Vaccinate the vector?

The new chair of Tulane’s department of tropical medicine, Dr. Nirbhay Kumar, is bringing to Tulane a promising malaria vaccine.
Malaria is a tropical parasitic disease carried by mosquitoes that kills about one million people a year. An effective vaccine against the disease has proven elusive. Malaria has been infecting humans for millions of years and has developed successful ways of evading the human immune response making vaccination strategies less effective.
Kumar will continue working on the vaccine at Tulane. He is also bringing money from his grant to set up a new laboratory and insectary at Tulane in order to perfect the vaccine.
Kumar said, “Hopefully, we will be able to start clinical trials at Tulane in two years.”
The last vaccine trial, just recently published, was conducted in mice and baboons. The vaccine was over 97 percent efficient in the baboons.
Dr. Mark James, professor of immunology and vice chair of tropical medicine, said “The vaccine shows encouraging results.”
Kumar said that the vaccine should be cheap and easy to produce.
“The vaccine will hopefully be able to be provided at little or no cost in developing countries.” He said.
The vaccine that Kumar is currently developing is a transmission-blocking vaccine. The vaccine would not protect the individual vaccinated, but rather lower the chance that that person could transmit the disease. This type of vaccine is commonly referred to as an “altruist vaccine”, referring to the fact that while the vaccine may not protect the individual, it could protect the community.
“People will be willing to get vaccinated if it protects their children and other family members.” Kumar said.
There is another malaria vaccine which is currently in clinical trials, called RTS,S after the protein it immunizes against. It is an infection blocking vaccine and protects the individual immunized, like most traditional vaccines. Potentially the two vaccines could be used in conjunction to thwart infection, and then, if the first vaccine fails, hinder transmission. Kumar, however, would also like his vaccine to be administered alone, and believes it should be effective by itself.
The vaccine is a protein, called Pfs48/45, expressed by the sexual stages of malaria. Escherichia coli (E. coli) bacteria are induced to make the protein, which allows the protein to be made inexpensively and in large quantities. The vaccine is only directed against one species of malaria, Plasmodium falciparum.
The vaccine works by promoting the body’s production of antibodies against the sexual stages of the malaria parasite. The feeding mosquito ingests both parasites and antibodies with the blood meal. The antibodies prevent the parasites from mating in the mosquito and thus can stop transmission of the disease.
James said “The most promising use of the vaccine will probably be in unstable transmission areas. It could be boosted before prime transmission season to curb epidemics.”
The vaccine is currently administered in three separate doses, but Kumar thinks that it is possible that only two will be required for effective immunization.
Tulane’s school of public health and tropical medicine has a strong commitment to global health, and Kumar’s work will hopefully reinforce the school’s reputation.
James said, “It’s good to have someone working on a malaria vaccination at Tulane.”
Kumar also gave high praise to his new university.
He said, “I’m excited to be working at Tulane. It has an excellent history and reputation in tropical medicine.”

Compostable Bags

Shopping trips to Wal-Mart can be quite depressing. Today, however, I was pleasantly surprised. What greeted me as I slinked into the store (other than a creepy old man) were Sun Chips in compostable bags. Intriguing.

After delving into subject, I discovered that the bags are apparently manufactured by a company called NatureWorks, which specializes in creating packaging from corn. The bags start as dextrose (a sugar) derived from corn which is then fermented and becomes lactic acid (the same chemical that causes sore muscles after a workout). The lactic acid is then polymerized, or attached to one another to make a long chain of lactic acid molecules. The polymerized lactic acid can then be used like a plastic (which is also a polymer).

The cost of such a process is apparently now competitive with traditional plastics, and, of course, is more environmentally friendly. Not only are these products compostable, but they do not rely on oil to manufacture.

There are potential problems with this system, however. Corn is a food crop, and as we are experiencing with biofuel, using it for other purposes can drive up food costs. Corn also requires quite a bit of energy and water to grow. With this being said, the technology is simple enough that it can easily be used with some other source of sugar – perhaps a microbe – that will be more energy efficient.

Unfortunately, the Sun Chip bags are not completely made of this lactic acid polymer, but the company assures that they will be as soon as possible. And they are still compostable, though apparently they will not degrade in landfills (at least very quickly). Never-the-less, it is a noble effort and I, for one, encourage people to support it.

Learn more:
• Farrington, D.W.; Lunt, J.; Davies, S; Blackburn, R.S.; “Poly(lactic acid) fibers.” Biodegradable and sustainable fibres. Woodhead Publishing Limited, 2005. Chapter 6.
• http://www.natureworksllc.com/
• http://www.sunchips.com/healthier_planet.shtml

Clean power from trash?

