Fight nematode parasites with compounds in worms

Worms are important decomposers in soil, but in humans they spell trouble. Parasitic nematodes infect some 2 billion people.

Researchers are hopeful the discovery of a new class of molecules could lead to prevention and treatments for worm parasites.

(Credit: Image of "Caenorhabditis elegans" via Shutterstock)

Hookworms, whipworms, Ascaris, Guinea worms, and trichina worms are just a few parasitic nematodes that infect some 2 billion people.

Researchers report that nematodes use the newly discovered class of small molecules to signal such processes as growing, developing, mating, and moving toward or away from an area.

“All of these nematodes speak the same chemical language,” through the use of compounds called ascarosides, says study co-author Frank Schroeder, a research scientist at the Boyce Thompson Institute for Plant Research and adjunct assistant professor at Cornell University.

The study, published online in the journal Current Biology, was led by Stephan von Reuss, a postdoctoral associate in Schroeder’s lab, and Andrea Choe, a postdoctoral scholar in the lab of co-author Paul Sternberg, a biologist at the (WormLab) California Institute of Technology.

Since nematodes are the only known organisms to use ascarosides, “we don’t have to be afraid of interfering with similar biochemistry in animals, plants, or humans,” Schroeder says, as researchers seek to identify species-specific ascaroside molecules that may enable novel approaches to deter or disrupt the survival or reproduction of parasitic worms.

Researchers in Schroeder’s lab have already filed for three patents, one that covers the structures of various ascarosides, one that covers ascarosides for use as agents to protect plants, and one that makes claims to how to use the compounds to treat or prevent human disease.

The researchers first discovered ascarosides as a signaling molecule in C. elegans, a nematode used as a model organism to study cell, developmental, and nervous system biology, as well as human aging and diabetes.

“We then thought, if C. elegans uses this chemical language, perhaps other nematodes do too,” Schroeder says.

Raed the full report here:  DOI: 10.1016/j.cub.2012.03.024

Malaria: Cell Phone Cameras Capture Microscopic Images

Smart phone apps can help you check your vision, keep tabs on your blood-glucose levels and track your blood pressure. Earlier this year the U.S. Food and Drug Administration even approved an app that allows doctors to view scans on an iPhone or iPad to help them make diagnoses on the go.

But fancy apps aside, the cameras on these devices and others can help health care workers in remote or understaffed areas submit photos of complicated conditions to doctors who can verify or make a diagnosis.

One question that quickly surfaces is whether cell phone cameras are good enough to transmit microscopic information to experts.

A new study found that many simple bar phones with cameras could snap a good enough picture through a standard microscope to allow a remote assessment of a sample. The results were published online Wednesday in PLoS ONE.

“Poor and vulnerable populations are most affected by weak laboratory services because they carry the largest burden of ill health,” noted the researchers behind the study, which was led by Coosje Tuijn, of the Royal Tropical Institute of Biomedical Research in Amsterdam.

And although microscopy is often pivotal in diagnosing common diseases, such as malaria, tuberculosis and other bacterial or parasitic diseases, in poor areas, “microscopy services are often suboptimal,” the researchers noted.

And “as a result, many common diseases are misdiagnosed and improperly treated, ” which can affect patients—and cost the health system time and money.

In Uganda, where there are only eight physicians for every 100,000 people, getting a definitive diagnosis can be difficult. The research team enlisted local health workers to try using their own (or borrowed) cell phones to capture photos and videos of microscopic images to send off for remote diagnosis.

The best images were obtained with cameras that were two megapixels or higher, which are common in smart phones and are in some slimmer Nokia, Samsung and Sony bar phones.

And some of the most successful diagnoses were those of samples that contained malaria parasites, which “were often so clear that specific stages of the malaria parasite could be identified”—thus improving targeted treatment.

TB was a little more challenging (owing to the small size of its bacteria) and required a fluorescent microscopy and a five-megapixel camera.

But phones with video could also grab clips that revealed some other microbes as they moved around, helping to improve the remote diagnosis.

Once the pictures were snapped, health workers could send them directly to a website that could make them accessible to experts for diagnosis and/or students for training.

Direct feedback, via phone call or text, could then be sent to the user’s phone.

Mobile app diagnoses malaria from a single drop of blood

The virtual ink had barely dried on our story about the Skin Scan app for diagnosing melanoma when we received word of another, equally compelling mobile diagnostic tool.

Focusing this time on the millions of people at risk from malaria in sub-Saharan Africa and other parts of the world, Lifelens is a project that has created a smartphone app to diagnose the insidious, mosquito-borne disease.

More than one million people die each year from Malaria, and roughly 85 percent of them are children under the age of 5, the Lifelens project notes. The most prevalent diagnostic tool, meanwhile, is the rapid diagnostic test (RDT), which is known to be associated with a 60 percent incidence rate of false positive results.

That, in turn, results in the treatment of many people who don’t actually have Malaria, driving up the costs of anti-Malaria treatment significantly. The Lifelens project, on the other hand, aims to make the process both cheaper and more accurate by analyzing blood digitally instead.

Specifically, once blood is stained to reveal the Malaria parasites, the project’s smartphone app can analyze a magnified image of a drop of blood captured via simple finger prick, including counting the various types of cells it includes. Malarial parasites are among those it can identify, making false results much less likely.

Once analysis is complete, data is uploaded to the Web, where it can be mapped for a high-level view of where Malaria outbreaks are occurring.

The video below demonstrates Lifelens in action:

Memes: Replace Genes as Engine driving Human Evolution

The idea of memes as a cultural analogue of genes has been much maligned, and most biologists still reject it. Yet memetics has much to offer in explaining human nature.

MemeTheory
According to meme theory, humans are radically different from all other species because we alone are meme machines.

Human intelligence is not just a bit more or a bit better than other kinds of intelligence, it is something completely different, based on a new evolutionary process and a new kind of information.

Differentiating
The main difference between conventional theories and memetics is this: most biologists assume that culture and language evolved because they helped humans survive and pass on their genes, and that genes retain ultimate control.

Memetics challenges that assumption. Although the capacity for imitation must once have been adaptive for the apes who started it, evolution has no foresight and could not have predicted the consequences of letting loose a new evolutionary process. Nor could it have retained control of memes once they began evolving in their own right.

Proliferation
So memes began to proliferate. What began as an adaptation soon became like a parasite - a new evolving entity that changed the apes and their world forever. Once memes were proliferating, individuals benefited from copying the latest and most successful ones, and then passed on any genes that helped them do so.

Memetic Drive
This "memetic drive" forced their brains to get bigger and bigger, and to become adept at copying the most successful memes, eventually leading to language, art, music, ritual and religion - the successful designs of human culture.

Clickety Click here for the full Article from New Scientist