CochlearWords

-- Cochlear Implants Maintain Nerve Health in Deaf Cats --

Scientists from the Johns Hopkins University Center for Hearing and Balance have discovered why cochlear implants – devices intended to restore hearing –benefit some deaf children, but not others.

David Ryugo, P.h.D. and lead investigator of the study, used cochlear implants to electrically stimulate the nerves responsible for hearing in young, deaf cats. His results point to a link between introduced nerve activity, and the structure – abnormal or not – of the auditory nerve ending. Cochlear implants function to promote hearing, according to his study, because they preserve normal structure at the end of the auditory nerve.

Deaf humans probably benefit from implants in the same way that Ryugo’s cats did. Both species have similar auditory systems, and “the cochlear implants used in these cats are the same technology that was developed for deaf children,” he said. ”but smaller.”

Until now, scientists have not understood how cochlear implants work. “It has just been assumed that the auditory system functions normally when an implant is inserted,” Ryugo explained. “The reasoning has been something like this: if a car runs out of gas, it stops. Put gas in, and the car runs again.” Ryugo’s work is filling in the gaps, though, illustrating exactly how the “gas” – or cochlear implants – jumpstart the hearing process in congenitally deaf children.

Each year, 3 out of 1000 children in the United States are born unable to hear. Not every parent of a deaf child considers cochlear implantation, but for those who do, understanding the trade-off between waiting and acting is important. The success of implantation, according to Ryugo’s study, depends upon how far nerve ending abnormalites can advance. If children born deaf are left untreated for too long, their nerve endings start to wither. Eventually, this withering abnormality may become irreversible; implants can’t restore the nerve.

“Younger is clearly better, as far as treatment with cochlear implants goes,” explained Ryugo. “In Europe, they’re even putting implants in kids at 12 months,” Ryugo said, “but it is always difficult to know the age at which a child is strong enough to endure the surgical process, and to know how much leeway doctors have when deciding how long they can wait to perform surgery.” Ryugo’s work will help define the “window of opportunity” for cochlear implantation though, by illustrating how these devices impact physical abnormalities in the nerve ending of a deaf ear.

In his study, published in Science on December 2nd, young deaf cats with implants responded to sounds in their environment. “They exhibited certain behavior responses that alerted us to the fact that they were hearing,” Ryugo said. He had trained each implanted cat that a particular sound -- a rhythmic cadence, finger-snapping, or hand clap, for example -- signaled a special food treat. Different sounds signaled different treats (tuna, roast beef, sardines) to the different cats, he explained, “and voila! They would come to these sounds the same way a hearing cat comes when you shake its food box. We knew they could hear.”

Ryugo’s graduate student Erika Kretzmer compared nerve tissue from the inner ears of three groups: deaf cats with implants, deaf cats without them, and normal hearing cats. She discovered that deaf cats that had received cochlear implant stimulation actually maintained the nerve connections critical to hearing.

“There wasn’t a significant difference between nerve endings of normal hearing cats and implanted cats,” Ryugo said.

In the deaf cats without implants, however, nerve connections were withered. “Their nerve endings were disrupted,” explained Ryugo. “They were stubby and truncated, like trees growing on the edge of a windy cliff.”

Nerve endings promote communication between neurons in the auditory pathway. They exhibit structural characteristics which advance the release and capture of chemicals called neurotransmitters. This process permits sound to reach the brain. It permits hearing.

Until now, there’s never been a good group of animal models to use for studying the effects of cochlear implants in the deaf. “We’re the only ones in the country with a colony of congenitally deaf cats,” Ryugo explained. The cochlear implants were unique, too; Advanced Bionics specially miniaturized the implants just for his study.

Cochlear implants work by performing an essential step in the hearing process: they convert sound vibrations into electrical impulses that hit the auditory nerve, and then travel to the brain. A deaf child has inner ear damage that prevents him from generating these electrical signals, however. So the cochlear implant does it for him. Ryugo’s research suggests that implants are only capable of preserving auditory nerve structure if inserted in a timely fashion, before the nerve ending withers away.

