Tag: sciencesunday

Tapeworm holes

I was interested in learning more about my dog’s tapeworm infection so Google sent me down the worm rabbit hole. She was asymptomatic. We had her stool checked as a requirement for a daycare center. It came back positive for tapeworm and she was given Panacur ™ (Fenbendazole). The handout that the vet gave us talked a lot about Dipylidium caninum, which is a tapeworm that is transmitted by fleas. We didn’t notice any fleas on our dog and she is not scratching excessively. So I talked to the vet and he said she has a different type of tapeworm. It was close to closing time so I didn’t press him for more information. I went down the rabbit hole, I mean wormhole looking for more information. It turns out that Panacur ™ only works for Taenia pisiformis, which is a type of tapeworm with rabbits as an intermediate host.

§ Life cycle

The general life cycle of a tapeworm starts with proglottids or eggs in the feces of the primary host. Proglottids is a segment of the tapeworm that contains a complete set of reproductive organs. The intermediate host gets infected with the eggs or proglottids, for D. caninum that would be fleas and for T. pisiformis it would be rabbits. The primary host gets D. caninum by eating the fleas, not by flea bites. If your dog or cat gets bitten, they would naturally scratch the bite with their teeth and would get the larvae into their mouths. So infants can get D. caninum by putting an infected flea in their mouth. That’s why it’s rare for humans to get D. caninum. For T. pisiformis, it’s a bit more gruesome because the main way to get infected is to bite an infected rabbit because it’s their viscera (internal organs, predominantly in the abdomen) that contains the larvae. The larvae travel from the rabbit’s intestines, into the blood stream, and then to the viscera. I’m still not sure how my dog got infected. I bet Tommy Leung can tell us more about tapeworms.

§ So how does Fenbendazole work?

Fenbendazole is in a class of drugs called anthelmintics, which are drugs that expel worms from the body by killing them or stunning them. In the case of Fenbendazole, it interferes with tubulin polymerization. Microtubules are part of the cytoskeleton. If tubulin polymerization is disrupted, the cells essentially dissolve/collapse.

More information and images here: http://goo.gl/qBZc4p

§ About the image:

It might look like a beautiful flower, but this image of the week is more the stuff of nightmares! The picture above shows a dog tapeworm (Taenia pisiformis) taken using a light microscope. The image clearly shows the hooks of the tapeworm on its head (scolex), which it uses (along with four suckers) to attach to the small intestine of canids like dogs and foxes.

The image was taken by Spike Walker. The tapeworm was on a microscope slide, giving it a slightly squashed look. The muscle and other tissue of the tapeworm were stained red, but the hooks (made of chitin) don’t stain. Therefore, Spike used a contrast enhancement technique called Rheinberg illumination, which gives the hooks their bright colours against a blue background. First demonstrated over a hundred years ago by Julius Rheinberg, this involves using coloured filters so a transparent sample can be seen.

Image source: http://goo.gl/hOAAJK

#ScienceSunday  

Busting the hype, sorry kid

This is a very interesting read about why the Ocean Cleanup Array project is full of naïveté. 

It’s nicely connected with Tommy Leung’s post:

Markers Of The Anthropocene

https://plus.google.com/u/0/111479647230213565874/posts/H87PSjm6sXT

h/t Cindy Brown 

#ScienceSunday  

Originally shared by Cindy Brown

Best place to start is at home.

Do read this.  It outlines the massive scope of the problem in the first place.  But it also points out the inherent problem with the “recyclability” of plastic in the first place:

But even when plastics do get recycled, in the vast majority of cases, recycling only kicks the can down the road one generation by creating a product that can’t or won’t (because of economic constraints) be recycled again. In short, the vast majority of the recycling industry isn’t doing anything to solve marine plastic pollution, and for the most part, recycling is just creating a secondary market for waste. Even if the economics of Slat’s Ocean Cleanup Array didn’t further impede its viability, more plastic would still be entering the ocean than his device would pull out. Placing fees on producers of virgin plastics, and giving breaks to those who use 100% recycled content or are actively working towards it, would help to balance this equation out and would be great news for the ocean.

h/t various sources including Cod Codliness 

http://inhabitat.com/the-fallacy-of-cleaning-the-gyres-of-plastic-with-a-floating-ocean-cleanup-array/

Science on Display, not just a Phage

Rajini Rao’s post made me think of phage display libraries. Check out her post here:

The Enemy of My Enemy

https://plus.google.com/u/0/+RajiniRao/posts/LvxVPMLNyTV

What is a phage? A phage or more accurately a bacteriophage, is a virus that infects bacteria. You can read more about phages in Rajini’s post. Phage display libraries use phages to screen for peptides for diagnosis or treatment.

