Team deploys hundreds of tiny untethered surgical tools in first animal biopsies

Public release date: 23-Apr-2013
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Contact: Phil Sneiderman
prs@jhu.edu
443-287-9960
Johns Hopkins University

By using swarms of untethered grippers, each as small as a speck of dust, Johns Hopkins engineers and physicians say they have devised a new way to perform biopsies that could provide a more effective way to access narrow conduits in the body as well as find early signs of cancer or other diseases.

In two recent peer-reviewed journal articles, the team reported successful animal testing of the tiny tools, which require no batteries, wires or tethers as they seize internal tissue samples. The devices are called "mu-grippers," incorporating the Greek letter that represents the term for "micro." Instead of relying on electric or pneumatic power, these star-shaped tools are autonomously activated by the body's heat, which causes their tiny "fingers" to close on clusters of cells. Because the tools also contain a magnetic material, they can be retrieved through an existing body opening via a magnetic catheter.

In the April print edition of Gastroenterology, the researchers described their use of the mu-grippers to collect cells from the colon and esophagus of a pig, which was selected because its intestinal tract is similar to that of humans. Earlier this year, the team members reported in the journal Advanced Materials that they had successfully inserted the mu-grippers through the mouth and stomach of a live animal and released them in a hard-to-access place, the bile duct, from which they obtained tissue samples.

"This is the first time that anyone has used a sub-millimeter-sized device -- the size of a dust particle -- to conduct a biopsy in a live animal," said David Gracias, an associate professor of chemical and biomolecular engineering whose lab team developed the microgrippers. "That's a significant accomplishment. And because we can send the grippers in through natural orifices, it is an important advance in minimally invasive treatment and a step toward the ultimate goal of making surgical procedures noninvasive."

Another member of the research team, physician Florin M. Selaru of the Johns Hopkins School of Medicine, said the mu-grippers could lead to an entirely new approach to conducting biopsies, which are considered the "gold standard" test for diagnosing cancer and other diseases.

The advantage of the mu-grippers, he said, is that they could collect far more samples from many more locations. He pointed out that the much larger forceps used during a typical colonoscopy may remove 30 to 40 pieces of tissue to be studied for signs of cancer. But despite a doctor's best intentions, the small number of specimens makes it easy to miss diseased lesions.

"What's the likelihood of finding the needle in the haystack?" said Selaru, an assistant professor in the Division of Gastroenterology and Hepatology. "Based on a small sample, you can't always draw accurate inferences. We need to be able to do a larger statistical sampling of the tissue. That's what would give us enough statistical power to draw a conclusion, which, in essence, is what we're trying to do with the microgrippers. We could deploy hundreds or even thousands of these grippers to get more samples and a better idea of what kind of or whether a disease is present."

Although each mu-gripper can grab a much smaller tissue sample than larger biopsy tools, the researchers said each gripper can retrieve enough cells for effective microscopic inspection and genetic analysis. Armed with this information, they said, the patient's physician could be better prepared to diagnose and treat the patient.

This approach would be possible through the latest application of the Gracias lab's self-assembling tiny surgical tools, which can be activated by heat or chemicals, without relying on electrical wires, tubes, batteries or tethers. The low-cost devices are fabricated through photolithography, the same process used to make computer chips. Their fingerlike projections are made of materials that would normally curl inward, but the team adds a polymer resin to give the joints rigidity and to keep the digits from closing.

Prior to a biopsy, the grippers are kept on ice, so that the fingers remain in this extended position. An endoscopy tool then is used to insert hundreds of grippers into the area targeted for a biopsy. Within about five minutes, the warmth of the body causes the polymer coating to soften, and the fingers curl inward to grasp some tissue. A magnetic tool is then inserted to retrieve them.

Although the animal testing results are promising, the researchers said the process will require further refinement before human testing can begin. "The next step is improving how we deploy the grippers," Selaru said. "The concept is sound, but we still need to address some of the details. The other thing we need to do is thorough safety studies."

