Tuesday, 21 May 2013

Sunshine vitamin 'may treat asthma'

Sun peeking out from the clouds
The amount of time asthma patients spend soaking up the sun may have an impact on the illness, researchers have suggested.


A team at King's College London said low levels of vitamin D, which is made by the body in sunlight, was linked to a worsening of symptoms.

Its latest research shows the vitamin calms an over-active part of the immune system in asthma.
However, treating patients with vitamin D has not yet been tested.

People with asthma can find it hard to breathe when their airways become inflamed, swollen and narrowed.
Most people are treated with steroids, but the drugs do not work for all.
 
Sunshine
"We know people with high levels of vitamin D are better able to control their asthma - that connection is quite striking," said researcher Prof Catherine Hawrylowicz.

Her group investigated the impact of the vitamin on a chemical in the body, interleukin-17. It is a vital part of the immune system and helps to fight off infections.

However, it can cause problems when levels get too high and has been strongly implicated in asthma.
In this study, published in the Journal of Allergy and Clinical Immunology, vitamin D was able to lower levels of interleukin-17 when it was added to blood samples taken from 28 patients.

The team is now conducting clinical trials to see if giving the sunshine vitamin to patients could ease their symptoms. They are looking at patients who do not respond to steroids as they produce seven times more interleukin-17 than other patients.

Prof Catherine Hawrylowicz told the BBC: "We think that treating people with vitamin D could make steroid-resistant patients respond to steroids or let those who can control their asthma take less steroids."
She said a culture of covering up in the sun and using sun cream may have increased asthma rates, but "it is a careful message because too much sun is bad for you".

Malayka Rahman, from the charity Asthma UK, said: "For the majority of people with asthma, current available medicines are an effective way of managing the condition but we know that they don't work for everyone, which is why research into new treatments is vital.

"We also know that many people with asthma have concerns about the side effects of their medicines so if vitamin D is shown to reduce the amount of medicines required, this would have an enormous impact on people's quality of life.
"We look forward to the results of the clinical trial."


article from BBC

Monday, 20 May 2013

Malaria parasite lures mosquito to human odour

Anopheles gambiae mosquitoMosquitoes carrying the malaria parasite are more attracted to human body odour than uninfected insects, a study suggests.
Researchers found that infected insects were three times more likely to be lured towards a human scent.
They believe that the deadly parasites are seizing control of their biting hosts and boosting their sense of smell.
The research is published in the journal Plos One.
Dr James Logan, from the London School of Hygiene and Tropical Medicine (LSHTM), said: "One thing that always surprises me about parasites is how clever they are. They are these ever-evolving organisms that seem to be one step ahead of us the whole time."

Smelly feet
To carry out the study, the researchers infected malaria mosquitoes (Anopheles gambiae) with the most deadly form of parasite, Plasmodium falciparum.

They placed about 100 of the infected insects into a container, along with some nylon stockings that had been previously worn by volunteers for 20 hours.
"It is a very effective way of collecting body odour... the odour can remain attractive for months," explained Dr Logan.
The scientists repeated the experiment with uninfected insects.
They found that mosquitoes carrying the deadly parasite were three times more likely to be attracted to the smelly stockings.
The scientists believe this is because the tiny parasitic organisms are manipulating their hosts' sense of smell.
Dr Logan said: "We think it is giving them a heightened sense of smell. We are hypothesising there is an alteration somewhere in their olfactory system that allows them to find us quicker."

Smart tactics
By making humans an easier target, the parasite is more likely to be passed into the blood stream - ensuring its survival and continuing the spread of the deadly disease.

The researchers will now begin a three-year project, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), to learn more about how the parasites are doing this.
Dr Logan said that understanding how the malaria-infected mosquitoes respond to human odour could help them to fight the disease.
He said: "If we know how the parasite is able to manipulate the olfactory system... perhaps we can identify new attractants for infected mosquitoes and we will be able to increase our efficiency with trapping techniques."
According to the latest figures, the World Health Organization said there were about 219 million cases of malaria in 2010 and 660,000 deaths.
Africa is the most affected continent: about 90% of all malaria deaths occur there.

ARTICLE FROM  BBC

Monday, 13 May 2013

'Weight loss gut bacterium' found

Bacteria in Petri dishBacteria that live in the gut have been used to reverse obesity and Type-2 diabetes in animal studies.
Research, published in Proceedings of the National Academy of Sciences, showed that a broth containing a single species of bacteria could dramatically alter the health of obese mice.
It is thought to change the gut lining and the way food is absorbed.
Similar tests now need to be take place in people to see if the same bacteria can be used to shed the pounds.
The human body is teeming with bacteria - the tiny organisms outnumber human cells in the body 10 to one.
And there is growing evidence that this collection of bacteria or "microbiome" affects health.

Obesity
Studies have shown differences between the types and numbers of bacteria in the guts of lean and obese people.
Meanwhile gastric bypass operations have been shown to change the balance of bacteria in the gut.
Researchers at the Catholic University of Louvain, in Belgium, worked with a single species of bacteria Akkermansia muciniphila. It normally makes up 3-5% of gut bacteria, but its levels fall in obesity.
Mice on a high fat diet - which led them to put on two to three times more fat than normal, lean, mice - were fed the bacteria.
The mice remained bigger than their lean cousins, but had lost around half of their extra weight despite no other changes to their diet.
They also had lower levels of insulin resistance, a key symptom of Type-2 diabetes.
Prof Patrice Cani, from the Catholic University of Louvain, told the BBC: "Of course it is an improvement, we did not completely reverse the obesity, but it is a very strong decrease in the fat mass.

"It is the first demonstration that there is a direct link between one specific species and improving metabolism."

Surprise
Adding the bacteria increased the thickness of the gut's mucus barrier, which stops some material passing from the gut to the blood. It also changed the chemical signals coming from the digestive system - which led to changes in the way fat was processed elsewhere in the body.
Similar results were achieved by adding a type of fibre to diets which led to an increase in the levels of Akkermansia muciniphila.
Prof Cani said it was "surprising" that just one species, out of the thousands in the gut, could have such an effect.
He said this was a "first step" towards "eventually using these bacteria as prevention or treatment of obesity and Type-2 diabetes" and that some form of bacteria-based therapy would be used "in the near future".
Prof Colin Hill, a microbiologist at University College Cork, said: "It's a very exciting study, we've had lots linking bacteria and weight gain but this is the first time an intervention seems to work.
"I don't think it's feasible that you can eat cream cakes and chips and sausages all day long and then eat bacteria to reverse all that."
He said it was more likely that the research would lead to understanding of exactly what happens in the gut, which could lead to tailored dietary advice for people trying to lose weight.

ARTICLE FROM  BBC