❈ What is a peptide?

Peptides are short chains (polymers) of amino acids. Think of peptides as the building blocks for proteins. So DNA gets translated into amino acids via mRNA, which make up peptides, which combine to make proteins. That’s an oversimplification but it’s easy to get the picture. 

You can read more here: http://goo.gl/aYzy7r

An example of two peptides are shown below.

❈ Phage display

George P. Smith at the University of Missouri developed phage display in 1985. He figured out that bacteriophages could be modified to incorporate “foreign” DNA and translate that to a peptide on their surface, hence the “display” aspect. After incorporating a DNA sequence into a phage, it can display the corresponding peptide on its surface. Why is that important and how can we take advantage of that? You can create a whole library of phages and see which phage has the best targeting for your particular model/system.

❈ Antibodies

You probably know that antibodies are part of the immune system and that they are specific for an antigen, e.g. bacterium. The thinking is that if you can make an antibody for say a particular tumor or protein involved with Alzheimer’s Disease, you could attach a therapeutic or diagnostic agent. Say you have such an antibody. You add a fluorescent component or radioactive element to make it diagnostic. Where ever the antibody binds, you will be able to image. Alternatively, say you take the antibody and add a drug so that the drug is now targeted. You can lower the dose because you don’t need to flood the whole body. So why doesn’t that really work? It has been tried. Antibodies are specific but have poor clearance and are bulky. When you have to add something to them, either a diagnostic or therapeutic component, it only gets more bulky, maybe too bulky to cross the blood brain barrier or too bulky to be cleared from the body in a reasonable time, so you end up with more side effects.

If you search Google Scholar for RGD (Arginine-Glycine-Aspartic acid) you’ll find over 50,000 hits. RGD is a peptide that’s associated with integrins. Integrins are cell surface receptors that are involved with cell signaling, for example in wound healing and cancer. Since a phage is smaller than an antibody, you can imagine that a phage display should be more effective than an antibody in terms of clearance, especially after adding a diagnostic or therapeutic agent as compared to an antibody.

❈ Radio labeled phage

Say you create a phage that presents a peptide that’s specific for a certain integrin. You add a radioisotope and test it against a tumor that has a lot of those integrins. That’s what’s shown in the picture below. A phage that was designed to bind with an alpha V beta 6 integrin with indium-111, which is a gamma radiation emitting isotope, was used in a mouse model with two tumor types. The tumor on the left side is negative for the alpha V beta 6 integrin and the right side is positive. You can see that the indium-111 labeled phage is accumulating on the right but not the left. The histogram shows the accumulation of radioactivity, i.e., labeled phage, for the positive vs. negative alpha V beta 6 tumors.

Sources:

Structural guided scaffold phage display libraries as a source of bio-therapeutics.

PLoS One. 2013 Aug 9;8(8):e70452.

http://goo.gl/Ky4D3l

Phage Display in Molecular Imaging and Diagnosis of Cancer

Chem. Rev., 2010, 110 (5), pp 3196–3211

Susan L. Deutscher

http://pubs.acs.org/doi/full/10.1021/cr900317f

#ScienceSunday  

You don’t really F@^king Love Science

You don’t love science, you’re looking at its butt when it walks by. That sums up my feelings on a lot of the IFLS type shares. I have a passion for science and science outreach. Nic Hammond jokingly asked on his share of the Cyanide and Happiness cartoon, Do you even science, Bro?

