Carbohydrates may be key to better malaria vaccine: study

Agencies
September 17, 2017

Melbourne, Sept 17: Scientists have for the first time found that carbohydrates on the surface of malaria parasites play a critical role in malaria's ability to infect mosquito and human hosts.

The discovery may help improve the only vaccine approved to protect people against Plasmodium falciparum malaria - the most deadly form of the disease, researchers said.

The study found that the malaria parasite 'tags' its proteins with carbohydrates in order to stabilise and transport them, and this process was crucial to completing the parasite's lifecycle.

"We found that the parasite's ability to 'tag' key proteins with carbohydrates is important for two stages of the malaria lifecycle," said Justin Boddey, from Walter and Eliza Hall Institute in Australia.

"It is critical for the the earliest stages of human infection, when the parasite migrates through the body and invades in the liver, and later when it is transmitted back to the mosquito from an infected human, enabling the parasite to be spread between people," said Boddey, who led the study published in the journal Nature Communications.

Interfering with the parasite's ability to attach these carbohydrates to its proteins hinders liver infection and transmission to the mosquito, and weakens the parasite to the point that it cannot survive in the host, researchers said.

Malaria infects over 200 million people worldwide each year and kills around 650,000 people, predominantly pregnant women and children.

Efforts to eradicate malaria require the development of new therapeutics, particularly an effective malaria vaccine.

The first malaria vaccine approved for human use - RTS,S/AS01 - was approved by European regulators in July 2015 but has not been as successful as hoped, with marginal efficacy that wanes over time, researchers said.

"The protein used in the RTS,S vaccine mimics one of the proteins we have been studying on the surface of the malaria parasite that is readily recognised by the immune system," said Ethan Goddard-Borger from Walter and Eliza Hall Institute.

"With this study, we have shown that the parasite protein is tagged with carbohydrates, making it slightly different to the vaccine, so the antibodies produced may not be optimal for recognising target parasites," Goddard-Borger said.

He said there were many documented cases where attaching carbohydrates to a protein improved its efficacy as a vaccine.

"It may be that a version of RTS,S with added carbohydrates will perform better than the current vaccine," Goddard-Borger said.

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Agencies
June 19,2020

While coughing, fever and difficulty in breathing are common symptoms of COVID-19, a new case study has found that pink eye is also a reason to be tested for the disease.

The study, published in the Canadian Journal of Ophthalmology, determined that conjunctivitis and keratoconjunctivitis can also be primary symptoms of COVID-19.

The researchers noted that in March, a 29-year-old woman arrived at the Royal Alexandra Hospital's Eye Institute of Alberta with a severe case of conjunctivitis and minimal respiratory symptoms.

After the patient had undergone several days of treatment with little improvement -- and after it had been determined that the woman had recently returned home from Asia -- a resident ordered a COVID-19 test.

The test came back positive, according to the researchers.

"What is interesting in this case, and perhaps very different to how it had been recognised at that specific time, was that the main presentation of the illness was not a respiratory symptom. It was the eye," said Carlos Solarte, an assistant professor at the University of Alberta in Canada.

"There was no fever and no cough, so we weren't led to suspect COVID-19 at the beginning. We didn't know it could present primarily with the eye and not with the lungs," Solarte said.

Academic studies at the outset of the pandemic identified conjunctivitis as a secondary symptoms in about 10 to 15 per cent of COVID-19 cases, he said.

Since then, scientists have gained greater knowledge of how the virus can transmit through and affect the body's mucous membrane system, of which the conjunctiva -- the clear, thin membrane that covers the front surface of the eye -- is an extension.

While the finding provides important new health information for the public, it also makes eye exams more complicated for ophthalmologists and staff, the researchers noted.

"The patient in this case eventually recovered well without any issues. But several of the residents and staff who were in close contact with the patient had to be under quarantine," said Solarte.

"Fortunately, none who were involved in her care also tested positive," he said.

Patients coming into an eye clinic with conjunctivitis and keratoconjunctivitis are now treated as potential cases of COVID-19 and extra precautions are taken by staff, according to the researchers.

