Tag Archives: brown university

Researchers Make Living Model of Brain Tumor

By Guest PostFebruary 20, 2012Science3 d characteristics, 3 d model, 3d glioma model, agarose hydrogel mold, anti therapeutic agent, aruna sigdel, blood vessel, brain tumor, brown university, chenjie xu, concept, diameter, diffusion, don ho, endothelial cell, glioma, iron oxide nanoparticles, jeffrey morgan, magnetic resonance imaging, microns, microtissues, nanocarrier, nathan kohler, petri dish, raghu kalluri, rat, rg2 cell gliomas, richard lewis, shouheng sun, tissue culture, tissue model, tumstatin

*Researchers have created a living 3-D model of a brain tumor and its surrounding blood vessels. In experiments, the scientists report that iron-oxide nanoparticles carrying the agent tumstatin were taken by blood vessels, meaning they should block blood vessel growth. The living-tissue model could be used to test the effectiveness of nanoparticles in fighting other diseases. Results appear in Theranostics.*

PROVIDENCE, R.I. [Brown University] — Brown University scientists have created the first three-dimensional living tissue model, complete with surrounding blood vessels, to analyze the effectiveness of therapeutics to combat brain tumors. The 3-D model gives medical researchers more and better information than Petri dish tissue cultures.

The researchers created a glioma, or brain tumor, and the network of blood vessels that surrounds it. In a series of experiments, the team showed that iron-oxide nanoparticles ferrying the chemical tumstatin penetrated the blood vessels that sustain the tumor with oxygen and nutrients. The iron-oxide nanoparticles are important, because they are readily taken up by endothelial cells and can be tracked by magnetic resonance imaging. (more…)

‘Explorers’ Use Uncertainty And Specific Area of Brain

By Guest PostFebruary 11, 2012Scienceambiguity, architecture, bradley doll, brain, brown university, cognitive control, computational power, data, david badre, decision making strategy, explorers, function, functional architecture, mathematical model, michael frank, mri scanner, mystery, nicole long, nonexplorers, rostrolateral prefrontal cortex, status quo, thought process, uncertainty, virtual clock

*As they try to find the best reward among options, some people explore based on how uncertain they are about the outcome of the options. Those who employ that thought process, unlike people who use other strategies, uniquely harness the computational power of the rostrolateral prefrontal cortex, a new study finds.*

PROVIDENCE, R.I. [Brown University] — Life shrouds most choices in mystery. Some people inch toward a comfortable enough spot and stick close to that rewarding status quo. Out to dinner, they order the usual. Others consider their options systematically or randomly. But many choose to grapple with the uncertainty head on. “Explorers” order the special because they aren’t sure they’ll like it. It’s a strategy of maximizing rewards by discovering whether as yet unexplored options might yield better returns. In a new study, Brown University researchers show that such explorers use a specific part of their brain to calculate the relative uncertainty of their choices, while non-explorers do not. (more…)

Lecture or Listen: When Patients Waver on Meds

By Guest PostFebruary 5, 2012Healthadherence, aids and behavior, antiretroviral therapy, arv drugs, arv medication, Baltimore, brown university, detroit, hiv-positive, m barton laws, mary catherine beach, new york city, patient, portland, william rogers, yoojin lee

*According to a new analysis of hundreds of recorded office visits, doctors and nurse practitioners typically issued orders and asked closed or leading questions when talking to their HIV-positive patients about adherence to antiretroviral therapy. Attempts at problem-solving with patients who had lapsed occurred in less than a quarter of visits.*

PROVIDENCE, R.I. [Brown University] — Take your medicine, Doctor’s orders. It’s a simple idea that may seem especially obvious when the pills are the antiretroviral (ARV) drugs that add decades to the lives of HIV-positive patients. But despite the reality that keeping up with drug regimens is not easy for many patients, a new analysis of hundreds of recorded doctor’s office visits finds that physicians and nurse practitioners often still rely on lecturing, ordering, and scolding rather than listening and problem solving with their patients. (more…)

In Lab, Pannexin1 Restores Tight Binding of Cells Lost in Cancer

By Guest PostJanuary 31, 2012Health, Science3d petri dish, 3d system, accelerating effect, actin, biomechanical role, brain tumor, brian bao, brown university, c6, cancerous cell, carbenoxolone, charles lai, christian naus, drug, glioma, gross multicellular behavior, jeffrey morgan, mechanical integrity, molecule atp, pannexin1, probenecid, protein, rat, receptor, scaffold free, Technology, tissue, tumor cell

*By studying tumor cell behavior in a novel “scaffold-free” 3-D system, researchers have determined that the protein Pannexin1 may play an important biomechanical role in binding tissues together, an effect that is lost in cancerous cells.*

PROVIDENCE, R.I. [Brown University] — First there is the tumor and then there’s the horrible question of whether the cancerous cells will spread. Scientists increasingly believe that the structural properties of the tumor itself, such as how tightly the tumor cells are packed together, play a decisive role in the progression of the disease. In a new study, researchers show that the protein Pannexin1, known to have tumor-suppressive properties, plays an important role in keeping the cells within a tissue closely packed together, an effect that may be lost with cancer.

