Knowledge Update

Washington, Nov 23 (IANS) Aiming to understanding why the roundworm that causes river blindness has started developing resistance to the drug used as the first-line treatment for the disease, a new study sheds light on the genetic makeup of the parasite.

The drug ivermectin remains the first-line treatment to target the parasite. The drug's discoverers were honoured with the Nobel Prize in Physiology or Medicine just last year.

But after several decades of exposure to ivermectin, these parasites are beginning to show resistance.

"We want to understand the origin of this resistance," said senior study author Makedonka Mitreva, Associate Professor of medicine at Washington University School of Medicine in St. Louis.

The parasite that causes river blindness infects about 37 million people in parts of Africa and Latin America, causing blindness and other major eye and skin diseases in about five million of them. 

The parasite is a roundworm called Onchocerca volvulus and is carried by black flies that thrive near rivers and streams. 

"Are these parasites evolving to survive the treatment, or are the surviving worms actually new strains that have been introduced due to migration of the black flies or of the parasite itself?" Mitreva asked.

To find out, Mitreva and her colleagues studied samples of the roundworms that have been stored since the early 1990s, before large-scale ivermectin treatment programmes began. 

They also are sequencing present-day strains for comparison. The current study, published in the journal Nature Microbiology, reports data only from the historical samples.

"We worked hard to find samples of the parasite that had not been exposed to the drug because we needed to establish an ancestral baseline," Mitreva said. 

The new study included 27 roundworm samples taken in the early 1990s from four distinct regions -- West African forest, West African savanna, Uganda and Ecuador.

"In West Africa, there are two separate strains of this parasite based on geographic areas -- the savanna strain and the forest strain," Mitreva said.

"The severity of the disease caused by each strain is very different. The savanna strains are much more virulent and have been associated with higher rates of blindness. The forest strains cause a mild skin disease. That's why we wanted to see how they differ genetically," she added.

According to Mitreva, the Uganda strains, collected in central Africa, could not be classified as either the forest or savanna strain. Similarly, the strains from Ecuador, in South America, were also very different from the African strains.

In general, Mitreva said, large-scale control efforts -- including mass treatment with ivermectin and the use of insecticides to reduce black fly populations -- have been very effective over the past 30 years. 

But since pockets of drug resistance are showing up, she said studies such as this one are important if the World Health Organisation's goal of eliminating the parasite by 2025 is to be met

​Washington, Nov 23 (IANS) NASA has selected SpaceX to provide launch services for the agencys April 2021 mission designed to make the first-ever global survey of Earths surface water.

The mission is likely to be launched on a SpaceX Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Air Force Base in California.

The total cost for NASA to launch the Surface Water and Ocean Topography (SWOT) mission is approximately $112 million, which includes the launch service; spacecraft processing; payload integration; and tracking, data and telemetry support, the US space agency said on Wednesday.

Designed to make the first-ever global survey of Earth's surface water, in addition to high-resolution ocean measurements, the SWOT mission will collect detailed measurements of how water bodies on Earth change over time.

The satellite will survey at least 90 per cent of the globe, studying Earth's lakes, rivers, reservoirs and oceans, at least twice every 21 days, aid in freshwater management around the world, to improve ocean circulation models and weather and climate predictions. 

The SWOT spacecraft will be jointly developed and managed by NASA and the French space agency Centre National d'Etudes Spatiales (CNES).

NASA said its launch services programme at Kennedy Space Center in Florida will manage the SpaceX launch service. 

SpaceX currently has nine NASA missions on its planned launch manifest for upcoming contracts, but it still hasn't provided a definite date for resuming launches following the explosion of a SpaceX rocket during pre-flight checks on a launch pad in September, Techcrunch.com reported.

SpaceX's Falcon 9 rocket exploded on September 1 at Cape Canaveral, Florida during a pre-launch test, destroying the rocket itself and a $200-million communications satellite that was set to play a key role in Facebook's plans to provide internet access to remote villages in Africa. No one was injured in the explosion.

In a series of tweets in September, SpaceX CEO Elon Musk termed the launch pad accident as the "the most difficult and complex failure" in the company's 14-year history.

London, Nov 14 (IANS) Global carbon emissions from burning fossil fuels are projected to rise only slightly in 2016, marking three years of almost no growth, says a study.

