Saturday, December 15, 2007

Blurred Lines


A British Columbian monument is on the brink of extinction and it appears humans may be the catalyst for the acceleration of the evolutionary process yet again. According to researches from the University of Alberta, Dalhousie University and the Salmon Coast Field Station in Echo Bay, BC, infestations of the parasitic sea lice are contaminating salmon fish farms and proving fatal to wild stocks. It’s predicted wild pink salmon will be reduced to 99% of their present population in just four salmon generations or approx 8 years! The crustaceans attach themselves to the exterior of the salmon feeding on tissues, blood, and muscle; eventually resulting in death. Not surprisingly, juvenile populations are at most risk.

This bleak picture is a staggering realization of humans ever growing foot print. The bottle neck effect that these salmon farms could create will have devastating effects on the genetic diversity of local populations. And the most shocking angle of this study is it’s noted as an avoidable catastrophe.
Implementing legislation that will move farms from migration routes and replacing net pens with closed containment compounds will clean up the surrounding aquatic environment and ensure any parasitic threats are isolated from wild stocks. This, of course, comes at a price and owners are not keen on watching profits diminish and operating costs increase. It appears the moral line between profit, government and the environment continues to blur.

Reference: http://www.cbc.ca/technology/story/2007/12/13/tech-salmonfarm-lice.html


The need for medical professionals to study evolution

Evolution has a significant rule in human lives which makes it an important fact for medical professionals to understand evolution. The entire basis of evolution started “millions of years a go when life began spontaneously in a pond, and became more complex and it came to the point of the survival of the fittest”. Those who were less fit, injured or unable to adapt did not accompany evolution. Humans are the result of this process. Humans too adapt to certain environment and these days medical professionals are not really taught evolutionary explanations for “why our bodies are vulnerable to certain kinds of failures.” Existence of wisdom teeth, having genes that cause bipolar disease, and not knowing why appendix is still there?

There are lots of reasons where there is a need for understanding evolution in terms of medical field. Cancer is a good example of natural selection among cells in human body. Antibiotic resistance in today’s world also has brought up a lot of issues and concerns in medicine and showing evolution of microorganisms. Understanding spread of antibiotic resistance and its origin is another question of evolution. The more medical doctors and personals are aware of this issue there is a better chance to stop the abuse of antibiotics.

There are many reasons why it is hard to convince medical practitioners to embrace evolution in the nature of science. “Evolutionary hypotheses about human physiology are notoriously hard to investigate, given humans’ long generation times” thus giving a hard time to medial professionals.

I believe that every body especially doctors need to understand evolution to be able to help humans to stop antibiotic abuse, know the evolution process of other animals and how close we are related to other animals to find cures for diseases, evolution of our immune system is part of population genetics and natural selection.

This is a very broad topic with lots of other reasons that all needs to be reviewed and learned by our fellow medical precisionist for the hope of better care, cure and understanding human evolution.

http://www-personal.umich.edu/~nesse/EMN/editorial.pdf

http://www.pandasthumb.org/archives/2007/01/why_do_so_many.html

http://www.evolutionandmedicine.org/


Frogs and Amphibians getting closer to extinction


Scientists at the Zoological Society of San Diego have taken special note of the serious decline in the population of frogs and other amphibians in the last 30 or so years. Amphibians are often studied by scientists in order to gage environmental wellness because they are so sensitive to environmental changes. Amphibians can exist on both land and in the water and therefore they experience changes in both of these environments. However, scientists are becoming increasingly concerned because over 120 species of amphibians have now become extinct. We can guess at the main reasons for this decline in amphibian population. Scientists believe that changes in climate, pollution and diminishing habitats are the main threats to these creatures. The scientists at San Diego also point out that chytrid infections, caused by fungus can have a fatal affect on frogs. Frogs need the ability to respire through their skin and this disease affects this ability. One way to help the frog and amphibian populations is to create conservation programs for various species. This is being done by many concerned groups including the scientists at the San Diego Zoo. San Diego provided information about all of these topics in an article published by the Zoological Society of San Diego on their website. This article is entitled "A World without Frogs?". I personally believe that if we don't do everything we can to preserve the amphibian population we will be loosing a very valuable scientific resource. Not to mention, the devastating effects this could have on the "circle of life" as a whole. As previously stated, frogs provide us with very valuable information when it comes to the current health of the environment. Maybe if we can continue to study frogs and other creatures like them we can gain a better understanding of how to help the entire planet, not just one area, group, or species.

Komodo Dragon Spit-It's Aliiiiive!!!

Komodo island monitors are famous for being the world's largest lizard, they can reach three meters in length.  This may seem like reason enough not to mess with them, but you shouldn't be afraid of the dragons, just their thousands of tiny little friends...


Komodo dragons are scavengers and carnivores.  They'll eat most recently dead animals, and will hunt goats, wild boars, water buffalo and even horses and eat them.  But their hunting technique is quite unusual, they will stalk their large prey, then ambush it, not to kill it, but to bite it.  The lizard then simply follows the unfortunate prey around until it dies, either from blood loss or infection.  But what if the animal heals?  Well, this just doesn't happen.

Komodo dragon saliva contains over 50 different kinds of bacteria, once an animal is bitten it is almost guaranteed to develop a bad bacterial infection, a septic wound that will become so toxic it will end their life.

A study of the saliva of both captive and wild komodo dragons was published in the Journal of Wildlife Diseases in 2002.  In part of the study komodo dragon saliva was injected into mice.  One strain of bacteria was present in the blood of mice who died following injection, Pasturella multicoda.  The study stated that many strains of bacteria were isolated in the saliva, "54 of which were known pathogens" and "at least one species of which was highly lethal in mice".  

These findings certainly explain the hunting style of the komodo dragon, but why isn't the deadly bacteria in their saliva a problem for these animals?  Wouldn't a mere scratch to the gum be enough to introduce infection and kill them?  The really interesting finding of the study was that the plasma of komodo dragons contains an anti-Pasturella enzyme, so if the bacteria were to enter the bloodstream, it would be killed.

This fact shows that the giant lizards have evolved with their little friends, so that they can coexist without any danger of infection.  A sinister but fascinating kind of symbiosis!

sources:

Aerobic Salivary Bacteria in Wild and Captive Komodo Dragons

Animal Diversity Web


*This too was actually a post by Liz, sorry again*

Sleepy?


