UMD Bioscience Day: Scientific Advances in Treating Trauma and Disease

Presentations by experts in various fields of science and medicine

November 20th, 2014
University of Maryland, College Park. Stamp Student Union

Beyond Single Pathogens: how the human microbe impacts health and disease
Presented by Mihai Pop

Dr. Mihai Pop is professor at the University of Maryland, in the Department of Computer Science and the Center for Bioinformatics and Computational Biology. Dr. Pop was part of a Research team that studied the causes of Diarrheal in developing nations across the world. Dr. Pop discussed his research and its implications.

Diarrheal kills 800,000 people per year, which is more than HIV, Malaria, and Measles Combined. Diarrheal can be caused by a virus, bacteria, and eukaryotic pathogens. Mostly the symptom occurs in places where poor infrastructure leads to unsanitary water.

The group that Dr. Pop worked with, Global Enteric Multicellular Study, wanted to compare the stool of children, in developing nations, that had Diarrheal, with children that lived in the same area. Their goal was to try to figure out which pathogens caused diarrheal.

The researchers went to Gambia, Mali, Kenya, and Bangladesh, found children with diarrheal, and sampled their stool. While they could identify the symptom causing pathogen about half the time, there were many cases in which they could not. According to Dr. Pop, their biggest issue with simply testing for what they knew caused diarrheal was that the pathogens that they were testing for were known causes of Diarrheal in the developed world. Most of our knowledge about medicine is from the Western World, and sometimes the developing world react differently to different pathogens.

In order to blindly test everything in the stool, and then compare those pathogens with other samples, in order to definitively find out what exactly causes the Diarrheal, they would need to acquire mountains of information. The issue with this, is that with so much information, they needed a way for their computers to analyze the information.

Dr. Pop described his solution to analyzing the data by using target gene sequencing, in order to find out what DNA sequences correlate with children with the symptoms. They then use DNA clustering to compare those sequences with others in the stool.

What they found was very interesting. Instead of diarrheal being caused simply by having a certain pathogen in your body, the different bacteria interacts with each other and impacts each other. Some bacteria impedes the growth of other bacteria, so in some cases having two kinds of bacteria ,at the same time, that cause diarrheal can actually lead to a lower chance of getting the symptoms than had you only had one strand. This could lead to interesting future studies that might find that diarrheal prevention techniques might come in the form of infecting someone with a manageable bacteria that prevents the growth of other Diarrheal causing bacteria.

Overall I thought that this was an effective presentation and an interesting research study. The fact that bacteria could be used to prevent the growth of other Diarrheal causing bacteria is a very important step for researchers to being trying to find ways to prevent the symptom. Their techniques for correlating the DNA sequences were also very innovative.

My Only Critique of the study was that there were a few things that the researchers did not really take into account. While the researchers used the DNA sequences of pathogens in the stool and used them to correlate it with whether or not the kid had diarrheal, the researchers failed to take into account the fact that some people react to the same pathogen in different ways. What may give one child Diarrheal might have no effect on another child. This could potentially skew the results of the study.

On a final note, Dr. Pop had mentioned that a possible cause as to why the developing world react differently to bacteria compared with the developed world. His hypothesis is that the high presence of animals in close proximity to where people are living could be the cause. I think this is a very interesting theory, but I think he would need to properly test this before making a definitive statement.

My Fearless Idea Fights Cancer: the story of Seattle Genetics
Presented by Clay B. Siegall M.D.

Dr. Siegall, a UMD alum, received his Ph.D. in Genetics from George Washington University. After years of conducting research, mainly with the Bristol-Myers Squibb Pharmaceutical Research Institute, Dr. Siegall founded Seattle Genetics, a cancer research company.

For many years, there were two types of ways that cancer was combated. Cytotoxic treatments, most forms of chemotherapy, are substances that, while highly toxic to cancer cells, are not very specific and cause harm to other cells in the body. This is why chemotherapy can have drastic side effects. The second form of treatment is monoclonal antibodies. This form of treatment is very targeted towards the cancer cells, however it is not nearly as effective.

Dr. Siegall wanted to combine the specificity of monoclonal antibodies with the potency of cytotoxic treatments, so he developed what is called Antibodies Drug Conjugates. This is where he attaches a toxin to an antibody, so that the antibody will deliver the toxin right to the cancer cells, getting the specific nature of antibodies along with the effectiveness of chemotherapy.

He spent years testing many different "linkers", as in the molecule that would attach the toxin to the antibody, and after years of failure, finally found one that seemed to work.

They eventually moved to human trials and after good results, they were allowed to produce the drug. As with most cancer drugs, his new treatment could only be used in cases of patient relapses after previous treatments had failed. Seattle Genetics now distributes ADCETRIS worldwide.

My initial reaction to his idea was "this is genius, why is this method not being used so much more". But as he pointed out, he was faced with constant failure at trying to find a proper linker. To me this shows the beauty in continuously testing your theory until you find something that worked. I believe what was important to his success was that when one linker failed, he did not get too attached to it, he simply moved on.

Dr. Siegall showed that with proper scientific method, his goal could be achieved. He did not get too attached to any drug, thereby not letting bias get the best of him. Throughout clinical trials they would only proceed when they had the proper statistical evidence to back it up.

I thought that Dr. Siegall had a very easy to understand presentation, presenting his method in simply language while still giving his audience all the necessary details. Dr. Siegall mentioned that his company is now trying to develop similar treatments for other forms of cancer. Based on what I he presented, I am confident that by following the same methods, there is hope that he will once again be successful in reaching his next goal.

Reaction by David Millner

Last modified: 7 December 2014