In the future, Ryugo wants to further define the “window of opportunity” for cochlear implantation by performing time-course studies to elucidate exactly how nerve endings in the ear develop.

The researchers were funded by The Emma Liepmann Endowment Fund, and grants from the NIH and the Advanced Bionics Corporation. Authors on the paper are David Ryuogo, Erika Kretzmer, his graduate student, and John Niparko, all at Johns Hopkins School of Medicine.

.MGW.

MoxifloxacinWords

---Chaisson's Changes: Bringing Bayer (and beyond) to TB---

What worked for Grandpa may work for a lot of us, but it won’t work for Richard Chaisson. As principal investigator of CREATE, the Consortium to Respond Effectively to the AIDS-Tuberculosis Epidemic, he’s spent the past five years fighting to reduce tuberculosis – killer of 1 person every 15 seconds --throughout the world. But Chaisson’s been fighting a stagnant system. There has been no new tuberculosis medication for 40 years. “People working on TB don’t ever change,” he explained. “They don’t believe in change.”

Yet, change has come. It’s come on the shoulders of giants like the Bill and Melinda Gates Foundation, who funded CREATE in 2004, and, more recently, it’s come from Bayer Pharmaceuticals. The drug manufacturer has agreed to take an unusual step and give its most promising antibiotic –moxifloxacin- to TB patients in developing nations. Ultimately, the driving force behind these efforts, including Bayer’s decision to join in the fight against TB, has been Chaisson himself, the same man who claims that at one point, “tuberculosis was just a hobby.”

Today, Chaisson directs the Johns Hopkins Center for Tuberculosis Research, but his interest in infectious diseases was born in the early 1980s, with HIV. At that time, Chaisson was doing his medical residency at an AIDS clinic in San Francisco. “It was a perfect time to be studying infectious diseases” he said, “ because all of sudden- woah! AIDS just popped up.”

Something else popped up, too. A link between HIV, the newest invader on the immune scene, and TB, an epidemic of ancient proportions. Chaisson observed that many patients had both diseases. “AIDS patients were especially vulnerable to TB since their immune systems had already been compromised by the HIV virus,” he explained. “There was a huge overlap between TB and AIDS, yet research in the area was severely neglected.”

Now, neglect is the last thing that HIV/TB studies suffer, with Chaisson at the helm. Most recently, he persuaded Bayer to permit their best-selling, patented antibiotic to be tested against tuberculosis. Bayer makes about $500 million a year from this drug, moxifloxacin, and would stand to lose a lot of money by establishing a market in poor countries. In fact, when Chaisson first approached Bayer about using moxifloxacin, “they weren’t interested at all,” he said. But that soon changed.

With the formula for moxifloxacin in hand, courtesy of a Physician’s Desk Reference, Chaisson went to the Food and Drug Administration and applied for an IND, or Investigational New Drug application. An IND is required to gain FDA approval when studying new indications of a drug, as Chaisson would be doing by testing “moxi” against TB, versus pneumonia or sinusitis, for example. Bayer got wind of Chaisson’s effort, and changed their tune.

“When Bayer discovered that the studies were going to happen,” he explained, “they decided that they needed to be part of the process. So, they joined forces with those of us studying the drug through the TB Alliance.”

Chaisson explained that while academic researchers would have continued to study the drug with or without Bayer, the Global Alliance would only study the drug if Bayer joined in, so that the drug could be made available at an affordable price if it proved effective. “The Alliance really did something of great value with Bayer's cooperation and support,” he said.

Now, Bayer is actively engaged in the trials, which involve thousands of patients in eight nations, including Brazil, Zambia, Uganda and Spain. They are donating the drug and the placebo, overseeing the toxicity reporting, and will ask the FDA for approval after the studies are done. According to Chaisson, “now that Bayer is part of a partnership with the TB Alliance and others, including our group at Johns Hopkins, it doesn’t have to invest as much or risk as much as it would have otherwise.”

