.
The five-year study of nearly 500 healthy, middle-aged Americans found the coronary benefits of sleep remained even after adjusting for potential confounders such as age, smoking status, apnoea risk and other cardiac risk factors such as lipid levels and blood pressure.
The effect of sleep, or lack of, was so significant, the authors suggested sleep could rank alongside other more established coronary risk factors.
“The modelled effect of one additional hour of sleep on the odds of incident calcification was equal to the modelled effect of a 16.5mmHg decrease in systolic blood pressure,” researchers wrote.
Earlier research had already implicated sleep quality and quantity as a correlate of risk factors ranging from glucose and appetite regulation to inflammation and obesity.
However many of these studies relied on subjects’ self-reporting of sleep habits.
In this study, researchers chose a more objective measure of sleep duration and quality by using wrist activity monitors.
Researchers suggested a number of potential explanations for the association, including as-yet-unknown common factors affecting both sleep and calcification, mediators such as inflammation or cortisol, or diurnal variations in calcification. Read more.

Smacking ban could help save children's lives

From 6minutes.com.au, 5 January 2009:
Outlawing corporal punishment of children, and improved detection of early psychotic illness in mothers, could go a long way towards reducing the number of child homicides in Australia, according to research in the Medical Journal of Australia this week.
A study of 165 child homicides found 27 deaths were caused by offenders experiencing acute psychotic illness, and more than half of these offenders—almost all mothers, many from non-English speaking backgrounds—had never been treated with antipsychotic medication.
“Patients in first-episode psychosis had shown signs of mental illness for an average of six months and had acute psychotic symptoms for an average of six weeks before the homicide,” the authors wrote.
Most of these offenders had had some contact with health services in the two weeks before the homicide.
Child abuse was the most common reason for child homicide, blamed for 59 deaths including five from methadone overdose.
The authors suggested that reducing the incidence of child abuse by banning corporal punishment of children—an intervention already shown to be effective in Sweden—could help prevent some child homicides.
From 1987 to 2001, 437 Australian children aged under 15 years were murdered, with the highest incidence of child homicide being in children under one year old, the authors found.
The figures compare rather unfavourably with the United Kingdom. Australian children aged 0-4 are around 50% more likely, and those aged 5–15 years are twice as likely, to die by homicide compared to their British counterparts. Read more.

Head-banging hammers the brain

From ABC Science Online, News in Science, 18 December 2008:
Led Zeppelin's immortal song 'Dazed and Confused' might well have been a clinical observation on the state of their audience's brains, say Australian researchers who have found over-enthusiastic head-banging can cause mild brain injury.
In a study published in the British Medical Journal this week, two University of New South Wales (UNSW)researchers concluded that head-banging to a typical heavy metal tempo could cause mild traumatic brain injury or concussion, and neck injury, particularly as the tempo of the music and angle of movement increased.
"Clearly it's a serious issue," says Associate Professor Andrew McIntosh, co-author and professor of biomechanics at UNSW.
"If you observe people after concerts they clearly look dazed, confused and incoherent, so something must be going on and we wanted to look into it." Read more.