If you catch yourself nodding off in classes, on the bus, or anywhere else, you can probably think of a reason for your condition.  Perhaps you stayed up late studying for an important test, or to watch a movie with your roommate, or spent the night drinking.  But do you really know why your body is telling you to sleep?  What is the true purpose of that irresistible urge to close your eyes and drift away?  Why do we and almost all animals need to sleep?

The truth is, scientists still don't have a clear answer to this question.  They know that sleep plays an important role in memory and that cells function better in a rested person than in an exhausted one, but scientists say that so far as they can tell, animals could have evolved mechanisms to accomplish these things in a waking state, so why sleep?

 

I became interested in this topic after listening to a one of WNYC's Radiolab podcasts, called simply Sleep.  The podcast discussed different scientific ideas about why we sleep and what happens when we do and included some really interesting information on research currently being done to try to solve this puzzle.  One researcher they spoke to, Stephen Lima, is looking at sleep from an evolutionary standpoint to try to understand why animals evolved the need to sleep.  It may seem obvious that animals would evolve to sleep, rest must be good right?  Well, not really.  Sleep makes an animal incredibly vulnerable, it could be eaten while resting, its offspring could be threatened, anything could happen.  There is something about sleep that almost all animals need, and we still don't understand what that is.  According to Dr. Lima, "The fact that sleep is so dangerous is the best evidence that it is necessary, because if it weren't necessary, we wouldn't be doing it.".

 

The evolutionary approach to sleep research is a new one, Dr. Lima states that, "One of the reasons we don't understand sleep is that we haven't taken this evolutionary perspective on it".  The idea is that if we can understand why sleep evolved, we can understand why it is necessary and what it really does.  He and his team of researchers have been watching animals like iguanas, ducks and, yes, fruit flies sleep.  An article published in the New York Times also focuses on Dr. Lima's sleep research, as well as other researchers'.  One discovery they have made that is particularly interesting involves the sleeping habits of ducks.  When ducks sleep in a row, on a log or wherever, the ducks on the ends of the line will sleep with one eye, the one facing away from the other ducks, open.  Every so often they will stand up, turn around and sleep with the other eye open.  Dr. Lima discovered that the reason for this is that the ducks on the ends are only allowing half of their brain, the half controlling the closed eye, to sleep at a time.  The team is now doing research on iguanas to see if they share this strange behavior.  If they do, it will tell scientists that this half-brained sleep probably evolved early in animal evolution, and that early mammals may have been able to do it also, but then lost this ability later in their evolution.  

 

Another model for sleep research is the fruit fly.  A study published in the journal Science in 2006 focused on the sleeping habits of Drosophila (click here for abstract).  It found that the flies needed more sleep after social interaction and couldn't remember tasks taught to them if they were deprived of sleep for a certain period of time after they learned them.

 

This article from the Public Library of Science details a study done in 2006 on zebrafish sleep that found "both striking similarities to mammalian sleep and its regulation and intriguing differences.


This new evolutionary approach to understanding human behavior shows that there's more to phylogeny and systematics than endless debate over the seemingly trivial classification of obscure creatures most people have never heard of.  Hopefully through more research scientists like Dr. Lima will be able to solve more intriguing mysteries about our past, and help us to understand what has made us what we are.  

   

Sources:

http://www.wnyc.org/shows/radiolab/episodes/2007/05/25

(podcast)

 

Jones R (2007) Let Sleeping Zebrafish Lie: A New Model for Sleep Studies. PLoS Biol 5(10): e281doi:10.1371/journal.pbio.0050281


Waking Experience Affects Sleep Need in Drosophila

Indrani Ganguly-Fitzgerald, Jeff Donlea, Paul J. Shaw  http://www.sciencemag.org/cgi/content/abstract/313/5794/1775?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&andorexacttitleabs=and&fulltext=drosophila+sleep&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

 

Zimmer, Carl (2005) Down For the Count.  New York Times 

http://www.nytimes.com/2005/11/08/science/08slee.html?pagewanted=1&_r=1


*This blog says it's by Chicken but it's actually by Liz, who had to sign in as Chicken because she couldn't post as herself... sorry*



The Belgian Blue


In the fitness and selection topic of our course this semester we touched lightly on the Belgian blue and it’s lethal mutation of the gene that codes for myostatin (a protein that counteracts muscle growth). To sum it up this cow has no myostatin, which results in it building mass amounts of muscle and very little fat because the mutation also affects fat deposition.

If you’ve ever lived in Belgium it’s quite apparent that they love their cows. The meat is sold in the butcher section of the supermarkets, never laid out on display like ours, and the posters “Big, Blue, Belgian” are pretty much everywhere. I was actually quite shocked not to be able to find one on the Internet.

They just remind shoppers how good for you the meat is:

i.e.                   No hormones

Less fat

                        Better taste (although I disagree with this because when it comes to a good steak it’s all about the marbling which the Belgian Blue has 17% less of than our normal heifers)

 

Blues also yield 5- 7% more sellable meat than our normal cows at 80% and their carcass is bigger. For some reason they also produce a higher yield of milk. Anyhow, the list goes on and on for the many reasons why these cows are “better.”

 

Why are they not common here?

 

Ignoring most of the English sites on the Internet the truth is that roughly around 80% of these cows cannot give birth to their calves depending on their age. The calves are just too big for their mother’s birth canals. Also the older the mother; the more muscle mass she’s put on, thus she will need caesareans every time she has a calf after being a possible first time successful at a natural birth mom, if she had been that lucky.

 

In September 2001 I spent a year In Belgium on a Rotary youth exchange. I was lucky enough to have spent three months with a veterinarian. I had no idea at the time why he needed two pagers and a cell phone and thought he took his work far too seriously. He hardly ever made it through a full dinner without leaving unexpectedly and woke up multiple times throughout the nights, sometimes more than once.

About eight months into it I finally clued in and happened to be attending a function where he was when of course; he got a call. It took some begging and I had to chug the rest of the bottle of wine for his sheer amusement but he finally let me go with him. (Note: Belgian’s can drink more than you, despite what you may think. They still like to watch us suffer/ enjoy as much as they have)

 

Belgium, which is a tad smaller than Vancouver Island is set up a little differently than Canada. There are small towns everywhere, two big cities and the rest is all farmland. The Blues are EVERYWHERE; in the smaller towns they even sometimes get loose and just wander around the streets until found.