The partnership between Bayer and the TB Alliance was formed on October 18th. The trial will study the potential of moxifloxacin to shorten standard treatment time from 6 months to 4. It’s already been shown to do this in mice. If the antibiotic shortens TB treatment in humans, Bayer will make millions of doses and sell them, at reduced prices, to poor countries.

This effort is well worth it. TB infects one in three people in the world, killing 5,000 people a day. It has emerged as the leading killer of HIV-positive people, too, and many doctors believe that HIV cannot successfully be fought without also fighting tuberculosis. Chaisson’s energy is relentless, and it seems that in targeting TB years ago in San Francisco, he could not have directed it to a more worthwhile pursuit.


.MGW.

IntercessionWords

What the roommie and I will be up to over intercession... the written meets the digital -->

"Hi Meagan and Virginia,

We are delighted that you have agreed to teach a section each of expository writing to our Student Success Series group here at Hopkins. The course is called 'Digital Storytelling: Recording Personal History.'

I think you're going to have fun.

--Best, Rosemary Varner-Gaskins"

ohhhexcited. ScreenWords. words on the screen... mix it up, Media.

.MGW.

SchistosomeWords

-- Fighting "The Quiet Plague": Cedarwood Oil Disrupts Osmoregulation in Schistosome Parasites --

Lathering up with topical creams before each swim may no longer be necessary to prevent schistosomiasis, a water-borne parasitic infection also known as “the quiet plague.” Researchers at The Johns Hopkins Bloomberg School of Public Health recently showed that they could reduce the ability of schistosome parasites to infect their hosts by killing the larvae in their watery homes. A mix of red cedarwood oil and surfactant, sprayed on the surface of ponds or lakes, gets the job done.

Schistosomiasis affects 200 million people in 74 countries. It is the most socio-economically devastating parasitic disease, after malaria. In their larval stage, the parasites that cause this disease are released into the water by infected, aquatic snails. The parasites then localize at water surfaces, waiting to contact and penetrate host skin. There are topical creams to prevent infection, but the idea of covering all surface skin each time water immersion is contemplated is not a viable option for the public at large.

Instead of treating the skin, Johns Hopkins researchers, including microbiologist Clive Shiff and his post-doc Dr. Jean Naples, have developed a method to reduce infection by treating schistosome-infested waters. Their strategy is unique because it exploits the parasite’s normal host-seeking behavior. Typically, lipids (fats) on the skin alert schistosome parasites waiting in water surfaces to the fact that they’ve made human contact. They then begin the process of host invasion, shedding their outer coat, known as the glycocalyx. Without this coat the parasites cannot osmoregulate, and if they remain in an aqueous environment instead of penetrating the host, they will absorb too much water, swell, and die.

Shiff and his colleagues observed that the same effect occurred when they exposed parasites to the unsaturated fatty acids of red cedarwood oil, a food and fragance additive approved by the FDA. Sure enough, the glycocalyxes of these parasites broke down, visible with a microscopic analysis, and the parasites died within minutes. Shiff knew that the parasites’ ability to infect was compromised; while mice tails exposed to untreated, schistosome-infested water were infected with an average of 12 parasites, only 1 parasite was detected in a mouse tail infected with schistosomes previously exposed to cedarwood oil. A surfactant known as Tween 80 was also mixed with the oil in test tubes, to enhance oil dispersal on the water surface. The oil-surfactant combination was up to 99.2% effective in reducing schistosome’s ability to infect the mice. Large-scale tests still need to be done in nature, in lakes and ponds, but there are at least two factors that already point to feasibility of using red cedarwood oil to reduce schistosome infection: 1) this oil is biodegradable, and 2) due to its specific gravity, it floats in water in close to the same water compartment that schistosomes occupy, while waiting to encounter a host. This means that only the water surface – not the entire volume – would need to be treated for effective attack. Shiff’s work was published in the American Journal of Tropical Medicine and Hygiene.