Don’t get me wrong, I’m pleased that people are interested in science. What I’m annoyed with is the flashy, hyped, hipster style science related posts. In this Twitter/SMS-speak world, where people’s attention span is about 1 minute, not many people take the time to fully read any science posts. They plus the flashy image or hyped up title and that’s it. A while ago I found an image that looked photoshopped so I started thinking about the physics of it and wrote a post about it. How many of the IFLS people shared the original image/post versus my version that discussed why it was probably photoshopped? If you really F@^king love science, did you try the experiment yourself? You only need a glass and water. I’m sorry if this comes across as jealousy or sour grapes. That’s not my intention.

Photoshopped or Real: my vote is photoshopped

https://plus.google.com/u/0/+ChadHaney/posts/hzX8dQSC49o

Buddhini Samarasinghe has a great discussion going on, on her share of the Cyanide & Happiness cartoon with her own thoughts on the topic.

https://plus.google.com/u/0/+BuddhiniSamarasinghe/posts/Ua9gmTsQA8g

It takes a lot of work to do science and take the time to share it in layman’s terms. It’s also very rewarding when we get positive discussions. A lot of us, like Buddhini, Rajini Rao Allison Sekuler , Carissa Braun , Brian Koberlein etc work hard doing science and work equally hard sharing it on social media (that’s not meant to be an exhaustive list by any stretch).

We are working on breaking out of the stereotype that scientist are boring, white lab coat wearing, nerds. There is nothing wrong with nerds. I’m just not a fan of the trying to be nerdy to be ironic and hip. Nerd Nite (http://nerdnite.com/) is actually a really cool idea. I’d love to expand Nerd Nite to Google Hangouts. If you are passionate about something, share it with all the gory details but let’s skip some of the jargon.

Here’s an old post about the scientist stereotype. 

Hey scientist, smile!

http://goo.gl/2E8Cu

There is still work to do to get people really excited and involved with science. As a scientist, I have to look at my own evidence, and my science posts are dwarfed by my posts of drivel.

Science vs. drivel v2

http://goo.gl/FjBsj7

So if you really F@^king Love Science, try doing some science. Try engaging with some scientists here. Better yet, tell your legislative representative to support science with more research funding.

Image sources:

TwistedDoodles

http://goo.gl/JDeF88

via Amine Benaichouche

Cyanide & Happiness Explosm

http://explosm.net/comics/3557/

#ScienceSunday  

edit  h/t to Brent Neal  for the second cartoon.

What can you see, in your pee?

I’m vaguely familiar with the myth that your pee is essentially sterile. However, it turns out to be false. Dr. Linda Brubaker and colleagues examined the urine of 41 overactive bladder female patients and 24 control female patients. 48 of 65 of samples were negative, i.e., so-called sterile using standard urine culture procedures. However, using an expanded procedure, 80% of the samples were found to contain bacteria. I’m not a molecular biologist so I won’t try to explain the difference between the standard and expanded culture procedures. The interesting thing is that overactive bladder might be linked to changes in your microbiome. Again, we are learning more and more about the importance of our microbiome.

I’ve talked about microbiome before.

What’s buggin’ you?

https://plus.google.com/u/0/+ChadHaney/posts/gYFZudc9K4L

Bugged about diet induced obesity

https://plus.google.com/u/0/+ChadHaney/posts/Hn32hWR7jxP

Making a big stink

https://plus.google.com/u/0/+ChadHaney/posts/3jgfBfsR8Fw

Sources:

Urine is not sterile: use of enhanced urine culture techniques to detect resident bacterial flora in the adult female bladder.

J Clin Microbiol. 2014 Mar;52(3):871-6

http://www.ncbi.nlm.nih.gov/pubmed/24371246

Study debunks common myth that urine is sterile

http://goo.gl/qgIH4e

Image source:

http://goo.gl/qu0DLw

#ScienceSunday  

Bilateral prophylactic mastectomy

Kelly Rothe decided to get a bilateral prophylactic mastectomy, i.e. preventative removal of both breasts. She’s a big Red Wings fan (who isn’t) and in particular, a big fan of goaltender Jimmy Howard. Because the Red Wings organization is so classy, the video below shows what they did for this young lady.