 

After a 10-minute drive at 160km/hr we walked directly into a farmers barn to find our cow. (They HAVE to be at a certain stage in labor before a caesarean can be performed safely.) Since he had been there earlier that morning to check the cow he went straight to work.  The cow wasn’t tied down nor did it even seem to care. He gave about 10 needles straight down its left side by its hind leg and waited 10min. He tested to see if she was numb by poking her with his scalpel and seeing that she was, sliced her open. She didn’t bleed as much as I thought she would. Next he opened the sac the baby was in and pulled it out. After taking the crap off its face so it could breathe he sewed up mommy. What’s scary was the calf was almost as big as me.  The mom just ate hay while I tried not to throw up; the whole procedure took about 20min. We were back at the function in no time and hardly missed anything, except more drinking.

 

This vet who shall remain nameless performs roughly one caesarean a day on average but more like none some days and up to four on others. He charges 50- 150 euros depending on the relationship with the farmers. And those calves are worth 500- 1000 euros each, so it’s worth it for the farmers.

 

Warning: the blood is just the amniotic fluid.

Here is a video of a Blue caesarean:

http://www.youtube.com/watch?v=JPY9sH_MU5w

When I watched it live it didn’t need two people: note the time. Also take into account the retarded people whose comments imply that this is cruelty. Cruelty is letter the mothers body kill the baby when she can’t give birth; then the dead baby killing the mother.

 

The Dairy site:

http://www.thedairysite.com/breeds/beef/8/belgian-blue/overview

 

Info. On the Blue:

http://www.kuleuven.be/cwte/viewpic.php?LAN=E&TABLE=DOCS&ID=17

 

It's the end of the world as we know it...


Throughout the history of the earth the global climate has been punctuated with alternating periods of greenhouse warming and cooler "icehouse" phases. Researchers from the universities of York and Leeds have recently concluded that extinction rates are much higher during greenhouse phases of global climate. By comparing 350 million years worth of data from the fossil record on estimated temperatures and the levels of diversity in marine and terrestrial life, researchers have predicted that if global temperatures continue to rise we may be approaching a climate associated with past mass extinctions. Pollution and greenhouse gases are accelerating the heating process and if heating trends continue we could be heading to a 50% extinction of all plant and animal species on the earth. This is the first time global temperature trends have been compared to extinction rates for the entire fossil record, and the prognosis is not look so good. Of the five major mass-extinctions that have occurred in 350 million year span of the fossil record, four have occurred during greenhouse phases.

Whether or not mass exstinction is just scientific paranoia remains to be seen, however many species of plants and animals are already finding it increasingly hard to adapt to their changing habitats. The Polar Regions and the flora and fauna that inhabit them are especially in danger. If a mass extinction is unavoidable, then we are heading towards a reset of Earth’s animal hierarchy, and like mammals after the dinosaurs, a new species may inherit the earth. It would be interesting to hypothesise who the new dominant species might be; my vote is for the genetically modified mice.

Sources
http://www.york.ac.uk/admin/presspr/pressreleases/massextinctions.htm
http://www.livescience.com/strangenews/070808_GM_mass_extinctions.html

Can't Fight the Moonlight

Studies indicate the sunlight that is reflected off the moon’s surface may indeed be romantic! Following a full moon, mass spawning of corals in the barrier reef occurs due to the cryptochromes, or photoreceptors of plants that detect the blue light. This is what tells the coral that it is the right hour of the right few nights to spawn during the spring.

Cryptochromes are believed to be the predecessors of eyes and exist not only in coral, but also insects, humans, and other mammals. Linked with a system which repairs damage done by ultraviolet radiation, cryptochromes may have evolved in eyeless beings that were incompatible with sunlight.

Brain monitoring of night-migrating birds demonstrate increased usage of cryptochrome-expressing neurons as well as forebrain region, suggesting that cryptochrome receptors may also have a role in birds’ directions, providing night-migratory birds with a magnetic compass of sorts, dependant on blue light.

If cryptochromes are vital to a coral’s spawning and in the migration of birds, what are the effects of moonlight on our cryptochromes? Does a full moon really make us wild? If they are still in our DNA, do we still have a use for them?

There is no doubt that cryptochromes do have a function in the circadian rhythms of organisms, which regulate metabolism, physiology, and behavior. However, up to this point, studies on how moonlight or a full moon may affect human behavior are inconclusive.

From what I have heard from working professionals who deal with people- a nurse and a policeman, I suspect that it’s not just a superstition that a full moon has an effect on people. They didn’t say that people were more violent or aggressive (a theory is that more people will be assaulted during a full moon due to increased aggression), however they both agree that people do seem to get a little crazier and their late shifts get a little busier than normal. I think that the area of cryptochromes needs to be explored further; it’s really fascinating that the photoreceptors may have so many different functions.

http://www.scienceagogo.com/news/20070922011725data_trunc_sys.shtml
http://en.wikipedia.org/wiki/Cryptochrome#_note-2
http://www.flickr.com
http://www.plosone.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pone.0000937

A Bird's Eye View

















Here is my brat Parrot: Piper. About six years ago after my childhood Budgie had died and I had returned home from traveling I decided I needed another bird. I had worked a fair bit and saved some money so that I would be able to get pretty much any parrot I wanted, however, having worked in a bird store (for a short time when I was in middle school) I chose wisely:

 

African Gray’s and Amazon’s are too noisy; Lorri’s need special food; Cockatoo’s are destructive. It’s quite a tough decision if you’ve been around the different breeds.

 

Choosing a bird is like choosing a dog that is going to live for 40-80 years. I eventually narrowed it down to two breeds, which would fit my lifestyle: the eclectus and the pionus.

 

Piper is a white- capped pionus. I chose him because of the breeds versatility. They don’t normally travel in flocks, they don’t eat a lot of fruit (some birds need a lot of fruit to stay healthy), they don’t chirp like those annoying cockatiels, and they tend to mate for life. Translation: he can be left home alone while I work, he won’t scream to communicate with the outside birds, and he will bond nicely with people.

 

One thing I wasn’t expecting was the amount of people who didn’t think he was a parrot because he didn’t have pretty colours. He’s green and blue with a peach bum. The peach colour is on his underside though and isn’t visible if he isn’t flying above you.