Further development can be costly, however. The team has applied for grants to fund advances in the project, which is protected by provisional patents obtained through the Johns Hopkins Technology Transfer Office. Biotechnology investors might also help move the project forward.

"It is more a question of money than time as to how long it will take before we could use this in human patients," Selaru said

###

Along with Gracias and Selaru, the Johns Hopkins researchers who contributed significantly to the two journal articles were Evin Gultepe, Sumitaka Yamanaka, Eun Shin and Anthony Kalloo. Additional contributors were Kate E. Laflin, Sachin Kadam, Yoosun Shim, Alexandru V. Olaru, Berkeley Limketkai, Mouen A. Khashab and Jatinder S. Randhawa. The researchers are affiliated with School of Medicine, the Whiting School of Engineering and the Johns Hopkins Institute for NanoBioTechnology.

Funding for this research has come from the National Institutes of Health, the National Science Foundation, the Flight Attendants Medical Research Institute and the Broad Medical Research Institute.

Related links:

Gracias Lab: http://www.jhu.edu/chembe/gracias/
Division of Gastroenterology and Hepatology: http://www.hopkinsmedicine.org/gastroenterology_hepatology
Whiting School of Engineering: http://engineering.jhu.edu
School of Medicine: http://www.hopkinsmedicine.org/som/
Institute for NanoBioTechnology: http://inbt.jhu.edu/

THE JOHNS HOPKINS UNIVERSITY
OFFICE OF NEWS AND INFORMATION
Suite 540, 901 S. Bond St.
Baltimore, Maryland 21231

Media Contact:

Phil Sneiderman
Cell: 410-299-7462

---

[ | E-mail | Share ]

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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.

Public release date: 23-Apr-2013
[ | E-mail | Share ]

Contact: Phil Sneiderman
prs@jhu.edu
443-287-9960
Johns Hopkins University

By using swarms of untethered grippers, each as small as a speck of dust, Johns Hopkins engineers and physicians say they have devised a new way to perform biopsies that could provide a more effective way to access narrow conduits in the body as well as find early signs of cancer or other diseases.

In two recent peer-reviewed journal articles, the team reported successful animal testing of the tiny tools, which require no batteries, wires or tethers as they seize internal tissue samples. The devices are called "mu-grippers," incorporating the Greek letter that represents the term for "micro." Instead of relying on electric or pneumatic power, these star-shaped tools are autonomously activated by the body's heat, which causes their tiny "fingers" to close on clusters of cells. Because the tools also contain a magnetic material, they can be retrieved through an existing body opening via a magnetic catheter.

In the April print edition of Gastroenterology, the researchers described their use of the mu-grippers to collect cells from the colon and esophagus of a pig, which was selected because its intestinal tract is similar to that of humans. Earlier this year, the team members reported in the journal Advanced Materials that they had successfully inserted the mu-grippers through the mouth and stomach of a live animal and released them in a hard-to-access place, the bile duct, from which they obtained tissue samples.

"This is the first time that anyone has used a sub-millimeter-sized device -- the size of a dust particle -- to conduct a biopsy in a live animal," said David Gracias, an associate professor of chemical and biomolecular engineering whose lab team developed the microgrippers. "That's a significant accomplishment. And because we can send the grippers in through natural orifices, it is an important advance in minimally invasive treatment and a step toward the ultimate goal of making surgical procedures noninvasive."

Another member of the research team, physician Florin M. Selaru of the Johns Hopkins School of Medicine, said the mu-grippers could lead to an entirely new approach to conducting biopsies, which are considered the "gold standard" test for diagnosing cancer and other diseases.

The advantage of the mu-grippers, he said, is that they could collect far more samples from many more locations. He pointed out that the much larger forceps used during a typical colonoscopy may remove 30 to 40 pieces of tissue to be studied for signs of cancer. But despite a doctor's best intentions, the small number of specimens makes it easy to miss diseased lesions.

