Scientists discover role of skin in spreading leishmaniasis

Image result for Scientists discover role of skin in spreading leishmaniasisScientists at the University of York have discovered that parasites responsible for leishmaniasis – a globally occurring neglected tropical disease spread by sand flies – are mainly acquired from the skin rather than a person’s blood.

Visceral leishmaniasis is a parasitic infection that kills 20-40 thousand people each year across 56 countries, mainly in the developing world. There is no vaccine and drugs are prohibitively expensive or toxic.

Previously it was assumed that sand flies acquired the disease parasite directly from a host’s blood, through biting an infected person before spreading the disease to uninfected people in subsequent bites.

However, the number of parasites found in blood has often been puzzlingly low, leading some to question whether there is another source of parasites for transmission.

Now, mathematicians, experimental biologists, and immunologists have revealed a ‘patchy landscape of parasites’ found on carriers’ skin that determines how many parasites are picked up by sand flies.

Using mathematical modeling, they showed that some areas of skin can contain particularly high numbers of the parasite, while other areas may not.

This means that whether a sand fly becomes infected or not depends on where they bite a person.

This breakthrough is significant as it suggests current methods of treating leishmaniasis are too simple, as disease detection and treatment often focuses on levels of the parasite in blood samples.

The research also stresses that more attention should be focused on developing treatments that affect parasites in the skin, if the cycle of transmission is to be interrupted.

Johannes Doehl, Post-Doctoral Research Associate in York’s Centre for Immunology and Infection and lead author of the study, said: “Currently, to assess treatment success in visceral leishmaniasis, clinicians focus on monitoring parasite levels in a host’s blood.

“However, we now have conclusive proof that measuring parasites in the skin, not just the blood, is critical when assessing possible treatments. Clinical studies and elimination campaigns need to take this into account, and in particular measure how treatments affect the patchy landscape of parasites in the skin.”

Dr. Jon Pitchford, Reader in York’s Departments of Biology and Mathematics, said: “To effectively control leishmaniasis, we don’t just need to cure the disease in patients, we must also understand and try and break the transmission cycle. This research is the first step towards improving the treatment process and demonstrates how the application of mathematics can help solve important problems in medicine.”

[“Source-news-medical”]

Sex of the baby may play important role in would-be mother’s immunity

Sex of the baby may play important role in would-be mother's immunitySex of the baby may play important role in would-be mother’s immunity
A study reveals would-be mothers, carrying female fetuses may exhibit a heightened inflammatory response that can contribute to sickness-related symptoms, such as achiness and fatigue.

According to researchers, women, over the years, have claimed that body of a mother, carrying male and female baby, react differently.

The study, published in journal Brain, Behavior and Immunity, shows the sex of a baby is associated with pregnant women’s immune responses.

Inflammation is a critical part of the immune response involved in wound healing and responses to viruses, bacteria and chronic illnesses and excessive inflammation is stressful to the body and can contribute to sickness-related symptoms, such as achiness and fatigue.

Researchers from the Ohio State University’s wexner medical center in the US followed 80 pregnant women across the course of their pregnancy and examined whether women exhibited different levels of immune markers called cytokines based on fetal sex.

The analyses were conducted on levels of cytokines in the blood and levels produced by a sample of immune cells that were exposed to bacteria in the lab.

“While women didn’t exhibit differences in blood cytokine levels based on fetal sex, we did find that the immune cells of women carrying female fetuses produced more pro-inflammatory cytokines when exposed to bacteria,” said principal investigator of the study Amanda Mitchell.

“This means that women carrying female fetuses exhibited a heightened inflammatory response when their immune system was challenged, compared to women carrying male fetuses,” Mitchell explained.

Adding, “This research helps women and their obstetricians recognise that fetal sex is one factor that may impact how a woman’s body responds to everyday immune challenges and can lead to further research into how differences in immune function may affect how a women responds to different viruses, infections or chronic health conditions (such as asthma).”

source”cnbc”

Outdoor light has role in reducing short-sightedness in kids

Increasing exposure to outdoor light is the key to reducing the myopia (short-sightedness) epidemic in children, according to ground-breaking research by Australian optometrists.

Optometrist and lead researcher on the project, Associate Professor Scott Read who is the director of research at QUT’s School of Optometry and Vision Science, said children need to spend more than an hour and preferably at least two hours a day outside to help prevent myopia from developing and progressing.

Speaking at the Australian Vision Convention in Queensland on the weekend, Professor Read said it was not ‘near work’ on computer and other screens causing myopia, but a lack of adequate outdoor light.

“While screens are contributing to children spending more time indoors than in previous years, the research shows they are not the direct cause of the increased incidence of myopia,” he said.

“Optometrists need to make their patients aware that less than 60 minutes’ exposure to light outdoors per day is a risk factor for myopia.

“It looks like even for those with myopia already, increasing time outside is likely to reduce progression.”

Optometry Australia president Kate Gifford said “this new finding is of significant importance in our endeavour to mitigate the growing rate of myopia in children.”

In February, it was announced that half the world’s population will be short-sighted by 2050 with many at risk of blindness.

The global study, published by the Brien Holden Vision Institute, forecasts that 10 per cent of the world’s population will be at risk of blindness by 2050 if steps are not taken to stop myopia turning into high myopia (requiring glasses with a prescription of minus five or stronger).

The QUT study measured children’s eye growth via study participants wearing wristwatch light sensors to record light exposure and physical activity for a fortnight during warmer then colder months to give an overall measurement of their typical light exposure.

“Children exposed to the least outdoor light had faster eye growth and hence faster myopia progression,” Professor Read said.

“source -cncb”]