 

I found it weird that my parrot was boring so I researched him. It turns out that birds can see better than us humans. For starters, they can see ultraviolet light, whereas our eyes are sensitive to it and we loose our colour perception (when white glows and everything becomes purple).

Birds also have four dimensions of colour, which means everything that we see, they see in more vibrant hues. So a boring black crow to a bird is actually quite colourful and attractive.

 

Birds also use florescent colours to attract each other. That’s why some species have weird reflective markings: like a budgies cheek, a crows feather tips, or a ringneck’s, ring of colour around his neck. Take a good look at Piper again at the top of the page. Those multicolour feathers on the back of his head going down his neck are his reflective markings. They extend down his back and make him a pretty flamboyant bird when viewed by other birds, so he’s only a boring green/ blue hue to us.

 

Birds have many other advantages with their eyes and head. It is the most important part of their features for survival. The positioning of their eyes gives them a broader view than humans and they can also rotate their neck at least 180 degrees, sometimes more depending on the species. This allows them to see food or enemies and navigate when flying.

 

Ever wonder why pet birds rarely return home?

 The use of giant eyes have to be trained, it’s like returning vision to someone who was never able to see and then wondering why they can’t identify anything without touching it.  Birds need to learn how to navigate or they won’t know how. If a pet bird gets loose, unless he was taught how to find home again, he might not come back. You just have to hope he can’t fly far enough to get completely lost. This is why it’s good to let birds have a little bit of flight inside the house every now and again before you clip their wings (they learn to navigate how to land, and when they start getting obnoxious you clip them; some don’t need to be kept clipped it depends on behavior).

 

It’s sad that some birds are kept in cages. If they are looked after properly and trained they can learn to do everything a dog can do (fetch, rollover, speak). It takes time and patience but with a 40-80 year lifespan it just might be worth it.

 

On the angle of birds eyes:

http://birding.about.com/od/birdanatomy/a/birdsight.htm

 

On the colours that birds can see:

http://www.bio.bris.ac.uk/research/vision/4d.htm

 

 

Transformers of the Sea

We all know about how animals can camouflage themselves to hide themselves from predator and/or prey, but who has heard of an animal that will actually imitate other animals in their environment? Discovered in 1998, the Indonesian Mimic Octopus, Thaumoctopus mimicus has been found to impersonate several ocean dwellers. Preys to deep water carnivores, the Mimic Octopuses often take shape of more poisonous animals to deter these hunters; while on the opposite end of things, change shape to attract the prey that might normally be too quick for the octopi to catch. Like all octopi, the mimic octopus is very flexible and can contort itself well- well enough, in fact, to fool a crab into thinking it could be a possible mating partner. Shapes that the octopus has said to have been caught in include that of the sea snake, lionfish, flatfish, brittle star, giant crab, sea shell, stingray, jellyfish, sea anemone, and mantis shrimp.

These Octopi are found in the murky waters around the Indo-west Pacific Ocean and can grow up to two feet in length. They feed in many different ways. Firstly, it can catch prey with its arms and kill it with its beak. Second, it can suck up the insides of their prey after paralyzing them with a poison; third, it may dig into the holes of prey, taking up the food with its arms; and lastly, it can swirl small prey into its suckers, entrapping them. They are brown and white in color, but do have the ability to change in both color and texture. They have a large brain and great eyesight, but they are deaf.

The number of sea creatures that the octopus copycats is disputed somewhat as well as how they have come about this ability. Some think that over the years, only the good impersonator octopi have survived, leaving us the Mimic species; while other theories suggest that the mimicry is misinterpreted and is just part of their sexual selection.

After watching videos and seeing pictures, I can’t imagine how the imitations could not be done purposefully. I think the intelligence in the octopus is amazing. Imagine how much concentration it takes to dance and to be aware of where you are and how you are moving. This is what the mimic octopus can and must do (while swimming), and do a good enough job to fool predator and prey.
http://www.youtube.com/watch?v=knoAHiM7z_s

http://news.nationalgeographic.com/news/2001/09/0920_octopusmimic_2.html

http://en.wikipedia.org/wiki/Mimic_Octopus

http://www.flickr.com/

http://www.succeedsocially.com/coolanimals

Maggots Anyone?

Volunteering in a poor government hospital in Africa provides an individual the opportunity to see many things that they haven't been exposed to before. I had always heard of hospitals using leeches and maggots in modern medicine, but I had never had the chance to actually witness it. One of the most common problems seen in African hospitals are the complications due to uncontrolled diabetes. Many individuals in Africa can not afford the cost of buying insulin to control their disease and so their blood sugars skyrocket and remain uncontrolled. Uncontrolled diabetes can have serious consequences. Over time, high blood glucose levels damage the nerves and blood vessels which can lead to a loss of feeling or sensation in the extremities; this is called neuropathy (1; 2). Diabetics suffering from neuropathy can develop minor cuts, scrapes, blisters, or pressure sores that they may not be aware of due to the insensitivity. If these minor injuries are left untreated, complications may result and lead to ulceration and possibly even amputation (3). Damage to the extremities, the feet, in particular, are a huge risk (2). Minor injuries, such as wearing a shoe too tight can create a small blister that can cause major damage. Since diabetes decreases the blood flow through blood vessels, the body's ability to heal is severely decreased which increases risk of infection. In diabetics, infections spread quickly (2).

You can imagine the risk associated with poor Africans who have uncontrolled diabetes. The environment they live in does not provide them with safe and sanitary places; and some of them are lucky to even have shoes. One particular patient we saw in the hospital was a women with uncontrolled diabetes who was suffering from a severe 'diabetic foot'. She had hit her foot on a tree stump, didn't really notice any pain, and never paid attention to whether her foot had any sores or had been affected by the injury. By the time I had seen her in the hospital, her big toe had been amputated and she had severe necrosis of her tissue. (Necrosis is the death of living cells or tissue (4)). Half of her foot was essentially gone, was full of pus, the stench of dead tissue was unbearable, and maggots were colonizing in her wound. Instead of cleaning the wound and amputating her foot; however, the doctor's were trying to save it. They decided to leave the maggots in her foot to deal with the necrotic tissue. At first, I was thoroughly disgusted and had to excuse myself for a minute, but after getting used to dealing with her wound changes and talking to the doctors and understanding what the maggots provide, their use became more clear to me. Although we see maggots as disgusting little larvae creatures, beyond their development into flies, they do have a viable use in modern medicine.