According to Dr. Peter Neal, a urologist studying schistosomiasis infection at Marshfield Clinic-Indianhead Center in Rice Lake, Wisconsin, “this paper presents a novel method of exploiting the specialized behavior of the parasites with a readily available, non-toxic, stable, and seemingly easy to use substance. If the in vitro results are borne out in field tests, the use of red cedarwood oil extracts mixed with a surfactant could promise to diminish the suffering and health care costs associated with this common parasite. This organism potentially affects one billion people worldwide. A simple method of control is therefore highly desirable."

.MGW.

FreemanDysonWords

Okay. This is not an article. This is an articulation. Of pure excitation!!!!

Today--- I shook hands with FREEMAN DYSON!

Yes, at the Space Telescope Science Institute at Hopkins, where he spoke. AHHHHH!

Dyson is quite possibly the most charmingly, disarming scientist I've ever met. Even when discussing nuclear bombs.

LOTS to say about him... and little time to update this blog. But! If looking for a stellar read, scope "Disturbing the Universe." A masterpiece of his. Freeman Dyson -- a brilliant scientist, an innovator of his time -- has a way with words.

Interesting tidbit about Dyson-- he was a member of the JASONS, a group of 40 scientists who met each summer after 1959 to consider defense related problems for the Pentagon.

As the Vietnam War escalated in spring 1966, a Pentagon official close to President Johnson was heard by scientist Freeman Dyson to say, "It might be a good idea to toss in a nuke from time to time, just to keep the other side guessing."

This comment apalled several of the JASONS, Dyson included, and it spurred their study to systematically explore the utility of tactical nuclear weapons in the Vietnam War. The study looked at the effects of using nuclear weapons against a variety of targets, as well as the likely political effects of a nuclear campaign.

The conclusions drawn by the JASONS (about whom my advisor, Ann Finkbeiner, will soon release a book!) might be relevant today, given the possible conflicts faced by the United States. They also become relevant considering that the Bush administration has expressed willingness to use nuclear weapons against "rogue states."




More soon! much in the pipeline... Richard Chaisson/TB/Bayer. Ryugo & his congential felines. Perhaps some Schisto work... woah, Nelly!


-MGW-

StudentEssayWords

This semester, I am teaching a science-based/laced expository writing class at Hopkins. It's called "Reprogenetics and the American Family," and recently, I assigned a book to my students: My Sister's Keeper, by Jodi Picoult.

This book is a fictional account relating to issues that can stem from using one child as a genetic donor for a sibling in the same family. Anna, the novel's main character, was born with one purpose in mind - to be a donor for her older sister Kate, who was diagnosed with terminal leukemia at age 2. In the book, thirteen-year old Anna sues her parents for the rights to her own body - at the risk of losing her sister. The ensuing battle, both within the family and within the courtroom, shakes the concept of family to the very core, and calls into question the term "good parenting."

For all other essays this semester, I've had guided prompts- instructing the students, more or less, on how to enter an argument, develop a thesis, and convey a novel thought. This time around, with My Sister's Keeper, students had free reign. I asked them to touch on the debate about quality versus sanctity of life, and to incorporate outside sources -especially court cases- but every other element of this paper was to be theirs.

Here, I'd like to share a bit of sophomore Lindsay Brown's paper... specifcally, her introduction and the poem she wrote, to preceed it. Lindsay is pre-med. She's also an eloquent writer. Take a peek!

“Ode to a Peaceful Day”

I lie here in your bed of steel,
My arms are straight and taut,
You say you feel and understand,
So, why do you tighten my knot?

The doctor says my heart is weak,
My lungs can barely breathe,
I gasp and moan from pains I feel,
Oh, if only I could leave!

The tube is long, my throat is sore,
My lips are chapped and dry,
I want to talk so I can tell,
But no tears will fill my eye.

It hisses and purrs about my head,
The “machine of life” they say,
My time has come to see the sky,
So let me have my way.

My body’s weak, I want to sleep,
My eyelids feel like lead,
But peace evades my restless soul,
While I remain in this bed.

