Wednesday, May 31, 2017

Silica Affecting the Physiology of the Lungs

In class, we briefly discussed the physiology of the respiratory system within animals. I decided to look into some papers that involved the respiratory system. I eventually came across an old paper that talked about how exposing the lungs to different forms of silica can lead to increase tissue production. Originally this was thought to have been a possible therapeutic, however, when the authors decided to run these experiments on mice, most died. However, some rats did experience increase tissue production. If you are curious about this topic, I have provided a link.

Acidic Soap???

Acidic soap - I thought it would have been a good idea. 

Last week in class we learned about the innate immune system. One component of this was the skin and its acidic environment which deters microbes such as bacteria from entering our body. Therefore, when we wash our hands with soap, which is typically basic, we are essentially buffering or neutralizing this natural defense that we have.

So why don't we use acidic soap? That's the question I asked myself as I pictured a row of neatly stacked, yellow, soapy lemon bars sitting enticingly upon a bathroom counter-top. However, this isn't the case in our everyday lives. Why? 

Because it turns out that it doesn't really make a difference. A study done in 2013 in an intensive care unit recruited two groups of ICU patients -one group of patients which used an acidic hand wash and another group which used a normal hand soap. It was found that there was no significant difference in the micro-flora of the hands between these two groups, indicating that the basicity of soap doesn't have any long lasting effects on the bacterial levels or composition of the hands. However, it was found that the pH of the skin was consistently higher on those patients that used normal soaps than those who used the acidic cleanser. While this increased pH of the skin did not lead to an increase in bacterial colonization or an altered micro-flora, this pH increase may have other consequences. 

If you want to read more about the study, here's a link to the paper:

Tuesday, May 30, 2017

Want to lose weight? Simple - Don't Eat

After talking today about metabolism and the twinkie diet that Professor Mark Haub went on, I did some research and found a guy that actually didn't eat for 1 year and 17 days in order to lose weight. He ended up losing 275 lbs and went from from 456 to 181!

In 1965 in Scotland, the anonymous man went to the hospital at Dundee and told the doctors his plan and, despite the doctors advising against it, he went through with it and had the doctors monitor him throughout. He was only fed yeast, multivitamins, and potassium tablets over the time period. He also only defecated every 40 to 50 days.

Article on it

Unfortunately the event was not scientifically documented so I couldn't find any official information on it beyond random articles online. Even though some of the specific details are different throughout different articles the general story is the same, and there are also multiple other accounts of people doing something similar.

Interesting AMA on Reddit of a man that went through this

There are also (as expected) a large number of health risks that go along with this. The man who posted on reddit most likely has kidney disease, an unstable heart rate, and has had to undergo multiple surgeries. There are also others who have attempted starvation and have died from heart failure, small bowel obstruction, and lactic acidosis from refeeding after the fast.

Even though starving has worked for a couple people, it is still extremely dangerous and is likely to cause death. However it is pretty incredible to see people that have survived this to act as a testament for what the human body is capable of.

Saturday, May 27, 2017

Living Fossils

At the Museum of Natural History we learned that the California Condor's huge size made it much better adapted to the Pleistocene (when the average carcass was much larger) than to it's present day environment. So much so that in order to sustain wild populations dead cows are often carted out to condor habitats just so the condors have enough to eat.

This story reminded me of an article I read recently on evolutionary anachronisms. This term refers to characteristics of living species that are probably the result of co-evolution with another species that is now extinct. The remaining species is then left with some ridiculous adaption that probably requires significant energy expense and has no feasible benefit in it's current environment.

Here are a couple familiar examples:

Image result for avocados
Avocados- Avocados are clearly designed for animal dispersal with seeds covered in nutrient rich flesh. Unfortunately, the seeds are so big that most animals cannot swallow them without choking (except the occasional hungry jaguar) and don't often make it far from the parent tree. The 20 ft tall giant ground sloth was probably the avocado's original disperser but it went extinct over 13,000 years ago.

Related image
North American Pronghorn Antelope- Second fastest land animal in the world. Able run much faster than any known predator in North America. However, extinct predator's such as the American lion, the giant short-faced bear, the American Cheetah, or the Chasmaporthetes Hyena could have given the pronghorn's a run for their money (pun intended) when they were still around.

There are many more interesting examples of this phenomenon. Check out the Wikipedia page here!

If you're from Fresno you should read this. If you're not you should still read this.

So what's up with Fresno? Other than having a solid agricultural industry and an uncomfortable number of cows, you'd probably guess that not much is going on there. Guess again. You may not have known, but Fresno is the second most-polluted city in the US; and that's only because who can compete with a valley home to almost 4 million people surrounded by mountains that literally trap the smog in? Yea, Los Angeles will always be the dirtiest of them all (don't tell Las Vegas).

We all know pollution is bad, for the environment and for us, but what exactly is pollution doing to our bodies? It turns out, according to a recent study that came out in May of this year (Lee et. al, 2017) that exposure to the ubiquitous air pollutant produced by motor vehicles, polycyclic aromatic hydrocarbons (PAH), is shortening telomeres in children and adolescents. The authors selected 14 children and adolescents living in Fresno both with and without asthma based on their average annual PAH level and then measured their relative telomere lengths using peripheral blood mononuclear cells (PBMC). An inverse linear relationship was found between PAH levels and telomere length as well as age and telomere length. In addition, subjects with asthma had shorter mean telomere length than those without.

So what's the take home? Pollution is shortening your telomeres. And if you live in Fresno, you may want to move.