Maggot therapy, otherwise known as Maggot Debridement Therapy or larval therapy, is a type of biotherapy involving the intentional introduction by a health care practitioner of live, disinfected maggots into the non-healing skin and soft tissue wound of a human or animal for the purpose of selectively cleaning out only the necrotic tissue within a wound in order to promote wound healing (5). History of maggot therapy dates back to the Mayan Indians and Aboriginal tribes in Australia. There have also been reports of maggot treatment in the Renaissance times. During warfare, many military physicians observed that soldiers whose wounds have become colonized with maggots experienced significantly less morbidity and mortality than soldiers whose wounds had not become colonized (5). With the modern day advent of antibiotic resistant bacteria, maggot therapy has been successfully introduced into modern medical care as a safe and effective therapy (5). The current use of maggot therapy is estimated to involve over 3,000 doctors, clinics, and hospitals in over 20 countries (5).

The mechanisms of maggots have three principal actions. First, maggots debride wounds by dissolving only necrotic, infected tissue. Second, they disinfect the wound by killing bacteria, and third; they stimulate wound healing (5). Maggot therapy has been shown to accelerate debridement of necrotic wounds and reduce the bacterial load of the wound, leading to earlier healing, reduced wound odor and less pain. The combination and interaction of these actions make maggots an extremely potent tool in wound care (5).

Although in Africa, the maggots in this woman's foot were not disinfected and controlled like they would be in the modern world, after being in the hospital for a month, the woman's foot was looking immensely better. I was shocked and amazed at the benefit of keeping the maggots in her wound. Even more, I was impressed and moved by the resourcefulness and knowledge of the doctor's that I worked with at the hospital. It made me realize how medicine and care is still possible, even when you have so little.

Thinking about the use of maggots in terms of Biology, maggot therapy is just one more example of a possible symbiotic association between organisms. Using maggots in wound care provide nutrients to the developing larvae by digestion of the necrotic tissue and in turn the human benefits as well. It's kind of gross to think about, but in our modern world of more and more antibiotics, and extremely resistant strains of bacteria; if I ever get necrosis in the future....I just might ask the doctor to pass over the maggots.


References
1) WebMD. 2005 - 2007. Diabetes complications. Retrieved December 15, 2007, from http://www.webmd.com/a-to-z-guides/complications
2) American Academy of Orthopedic Surgeons. 1995 - 2007. The Diabetic Foot. Retrieved December 15, 2007, from http://orthoinfo.aaos.org/topic.cfm?topic=A00148
3) Foot.com: The foot health Network. 2005. The diabetic foot. Retrieved December 15, 2007, from http://www.foot.com/info/cond_diabetic_foot.jsp
4) Medicinenet.com. 1996 - 2007. Retrieved December 15, 2007, from http://www.medterms.com/script/main/art.asp?articlekey=4514
5) Wikipedia. 2007. Maggot therapy. Retrieved December 15, 2007, from http://en.wikipedia.org/wiki/Maggot_therapy
Picture References
1) Wikipedia. 2007. Magoot therapy. Retrieved December 15, 2007, from
2) Smith, N. 2006. Personal photo from Portreitz Hospital in Mombasa, Kenya.

Parasitic Conifer



So, New Caledonia is considered a "biodiversity hotspot" and has a high ratio of endemic species. (Yes, I know my last post was also about New Caledonia, but frankly, it's a rather amazing place.) For example, the island has approximately 3,270 plant species and 74% percent of those are endemic. This isn't particularly surprising consider New Caledonia is an isolated island and with such isolation, some rather unique life forms have developed including, Parasitaxus usta (or, as it is commonly known, the Corail), the only parasitic conifer in the world.

The Corail seems to lack proper roots and it attaches itself to the roots of Facatifolium taxoides and presents a "vesicular-arbuscular mycorrhiza" sort of parasitism. In other words, although the foliage of the Corail contains a few chloroplasts it does not photosynthesize particularly well and instead transfers sugars from the host plant via a fungal middle-man. Although, it seems that the Corail can also form a direct connection with the xylem of the host plant and in this way it can scavenge nitrogen. The plant itself is extremely delicate and, apparently, even stepping on the new shoots can kill them. Also, before the Corail was discovered to be parasitic, any attempts to extract it lead to the death of the specimen. Full grown, the Corail is a woody shrub with red or dark purple scaled leaves and is, honestly, a rather bizarre looking plant.

I feel unique species like the Corail serve to emphasize just how amazing island communities really are. In complete isolation from the mainland, species are free to develop and many have worked themselves into some rather unusual niches. Even though New Caledonia is relatively small, there are five different plant families and one hundred and eight genera which are endemic. There are only a few other countries with more endemic (including Australia and South Africa) and they are considerably larger than New Caledonia.

References
1. http://www.conifers.org/po/pa/
2. http://en.wikipedia.org/wiki/Parasitaxus_ustus
3. http://www.parasiticplants.siu.edu/parasitaxus.html (photo & text credit)
5. http://www.biodiversityhotspots.org/xp/hotspots/new_caledonia/Pages/default.aspx

Darwins' Islands






The Galapagos Islands are located 600 miles off the mainland of Ecuador. When Charles Darwin first stepped foot onto one of they islands in 1835 he had come across a biologists dream. I have been lucky enough to have visited the island on two separate trips. I recommend it to anyone with a love for biology. Do it soon because time is running out. Four of the main islands have a population of 17,000 people that keeps growing. As with any population of us human being comes pollution. Worse than the pollution is the introduction of non native animals. Many of the native animals have never had natural predators so they are tame as can be. You can walk up any animal without it running away. There were many occasions where i wanted to pick up marine iguana's because i knew it was possible but i would have broken a federal law. Now imagine an animal that tame to something as big as me and now introduce dogs. Dogs eat and kill just about anything they can get a hold of. Biologists on the islands are doing their best to protect these animals that are found nowhere else in the world. The biodiversity is astounding. Of course you could see all the finches made famous by Darwin but there is so much more. Blue footed boobies that arch their backs and whistle to the sky during mating rituals. Giant turtles you could literally ride on. The wave albatross that looks more like a hand glider than a bird. The span of diverse life goes on and on. Just don't be too late.