I hear the angels at my door,
I’m ready to move on,
The tubes and plugs are all removed,
My spirit fades away with the dawn.

*

“Sometimes I hate myself,” Anna murmurs.
“Sometimes,” I tell her, “I hate myself too.”
This surprises her. She looks at me, and then again at the sky again.
“They’re up there. The stars. Even when you can’t see them.”
-Picoult

*

The service-station boy, in his white uniform, seemed uneasy until the bill was paid. He said, “You people sure have got nerve.”
Tom looked up from the map. “What you mean?”
“Well, crossin’ in a jalopy like this.”
“You been acrost?”
“Sure, plenty, but not in no wreck like this.”
Tom said, “If we broke down maybe somebody’d give us a han’.”
“Well, maybe. But folks are kind of scared to stop at night. I’d hate to be doing it. Takes more nerve than I’ve got."
Tom grinned. “It don’t take no never to do somepin when there ain’t nothin’ else you can do. Well, thanks. We’ll move on.”
-Steinbeck, Grapes of Wrath

*

In literature, martyrs only come in one size or shape. Anna’s jalopy is a courtroom. Her wreck is her age. Like Tom, she doesn’t waiver, she had no other choice. John Steinbeck’s message in the Grapes of Wrath is no different than Jodi Picoult’s in My Sister’s Keeper. Authors, however, would never let a reader think such an absurdity could possibly be true, and disguise this truth with interplay of words and contexts.
Anna, perhaps in less obvious ways that Sara, clearly stands out as a martyr in Jodi Picoult’s, My Sister’s Keeper. Her going to court, in effect, to end her sister’s life is an ultimate act of love and devotion and a concrete reaction to her sister’s illness and subsequent desire to die. Campbell on the other hand acts as a martyr in leaving Julia. However unfounded his perceived notions about his own illness may have been, he acts, seemingly quite contrarily, to give Julia life. The irony is that in the end, it is Anna who gives Kate life and Campbell who takes a great deal of Julia’s away. Each act of sacrifice is marked by a distinct period of alienation and sadness, but save by this path of darkness may dawn and a period of great quality and sanctity of life be reached.
What happens when martyrdom jumps out of the pages of classics and into the modern world, and is palpable in a U.S. courtroom? How are service station boys, in the form of jury members, able to comprehend and judge the actions of a martyr and, most importantly, at what point the destruction of a period of alienation and sadness is not worth the final rewards?

.MGW.

SynapseWords

In the works... here's a preview...

Based on personal interviews with:
Dr. David Ryugo, Professor of Otolaryngology & Neuroscience at Johns Hopkins Medical School.
His manuscript - "Restoration of Auditory Nerve Synapse in Cats by Cochlear Implants"- is being sent to Science Magazine on November 8th, and should be published within a month or so after that.

Dr. David Ryugo has a very special collection of cats. He recently took me to the lower levels of Traylor Hall, at Hopkins Medical School, where he keeps them... a dozen or so furry white felines which cost him hundreds of thousands of dollars to purchase, and which are all congenitally deaf (deaf from birth). They are the only such population in the world, and they are perfect animal models for studying deafness.

In deaf humans, cochlear implants have restored hearing for many, but not all recipients. Dr. Ryugo wanted to know why... He performed tests to better comprehend synaptic plasticity in the auditory nerve, which is vital in understanding the beneficial effects of cochlear implants in congenitally deaf children. Dr Ryugo seeks to identify the latest stage at which implants could be placed in deaf children, so that they could still obtain some benefit. (If cochlear implants are inserted too late- if parents are hesitant, in other words- these instruments may not work at all to improve hearing.)

Previously, the clinical consensus as to why cochlear implants worked for some patients but not others was that language development prior to deafness lead to the best outcomes. Among congenitally deaf children, the younger the age of implant activation, the better the aural language results. These clinical experiences imply that uncorrected congenital deafness introduces irreversible abnormalities in the developing central nervous system. In mammalian models of congenital deafness, the synaptic structure of auditory nerve endings is abnormal. Ryugo wondered if the status of auditory nerve synapses represented an important link to the success or failure of cochlear implants.