"What's the likelihood of finding the needle in the haystack?" said Selaru, an assistant professor in the Division of Gastroenterology and Hepatology. "Based on a small sample, you can't always draw accurate inferences. We need to be able to do a larger statistical sampling of the tissue. That's what would give us enough statistical power to draw a conclusion, which, in essence, is what we're trying to do with the microgrippers. We could deploy hundreds or even thousands of these grippers to get more samples and a better idea of what kind of or whether a disease is present."

Although each mu-gripper can grab a much smaller tissue sample than larger biopsy tools, the researchers said each gripper can retrieve enough cells for effective microscopic inspection and genetic analysis. Armed with this information, they said, the patient's physician could be better prepared to diagnose and treat the patient.

This approach would be possible through the latest application of the Gracias lab's self-assembling tiny surgical tools, which can be activated by heat or chemicals, without relying on electrical wires, tubes, batteries or tethers. The low-cost devices are fabricated through photolithography, the same process used to make computer chips. Their fingerlike projections are made of materials that would normally curl inward, but the team adds a polymer resin to give the joints rigidity and to keep the digits from closing.

Prior to a biopsy, the grippers are kept on ice, so that the fingers remain in this extended position. An endoscopy tool then is used to insert hundreds of grippers into the area targeted for a biopsy. Within about five minutes, the warmth of the body causes the polymer coating to soften, and the fingers curl inward to grasp some tissue. A magnetic tool is then inserted to retrieve them.

Although the animal testing results are promising, the researchers said the process will require further refinement before human testing can begin. "The next step is improving how we deploy the grippers," Selaru said. "The concept is sound, but we still need to address some of the details. The other thing we need to do is thorough safety studies."

Further development can be costly, however. The team has applied for grants to fund advances in the project, which is protected by provisional patents obtained through the Johns Hopkins Technology Transfer Office. Biotechnology investors might also help move the project forward.

"It is more a question of money than time as to how long it will take before we could use this in human patients," Selaru said

###

Along with Gracias and Selaru, the Johns Hopkins researchers who contributed significantly to the two journal articles were Evin Gultepe, Sumitaka Yamanaka, Eun Shin and Anthony Kalloo. Additional contributors were Kate E. Laflin, Sachin Kadam, Yoosun Shim, Alexandru V. Olaru, Berkeley Limketkai, Mouen A. Khashab and Jatinder S. Randhawa. The researchers are affiliated with School of Medicine, the Whiting School of Engineering and the Johns Hopkins Institute for NanoBioTechnology.

Funding for this research has come from the National Institutes of Health, the National Science Foundation, the Flight Attendants Medical Research Institute and the Broad Medical Research Institute.

Related links:

Gracias Lab: http://www.jhu.edu/chembe/gracias/
Division of Gastroenterology and Hepatology: http://www.hopkinsmedicine.org/gastroenterology_hepatology
Whiting School of Engineering: http://engineering.jhu.edu
School of Medicine: http://www.hopkinsmedicine.org/som/
Institute for NanoBioTechnology: http://inbt.jhu.edu/

THE JOHNS HOPKINS UNIVERSITY
OFFICE OF NEWS AND INFORMATION
Suite 540, 901 S. Bond St.
Baltimore, Maryland 21231

Media Contact:

Phil Sneiderman
Cell: 410-299-7462

---

[ | E-mail | Share ]

?

AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.

Source: http://www.eurekalert.org/pub_releases/2013-04/jhu-tdh042313.php

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On Earth Day 2013: 13 excellent books to consume

Environmentalists are sometimes seen as modern-day apocalyptic prophets ? a group of seers doing their best to wake the rest of us up before it's too late.

The environmental movement started out with transcendentalism and conservationism and efforts to protect natural sites. Nowadays, however, many environmentalists tend to focus on the food industry and modern consumerism ? areas that are closer to home for the average reader. To celebrate Earth Day, here are 13 classic environmental titles to help reconnect you with nature.