Imagine your garbage morphing into the electricity that powers your home. Not only is this fantasy possible, but plans are already underway for it to be a reality, right here in New Orleans.
The technology is called plasma arc gasification. It utilizes super heated (over 7000 degrees Centigrade) gas called plasma to gasify or melt the trash that is fed into it. Plasma is also ionized, meaning that it carries an electric charge and generates a magnetic field. A frequently observed instance of such a plasma field is lightning.
Once the garbage is exposed to the plasma arc, the molecules of the substances break apart into pure atomic elements. The organic components of the trash become a gas – similar to natural gas – that can be used to generate power. The inorganic parts melt and become what is known as “slag.”
Despite some protests by local environmental groups, the facility will theoretically be environmentally friendly. Not only would the plant reduce landfill use, but since the actual molecular composition of the garbage is changed by this process, the plasma plant can take potentially hazardous materials and render them harmless. Dr. Louis J. Circeo, Director of the Plasma Applications Research Program at Georgia Tech Research Institute, claims that the plants can “accept all solid and liquid waste” including hazardous, toxic, and medical wastes.
Unlike other waste-to-energy facilities currently in the United States, plasma gasification does not burn the trash, thus eliminating a potential pollution problem. “It creates no waste” says D’Juan Hernandez, the owner of Sun Energy Group, the company planning to build a plasma gasification plant in New Orleans. “There are two products – slag, which can be reformed into construction materials, and syngas, which is used for power generation.” In a recent presentation, Dr. Circeo explained that the slag generated by plasma gasification can be used for concrete, asphalt, insulation, and can also produce recyclable metals.
However, since the molten slag can be molded into almost any shape, there are many other possible uses for it. In a recent book, Prescription for the Planet, Tom Blees suggested a use for slag that could assist with another environmental problem. Blees stated that “The molten slag could be poured into molds of various shapes optimally designed for use as artificial reefs.”
Hernandez also explained that using the syngas to create power will generate some emissions, but the plant should have emissions well under regulation standards and little to no other environmental consequences. Plasma gasification will not over-ride normal recycling, however. Recyclable materials will be sorted out at the facility and sold.
This technology may seem quite ground-breaking, but it has actually been used in several other countries for many years. Japan has been successfully operating two gasification plants for seven years. Canada, Taiwan, and England also have operational plasma gasification facilities. Plants similar to the one planned in New Orleans are currently under development in Florida, Pennsylvania, Minnesota, and Massachusetts.
Hernandez stated that Louisiana was targeted as a location for a gasification plant because “it is an industrial state and it has a high utilities cost and high landfill use rates.” According to Hernandez, the new plant is expected to create over one hundred jobs in the area and produce 115 megawatts of power by processing 2,500 tons of garbage daily. It is expected to be operational by the end of 2012.

A note of interest...

Possible transfusion-transmitted Yellow Fever? Interesting...

http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/yellow-fever.aspx

Catching cancer

Cancers are not usually considered contagious diseases. Normally they are caused by environmental and genetic factors that cause malfunctioning cells – not a disease that can be transferred between individuals. Of course, we know that a few species of viruses, which are contagious, can induce tumors – feline leukemia and HPV are two examples of this phenomenon. These viruses insert their genomes into their host’s DNA, which can cause improperly translated genes and thus cancer.

However, there is another form of cancer which is far more bizarre. This type of cancer is truly contagious in the sense that the actual cancer cells are transferred between individuals. Two naturally occurring cancers of this type exist; Canine Transmissible Venereal Tumor and devil’s facial tumor disease. CTVT is spread via sexual intercourse of dogs. The tumors are benign and spontaneously resolve. DFTD is transmitted through facial biting – the cancerous cells infect facial wounds Tasmanian devils inflict on each other. DFTD is fatal and heavily contributing to the current decline of the Tasmanian devil population

This type of cancer is caused by cancerous clonal cell lines. In the case of DFTD, a possible scenario is an individual Tasmanian devil developed a cancer, apparently of the myeloid sheath, which was immortal, as all cancer cells are. The cells then became able to leave their original host and transfer to other Tasmanian devils. CTVT probably emerged in a similar fashion. The tumor cells do not have the same genome as their host, as most tumor cells do, but instead they share a common genome distinct from the animals they have infected.

These fascinating cancerous diseases leave us with many questions. Should these cells be considered pathogenic organisms? How many other strains of contagious cancer exist? How do they emerge? Interesting questions for some well-funded scientists to answer in the future.

Learn more:

Murchison, Elizabeth P., et al. The Tasmanian Devil Transcriptome Reveals Schwann Cell Origins of a Clonally Transmissible Cancer. Science 1 January 2010:Vol. 327. no. 5961, pp. 84 - 87

The Fountain of Youth is Green?

Green tea has been drunk for centuries in Asia, and has been receiving increasing popularity in the United States. It has been labeled as everything from a weight loss agent to an anti-carcinogen to an immune enhancer. Now, recent research shows that a chemical in green tea, ECGC (the same chemical supposedly linked to weight loss, as well as a few other benefits) may prevent neurological diseases such as Alzheimer’s and Parkinson’s. The chemical apparently can degrade the protein plaques that form in the brain and causes neuron dysfunction. Green tea has also recently been shown to reverse fibrosis of the liver and increase bone density.

Full disclosure: I am somewhat of a green tea-phile. However, if science likes this continues to emerge, it seems like I might be on the right track.

Drink up!

For more info:
http://www.sciencedaily.com/releases/2009/12/091203091856.htm
Cabrera C, Artacho R, Gimenez R. Beneficial effects of green tea: a review. J Am Coll Nutr. 2006; 25:79-99.
Kim et al. Antifibrotic effects of green tea on in vitro and in vivo models of liver fibrosis. World Journal of Gastroenterology, 2009; 15 (41): 5200 DOI: 10.3748/wjg.15.5200

A dork out moment....

For those that have an unhealthy desire to track disease outbreaks (like me), check out:

http://healthmap.org/en

You can select different diseases and see where the latest outbreak has occurred on the world map. Nifty.

Thanks to ProMed for alerting me to this site.