He studied defects in the auditory nerve... specifically, he studied myelinated auditory never fibers called the endbulbs of Held. They transmit signals from the auditory nerve fiber to the postsynaptic cell with a high degree of fidelity. Congenitally deaf animals exhibit endbulbs with marked reduction in branching. Moreover, they contain fewer synaptic vesicles. These structural abnormalities have been associated with transmission irregularities at the synapse of endbulbs that may underlie loss of temporal resolution in the midbrain in neonatally deafened cats.

Ryugo stimulated deaf cats via a 6-channel cochlear implant and found that their endbulb synapses resembled those from normal hearing cats, after 3 to 6 months. I'm just brushing over the results here- until I write my article- but Ryugo hypothesizes that the changes observed after cochlear implantation at this crucial synapse enable the development of integrative and cognitive brain functions reflected in aural and oral communication in deaf children...

Beyond this angle, Dr. Ryugo is also interested in studying how chemicals could be imbedded in cochlear implants, to improve hearing. A pharmacological approach to improving deafness.

Side-note: Dr. Ryugo is one of the most enthusiastic people I've ever met. If you find yourself in Baltimore, look him (and his cats) up. A true delight.

-MGW-

Post-ReadingWords

On November 7th, I read several pieces of my work aloud for the Writing Seminars Department. (All grad students do this. It's fun!!)

One piece I read was about the Kalenjins- an African tribe that lives on a plateau 7,000 feet above the sea, in northwest Kenya. They make up only .0005% of the world's population, but win 40% of its top distance events.

They are "the superstars of marathon running." The long distance elite.

I explained the biology behind why. Their "runaway" success is definitely linked to genetics, and to three factors in particular: abnormally high levels of the enzyme resposible for lactate turnover and breakdown, the right genes for high altitude survival, and an overwhelming proportion of slow twitch fibers in their skeletal muscle mass.

I don't have my piece posted, nor do I have the personal account of my love o' running here (which I read aloud, too... oohhfun!). But, I do have a bit of sweet feedback- an email from a poet... A tribute to running. And to science writers.

"Hey there, great reading on Monday night. I'm so impressed with the science writers this year. Good stuff. Anyway, my Dad's friend Deneen owns the shop 5K in Fells Point, and he thinks she would probably really like to read your stuff on running... I never knew that running could be such a dance, a religion, a spirit... a life mantra! I think if everybody ran, the world would be a better place... as you made it sound. Good science. Good energy. Thanks, T"

LifeWords

Not-so-long-ago, these lines sparkled in an email, in my inbox...

"There are plenty of people in this world who might "work" but why should relationships have a different
standard. If nothing else, the relationship should be a higher standard. Everyday you work hard to reach your goals, to reach your expectations...demand nothing less in other people. They need to complement and complete your endeavors, your inspirations, your life."

-one of my favorite authors ;-)


.MGW.

Published(!)Words

I sold a clip to ScienceNOW this week! My first published story.
ScienceNOW is Science magazine's online news source.

You can see the article under my Links, if you'd like!
-->"My First Published Piece (ScienceNOW)"

You can visit ScienceNOW's homepage, too...
--> "New Alzheimer's Target Identified" --Meagan White (Nov.4)

I wrote this piece based on interviews I'd done with neurologist Katrin Andreasson at Johns Hopkins Medical School, and with pharmacologists at Vanderbilt University. Their paper was published on November 2nd, in the Journal of Neuroscience.

Essentially, by deleting a receptor in the brain, they've identified a new target -downstream in the cyclooxygenase pathway- for Alzheimer's therapeutics... and this could lead to drugs that are much safer than NSAIDs, those typically prescribed.

According to Vanderbilt University pharmacologist Oliver Boutaud, an expert on the COX pathway, "this study is a milestone in the search for new therapeutic targets for Alzheimer's."

beautifulSCIENCE. write on...

.MGW.