Mummified Dinosaur Rocks World of Science


Dakota, named after her discovery in North Dakota is no ordinary dinosaur find. The 67 million year old hadrosaur has begun unlocking secrets to the evolution of dinosaurs. This herbivore was mummified then fossilized preserving tendons and ligaments. It is very common to only find fossilized bones of dinosaurs, and very rare to find them joined together as they would be in real life. Some paleontologists say that if you find a complete fossilized dinosaur skeleton within your lifetime, you have hit the jackpot. For such an epic and preserved find the body had to come by many specific circumstances. The hadrosaur had to escape predators, scavengers, as well as decomposition due to the elements. Before bacteria was able to consume the tissue, it is believed to have been mineralized through a chemical process. It is miraculous how such an important specimen to science survived undamaged for approximately 67 million years. Using a CT scanner paleontologists were able to discover exactly how much muscle was in between the bones and skin of the tail. Dinosaurs are now believed to be even larger than first thought. The muscles at the base of the tail prove that this dinosaur moved much faster than predicted. A whopping estimate of 45 kilometers per hour. The muscle mass at the rear end of Dakota was calculated at 25% larger than first believed. This is an incredible find. Are all dinosaurs bigger and faster than first thought? Would mankind survive against these colossal reptiles? Will we ever find preserved cells leading to possible cloning? Would it really be a smart idea? All we can do is keep digging.


Mighty mice!





Much to the dismay of Peta activists, animal rights laws in most countries do not regulate the use of laboratory mice. Mice are the most commonly used mammalian model organism in labs, and since the advent of genetic research they have been subject to some remarkable genetic experiments. For instance, researchers in Cave Western Reserve University created genetically modified hyper-metabolic mice, which can run 6 kilometres for six hours straight without stopping. These "super-mice" eat 60% more than an average mouse, but are fitter, faster and live muce longer lives! Recently, Japanese researchers created a mouse that is completely unafraid of predators by disabling certain smell receptors that would normally cause the mouse to run away in fear. While obviously this is does not benefit the mouse in anyway, its human applications are worth considering. Scientists predict that this research may be used to help resolve anxiety disorders.





Another example of super-mice involves Myostatin, a naturally occurring protein that inhibits the growth of muscles. By inhibiting the Myostatin gene, the lack of any Myostatin protein allows muscle growth to continue unchecked. In mice growth dramatically increases, one report stated muscle mass increased by 60% in two weeks. The equivalent human gene coding for Myostatin was found in 2004 when a boy was born with a mutation preventing the Myostatin protein from forming. Myostatin gene-therapy has the potential to treat degenerative muscle disease but will also probably be abused by Barry Bonds.

Sources




Achondroplasia

Achondroplasia is a autosomal dominanat genetic (inherited) disorder that causes abnormal bone growth that results in a type of dwarfism. Autosomal genetic disorders affect a single gene on an autosome while the other gene is usually normal. There are two different inheritance partterns that are called dominant or recessive, depending on which type of gene has been mutated. Achondroplasia has one normal gene, giving a person that has this disease a fifty percent chance on passing on the gene to their offspring. However, if there are two copies of the mutant genes in one parent, it could be very fatal to the offspring, giving it a twenty five percent chance of the child death (stillbirth) before or after birth. Two other syndromes with genetic disorders similar to achondroplasia are hypocondroplasia and thanatophorphic dysplasia.

The growth of the brain and the intellectual level is usually normal, but the growth of the body and the limbs are disproportionate throughout the whole body. Irregular growth of bones and muscles in the body can cause compression of the spinal cord or obstruction of the airway passage, which is the common cause of infancy death. Obesity is a major issue that arises from achondroplasia due to the short body satuture.

Achondroplasia can be detected through clinical examinations. A prenatal ultrasound can be done before the birth of the child to test for the mutant genes in the DNA. The other ways in which this disorder can be detected is by the slow motor responses and movements as well as low muscle tone in the child.

There are no treatments present that are for achondroplasia today, however, there are surgical procedures that lengthen the limbs of the body. People with achondroplasia usually live life normally just like people who do not have this genetic disorder. Most people with achondroplasia do not hold back on physical acitivity or change their ways of living due to their height.


Sleeping Sickness, Antigenic Variation, Medicine and the Injustices of Making a Profit


Prelude
The mere mention of the word 'Africa' sets me into a myriad of emotions. Not only is this because I have a personal attachment to the continent, but because I have learned many things about the multiple injustices the people of Africa face everyday. When Dominic introduced the disease we call sleeping sickness in our class, he immediately caught my attention. My soon-to-be father-in-law has spent his life researching the parasite that causes the disease in his laboratory at the University of Saskatchewan, dragging his family to Kenya for 3 years (30 years ago) in order to investigate the parasite in its own habitat. During my graduate degree, two years ago, I took a Medical Anthropology course which spent a lot of time discussing the disease, the devastation it causes, and the political controversies and injustices that continue to progress surrounding the medication used in treating the parasite. Most recently, last year I spent two months volunteering in a government hospital in Kenya, Africa often aiding patients that were suffering from the complications that this disease causes. I was immediately interested in learning more about how the parasite works when Dominic introduced it in our Biology class.

What is Sleeping Sickness?

Human African Trypanosomiasis, also known as sleeping sickness, is a vector-borne parasitic disease caused by the protist kinetoplastid Trypanosoma (1). Kinetoplastids are characterized by a single, large mitochondrion that contains an organized mass of DNA called a kinetoplast (2). The protist is transmitted to humans by the bite of the tsetse fly which have acquired their infection from human beings or from animals harbouring the human pathogenic parasites (1). While taking blood from a human host, an infected tsetse fly injects metacyclic trypomastigotes into the skin tissue (3). Inside the host, they transform into bloodstream trypomastigotes, are carried to other sites throughout the body, reach other blood fluids such as lymph, and spinal fluid , and continue their replication by binary fission (3). The first stage of the disease, known as the haemolymphatic phase, entails bouts of fever, headaches, joint pains and itching (1). Due to the fact that the parasite migrates to the lymph system, lymph nodes often swell up to tremendous sizes. Winterbottom's sign, the telltale swollen lymph glands along the back of the neck may appear. If untreated, the disease slowly overcomes the defenses of the infected person, and symptoms spread to include anemia, endocrine, cardiac, kidney diseases and disorders (3). The second stage of the disease begins when the parasite passes through the blood-brain barrier. The symptoms of the second phase give the disease its name; besides confusion and reduced coordination, the sleep cycle is disturbed with bouts of fatigue punctuated with manic periods progressing to daytime slumber and nighttime insomnia (1;3). Without treatment, the disease is fatal, with progressive mental deterioration leading to coma and death (1;3).