The researchers said that carbon emissions did not grow last year and the projected rise of only 0.2 per cent for 2016 marks a clear break from the rapid emissions growth of 2.3 per cent per year in the decade to 2013, with just 0.7 per cent growth seen in 2014.

The study, published in the journal Earth System Science Data, however, pointed out that although the break in emissions rise ties in with the pledges by countries to decrease emissions until 2030, it falls short of the reductions needed to limit climate change well below two degrees Celsius.

"This third year of almost no growth in emissions is unprecedented at a time of strong economic growth. This is a great help for tackling climate change but it is not enough. Global emissions now need to decrease rapidly, not just stop growing," Corinne Le Quere, Professor at University of East Anglia (UEA) in Britain who led the data analysis, said.

The analysis by researchers at the University of East Anglia and the Global Carbon Project, a group of scientists who measure how much carbon dioxide (CO2) humans emit every year, and how much is subsequently absorbed by plants, land surfaces and oceans, showed emissions growth remained below one per cent despite GDP growth exceeding three per cent.

The researchers identified decreased use of coal in China and the US as the main reason behind the three-year slowdown.

China - the biggest emitter of CO2 at 29 per cent - saw emissions decrease by 0.7 per cent in 2015, compared to growth of more than five per cent per year the previous decade. 

The scientists have projected a further reduction of 0.5 per cent is projected for 2016.

The US, the second biggest emitter of CO2 at 15 per cent, also reduced its coal use while increasing its oil and gas consumption and saw emissions decrease 2.6 per cent last year.

US emissions are projected to decrease by 1.7 per cent in 2016.

The European Union's 28 member states are the third largest emitter causing 10 per cent of emissions. The EU's CO2 emissions went up 1.4 percent in 2015, in contrast with longer term decreases.

India contributed 6.3 per cent of all global CO2 emissions in 2015, the study said.

The Global Carbon Budget analysis showed that, in spite of a lack of growth in emissions, the growth in atmospheric CO2 concentration was a record-high in 2015, and could be a record again in 2016 due to weak carbon sinks.

"Part of the CO2 emissions are absorbed by the ocean and by trees. With temperatures soaring in 2015 and 2016, less CO2 was absorbed by trees because of the hot and dry conditions related to the El Niño event. Atmospheric CO2 levels have exceeded 400 parts per million (ppm) and will continue to rise and cause the planet to warm until emissions are cut down to near zero," Le Quere said.

​Toronto, Nov 15 (IANS) Indian-origin researchers at York University in Toronto have developed a solution for water treatment that uses only naturally available antimicrobial substances and sugar.

The paper strip solution called "DipTreat" is laced with sugar to kill E. coli bacteria in contaminated water.

"We were able to efficiently remove almost 90 per cent of bacteria by dipping the special paper strip, DipTreat, in contaminated water samples," said one of the researchers Sushanta Mitra.

The discovery will be key to developing a new generation of inexpensive and portable water treatment devices, with human health benefits around the world - from the far north of Canada to the remote villages of India, Mitra said.

"Now with DipTreat, we have learned it will take less than two hours to fish, trap and kill E. coli in water," Mitra, Professor at York University's Lassonde School of Engineering.

While using porous paper strips to trap the bacterial cells, for killing, the researchers used an antimicrobial agent extracted from the seeds of moringa -- commonly known as drumstick or horseradish tree. 

As a result, the DipTreat solution for water treatment uses only naturally available antimicrobial substances and sugar, with minimal environmental and health impact. 

Currently, popular water treatment systems use silver nanoparticles and clays, whose long term impact on human health is yet to be fully understood, according Mitra. 

So far, DipTreat is effective for small quantities of water. For example, someone who is hiking can collect a glass of water and then dip the paper strips to purify it before drinking. 

The researchers believe that the invention could lead to a much greater impact. 

Published in the journal Environmental Science Water Research & Technology, the study is co-authored by Mitra, Saumyadeb Dasgupta and Naga Siva Gunda.

​New York, Nov 22 (IANS) Researchers have identified that X chromosome -- one of the sex chromosomes that determines whether an individual is male or female -- plays a major role in the increased incidence of cancer occurrence in males.

