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Archive for June, 2014

A Flu Virus That Killed Millions In 1918 Has Now Been Recreated


Wikimedia Commons

Spanish flu

Scientists have recreated a nearly exact replicate of the deadly flu virus that killed an estimated 50 million in the 1918 Spanish flu pandemic.

But don’t worry, they say it’s totally safe.

Researchers at the University of Wisconsin-Madison reverse engineered an influenza virus from a similar one found in birds, combining several strains to create one that is nearly identical to the one that caused the 1918 outbreak. They then mutated the genes to make it airborne, and to study how it spreads between animals.

“Our research indicates the risks inherent in circulating avian influenza viruses,” Yoshihiro Kawaoka, the scientist who led the research team, told VICE News. “Continued surveillance of avian influenza viruses — and not only viruses that we know pose risks for humans, such as H5N1 and H7N9 influenza viruses, and attention to pandemic preparedness measures is important.”

According to the statement summarizing the project published this week, the “analyses revealed the global prevalence of avian influenza virus genes whose proteins differ only a few amino acids from the 1918 pandemic influenza virus, suggesting that 1918-like pandemic viruses may emerge in the future.”

In other words, a common avian flu virus that has been circulating in wild ducks is pretty much the exact same one that infected humans a century ago. And now is in a lab.

The research was funded by the National Institute of Health as a way to find out more about similar virus’ and their transmissibility from animals to humans. It was done in a lab that complied with full safety and security regulations, said Carole Heilman, director of the Division of Microbiology and Infectious Diseases, at National Institute of Allergy and Infectious Diseases (NIAD), a division of NIH.

“It was an question of risk versus benefit,” Heilman told VICE News. “We determined that the risk benefit ratio was adequate if we had this type of safety regulations.”

But many scientists disagree and have condemned research that recreates virus’ such this, stating that if released accidentally, a virus could spread to humans and cause a pandemic. Marc Lipsitch, an epidemiologist at Harvard, has criticized research such as Kawaoka’s as unnecessarily risky.

“There is a quantifiable possibility that these novel pathogens could be accidentally or deliberately released. Exacerbating the immunological vulnerability of human populations to PPPs is the potential for rapid global dissemination via ever-increasing human mobility,” Lipsitch said in a paper about experiments with transmissible virus’. “The dangers are not just hypothetical.”

Lipsitch points out that many of the H1N1 flu outbreaks that have occurred between 1977 and 2009 were a result of a lab accident.

Kawaoka disagrees, saying, “We maintain that it is better to know as much as possible about the risk posed by these viruses so we may be able to identify the risk when viruses with pandemic potential emerge, and have effective countermeasures on-hand or ready for development.”

This article originally appeared at VICE News. Check them out on YouTube, Facebook, and Instagram. Copyright 2014. Follow VICE News on Twitter.

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GM Mosquitos Could Eradicate Wild Populations By Only Producing Male Offspring


photo credit: James D. Gathany/CDC

Over 200 million people are infected by malaria each year, and the majority of the 627,000 deaths per year are children younger than five. The disease is carried by mosquitos who act as vectors for the parasite. It’s only transmitted to humans by female mosquitoes, as they’re the only ones who bite. A team of researchers led by Andrea Crisanti of the Imperial College London managed to genetically modify mosquitos to produce 95% male offspring, eliminating mosquito populations along with the risk of malaria. The results of the study were published in Nature Communications.

In most species of mosquito, the females need a blood meal in order to acquire the nutrients to create viable eggs. When she does, she can lay about 200 eggs at a time in water, and up to 3,000 eggs over the course of her lifetime. About half of those offspring will be daughters, many of whom will live long enough to produce that amount of offspring also. For humans living near mosquitos carrying the parasite that causes malaria, those numbers of female mosquitos present a very real threat.

But what if the numbers could be skewed so that the sex ratio favors males, who are harmless to humans? This is exactly what Crisanti’s team set out to do with Anopheles gambiae, a species of mosquito endemic to sub-Saharan Africa, where 95% of malaria deaths occur. The researchers modified the males with the enzyme I-Ppol, which excises the X chromosome during spermatogenesis. This renders sperm that would produce daughters to be non-functional, while the sperm that will create male offspring are unaffected. As a result, about 95% of the resulting offspring are male.

Next, modified males were introduced to five caged wild-type populations. As the males mated with the females, they passed along the same mutation until it dominated the population. For four of the five populations, it took only six generations for the mosquitos to die out due to a lack of females.

“What is most promising about our results is that they are self-sustaining,” co-author Nikolai Windbichler said in a press release. “Once modified mosquitoes are introduced, males will start to produce mainly sons, and their sons will do the same, so essentially the mosquitoes carry out the work for us.”

This study was the first to successfully manipulate mosquito sex ratios, and it was done in a big way. The researchers hope that this information will be used to develop genetic mutations to be used in the wild, bringing large populations of mosquitos to their knees.

“The research is still in its early days, but I am really hopeful that this new approach could ultimately lead to a cheap and effective way to eliminate malaria from entire regions,” added lead author Roberto Galizi. “Our goal is to enable people to live freely without the threat of this deadly disease.”

