24 Nov 2017

Introduction to Gene Therapy: It Sounds Simple, But It's Sure Not Easy

by L. E. Carmichael

Muscular dystrophy, hemophilia, Leber congenital amaurosis (LCA), cancer... they all have one thing in common. They are genetic diseases, ultimately caused by missing or malfunctioning genes in the patient's DNA. Until recently, we could treat the symptoms of many genetic diseases, but not the causes. There was no way to reach inside a person's genes and repair the faulty code that started the whole problem.

Research into gene therapy aims to change that.

What is gene therapy?

Genes are blueprints for proteins. A complete set of working proteins makes a working human. In contrast, missing or malfunctioning proteins sometimes lead to disease. Many genes and proteins have to be affected to lead to diseases like cancer. Other diseases, like LCA and Lesch-Nyhan syndrome, result from a single broken gene.

The logic behind gene therapy is very simple: if a missing or malfunctioning gene is causing disease, a working copy of the gene could cure the patient. There are two ways to provide a working copy:
  1. Fix the gene that's already in the patient's DNA. This is easiest when the malfunction is caused by what's known as a "point mutation," which is basically a typo in the genetic code. Not all such typos are dangerous, but the right typo in the wrong place can knock out the entire gene.
  2. Provide a new copy of the entire gene. This strategy applies for genes with larger insertions - extra code - or deletions - missing code.
Once a working gene is present in the patient's cells, his or her body can make a functional protein... and in some cases, that may be enough to cure the disease.

That Does Sound Simple... So Why Is Gene Therapy So Hard?

Lots of reasons, but we're going to focus on two:
  1. Cells have lifespans. Dying cells are replaced by new cells, which are created by cell division. During this process, the cell's genome (all the DNA a person was born with) is copied so that each new daughter cell gets a complete set of instructions. There is no guarantee that a therapy gene that's simply floating around in the cell will end up in both daughters - to ensure that the shiny new gene will always be passed on, making the cure permanent, that gene has to become part of the original genome. Which means that, either
    1. the patient's original gene has to be edited in place, or
    2. the complete new gene has to embed itself into the patient's existing DNA.
  2. According to one estimate, there are 37.2 TRILLION cells in the human body. Not every disease affects every cell in the body. For example, LCA is a form of blindness caused by a faulty gene in the cells of the retina. To cure LCA, only retina cells would need to be treated. Far fewer than the whole 37.2 trillion, but still enough that getting a working gene into EVERY retinal cell is still a huge challenge.
So How Do Scientists Solve These Problems?

Stay tuned! In Part 2, I will explain what CRISPR is and why scientists are so excited about it. In Part 3, we'll tackle the "every cell" problem... and some awesome/scary breakthroughs that have recently hit the news.

In the meantime, you or your teenager might want to check out my YA science book, Gene Therapy. It's a couple years old now, but is still a solid introduction to the history and science of this cutting edge medicine.

10 Nov 2017

Who Writes for Science Centres and Museums, and How?

by Adrienne Montgomerie 

There are words everywhere at museums and science centres: on the walls, in the guide books, in their newsletters, blog posts, and marketing materials, in the visitor activities and kids’ clubs, and in the audio guides and press releases. And that’s just the stuff the public sees. Behind the scenes there are funding requests to write, reports, journal papers, and things like that.

Sci/Why wanted to know what it was like to work on those materials, so we asked some experts to tell us about it. What follows came out of interviews with three writers from Canada and the United States who specialize in writing for science centres and museums.

How Writers Write Content for Museums

The writers and editors don’t have to have all the knowledge, they just have to know where to find it. Sometimes they get to work with subject experts—scientists and researchers—one-on-one to gather info. Other times they read what experts wrote, to gather facts to share with the public.

“It’s really an exercise in cutting,” said Kimberly Moynahan, to make the expert knowledge fit on a very short panel. She works on exhibits for the likes of the Ontario and Saskatchewan science centres in Canada. Panels explaining exhibits can be super short. “A whole panel might be 60 words. And you’re going to explain fusion,” she said. “What really are the key messages? Everything you write has to add more information. You never repeat anything, because you don’t have room for that.”

“It’s super important to keep it fun,” Moynahan said. “We try to get kids to engage with other parts of the room or activities by challenging them with questions: Can you think of something bigger than an elephant? How many equilateral triangles do you see? Hint, look at the windows.

Imagine these panels on the wall beside an exhibit: “There’s a big header with question on it, then underneath that, a bold sentence with the secondary information. Beneath that, there might be one or two big sentences not quite as bold, then a paragraph of two to three sentences. A lot of people will only read the headers,” Moynahan explained.

Who the Museum Writers Target Audience Is 

When editing words the public will read, “I often have to eliminate a lot of jargon,” said Sara Scharf, editor in paleontology for materials at the Royal Ontario Museum in Canada. “I try to write for a grade 6 reading level or so.”

Aiming for that 11- or 12-year-old visitor is key, agrees Moynahan. “We might have some messaging for adults,” she said. “But the general audience for tone, language, and facts hit that middle school audience. That age group is the bulk of visitors—with schools coming through.”

Maggie Goodman is writing for younger kids (grades 3–5) because her work at the Chicago Museum of Science and Industry in the USA was for a science club as well as a summer program at the public libraries. “Language needs are very important when we’re looking through to make sure things work,” Goodman said. She also considers what kids are interested after 5 pm (outside of school hours).