- Ben Frederick,?Contributor

1. "Silent Spring," by Rachel Carson

Let's start at the very beginning, a very good place to start. Rachel Carson's book about the effect of DDT and pesticides on the environment sparked the modern environmental movement. Even without the historical context, it's still a fantastic read and surprisingly relevant. First published in 1967, it put Carson on the list of Time's 100 most influential people of the century list.

Source: http://rss.csmonitor.com/~r/feeds/csm/~3/2Hdd0Ly1EsY/On-Earth-Day-2013-13-excellent-books-to-consume

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Change diet, exercise habits at same time for best results, study says

Apr. 21, 2013 ? Most people know that the way to stay healthy is to exercise and eat right, but millions of Americans struggle to meet those goals, or even decide which to change first.

Now, researchers at the Stanford University School of Medicine have discovered that focusing on changing exercise and diet at the same time gives a bigger boost than tackling them sequentially. They also found that focusing on changing diet first -- an approach that many weight-loss programs advocate -- may actually interfere with establishing a consistent exercise routine.

Their findings were published online April 21in the Annals of Behavioral Medicine.

"It may be particularly useful to start both at the same time," said Abby King, PhD, lead author of the study and a professor of health research and policy and of medicine. "If you need to start with one, consider starting with physical activity first."

The few published studies on how to introduce more than one shift in healthy habits report conflicting findings -- and few have looked at exercise and dietary change together. In examining the issue, the researchers also wanted to study people who specifically complained that the demands of their schedules didn't give them enough time to make healthy dietary and exercise choices. The reasoning was that if successful programs could be developed for these time-strapped individuals, they would likely work for others, as well.

Researchers split 200 initially inactive participants, ages 45 and older and with suboptimal diets, into four different groups. Each group received a different kind of telephone coaching. The first group learned to make changes to diet and exercise at the same time. The second group learned to make dietary changes first and didn't try changing their exercise habits until a few months later. The third group reversed that order and learned to change exercise habits before adding healthy dietary advice. The fourth group, for comparison, did not make any dietary or exercise changes, but was taught stress-management techniques. Researchers tracked participants' progress in all four groups for a year.

Despite the challenge of making multiple changes to their already-busy routines at once, those who began changing diet and exercise habits at the same time were most likely to meet national guidelines for exercise -- 150 minutes per week -- and nutrition: five to nine servings of fruit and vegetables daily, and keeping calories from saturated fats at 10 percent or less of their total intake.

Those who started with exercise first did a good job of meeting both the exercise and diet goals, though not quite as good as those who focused on diet and exercise simultaneously.

The participants who started with diet first did a good job meeting the dietary goals but didn't meet their exercise goals. King, who also is a senior researcher at the Stanford Prevention Research Center, speculates this is because changing diet and introducing exercise both have unique challenges. "With dietary habits, you have no choice; you have to eat," she said. "You don't have to find extra time to eat because it's already in your schedule. So the focus is more on substituting the right kinds of food to eat."

But, she said, finding time for exercise if you already have a busy schedule can be challenging. She pointed out that even the most successful group, those receiving the two behavioral health programs simultaneously, lagged behind in meeting the physical activity goal at first, though over the course of a year were eventually able to meet it.

King credits the way health educators explained the dietary and exercise advice to participants for their overall success and the study's high retention rate. They met with participants in person just once at the beginning of the one-year period. After that, they called once a month, spending as little as 10 to 15 minutes -- and no more than 40 minutes -- providing advice and support for diet and exercise.

For the participants, whose schedules and stressful lives had previously interfered with making healthy lifestyle choices, this approach worked, King said. She said that telephoning participants was a convenient and flexible way to provide personalized information. "These health behaviors aren't things that we change over a six-week period and then our job is done," she said. "They're things that people grapple with their whole lives, so to develop 'touches' of advice and support in a cost-efficient way is becoming more and more important."