"Across virtually every type of cancer, occurrence rates are higher in males than in females. In some cases, the difference might be very small -- just a few percent points -- but in certain cancers, incidence is two or three times higher in males," said Andrew Lane from at Dana-Farber Cancer Institute in Massachusetts, US. 

Men outpace women in developing many cancers, including those associated with tobacco use, such as kidney, renal, bladder, and oral cancers, Lane said. 

The disparity is present among boys and girls, as well as men and women.

"Data from the National Cancer Institute show that males carry about a 20 per cent higher risk than females of developing cancer. That translates into 150,000 additional new cases of cancer in men every year," Lane added.

In the study, the researchers specifically focussed on tumour suppressor genes -- which protect the cells from cancer. In cancers, these tumour suppressor genes are often mutated or deleted and are no longer functional.

X chromosome were the only genes that were mutated more frequently in male cancers than female cancers.

Males have an X and a Y chromosome, and females have two X. 

In females, one of the X chromosomes shuts down and remains inactive for life to balance out the gene expression. 

The study showed that some genes on the inactivated X chromosome in female cells "escape" that dormant state and function normally. 

Thus females are protected from cancer to some relative extent because they have two copies of these genes whereas males only have one, the researchers said. 

So if they are going to get a cancer that those genes are involved in, they have to mutate them twice, whereas males only have to have one mutation, Lane said.

The study was reported in a paper published online in the journal Nature Genetics. 

​New York, Nov 22 (IANS) In a new breakthrough research, Brazilian scientists have developed a new technology that will enable parents to watch their unborn babies grow in realistic three-dimensional immersive visualisation.

The new technology combines magnetic resonance imaging (MRI) -- which provides high-resolution foetal and placental imaging with excellent contrast -- and ultrasound data to scan segments of the mother's womb and foetus to build a 3-D model which can be brought to life by using a virtual reality (VR) headset.

"The 3-D foetal models combined with virtual reality immersive technologies may improve our understanding of foetal anatomical characteristics and can be used for educational purposes and as a method for parents to visualise their unborn baby," said Heron Werner Jr. from the Clinica de Diagnostico por Imagem, in Rio de Janeiro, Brazil.

Sequentially-mounted MRI slices are used to begin construction of the model. A segmentation process follows in which the physician selects the body parts to be reconstructed in 3-D. 

Once an accurate 3-D model is created -- including the womb, umbilical cord, placenta and foetus -- the virtual reality device can be programmed to incorporate the model, the study said.

The virtual reality foetal 3-D models are remarkably similar to the post-natal appearance of the newborn baby. 

They recreate the entire internal structure of the foetus, including a detailed view of the respiratory tract, which can aid doctors in assessing abnormalities, Werner added.

The technology also can help coordinate care with multidisciplinary teams and provide better visual information to parents to help them understand malformations and treatment decisions.

"We believe that these images will help facilitate a multidisciplinary discussion about some pathologies in addition to bringing a new experience for parents when following the development of their unborn child," Werner said.

The study will be presented at the annual meeting of the Radiological Society of North America in Chicago, US.

​New York, Nov 22 (IANS) Teenagers who are obese as well as those who lose excessive weight may both be at risk of irreparable damage to their bones, a new study has found.

Obesity has been previously associated with the risk of cardiovascular diseases and diabetes, but the study found that it can also affect the bone structure in childhood and adolescence.

"While obesity was previously believed to be protective of bone health, recent studies have shown a higher incidence of forearm fractures in obese youth," said lead author Miriam A. Bredella, Associate Professor at Harvard Medical School in Boston, US.

Having a high amount of visceral fat -- the deep fat in the abdomen that surrounds the internal organs -- coupled with a low amount of muscle mass -- anorexia nervosa -- puts adolescents at risk for weakened bone structure, the study said.

"Visceral fat secretes substances that promote chronic inflammation, and chronic inflammation stimulates formation of osteoclasts, which are the cells that resorb or break-down bone. In addition, vitamin D, which is important for bone health, is soluble in adipose tissue and gets trapped within fat cells," Bredella said.

Growth hormone, which is important for bone health, is also lower in adolescents with visceral obesity.