The Museum Writers' Reference Shelf 

For the facts, the experts on the team are the writers’ most important resource. For the other parts, writers look to school curriculum (available online by province) to find words and ideas that are familiar to kids. Museums and science centres love to teach visitors new things. Knowing what the visitors might already be familiar with helps them build on and extend that knowledge, taking visitors from the familiar to the unfamiliar, and on to new reaches of knowledge. In the USA, Goodman refers to the Next Generation Science Standards that outlines the progression of scientific concepts and depth of understanding across the grade levels.

For checking the use and style of science jargon, writers ask their experts, and check books like Scientific Style and Format and AP Stylebook, and science dictionaries as well as standard school curriculum, and reputable websites. (Also see our article on science vocabulary by grade.)

The Museum Writers' Background 

Writers and editors working in a niche often know something about the topic beforehand, but sometimes their expertise is primarily in language. Scharf has a PhD in the history and philosophy of biology and Moynahan has a degree in zoology. Goodman has a background in educational development, but not in science. Sometimes not being a subject expert can help the editor or writer put themselves in the public’s shoes. They have to write materials that can be understood by visitors who are completely new to the subject, after all.

Moynahan says that her training as a scientist helps her a lot: “It’s helped our design team that I can do some of the research so they don’t have to farm it out. I already have a basic understanding and know what to Google. Most of the time, what you’re writing is not deep science. It’s very helpful to have a science background because you have to pull from three pages and get a story arc onto three [60-word] panels.” The scientists like working with her, she says, because “I can talk with research scientists who are truly expert in the field, and understand [them] enough that they don’t really have to explain [the science].”

What Museum Writers Want You to Know 

Moynahan wants others to know “the fact that it is a career path for a writer. It never occurred to me as a freelancer that there is work [for us in museums].”

“There is that false idea that there’s a gatekeeper to understanding science and liking science,” Goodman said. “We are really trying to tear that down at the Museum of Science and Industry. I’m really proud that there’s a universal ownership to science learning and exploration that’s occurring. Everybody has that on a daily basis, they’re just often not doing that in the terms that are used in a STEM [science, technology, engineering, and math] setting.”

“I like looking at the same material from multiple angles, helping to bring cutting-edge research to a broader audience,” Scharf said. “And the challenge of doing so in a variety of voices and registers.”

Do you remember an exhibit whose writing really stood out? Did you ever think about being on that creative team? Did you learn something when writing an exhibit that you’d like to share? Leave a comment and tell us about it.

5 Nov 2017

Nanotechnology: Corneal implants

By Simon Shapiro

A quick summary of how our eyes work: they refract (bend) light and focus it on the retina. The job of doing the refraction is split between the cornea and the lens. Two thirds of the refraction is done by the cornea, so it's critical in enabling vision. After light passes through the cornea, it passes through the pupil (in the centre of the iris) to reach the lens. Muscles in the eye (the ciliary muscle) can change the shape of the lens and allow the eye to focus nearer or further. The lens focuses light on the retina, which passes signals to the brain via the optic nerve.

It's all pretty neat, but some things can go wrong, especially as you get older. Common problems are that the lens and/or the cornea can become cloudy.

Cloudy lenses

When this happens to the lens, it's called a 'cataract'. Medical science has done an incredible job of fixing this problem. It sounds pretty radical and perhaps icky, but here's what ophthalmologists do: they make a tiny incision in the eye, suck the lens right out with a tiny 'vacuum cleaner', and put a plastic replacement lens in place. If you needed glasses before the surgery, the new lens will be the same prescription as your glasses and you won't need glasses after the operation. While it sounds complicated, the surgery takes less than 30 minutes and is done on an outpatient basis – no hospital stay is needed! Tens of millions of these operations are done every year, with a success rate of 98%.

Cloudy corneas

But when it's the cornea that gets cloudy, it's not that easy. It's possible to do a corneal transplant. A section of the cloudy cornea is removed, and replaced with a section of cornea from a donated eye from someone who has died. This surgery is much more difficult than cataract surgery, and of course it's dependent on having a suitable donor. Only tens of thousands of these operations are done, and the success rate is around 80-90%. More corneal replacements would be done, but there just aren't enough donated eyes.

So all of this means that a new idea for treating cloudy corneas is very exciting. Instead of transplanting human corneal tissue, a company called Corneat Vision has developed a synthetic cornea. The procedure is to remove a disc of the cloudy cornea and implant in its place a nanofiber 'skirt' with a clear lens at the centre. The skirt is made up of a sort of a nanofiber skeleton which corneal cells will grow into. The 'magic' of this device is the nanotechnology fiber and how cells grow right into the skeleton, making the implant really part of the eye.

Nanotechnology is becoming a very important field. It deals with particles ranging in size from 1-100 nanometers. A nanometer is one millionth of a meter. That's pretty small: a newspaper page is about 100,000 nanometers thick. When you get to the nano scale, materials start behaving differently, because you're getting to the scale of individual atoms and molecules. Atoms are about .1 - .5 nanometers in diameter, and molecules are over a nanometer across.  Finding out how materials behave differently on a nano scale and finding uses for that, is what makes the field so exciting.

More on nanoscience and nanotechnology in future blogs.