Participants in this study were not actively trying to lose weight, just trying to develop healthy habits. King's next step is to test the same sequential-versus-simultaneous approaches among people who are trying to lose weight.

Other Stanford authors of the study include senior research scholar Cynthia Castro, PhD; statistical analyst David Ahn, PhD; and former postdoctoral scholars Matthew Buman, PhD, and Eric Hekler, PhD, (who are both now at Arizona State University) and Guido Urizar, PhD (now at Cal State Long Beach).

The study was supported by the National Institute on Aging (grant R01AG21010) and the National Heart, Lung and Blood Institute (grant 5T32HL007034).

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Story Source:

The above story is reprinted from materials provided by Stanford University Medical Center. The original article was written by Rina Shaikh-Lesko.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

---

Journal Reference:

1. King AC et al. Behavioral Impacts of Sequentially versus Simultaneously Delivered Dietary Plus Physical Activity Interventions: the CALM Trial. Annals of Behavioral Medicine, 2013 DOI: 10.1007/s12160-013-9501-y

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/living_well/~3/gooWPdOXUec/130422101300.htm

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New research constructs ant family tree

Monday, April 22, 2013

Anyone who has spent time in the tropics knows that the diversity of species found there is astounding and the abundance and diversity of ants, in particular, is unparalleled. Scientists have grappled for centuries to understand why the tropics are home to more species of all kinds than the cooler temperate latitudes on both sides of the equator. Several hypotheses have been proposed to explain the higher species numbers in the tropics, but these hypotheses have never been tested for the ants, which are one of the most ecologically and numerically dominant groups of animals on the planet.

New research by evolutionary biologists Dr. Corrie Moreau of Chicago's Field Museum and Dr. Charles Bell of the University of New Orleans is helping answer these questions. Their findings are presented this week in the journal Evolution.

The scientists used DNA sequence data to build the largest ant tree-of-life to date. This tree-of-life, or family tree of ants, not only allowed them to better understand which ant species are related, but also made it possible to infer the age for modern ants because information from the fossil record in the form of geologic time was included in the research.

This ant tree-of-life confirmed an earlier surprising finding that two groups of pale, eyeless, subterranean ants, which are unlike most typical ants, are the earliest living ancestors of the modern ants. The time calibrated ant tree-of-life showed that the ants found on the planet today can trace their evolutionary origins back to between 139 and158 million years ago ? during the time the dinosaurs walked the Earth (a finding in line with previous studies).

But why are there more species of ants in the tropics? To explain this pattern of higher species diversity for many tropical organisms, biologists have used the analogies of the tropics acting as a "museum" or "cradle" for speciation. In the case of the museum analogy, the tropical climates have more species because this is where the oldest groups persist throughout evolutionary time. The converse of this explanation is that the tropics are a cradle where new species are more likely to be generated.

To better understand where on the planet the ants arose and if any single geographic area was more important for their evolutionary origins, Moreau and Bell reconstructed the biogeographic history of the ants. These analyses found that the Neotropics of South America were vital to the deep and continued evolutionary origin of the ants. This finding suggests that for the ants the rainforests of the Neotropics are both a museum, protecting many of the oldest ant groups, and also a cradle that continues to generate new species.

As ants are one of the most ecologically important groups of terrestrial organisms, these findings suggest that protecting the rainforests of the Neotropics are vital to the health and success of both the ants that live in them and all the other animals, plants, fungi, and microbes worldwide that rely on ants to survive.

###

Field Museum: http://www.fieldmuseum.org

Thanks to Field Museum for this article.

This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.

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Source: http://www.labspaces.net/127846/New_research_constructs_ant_family_tree

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Napolitano to talk immigration before Senate panel

WASHINGTON (AP) ? Republican senators skeptical of new immigration legislation and of the Obama administration's record on border security are getting a chance to question Homeland Security Secretary Janet Napolitano (neh-pahl-ih-TAN'-oh).

