Author Archives: Paul Yi

Lethal Adaptations In Nature: Tapeworms linking infection and cancer

Parasites are some of the oldest and basic forms of life on the planet. Each and every species having honed their specific traits to leech and infest their host often through millions of years of natural selection. It’s a scary thought, to say the least. And one particular widespread parasitic species has recently been discovered to have made significant jump. Tapeworms.

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Tapeworm proglottids (50cm in length)
Author: Nathan Reading via Flickr Commons

It’s a certain parasite that I’m quite concerned about every time I pick up an egg sandwich at local gas station. Tapeworms often infest the digestive tract of animals and use their hosts are intermediary stages in their life cycle. In the case of humans, that infection is usually caused by consuming undercooked foods. The photo of a vomited tapeworm above was taken from a pregnant 26-year-old patient who had been living in East Africa. As you can see, they can grow immensely large in your intestine without any symptoms (one of the optimal traits of a model parasite).

If that wasn’t enough to make your skin crawl, a study published in 1999 found that up to 75 million people may carry the dwarf tapeworm with 25% of children affected in certain areas. When taking a much closer look with an electron microscope (image below), you can clearly see that tapeworms have an effective adaption on its head: suckers, muscular grooves, and hooks to latch onto your inner digestive system. Though rarely lethal, newly published research has uncovered a potentially deadly link between these worms and cancer.

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Hymenolepis microstoma (rodent tapeworm)
Author: Magdalena ZZ via Wikimedia Commons

A brief report was published this past week in the New England Journal of Medicine, detailing an unprecedented case of a tapeworm (or any parasite of that matter) transferring cancer cells into a human. The team of American researchers led by Dr. Atis Muehlenbachs from the Centers for Disease Control and Prevention claim it to be the first reported case of its kind. Easing public fears, it’s also been described as extremely unusual and rare.

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Source: The New England Journal of Medicine

The story begins in Columbia in 2013 when a 41-year-old man stumped local doctors of his deteriorating condition. He was ill, losing weight, and struggling with a prior HIV infection. Upon further examination, a CT scan of his lungs showed many tumorous growths which were made of cells not identified as human. That shocking revelation prompted them to contact scientists at the U.S. CDC.

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Figure 1 (A). Radiographic and Pathological Features of Malignant Hymenolepis nana.
(Muehlenbachs et al. 2015)
Source: The New England Journal of Medicine

The CDC center in Atlanta found the cells to be much smaller than human ones. Ten times smaller. Eventually, a genetic analysis found the strange cells had DNA from Hymenolepis nana (the dwarf tapeworm). The current theory is that the HIV patient’s compromised immune system and a mutation in the tapeworm caused this spread of cancerous cells from parasite to host.  For a more detailed explanation of the biological mechanisms involved, check out the helpful video below courtesy of the New England Journal of Medicine.

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It’s important to note that original patient died before he was correctly diagnosed. However, perhaps the results of this investigation may prove to be fruitful for others in the future as millions of people suffer from both tapeworms and HIV.

Tragedy aside, one has to admire how amazing this discovery is. For myself, I’m so impressed by the international collaboration of medical experts as well as the nature of the case. Even the language used in the original paper sounds very dramatic, Invasion of human tissue by abnormal, proliferating, genetically altered tapeworm cells is a novel disease mechanism that links infection and cancer.”  (*I’ve underlined some phrases to emphasize their impact.)

It feels like something out of the TV show House MD: a medical mystery, bizarre clues, the elusive search, and the extraordinary resolution. It’s the kind of passion that I believe Muehlenbachs shares.

“We were amazed when we found this new type of disease – tapeworms growing inside a person, essentially getting cancer, that spread to the person, causing tumor…” – Dr. Atis Muehlenbachs of the U.S. CDC

Furthermore, I’m sure this case will spark a new field in medical research of cross-species oncology. I admit that this mutation may not be very beneficial to the tapeworm as it prematurely kills off its human host and may end up being a once-in-a-life phenomenon. Nonetheless, it’s a great example of how a parasite can dramatically change the relationship with its host and how we should approach treatment of unknown diseases.

By Paul Yi

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NASA Confirms Flowing Water On Mars: Unlocking the Mysteries of the Red Planet

The fourth celestial body from the Sun and one of Earth’s closest neighbors has just got a little brighter in the public eye. Scientists at NASA have made a ground-breaking announcement regarding one of the oldest questions surrounding Mars. The discovery of extraterrestrial life? Sorry, no. But something just as exciting. In a press release on Monday, NASA confirmed that it has found evidence of water flowing on present-day Mars.

Author: NikoLang Courtesy of Wikimedia Commons

Description: Mars Dayside in Celestia with Addon
Author: NikoLang
Courtesy of Wikimedia Commons

Data from NASA’s Mars Reconnaissance Orbiter, or MRO, showed seasonal changes in the level of hydrated minerals on the surface of the Red Planet. Spectral imaging analysis of certain Martian slopes indicated a cycle of liquid water flowing downhill during warmer seasons. This flow would then recede in colder seasons, not unlike on our own planet. This pattern was found in several locations on the Martian surface which were once considered mysterious due to unexplained observable streaks. For a science geek like myself, it feels like the start of a brand new chapter in space education. And I’m sure publishers are salivating at the chance to revise hundreds of thousands of science textbooks.

Courtesy of NASA via YouTube

In addition, the discovery has major implications if whether Mars is able to currently support life and if humans will one day be able to utilize this precious resource. John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate, described it as a meaningful step in mankind’s exploration of space.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected.”

Furthermore, NASA’s latest revelation is an excellent example in how the agency is reaching out to the general public. NASA scientists opened a digital dialogue via Reddit.com, answering Mars-related questions from online users. In my opinion, this form of two-way communication allows NASA to send a much clearer message to the general public without news producers filtering it within the web of mass media. It also gives that message a more personal touch, which may be more interesting and inspiring to a younger generation that did not grow up watching the shuttle missions.

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NASA Subreddit Logo
Courtesy of Reddit.com

YouTube and social media were also utilized to spread the news. Such efforts are important as NASA’s funding has reached record-low levels in recent years, in terms of proportion of spending of the U.S. federal budget. This drop in relative funding has now forced the world’s space program to solely rely on Russia to transport astronauts to the International Space Station. However, the decline of NASA’s influence may have a silver lining as private companies have cropped up to fill the void and perhaps one day step up to take the lead in this field. Virgin Galactic and SpaceX are just some of the more prominent firms that come to mind.

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NASA Budget as a Percentage of U.S. Federal Budget
Author: 0x0077BE
Courtesy of Wikimedia Commons

The announcement also comes at an opportune time for the American space agency with the theatrical release of “The Martian”. The highly-anticipated film about a stranded astronaut is expected to boost public interest in a manned mission to the Red Planet.

Courtesy of 20th Century Fox via Twitter

The Martian (2015)
Courtesy of 20th Century Fox via Twitter

It’s a spectacular journey that NASA is already planning for. However, it still remains to be seen whether the cash-strapped agency can build upon this new momentum in order to transform its sci-fi dream into reality.

-Paul Yi