Human African Trypanosomiasis can take on two forms, depending on the parasite involved:

- Trypanosoma brucei gambiense is found in west and central Africa. This form represents more than 90% of reported cases of sleeping sickness and causes a chronic infection. A person can be infected for months or even years without major signs or symptoms of the disease. When symptoms do emerge, the patient is often already in an advanced disease stage when the central nervous system is affected (1).

- Trypanosoma brucei rhodisiense is found in eastern and southern Africa. This form represents less than 10% of reported cases and causes an acute infection. The first signs and symptoms are observed after a few months or weeks. The disease develops rapidly and invades the central nervous system (1).

Antigenic Variation
The most devastating yet interesting thing about the Trypanosoma parasite evolutionary and diversity wise is its ability to evade the human immune system. Trypanosoma parasite lacks intracellular stages which makes the parasite a target for human antibody-mediated destruction (4). Indeed, many trypanosomes are cleared from the blood by liver macrophages; however, the remaining parasites survive and establish the infection due to their ability of antigenic variation of their variant surface glycoprotein [VSG] (4). Each trypanosome carries a large repertoire of VSG variants with different primary sequence and expresses a single VSG gene at any one time by replacing the previous gene at the telomeric active site of transcriptional expression with the new one (4). As a result, this repeated antigenic change of the VSG in trypanosomes allows them to evade the thymus-dependent humoral response, resulting in successive surges of parasitemia, a situation similar to being infected successively by related, but not identical pathogens (4). Due to this ability in the parasite, it makes it extremely difficult to develop a vaccine targeting the disease.

Since the pathogensis is linked to the inability of the patient to eliminate the parasite, attempts have been made to determine how the parasite interacts with the immune system and disturbs the balance of cytokines and other mediators, thus allowing the pathology to progress (4). This theory has provided the basis by which my soon-to-be father-in-law has spent 45 years of his life investigating.....since they still haven't found a vaccine for the disease, I'd say that the parasite has a pretty evolved mechanism!!

The Medicine
The history of treatment for sleeping sickness began with the introduction of an arsenic based compound called, Atoxyl, for the treatment of the disease (5). In 1920 a drug called, Suramin, was used to treat the first stage of the disease (3). By 1922, Suramin was generally combined with Tryparsamide, less toxic than Atoxyl, in the treatment of the second stage of the gambiense form (3;5). Suramin was used during the grand epidemic in West and Central Africa in millions of people and was the main form of therapy until 1969 (3). Pentamidine, another drug that was seen as highly effective in the first stage of the disease, began to be used in 1939. During the 1950's, it was widely used as a prophylactic agent in Western Africa, leading to a sharp decline in infection rates. At the time, it was thought that eradication of the disease was at hand......they were wrong (3;5). In 1932, 700 patients became blind after receiving the wrong dose of Atoxyl (5). In response to this disaster, a Swiss physician and chemist named, Professor Friedham, developed the drug Melarsporal, the bold concept of which was a single product containing a highly toxic arsenic-based molecule and its antidote (3;5). Melasporal was effective in controlling the disease; however, because it is arsenic-based, when injected it is extremely painful and burns the veins used for treatment (6). Additionally, 3-10% of patients injected have reactive encephalopathy and 10-70% of such cases result in death; also causing irreversible brain damage in those who survive the encephalopathy. Psychological effects from the drug are not uncommon and many patients have to be tied to their bed during treatment (6). Due to its effectiveness; however, Melasporal is still used today (3;6).

The most modern and safe treatment for sleeping sickness is a drug called Eflornithine. The drug was developed in the 1970's by Albert Sjoerdsmanot and underwent clinical trials in the 1980's (3). The drug was approved by the United States Food and Drug Administration in 1990, and was extremely effective against sleeping sickness, producing very little side effects; however, the drug was dropped from production in 1999 due to the fact that it was unprofitable (3;6). Apparently millions of Africans infected with the disease that the drug cures, can't pay astronomical amounts for the drug, so the drug company responsible - Bristol Myers Squibb and Aventis - decided they were not going to produce it anymore (6). When a vigilant Medicins Sans Frontieres supporter discovered that 'Vaniqa' facial hair cream, containing Eflornithine, was being sold in the United States, for $54.00 a tube, the ensuing publicity mobilised the drug companies responsible to restart their production of the Eflornithine medication (6). Million of dying Africans weren't enough motivation to produce the drug, but apparently at $54.00 a tube, production of a facial hair cream, was more important. In 2001, Aventis, in association with Medicins Sans Frontieres and the World Health Organization, signed a long-term agreement to manufacture and donate the drug (3;6). In addition, Aventis handed over the patent rights for the drug to the World Health Organization (6). Although this sounds like a happy ending, resistance to Eflornithine is emerging as the parasite develops new mutations which help to resist the mechanisms of the drug. Combination therapy is sometimes necessary. The number of doses and time span for treatment has doubled while debates for how long the drug will be donated continue.....(7).

Last Words

Sadly, the tale of Sleeping Sickness and the political controversies surrounding the medication produced to aid in its symptoms is not a unique one. Currently, in modern corporate-dependent societies, all things medical have been commodified (7). Nowhere is this as clear as in the TRIPS Agreement (Trade-Related Aspects of Intellectual Property Rights), which pits the public health community and the poor against the vast resources of a multi-billion dollar industry (8). In short, as commodities, all forms of medical goods, services and access to them are controlled by profit-seeking interest groups and political cliques. Governments that buy access to those goods and services also ration them (7). The TRIPS Agreement recognizes patents and the right to protect them for profit. Due to the fact that the TRIPS Agreement is international in scope, it allows countries in which a drug has been patented to prevent other countries from producing generic strains of a drug for which profitable royalties cannot be paid to the patent holder (7). Even when another country has bought production rights, it cannot sell its generic product to another country that does not have production capacity (7). In addition, the TRIPS provision that allows for the free flow of drugs in the face of epidemic diseases is not being honoured by the USA (7).
Commodification has also led to the 'direct selling' of medicine to the public. It is a strategy intended by the pharmaceutical companies to expand their market (7). Where there are pharmacare programs, refusal to release a new drug is often intended to coerce governments into putting the drug on the list to ensure greater sales (7). As a result, these practices have chipped away at our system we call 'universal health care'.