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Agencies
June 29,2020

Washington DC, Jun 29: Young children with narrow retinal artery diameters were more likely to develop higher blood pressure, and children with higher blood pressure levels were more likely to develop retinal microvascular impairment during early childhood, according to a new study.

The first study to show this connection in children was published today in Hypertension, an American Heart Association journal.

High blood pressure, the main risk factor for the development of cardiovascular disease (CVD), can manifest as early as childhood, and the prevalence of high blood pressure among children continues to rise. In previous studies, analysis of blood vessels in the retina has shown promise as a predictor of CVD risk among adults. In the study titled, "Retinal Vessel Diameters and Blood Pressure Progression in Children," researchers sought to predict the development of high blood pressure in children over four years based on retinal blood vessel measurements.

"Hypertension continues as the main risk factor for the development of cardiovascular diseases and mortality," says Henner Hanssen, M.D., the study's lead author and a professor in the department of sport, exercise and health at the University of Basel in Switzerland. 

"Primary prevention strategies are needed to focus on screening retinal microvascular health and blood pressure in young children in order to identify those at increased risk of developing hypertension. The earlier we can provide treatment and implement lifestyle changes to reduce hypertension, the greater the benefit for these children."

Researchers screened 262 children ages six to eight from 26 schools in Basel, Switzerland, in 2014, for baseline blood pressure and retinal arterial measurements. Both measures were taken again in 2018. Blood pressure measurements at both baseline and follow-up were performed in a sitting position after a minimum of five minutes of rest and were categorized based on the American Academy of Pediatrics' blood pressure guidelines. These guidelines utilize the same measurements as the American Heart Association/American College of Cardiology 2017 Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults.

Results from the analysis indicate: children with narrower retinal vessel diameters at baseline developed higher systolic blood pressure at follow-up; retinal vessel diameters could explain 29 -31 per cent of the changes in systolic blood pressure progression between 2014 and 2018; children with higher blood pressure levels at baseline developed significantly narrower arteriolar diameters at follow-up, depending on weight and cardiorespiratory fitness; and initial blood pressure measures explained 66-69 per cent of the change in retinal arteriolar diameter from baseline to follow-up.

"Early childhood assessments of retinal microvascular health and blood pressure monitoring can improve cardiovascular risk classification. Timely primary prevention strategies for children at risk of developing hypertension could potentially counteract its growing burden among both children and adults," said Hanssen.

Researchers noted limitations of their study include that they could not confirm blood pressure measurements over a single 24-hour period, so they would not account for "white coat" hypertension, a condition where patients have high blood pressure readings when measured in a medical setting.

Developmental stage including puberty status of each child was not accounted for in the study, as well as genetic factors or birth weight - variables that could impact blood pressure development and microvascular health.

In addition, reference values for appropriate retinal vessel diameters in children do not currently exist, so future studies are needed to determine age-related normal values during childhood.

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Agencies
January 4,2020

Washington D.C., Jan 3: A new study has found out that diet significantly affects the mental health and well being of an individual.

The study was published in the journal European Neuropsychopharmacology.

"We have found that there is increasing evidence of a link between a poor diet and the worsening of mood disorders, including anxiety and depression. However, many common beliefs about the health effects of certain foods are not supported by solid evidence," said the lead researcher, Professor Suzanne Dickson.

According to the researchers, the link between diet and mental health can be firmly established in certain cases like that of the ability of a ketogenic diet being helpful for children with epilepsy and the impact of vitamin B12 deficiency on poor memory, depression and fatigue.

"With individual conditions, we often found very mixed evidence. With ADHD for example, we can see an increase in the quantity of refined sugar in the diet seems to increase ADHD and hyperactivity, whereas eating more fresh fruit and vegetables seems to protect against these conditions," said Dickson

But there are comparatively few studies, and many of them don't last long enough to show long-term effects," added Dickson.

The study further concludes that some food items can be associated with treatment and the betterment of certain mental health conditions.

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