Napolitano was appearing Tuesday before the Senate Judiciary Committee at its third hearing on a bipartisan immigration bill that aims to strengthen border security, improve legal immigration and create a path to citizenship for some 11 million people here illegally.

She originally was scheduled to appear last Friday but that was canceled because of the Boston Marathon bombings.

Napolitano's appearance comes after a daylong hearing Monday that exposed deep divisions on the immigration bill, with Republicans arguing it does too little on border security and some also saying the measure should be re-examined in light of the events in Boston.

Source: http://news.yahoo.com/napolitano-talk-immigration-senate-panel-071732773--politics.html

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Microsoft CFO to leave; profit, shares rise

By Bill Rigby

SEATTLE (Reuters) - Microsoft Corp Chief Financial Officer Peter Klein is leaving at the end of June after 3-1/2 years in the post, as the world's biggest software company struggles with sharply declining personal computer sales and a lukewarm reception for the new Windows 8 operating system.

The 11-year Microsoft veteran becomes the latest in a line of top-level executives to leave the company, following Windows head Steven Sinofsky last November. Some have questioned whether Chief Executive Steve Ballmer is still the right leader for Microsoft, whose shares have remained essentially flat for the last decade.

Microsoft said a new CFO would be named in the next few weeks from within its ranks.

"The CFO departure is a little bit troubling," said Brendan Barnicle, an analyst at Pacific Crest Securities. "We've had a lot of executives leaving Microsoft recently. This also makes a departure by Steve Ballmer less likely. It would be very unusual to have a CEO leave soon after a CFO departure."

Microsoft shares rose 1.5 percent in after-hours trading after the company posted an 18 percent climb in revenue and earnings well ahead of Wall Street expectations - a seemingly strong performance for a quarter with the worst decline in PC sales on record.

But excluding revenue "deferred" from previous quarters, the flagship Windows unit showed zero growth, disappointing investors hoping for a stronger showing from the new Windows 8 system.

HIGH HOPES

Many in the industry had hoped the arrival of Microsoft's touch-friendly Windows 8 software might give the shrinking PC market a shot in the arm. But industry analysts have since noted that the unfamiliarity of the 'tile'-based interface and the paucity of competitive-priced gadgets turned off consumers.

This week, Intel Corp forecast its current-quarter revenue would decline as much as 8 percent as personal computer sales continue to slide in favor of tablets and smartphones, though it expects sales in general to improve in the second half as more polished ultra-thin laptops and other tablet devices based on Windows hit the market.

On Thursday, Microsoft reported a profit of $6 billion, or 72 cents per share, in the fiscal third quarter, up from $5.1 billion, or 60 cents per share, in the year-ago quarter. That beat Wall Street's average estimate of 68 cents, according to Thomson Reuters I/B/E/S.

But analysts have been pegging back profit forecasts for Microsoft in the light of flagging PC sales. As recently as April 5 the average analyst estimate was 76 cents.

Profit was boosted by some deferred revenue from its Windows, Office and video game operations, but cut severely by a $733 million fine by European antitrust regulators for breaking promises relating to expanding the choice of Internet browsers on Windows.

Overall, sales rose to $20.5 billion from $17.4 billion a year ago, in line with analysts' estimates.

"There's nothing in the report that's going to make the stock break out of the range that it's been in," said Colin Gillis, an analyst at BGC. "The stock's trading at $29.11 - what we were at 11 years ago."

(Additional reporting by Alistair Barr and Malathi Nayak in San Francisco; Editing by Edwin Chan, Richard Chang)

Source: http://news.yahoo.com/microsoft-cfo-exits-profit-rises-201121288--finance.html

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Letter to Obama tests positive (CNN)

Share With Friends: | | Politics - Top Stories Stories, RSS and RSS Feed via Feedzilla.

Source: http://news.feedzilla.com/en_us/stories/politics/top-stories/299959992?client_source=feed&format=rss

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