Category Archives: Life Science

Science Continues to Explore Causes of Weight Gain

Science is amazing when it explains very cool ideas. It is also very interesting (if a bit frustrating) when the scientific inquiry process is ongoing and open to debate. Weight gain is one such area that is of great concern and large amount of study but some issues are still unclear. I have discussed this before. I think that calories in compared to calories consumed is a good first approximation. I believe it makes sense that the efficiency of our bodies at capturing the calories and turning them into weight gain could be affected by things other than the total calories in. It might be the type of calories or it might be other factors (bacteria or chemical present)…

What’s Really Making Us Fat?

Researchers in a relatively new field are looking at the role of industrial chemicals and non-caloric aspects of foods — called obesogens — in weight gain. Scientists conducting this research believe that these substances that are now prevalent in our food supply may be altering the way our bodies store fat and regulate our metabolism. But not everyone agrees. Many scientists, nutritionists, and doctors are still firm believers in the energy balance model. A debate has ensued, leaving a rather unclear picture as to what’s really at work behind our nation’s spike in obesity.
…
A widely reported study that came out in January in The American Journal of Clinical Nutrition (AJCN) would seem to dispute this finding: it confirms the belief in the energy balance model, and has been cited as proof by many researchers working in the field. I asked an author of the study, Dr. George Bray, professor of medicine at Louisiana State University, about the myriad of additives and industrial ingredients in our food that were not accounted for in this study. “It doesn’t make any difference,” he said in a telephone interview. “Calories count. If you can show me that it doesn’t work, I’d love to see it. Or anybody else who says it doesn’t — there ain’t no data the other way around.”

It seems to me that it certainly makes sense to reduce calories if you need to lose weight. And it sure seems the strongest evidence is for calories being the most important factor.

I also believe exercise is good, for overall health. It also seems more and more evidence is being found about how difficult it is to lose weight which reinforces the importance of preventing the weight gain in the first place.

Exploring Eukaryotic Cells

This webcast is packed with information on the makeup and function of eukaryotic cells, which are the type of cells found in animals. It is part of a interesting series of science webcasts by Crash Course. The webcast style might be a bit too hyperactive and flippant for some but the content is quite interesting and the videos they are are of similar style and quality so if you like this one you can subscribe to their channel. They offer quite a few webcasts on science but they also offer webcasts on history.

Bacteriophages Enter Bacteria Using an Iron Tipped Spike

Bacteria-Killing Viruses Wield an Iron Spike

Forget needles in haystacks. Try finding the tip of a needle in a virus. Scientists have long known that a group of viruses called bacteriophages have a knack for infiltrating bacteria and that some begin their attack with a protein spike. But the tip of this spike is so small that no one knew what it was made of or exactly how it worked. Now a team of researchers has found a single iron atom at the head of the spike, a discovery that suggests phages enter bacteria in a different way than surmised.

Wherever there are bacteria you will find bacteriophages; digestive tracts, contaminated water, and feces are usually a good start. These viruses begin their dirty work by drilling into the outer membrane of bacteria. Once completely through all of a bug’s defenses, the phages inject their DNA, which essentially turns the bacterium into phage-producing factories. Eventually, the microbes become filled with so many viruses that they burst, releasing a new horde of phages into the environment.

Bacteriophages are amazing. It is so interesting to learn about amazingly creative solutions that have evolved over time. Real-life science is not easy to match with fiction that springs from our imaginations.

How Bee Hives Make Decisions

The Secret Life of Bees by Carl Zimmer

The decision-making power of honeybees is a prime example of what scientists call swarm intelligence. Clouds of locusts, schools of fish, flocks of birds and colonies of termites display it as well. And in the field of swarm intelligence, Seeley is a towering figure. For 40 years he has come up with experiments that have allowed him to decipher the rules honeybees use for their collective decision-making. “No one has reached the level of experimentation and ingenuity of Tom Seeley,” says Edward O. Wilson of Harvard University.
…
Enthusiasm translates into attention. An enthusiastic scout will inspire more bees to go check out her site. And when the second-wave scouts return, they persuade more scouts to investigate the better site.

The second principle is flexibility. Once a scout finds a site, she travels back and forth from site to hive. Each time she returns, she dances to win over other scouts. But the number of dance repetitions declines, until she stops dancing altogether. Seeley and his colleagues found that honeybees that visit good sites keep dancing for more trips than honeybees from mediocre ones.

