Friday December 15, 2017

Anti-dengue Antibody Drug May Neutralize Zika Virus

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Test for Zika more than once during pregnancy: Study

Washington, Sep 26: An anti-dengue antibody-based drug could potentially protect a mother and her foetus from the deadly Zika virus as well, suggests new research.

In experiments with mice, the researchers found that an antibody that protects against dengue virus is also effective against Zika.

“We found that this antibody not only neutralises the dengue virus but, in mice, protects both adults and foetuses from Zika disease,” said Michael Diamond, Professor at Washington University School of Medicine in St. Louis, and senior author of the study published in the journal Nature Immunology.

Antibodies remain in the bloodstream for weeks, so one or a few doses of an antibody-based drug given over the course of a woman’s pregnancy potentially could protect her foetus from Zika, with the added benefit of protecting her from both Zika and dengue disease, the researchers said.

Dengue causes high fever, severe headaches, and joint and muscle pain in children and adults but does not directly harm foetuses.

Since dengue and Zika are related viruses, the researchers reasoned that an antibody that prevents dengue disease may do the same for Zika.

In collaboration with Gavin Screaton of Imperial College London, who had generated a panel of human anti-dengue antibodies years before, the scientists infected nonpregnant adult mice with Zika virus and then administered one of the anti-dengue antibodies one, three or five days after infection.

For comparison, another group of mice was infected with Zika virus and then given a placebo.

Within three weeks of infection, more than 80 per cent of the untreated mice had died, whereas all of the mice that received the anti-dengue antibody within three days of infection were still alive, and 40 per cent of those that received the antibody five days after infection survived.

To find out whether the antibody also could protect foetuses from infection, the researchers infected female mice on the sixth day of their pregnancies with Zika virus and then administered a dose of antibody or a placebo one or three days later.

On the 13th day of gestation, the amount of Zika’s genetic material were significantly lower in the placentas and in the foetal heads from the pregnant mice that were treated one day after infection, compared with mice that received the placebo.

However, administering the antibody three days after infection was less effective, the findings showed.

These findings suggest that for the antibody to effectively protect foetuses from Zika infection, it must be administered soon after infection.

Such a goal may be unrealistic clinically because women rarely know when they get infected.

However, giving women the antibody as soon as they know they are pregnant could provide them with a ready-made defence against the virus should they encounter it.

“We mutated the antibody so that it could not cause antibody enhancement of dengue infection, and it was still protective,” said Diamond.

“So now we have a version of the antibody that would be therapeutic against both viruses and safe for use in a dengue-endemic area because it is unable to worsen disease,” Diamond added.(IANS)

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Researchers found a new Drug to Reduce Alcohol Addiction in Teenagers

The drug is (+)-Naltrexone can reduce the drinking habit in teenagers.

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A new drug can reduce Alcohol addiction in teenagers
A new drug can reduce Alcohol addiction in teenagers. Pixabay
  • Researchers have found a new drug that may eventually help to reduce alcohol addiction in adults who used to binge during their adolescent years.

A new drug found which can reduce Alcohol addiction in teenagers

“During our teen years, the brain is still in a relatively immature state. Binge drinking worsens this situation, as alcohol undermines the normal developmental processes that affect how our brain matures,” said lead author Jon Jacobsen, a Ph.D. student at the University of Adelaide, Australia.

“Therefore, when an adolescent who has been binge drinking becomes an adult, they’re often left with an immature brain, which assists in the development of alcohol dependence,” Jacobsen added.

For the study, published in the Journal Neuropharmacology, researchers observed that adolescent mice involved in binge drinking behavior developed an increased sensitivity to alcohol as adults and engaged in further binge drinking.

The researchers were able to prevent some of these detrimental behaviors observed in adulthood, by giving mice a drug that blocks a specific response from the immune system in the brain.

The drug is (+)-Naltrexone, known to block the immune receptor Toll-like receptor 4 (TLR4).

“This drug effectively switched off the impulse in mice to binge drink. The mice were given this drug still sought out alcohol, but their level of drinking was greatly reduced,” says senior author Professor Mark Hutchinson, Director of the ARC Centre of Excellence for Nanoscale BioPhotonics at the University of Adelaide.