Friday, May 26, 2017

Some Things to Know About Your Gut Microbiota

If you read my previous post on tyhpoid fever's ability to inhibit the mammalian anorexic response, which as a facet of the innate immune system attempts to starve out bacterial invaders, then you'll notice that there is a bit of a gut microbes theme here.

Regardless, below are some neat facts about the microbes in your gut, gathered from this review paper from Cell:
  • Certain bacteria, like Christensenellaceae, proliferate in hosts with low body mass indices, and when cultivated in mouse models, cause a reduction in weight gain. This could signal a some epigenetic and phenotypic bacteria-host relations, as well as some element of heredity because Christensenellaceae is, according to the authors, one of the most heritable gut bacteria.
  • Your original microbiota is inherited from your parents, but becomes fixed during your early childhood. That means that the diversity of bacteria within your gut doesn't undergo any significant development past childhood, and that if for some reason (perhaps because of intense antibiotics) some of the bacteria is wiped out, it is possible that it will not ever return to its pervious state. 
  • The microbiota of mice models were observed after some mice were fed a "Western" diet, that was high in fats and simple carbohydrates and others were fed a "Traditional" diet. Those that were fed a "Traditional" diet had higher microbiota diversity.
To learn more specifics about how these results were determined and to learn more about host-associated microbial communities, read the article linked above.

Pathogen-Mediated Inhibition of Anorexia

Have you ever gotten sick with some bacterial gut infection and lost your appetite? Well this is a natural response, because when your inflammasome (which is responsible for the innate immune response to common bacterial traits such as flagella) is activated, it activates an enzyme called IL-1B, a cytokinase, which both facilitates inflammation and interacts with the vagus nerve, which connects your gut and your brain through the central nervous system. When the vagus nerve is stimulated by IL-1B, you lose your appetite and starve out the invading bacteria. Brilliant, right?

Wrong. The bacteria are tricky. Salmonella Typhimurium (also known as typhoid fever) has developed an enzyme called Salmonella Leucine Rich Repeat Protein (SlrP) which inhibits the activation of IL-1B, which inhibits your ability to mount an anorexic response. This means that the bacteria not only continues to be nourished by your natural bodily functions, but it is more capable of spreading than before.

This is particularly bad for mice, because S. Typhimurium spreads via fecal matter, and mice eat one another's poop. There's a happy thought for your memorial day weekend!

If you want all of the fascinating details, check our this article. It's not a tough read and I thought it was quite exciting!

Wednesday, May 24, 2017

Sponges Reclaim Their "Rightful" Place on the Tree of Life

So in 7th grade I remember being taught that sponges were "the first group of animals to evolve" - or more aptly put now - the earliest branching animal lineage. This thus made the sponges the sister group to all other animals, and I went on believing this lie for many years. But then my whole life was uprooted when, in CCS bio, John enlightened us to the current interpretation of the tree of life where ctenophores (comb jellies) kicked sponges out of their original position on the tree of life. I was shook. But as I was looking further into this topic after class, I found a recently published paper which discussed a new phylogenetic analysis that took place and restored sponges to their original position on the tree of life. Yay!

The new analysis used a much larger and more robust data set for their phylogenetic analysis than any other previous study tackling the issue - using a set of 1,719 "high quality" genes and 79 species. The researchers found that the most parsimonious interpretation of their results yields a tree of life where sponges branch off first in the metazoans and are monophyletic. These results also remove the implication that neurons and muscle cells had to evolve twice in the animal lineage - once in the ctenophores, then being lost in sponges, and evolving once again in bilaterals - as would have been the case if ctenophores branched first.

Previous phylogenetic analysis studies likely developed a different view of the tree of life due to an artifact or error known as long branch attraction which occurs when organisms with a high rate of molecular evolution, such as ctenophores, are grouped together simply because of this high rate of molecular evolution. This groups lineages that are not necessarily related together and thus produces errors.

If you want to look into this study in greater depth, here is a link to the article:

Monday, May 8, 2017

What your parents aren't telling you about weed.

Weed. Marijuana. Mary Jane. Whatever you call it, it's a drug; it comes from a plant; and it can make you high. It's also used as a pain killer. You probably already knew all of this. But what I bet you didn't know is that new research suggests that marijuana may be able to reverse aging!! This is probably because WHO WOULD HAVE THOUGHT and also
because the paper was just published today. Believe it or not, researchers were able to return the state of old mice to that of two-month-old mice with prolonged low-doses of THC. They are now looking to start clinical trials in people. This novel role for marijuana holds exciting possibilities for the development of future treatments for age-related diseases such as dementia. Read the full article at the link below. Crazy stuff man!

Tuesday, May 2, 2017

Fancy New Species

Hey guys!
So after Claudia talked about the cool new species in class I did some research to see what else was discovered recently.
My personal favorites are

Lasiognathus Dinema - this is a type of Angler fish living at depths below 500m. The thing that drew me to this was how crazy it looked! I feel like most biologists have an idea of what an angler fish is supposed to look like (especially with movies like Finding Nemo) but check this out!

Lasiognathus dinema, female about 30 mm long. Image credit: Theodore Pietsch.

It was discovered very recently so there aren't really any papers on it, but here's an article talking about its discovery.

Phyllopteryx Dewysea - also known as the Ruby Seadragon. Not only does this look pretty cool since it is related to seahorses, but it is only known from 4 preserved specimens!

Image result for Phyllopteryx dewysea

Recently it was found in the ocean and they actually got a video of it! Check out the video here.

Anyways, I thought these were pretty cool. Unfortunately there isn't too much research on either of these due to a lack of availability (only 4 ruby seadragons found, and the angler fish is super deep and very rare/hard to find) but hey if you're interested it seems like a cool area of research!