The rest of this post focuses on the science. You may recall that kerfuffle when Angelina Jolie decided to get a bilateral prophylactic mastectomy. So here is some info and links to hopefully inform you a bit more. 

I’m not sure where Kelly get the 85% risk from. However, the risk is certainly higher for some women with specific genetic profiles.

In two studies, the estimated risks of developing breast cancer by age 70 years were 55 to 65 percent for women who carry a deleterious mutation in the BRCA1 gene and 45 to 47 percent for women who carry a deleterious mutation in the BRCA2 gene (6,7). Estimates of the lifetime risk of breast cancer for women with Cowden syndrome, which is caused by certain mutations in the PTEN gene, range from 25 to 50 percent (8,9) or higher (10), and for women with Li-Fraumeni syndrome, which is caused by certain mutations in the TP53 gene, from 49 to 60 percent (11). (By contrast, the lifetime risk of breast cancer for the average American woman is about 12 percent.)

http://www.cancer.gov/cancertopics/factsheet/Therapy/risk-reducing-surgery

Why do BRCA1 mutations cause primarily breast and ovarian cancers?

http://goo.gl/jTpcXA via Ian Bosdet

Breast Cancer Signs & Symptoms

http://goo.gl/ScqWsk via Letha McGarity

Bras and Breast Cancer

http://goo.gl/FNqrnS via Buddhini Samarasinghe

Salty MRI

https://plus.google.com/u/0/+ChadHaney/posts/VJ2k6h2taRQ

At a seminar about BRCA1 and BRCA2, Dr. Olopade shared a story about finding women in South America that had unknown Jewish ancestors from Spain. The South American women were carriers of BRCA mutations and did not know that their Jewish ancestors fled from Spain to South America.

Haplotype structure in Ashkenazi Jewish BRCA1 and BRCA2 mutation carriers.

http://www.ncbi.nlm.nih.gov/pubmed/21597964

Ashkenazi Jews

http://www.jewfaq.org/ashkseph.htm

#ScienceSunday  

http://www.youtube.com/watch?v=0B9h6-rjK-0

Alzheimer’s Disease Research

h/t Letha McGarity for triggering this lazy #ScienceSunday  post about Alzheimer’s Disease (AD). Many of you may have heard of amyloid plaques and how patients with AD have brains riddled with amyloid plaques. In fact, Auguste Deter pictured below, was the first AD patient and her brain was riddled with what we now know are amyloid plaques.

However, I’m going to do a lazy post and direct you to a series of videos here:

http://news.neurobiology.northwestern.edu/2013/10/dr-klein-segmented-journey-how-alzheimers-disease-affects/

Full disclosure, I collaborate with Dr. Klein. However, he really is a great scientist and a great guy. In the videos he’ll explain how the hippocampus plays a role and how oligomers are the real story.

Image source: http://en.wikipedia.org/wiki/Auguste_Deter

#ScienceSunday  

Schlieren Flow Visualization, let the science flow

Many thanks to Koen De Paus for sharing this. I learned something new today. I had not heard of Schlieren flow visualization before.

#ScienceSunday  

Originally shared by DaFreak

Casting Light on Sound to See its Shadow

“When light passes between areas of different air density, it bends. You’ve probably noticed the way distant pavement seems to shimmer on a hot day, or the way stars appear to twinkle. You’re seeing light that has been distorted as it passes through varying air densities, which are in turn created by varying temperatures and pressures.

In the mid-19th century, German physicist August Toepler invented a photography technique called Schlieren Flow Visualization to visually capture these changes in density. The setup is a bit hard to explain in words (watch the video above for a full explanation) but it allows scientists and engineers to see things that are normally invisible: the rising heat from a candle, the turbulence around an airplane wing, the plume of a sneeze.

It can also be used to see sound. Sound, after all, is just another change in air density — a traveling compression wave. A speaker pushes on the surrounding air, creating a wave that travels outward until it encounters the ear drum.”

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

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

High Speed Schlieren Video of Premixed Flame, Spark Ignition

http://www.npr.org/2014/04/09/300563606/what-does-sound-look-like

#ScienceSunday  | ScienceSunday 

https://www.youtube.com/watch?v=px3oVGXr4mo