“We’re excited by the finding that we can potentially block binge drinking in an adult after they have experienced such behavior during adolescence, by stopping the activation of the brain’s immune system. It’s the first time this has been shown and gives us hope that our work has implications for the eventual treatment of alcohol addiction in adults,” Hutchinson noted.(IANS)

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Dinosaur-killing asteroid could hold the cure for cancer

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Dinosaur-killing asteroid could hold the cure for cancer

London: A 10-km wide asteroid that wiped out dinosaurs when it crashed into earth over 65 million years ago contains a rare metal — iridium — that could be used in the effective treatment of cancer, researchers have found.

Scientists from the UK and China have demonstrated that iridium — a rare metal delivered to Earth by the asteroid — can be used to kill cancer without harming healthy cells.

Laser-based techniques are emerging as viable treatments for cancer, targeting tumours far more precisely than the shotgun blast of radiation and chemotherapy. Researchers from the University of Warwick in the UK and Sun Yat-Sen University in China have found that laser light can turn iridium into an effective cancer killer, the newatlas.com reported.

The team created a compound of iridium and organic materials, and then introduced it into a lung cancer tumour grown in the lab. When red laser light is shone onto it through the skin, the compound is activated, converting the oxygen in the tumour into singlet oxygen, a poisonous form of the element that effectively kills the cancer cells from the inside. With cancer becoming resistant to certain treatments, it’s crucial to find new methods such as this.

Further study found that the compound was effective as it managed to penetrate every layer of the tumour.

The team used ultra-high resolution mass spectrometry to highlight which proteins in the cancer cells were being targeted. They found that the compound had damaged proteins that manage heat shock stress and glucose metabolism, which are known to be crucial molecules for cancer’s survival.

When the researchers tested the iridium compound on a clump of non-cancerous tissue they found it had no effect, meaning it seems to be a highly targeted treatment that doesn’t attack healthy cells. The research was published in the journal Angewandte Chemie.

Iridium is relatively rare on Earth naturally, but scientists have found a spike in the Chicxulub crater, an impact crater buried underneath the Yucatán Peninsula in Mexico, which is often associated with the asteroid impact that wiped out the dinosaurs.

“The precious metal platinum is already used in more than 50 per cent of cancer chemotherapies,” says Peter Sadler, lead author of the study. “The potential of other precious metals such as iridium to provide new targeted drugs that attack cancer cells in completely new ways and combat resistance, and which can be used safely with the minimum of side-effects, is now being explored. It’s certainly now time to try to make good medical use of the iridium delivered to us by an asteroid 66 million years ago!” — IANS

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Test for Zika more than once during pregnancy: Study

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Zika
Test for Zika more than once during pregnancy: Study

New York, November 2,2017:  Women should be tested for the Zika virus more than once during pregnancy as the pathogen can be intermittently present in the urine for up to seven months, researchers suggested.

The study showed that the test could again be positive for the Zika virus even after the viral load had disappeared in previous tests.

 The virus can be detected in a patient’s urine for as long as seven months.

“These results suggest the virus continues replicating during pregnancy, in the foetus or the placenta, which must serve as a reservoir for the pathogen,” said Mauricio Lacerda Nogueira, Professor at the Sao Paulo Research Foundation (FAPESP) in Brazil.

“However, viral load in the mother’s fluids is intermittent and very low, almost at the detection threshold,” Nogueira added, in the paper appearing in the journal Emerging Infectious Diseases.

Molecular tests to detect Zika virus enable identification of the pathogen’s genetic material in body fluids such as blood, urine, semen and saliva during the acute phase of infection.

These tests have also been used routinely in prenatal checkups for pregnant women with symptoms of the disease.

According to Nogueira, if the result of a molecular test is negative, it should ideally be repeated at least twice at intervals of no less than a week.

“We typically test urine samples because they are easier to obtain and because the blood viral load is lower and disappears faster,” he said.

For the study, the team included women in different stages of pregnancy (four weeks to 38 weeks).

Some women had babies with complications — such as hearing loss and brain cyst — that were probably caused by Zika.

However, the researchers were unable to establish a correlation between the number of times the virus was detected in the mother and the occurrence of an adverse outcome.(IANS)