On the other hand, anorexia nervosa also leads to an increased fracture risk in adolescence, which persists to adulthood, even after normalisation of body weight, Bredella said, adding that it is important to address this problem early on. 

Lean mass was positively associated with trabecular density -- a marker for the risk of osteoporosis --, volume and integrity.

"The best way to prevent bone loss is a healthy diet that contains adequate amounts of calcium and vitamin D, along with sufficient exercise," Bredella said.

The study will be presented at the annual meeting of the Radiological Society of North America in Chicago, US.

​Canberra, Nov 21 (IANS) Australian scientists have taken a step in the "right direction" to creating a vaccine for the deadly HIV virus.

Researchers from South Australia's University of Adelaide and the Queen Elizabeth Hospital have used a common cold virus to introduce their DNA-based vaccine into the immune system of laboratory mice, Xinhua news agency reported.

Branka Grubor-Bauk from the University of Adelaide said the team targeted the vaccine into areas in which the HIV infection is most commonly found, and discovered that the testing achieved a "significant reduction" of infection rates in the mice.

"You need to get protection where your body encounters the virus first and you need to stop that virus from either entering, or you need to stop it from replicating and stop it from spreading," Grubor-Bauk said on Monday.

"We're hoping our discovery is definitely pointing us in the right direction."

She said now the team had made the important breakthrough, and it was vital that research continues into a human vaccine for the HIV infection.

"After a long four years of study, we were able to create this common cold virus that encoded proteins of HIV and we vaccinated mice and we were successful in creating immunity in mucosal surfaces," Grubor-Bauk said.

"We also have a DNA vaccine we administered intradermally, like the influenza vaccine, and we found by administering this vaccine we were able to get a systemic immunity throughout the whole body."

The results of the testing were published in the Scientific Reports journal. 

​New York, Nov 20 (IANS) Extracts and isolated compounds from avocado seeds can potentially be used as a natural additive incorporated into ready-to-eat foods to control microbes that cause bacterial illness, researchers say.

The researchers found that the extracts from avocado seeds could be effective in controlling microbes that cause Listeria, a foodborne bacterial illness that can be very serious for pregnant women and people with impaired immune systems.

In the study, the researchers from Tecnologico de Monterrey, in Mexico compared enriched acetogenin extract (EAE) from avocado seeds with two name-brand synthetic antimicrobials.

They found that the EAE presented similar listeria-properties and chemical profiles to the synthetic antimicrobials.

The EAE was effective at 37 degrees celsius and at a refrigeration temperature of four degrees celsius.

Avocado seeds are a waste product of the food industry, and these results offer a value-added, sustainable opportunity for manufacturers, the researchers said.

Food products are usually formulated with synthetic additives that enhances the flavour so that it gives food a particular taste or smell. It may be derived from natural ingredients or created artificially.

However, food still has to be safe for consumers to eat, so food scientists are looking for ways to replace synthetic additives.

Since some additives are needed for food safety reasons, food product developers are faced with the challenge of developing more "natural" additives that can produce comparable results, the study said.

The study was published in the Journal of Food Science.

​New York, Nov 20 (IANS) Scientists from the Netherlands said they have made an important advance towards creating a functional bioartificial kidney that could one day replace the need for dialysis or transplantation in the millions of patients with kidney failure.

"The strategies and methods of this work could be relevant to the development of other bioartificial organs, such as a bioartificial liver or bioartificial pancreas, and organs on chips -- such as a kidney on chip, a lung on chip, or a liver on chip," said Dimitrios Stamatialis, from the University of Twente in the Netherlands.

A key requirement for bioartificial kidney is the formation of a "living membrane" that consists of a tight kidney cell layer on artificial membrane surfaces and can transport molecules from one side to the other. 

In a paper presented at American Society of Nephrology (ASN) Kidney Week 2016 at McCormick Place in Chicago, Illinois, the researchers achieved this using conditionally immortalised human renal proximal tubular epithelial cells (ciPTECs) on polyethersulfone-based hollow fiber membranes. 

They demonstrated that the cell monolayer is indeed functional as a living membrane.

"This study shows the successful development of a living membrane consisting of a reproducible ciPTEC monolayer on hollow fiber membranes, an important step towards the development of a bioartificial kidney device," Stamatialis said.