This decaying dance allows a swarm to avoid getting stuck in a bad decision. Even when a mediocre site has attracted a lot of scouts, a single scout returning from a better one can cause the hive to change its collective mind.
…
“Bees are to hives as neurons are to brains,” says Jeffrey Schall, a neuroscientist at Vanderbilt University. Neurons use some of the same tricks honeybees use to come to decisions. A single visual neuron is like a single scout. It reports about a tiny patch of what we see, just as a scout dances for a single site. Different neurons may give us conflicting ideas about what we’re actually seeing, but we have to quickly choose between the alternatives. That red blob seen from the corner of your eye may be a stop sign, or it may be a car barreling down the street.

To make the right choice, our neurons hold a competition, and different coalitions recruit more neurons to their interpretation of reality, much as scouts recruit more bees

Very cool stuff.

Potential Antibiotic Alternative to Treat Infection Without Resistance

Researchers at the University of Michigan have found a potential alternative to conventional antibiotics that could fight infection with a reduced risk of antibiotic resistance. Sadly Michigan is another school that is allowing work of those paid for by the citizens of Michigan to be lock away, only due to the wishes of an outdated journal business model instead of supporting open science. The Big Ten seems much more interested in athletic riches than in promoting science. The Big Ten should be ashamed of such anti knowledge behavior and require open science for their schools if they indeed value knowledge.

By using high-throughput screening of a library of small molecules, the team identified a class of compounds that significantly reduced the spread and severity of group A Streptococcus (GAS) bacteria in mice. Their work suggests that the compounds might have therapeutic value in the treatment of strep and similar infections in humans.

“The widespread occurrence of antibiotic resistance among human pathogens is a major public health problem,” said David Ginsburg, a faculty member at LSI, a professor of internal medicine, human genetics, and pediatrics at the U-M Medical School and a Howard Hughes Medical Institute investigator.

Ginsburg led a team that included Scott Larsen, research professor of medicinal chemistry and co-director of the Vahlteich Medicinal Chemistry Core at U-M’s College of Pharmacy, and Hongmin Sun, assistant professor of medicine at the University of Missouri School of Medicine.

Work on this project is continuing at U-M and the University of Missouri, including the preparation of new compounds with improved potency and the filing of patents, Larsen said. Large research schools are also very interested in patents. That is ok, though seems to cloud the pursuit of knowledge too often when too large a focus is on dollars at many schools. But, it seems to put the schools primary focus on dollars; education seems to start to be a minor activity at some of these large schools.

Current antibiotics interfere with critical biological processes in the pathogen to kill it or stop its growth. But at the same time, stronger strains of the harmful bacteria can sometimes resist the treatment and flourish.

An alternate approach is to suppress the virulence of the infection but still allow the bacteria to grow, which means there is no strong selection for strains that are resistant to antibiotics. In a similar experiment at Harvard University, an anti-virulence strategy was successful in protecting mice from cholera.

About 700 million people have symptomatic group A Streptococcus infections around the world each year, and the infection can be fatal. Most doctors prescribe penicillin. The newly identified compounds could work with conventional antibiotics and result in more effective treatment.

Our Genome Has Adopted Virus Genes Critical to Our Survival

Mammals Made By Viruses by Carl Zimmer

Viruses have insinuated themselves into the genome of our ancestors for hundreds of millions of years. They typically have gotten there by infecting eggs or sperm, inserting their own DNA into ours. There are 100,000 known fragments of viruses in the human genome, making up over 8% of our DNA. Most of this virus DNA has been hit by so many mutations that it’s nothing but baggage our species carries along from one generation to the next. Yet there are some viral genes that still make proteins in our bodies. Syncytin appeared to be a hugely important one to our own biology. Originally, syncytin allowed viruses to fuse host cells together so they could spread from one cell to another. Now the protein allowed babies to fuse to their mothers.
…
The big picture that’s now emerging is quite amazing. Viruses have rained down on mammals, and on at least six occasions, they’ve gotten snagged in their hosts and started carrying out the same function: building placentas.
…
Some mammals that scientists have yet to investigate, such as pigs and horses, don’t have the open layer of cells in their placenta like we do. Scientists have come up with all sorts of explanations for why that may be, mainly by looking for differences in the biology of each kind of mammals. But the answer may be simpler: the ancestors of pigs and horses might never have gotten sick with the right virus.

More amazing facts from science. This stuff is so interesting. Carl Zimmer is a fantastic science writer and he has written several great science books.