“In healthy tissues, the recently discovered protein Pannexin1 may be playing an important role in upholding the mechanical integrity of the tissue,” said first author and Brown University M.D./Ph.D. student Brian Bao. “When we develop cancer, we lose Pannexin1 and we lose this integrity.” (more…)

Biochip Measures Glucose in Saliva, Not Blood

By Guest PostJanuary 22, 2012Sciencealec roelke, americans, biochip, biological device, blood, brown university, chip, convergence, diabetics, domenico pacifici, environmental substances, glucose concentration, glucose levels, grooves, human hair, human saliva, interaction of electrons, interference, jing feng, light, light intensity, maxima and minima, measure, microfluidic channels, milligrams per deciliter, Nanotechnology, ocean waves, photons, plasmonic interferometers, steve rhieu, surface plasmon polariton, surface plasmon waves, surface plasmonics, tayhas palmore, vihang mehta, vince siu, wavelength

*Engineers at Brown University have designed a biological device that can measure glucose concentrations in human saliva. The technique could eliminate the need for diabetics to draw blood to check their glucose levels. The biochip uses plasmonic interferometers and could be used to measure a range of biological and environmental substances. Results are published in Nano Letters.*

PROVIDENCE, R.I. [Brown University] — For the 26 million Americans with diabetes, drawing blood is the most prevalent way to check glucose levels. It is invasive and at least minimally painful. Researchers at Brown University are working on a new sensor that can check blood sugar levels by measuring glucose concentrations in saliva instead.

The technique takes advantage of a convergence of nanotechnology and surface plasmonics, which explores the interaction of electrons and photons (light). The engineers at Brown etched thousands of plasmonic interferometers onto a fingernail-size biochip and measured the concentration of glucose molecules in water on the chip. Their results showed that the specially designed biochip could detect glucose levels similar to the levels found in human saliva. Glucose in human saliva is typically about 100 times less concentrated than in the blood. (more…)

North American Mammal Evolution Tracks with Climate Change

By Guest PostJanuary 1, 2012Environment, Nature, Science65 million years, anthropogenic climatic change, borja figueirido, brown university, changes in climate, christine janis, climate changes, deep sea microorganisms, diversity, early middle eocene fauna, early miocene epoch, evolutionary biologists, evolutionary faunas, fossil record, future climactic changes, global paleotemperatures, herbivores, history, immigration events, jack sepkoski, juan perez claros, levels of atmospheric oxygen, life on earth, mammal species, miocene fauna, natural history, North America, paleocene fauna, paleontologist, paul palmqvist, potential connection, quantitative analysis, rise and fall, savannah, six waves of species diversity, species migrations, university of chicago, vegetation, warming and cooling periods, waves, woodland

*Climate changes profoundly influenced the rise and fall of six distinct, successive waves of mammal species diversity in North America over the last 65 million years, shows a novel statistical analysis led by Brown University evolutionary biologists. Warming and cooling periods, in two cases confounded by species migrations, marked the transition from one dominant grouping to the next.*

PROVIDENCE, R.I. [Brown University] — History often seems to happen in waves — fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity or “evolutionary faunas.” What force of history determined the destiny of these groupings? The numbers say it was typically climate change.

“Although we’ve always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion,” said Christine Janis, professor of evolutionary biology at Brown University. “We show that the rise and fall of these faunas is indeed correlated with climatic change — the rise or fall of global paleotemperatures — and also influenced by other more local perturbations such as immigration events.” (more…)

Novel Device Removes Heavy Metals From Water

By Guest PostDecember 18, 2011Environmentacid, base, brown university, cadmium, cathodic particles, cation concentration, cations, cep system, charged metal ions, concentration, copper, cyclic electrowinning precipitation, electrochemical reduction, electroextraction, engineers, environmental contaminant, environmental remediation, genie in the bottle, george hradil, heavy metal ions, hydroxides, joseph calo, landfills, metal recovery, metal removal technique, method, nickel, parts per million, pengpeng grimshaw, ph, ppm, reduction of heavy metal ions, release of heavy metals, remove, sodium hydroxide, spe, spouted particulate electrode, sulfides, sulfuric acid, technic inc, textile factories, toxic sludge, trace heavy metals, unhealthy byproduct, water, waterways, zero valent metal

*Engineers at Brown University have developed a system that cleanly and efficiently removes trace heavy metals from water. In experiments, the researchers showed the system reduced cadmium, copper, and nickel concentrations, returning contaminated water to near or below federally acceptable standards. The technique is scalable and has viable commercial applications, especially in the environmental remediation and metal recovery fields. Results appear in the Chemical Engineering Journal.*

PROVIDENCE, R.I. [Brown University] — An unfortunate consequence of many industrial and manufacturing practices, from textile factories to metalworking operations, is the release of heavy metals in waterways. Those metals can remain for decades, even centuries, in low but still dangerous concentrations.

Ridding water of trace metals “is really hard to do,” said Joseph Calo, professor emeritus of engineering who maintains an active laboratory at Brown. He noted the cost, inefficiency, and time needed for such efforts. “It’s like trying to put the genie back in the bottle.” (more…)

Chinese Health Coverage Improves With Government Efforts

By Guest PostDecember 11, 2011Economy, Generalbrown university, China, chinese government, chinese provinces, government interventions, health care, health care coverage, health care in china, health insurance, hongwei xu, policy interventions, population, rates, reimbursement rates, rural areas, rural chinese, susan e short, university of michigan, villages

*A new study of health insurance in nine Chinese provinces shows that individual coverage surged within a two-year time frame, from 2004-2006, coinciding with new government interventions designed to improve access to health care. The changes were most dramatic in rural areas.*

PROVIDENCE, R.I. [Brown University] — Health care coverage increased dramatically in parts of China between 1997 and 2006, a period when government interventions were implemented to improve access to health care, with particularly striking upswings in rural areas, according to new research by Brown University sociologist Susan E. Short and Hongwei Xu of the University of Michigan. The findings appear in the December issue of Health Affairs.

Led by Xu, a former Brown graduate student, the study analyzed data from the China Health and Nutrition Survey, which follows households in nine provinces that are home to more than 40 percent of China’s population. Xu and Short specifically focused on patterns of coverage among rural and urban residents. (more…)