So,.....although evolution and diversity in parasites provides an interesting basis for us to research, investigate and solve problems; the issues surrounding treatment for parasites and other diseases becomes much more complicated and heated. Although I think studying Biology is a fascinating Science, I also think it's important to recognize its relatedness to all aspects within our society; health-wise, politically, and socially.


References
1) World Health Organization. 2007. African trypanosomiasis (sleeping sickness). Retrieved December 12, 2007, from http://www.who.int/mediacentre/factsheets/fs259/en/
2) Bergeron, D. (2007). Biology 124: Evolution and Diversity, lecture Notes. Camosun College.
3) Wikipedia. 2007. Sleeping Sickness. Retrieved December 15, 2007, from http://en.wikipedia.org/wiki/Sleeping_sickness
4) Zambrano-Villa, S., Rosales-Borjas, D., Carrero, J. C., & Ortiz-Ortiz, L. (2002). How protozoan parasites evade the immune response. TRENDS in Parasitology, 18(6), 272 - 278.
5) MicrobiologyBytes. 2007. Trypanosomiasis. Retrieved December 12, 2007, from http://www.microbiologybytes.com/introduction/Trypano.html
6) Botting, H. (2005). Anthropology 324: Medical Anthropology, lecture notes. University of Victoria.
7) Jackson, N. (2002). Saving lives in the name of vanity. Medicines Sans Frontieres Article [Electronic Version]. Retrieved September 30, 2005 , from http://www.msf.org/
8) Reid, M., & Pearse, E. J. (2003). Whither the world health organization? The Medical Journal of Australia, 178(6), 9 - 12.
Photo References
1) International Atomic Energy Agency. 2007. Retrieved December 15, 2007, from http://www.iaea.org/NewsCenter/Features/Tsetse/index.shtml
2) University of Wisconsin-Oshkosh, Medical Technology. 2004. Retrieved December 15, 2007, from http://www.uwosh.edu/med_tech/teaching/microscopy.php
3) DFID Animal Health Programme: Controlling Tsetse-transmitted trypanosomiasis. 1997. Retrieved December 15, 2007, from http://www.dfid-ahp.org.uk/index.php?section=4&subsection=42
4) Todd and Brad Reed Photography. 2007. Retrieved December 15, 2007, from www.toddandbradreed.com/links

Friday, December 14, 2007

Yeast, Genes, and Intoxication


I will bet that many students will raise their glasses in celebration at the end of exams.  Humans experience the intoxication of alcohol all thanks to Saccharomyces cerevisiae, otherwise known as brewers yeast.   Brewers yeast is a single-celled fungus that plays an important role in the lives of humans from our distant past through to today.   


The Genome News Network states that brewers yeast, and its evolution, is often studied because many genes that control the yeast's function are important in humans.  Brewers yeast provides the first clear example that whole-genome duplication plays a role in evolution not just.  This is important for understanding how gene duplication works, and its role in evolution. 
Its good to understand how brewers yeast produces alcohol.  Here are the basics, as taken from a  December 2006 New Scientist article.  "S. cerevisiae ... converts sugars into ethanol, generating a meagre two molecules of ATP per glucose molecule. Most cells resort to anaerobic respiration only when oxygen is in short supply, but give S. cerevisiae some sugar and it will churn out alcohol even when oxygen is plentiful - sacrificing huge amounts of energy in the process".  It is amazing how evolution works.  If you were to look at this process on its own, it would seem absurd and wasteful for brewers yeast to function as it does.  A person may conclude that this was a horrible evolutionary mistake.  Yet, we must not forget that every factor, and every possible element that influences brewers yeast survival, is essential to its evolutionary path.  Holism is key to addressing evolutionary forces.  

The gene duplication which occurred would have been a response to competition from other similar organisms.  "Ethanol is toxic to most microbes, so acquiring the ability to turn all the glucose available in a fruit in to a sea of the stuff gave S. cerevisiae's ancestors a big competitive advantage" (New scientist).  Ripened fruit contains higher levels of alcohol and is a food source for other larger organisms such as primates.   Heres where human ancestors came in.   New Scientist notes that "primates have long feasted on fruit, and many researchers think that our ancestors evolved to love the scent of alcohol that helped them discover ripe fruit". Throughout human prehistory and history, we have influenced plant growth by purposefully selecting for certain traits.  This may be an early example of the human imprint on evolution in other organisms.  Again, everything is connected.  Skeptics point out that tests conducted as of April 2004 have found only very small doses of alcohol in fruits, perhaps one-tenth or one-hundredth of that found in a single cocktail.  To learn more about human ancestors role, scientists are studying how much ethanol primates consume in the wild (New Scientist).  The comparative approach between chimpanzees and humans is a common technique to help gain insight to human ancestors.  Any results will help understand the effects brewers yeast may have had on human evolution.  

According to New Scientist, we, like other primates, have an enzyme called adlehyde dehydrogenase that clears acetaldehyde, a toxic breakdown product of alcohol, from our bodies.  As we know, where there are genes, there are gene mutations.  There is a mutant gene for aldehyde dehydrogenase that makes the enzyme slower at clearing acetaldehyde from the body (New Scientist).  This causes hot flushes and nausea after drinking alcohol (New Scientist).  Up to 80% of Han Chinese, Korean, and Japanese people, however, have at least one copy of [the mutant gene]" (New Scientist).  This article also notes that although the effects may appear as a disadvantage, they may be an asset since alcoholism is less common among those with the mutant adlehyde degydrogenase gene.  Humans today enjoy and abuse alcohol in a variety of ways.  Perhaps this mutant gene will mean more to us in the future, or maybe not.  Time will tell. 
Currently, human evolution is effected by evolutionary forces in different ways than our distant and not so distant ancestors. Today, gene flow, genetic drift, and mutations are more influential than natural selection on human evolution in many areas of the world.  There is the possibility, and likelihood of change in frequency of the mutant aldehyde dehydrogenase enzyme.  Whether the effects will be disruptive, stabilizing, or directional in the human population is the question.  I expect gene flow to play the most important role in this case. Increased migration, travel, and interactions between people all over the world result in the movement of genes throughout the global human population.  
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