Cool Animation of a Virus Invading a Person’s Body

Flu Attack! How A Virus Invades Your Body

First, some new viruses get caught in mucus and other fluids inside your body and are destroyed. Other viruses get expelled in coughs and sneezes. Second, lots of those new viruses are lemons. They don’t work that well. Some don’t have the right “keys” to invade healthy cells so they can’t spread the infection. And third, as the animation shows, your immune system is busy attacking the viruses whenever and wherever possible.

That is why most of the time, after a struggle (when you get a fever and need to lie down), your immune system rebounds, and, in time, so do you.

A health body with a strong immune system is able to fight off viruses, and other health issues more easily. Also when you body has run across a specific virus before it is ready to fight it. It has cataloged that virus and is on the look out for it and is prepared to produce specialized cells to attack it. The flu vaccinations you get are priming your body to be ready to attack if that virus is found. Those antibodies take about 2 weeks to build up in sufficient numbers to offer protection against the flu. Viruses are constantly mutating which helps them evade your detectors. This stuff is so amazing. And your body is just doing this stuff every day while you watch youtube or play basketball or…

NASA Biocapsules Deliver Medical Interventions Based Upon What They Detect in the Body

Very cool innovation from NASA. The biocapsule monitors the environment (the body it is in) and responds with medical help. Basically it is acting very much like your body, which does exactly that: monitors and then responds based on what is found.

The Miraculous NASA Breakthrough That Could Save Millions of Lives

The Biocapsules aren’t one-shot deals. Each capsule could be capable of delivering many metred doses over a period of years. There is no “shelf-life” to the Biocapsules. They are extremely resilient, and there is currently no known enzyme that can break down their nanostructures. And because the nanostructures are inert, they are extremely well-tolerated by the body. The capsules’ porous natures allow medication to pass through their walls, but the nanostructures are strong enough to keep the cells in one place. Once all of the cells are expended, the Biocapsule stays in the body, stable and unnoticed, until it is eventually removed by a doctor back on Earth.
…
Dr. Loftus [NASA] thinks we could realistically see wildspread usage on Earth within 10 to 15 years.
…
The cells don’t get released from the capsule. The cells inside the capsule secrete therapeutic molecules (proteins, peptides), and these agents exit the capsule by diffusion across the capsule wall.

NASA plans to use the biocapsules in space, but they also have very promising uses on earth. They can monitor a diabetes patient and if insulin is needed, deliver it. No need for the person to remember, or give themselves a shot of insulin. The biocapsule act just like out bodies do, responding to needs without us consciously having to think about it. They can also be used to provide high dose chemotherapy directly to the tumor site (thus decreasing the side effects and increasing the dosage delivered to the target location. Biocapsules could also respond to severe allergic reaction and deliver epinephrine (which many people know have to carry with them to try and survive an attack).

It would be great if this were to have widespread use 15 years from now. Sadly, these innovations tend to take far longer to get into productive use than we would hope. But not always, so here is hoping this innovation from NASA gets into ourselves soon.

Webcast of a T-cell Killing a Cancerous Cell

Very cool. Very good job by University of Cambridge to make this kind of material available openly online. I find this kind of video amazing. Every day you body has this going on all day long. How amazing.

This is what it looks like when cancer gets smacked down by a T cell

This was shot by University of Cambridge medical researcher Alex Ritter, and is 92 times faster than real time.
…
Cells of the immune system protect the body against pathogens. If cells in our bodies are infected by viruses, or become cancerous, then killer cells of the immune system identify and destroy the affected cells. Cytotoxic T cells are very precise and efficient killers. They are able to destroy infected or cancerous cells, without destroying healthy cells surrounding them.

Ritalin Doesn’t Show Long Term Effectiveness for ADHD

From the New York Times opinion piece, Ritalin Gone Wrong, by L. Alan Sroufe is a professor emeritus of psychology at the University of Minnesota’s Institute of Child Development:

Attention-deficit drugs increase concentration in the short term, which is why they work so well for college students cramming for exams. But when given to children over long periods of time, they neither improve school achievement nor reduce behavior problems. The drugs can also have serious side effects, including stunting growth.
…
To date, no study has found any long-term benefit of attention-deficit medication on academic performance, peer relationships or behavior problems, the very things we would most want to improve. Until recently, most studies of these drugs had not been properly randomized, and some of them had other methodological flaws.

But in 2009, findings were published from a well-controlled study that had been going on for more than a decade, and the results were very clear… At first this study suggested that medication, or medication plus therapy, produced the best results. However, after three years, these effects had faded, and by eight years there was no evidence that medication produced any academic or behavioral benefits.

As I have written before I am skeptical of the amount of drug use our health care system encourages: Lifestyle Drugs and Risk.