Of course, while eradicating the mosquitos would be fantastic for eliminating the threat of malaria, what other affects would it have? Wouldn’t there be harsh consequences for the ecosystem? After all, mosquitos have been on the planet for about 100 million years and represent 3,500 species. As it turns out, mosquitos wouldn’t really be missed if they were to disappear. While mosquitos can act as pollinators as well as a food source for other animals, their absence would be merely a temporary setback before another species filled the niche. Of course, there is a gamble in assuming the replacement organism would be harmless.

“Malaria is debilitating and often fatal and we need to find new ways of tackling it. We think our innovative approach is a huge step forward. For the very first time, we have been able to inhibit the production of female offspring in the laboratory and this provides a new means to eliminate the disease,” Crisanti explained.

Each year, sub-Saharan Africa loses about $12 billion in economic productivity due to malarial infections. Considering developed areas in these countries have per capita incomes of about US$1500, this would have very real implications for the quality of life for people in those areas. Eliminating that disease would also allow doctors and hospitals to address other health concerns, and the environment would likely benefit from not having to use insecticides.

 

REFERENCE:

Galizi, R. et al. 2014. ‘A synthetic sex ratio distortion system for the control of the human malaria mosquito’. Nature Communications, 10 June 2014.

Hand Transplantations and Bionic Prostheses


Recently I attended an international medical student congress, Medical Student Journal Club – Pro et Contra, which took place on 23. and 24. May 2014 in Ljubljana, Slovenia.

It was a great congress, with a lot of interesting debates preesented by great speakers.

Myself, I have also registred as an active speaker, together with a colleague of mine, Barbara Šijaković. We debated on topic “Reconstructive surgery should focus on development of cadaver body parts transplantation rather than bionic prosthesis implantation“.

Below is a transcript of our debate.

And just for elaboration, the whole keynote was actually made with only videos tu support theses.


Reconstructive surgery should focus on development of cadaver body parts transplantation rather than bionic prosthesis implantation

Luka: Hello, it’s me up here again. So, I thought I could start with an old Marx brothers joke. No wonder it looks like the same room, because it is the same room. Ok, it doesnt go…

Well, since it’s Saturday afternoon and this is the last debate of this congress, we’ll try to be as interesting and short as possible. My name is Luka, on my left a college of mine, Barbara, and, already introduced, our mentor, Nina Suvorov, MD.

Before we actually start with the debate, let us ask you a question. Imagine you’ve lost your hand sometime in the past and now you are presented with two options. Either hand transplantation or bionic prosthesis. Which would you, right now, choose. Would you go for hand transplantation, or would you rather go with a bionic prosthesis. How many of you would choose hand transplantation? And how many bionic prosthesis? Interesting; 60% for bionics and 40% for transplantation. We’ll keep that number in mind.

Barbara: Now, before we begin, let’s clear the terms. Luka, could you tell us what a reconstructive transplant is?

Luka: Thank you, Barbara. A reconstructive transplant, or also called a composite tissue allograft, is an operation that involves transplantation of bone, tissue, muscle and blood vessels. According to WHO “transplantation is the transfer or rather engraftment of human cells, tissues or organs from a donor to a recipient with the aim of restoring function(s) in the body. And in cases when transplantation is performed between different species, e.g. animal to human, it is named xenotransplantation.

Now, Barbara, would you care to briefly explain what a bionic prosthesis is and how it works?

Barbara: Bionic creativity engineering is basically implementation of biological systems in the developing modern technology. Bionic hand isn’t just the hook. It mimics the real human hand. In some cases bionic hand even superposes human hand, as we shall see later.

There are different bionic prostheses, today I’ll talk about i-Limb Ultra, the one most advanced for now.

Here is how it looks: we can see power button here, the digits are motorized. It’s made out of plastic, titanium and silicone.

And just some mechanical properties…

This is a myoelectric prosthesis, which means it uses electrical sensors to detect contractions in the selected muscles of the residual limb. These contractions are than translated into movement of the bionic hand by a specific algorithms.

Luka: Ok, so which is better? Let’s start with transplantations of the hand. We will focus mainly on the hand, since leg prosthetics are nearly perfect, but with hand it’s different. You have many small and fine movements that are incorporated in every day’s life and you simply cannot function without a hand.

Just some short history for the beginning. The first hand transplant was actually performed in Ecuador in 1964, but the patient suffered from transplant rejection after only two weeks. Then, there was basically a long period of nothing. Up until January 1999. The first successful hand transplantation. Now, you should notice, we are talking about transplantation, not about replantation. The first successful replantation was performed in Shanghai, China, in January 1963.

So, in January 1999 the first person (a baseball player) underwent an operation. This kind of operation is probably one of the longest there is. It takes approximately 12 to 16 hours. In comparison, a typical heart transplant takes 6 to 8 hours and a liver transplant, 8 to 12 hours.

Hand transplantation is an extremely complex procedure, but may not be as difficult as a hand replantation in that a replantation usually involves crushed or mangled bones, tendons, and ligaments.

Barbara: Would you care to elaborate on how this is done? Read more…