Posts tagged medicine
Articles and news from the latest research reports.
John Rogers of the University of Illinois at Urbana-Champaign and colleagues have designed a flexible circuit that can be worn over the fingertips. It contains layers of gold electrodes just a few hundred nanometres thick, sandwiched between layers of polyimide plastic to form a “nanomembrane”. This is mounted on a finger-shaped tube of silicone rubber, allowing one side of the circuit to be in direct contact with the fingertips. On the other side, sensors can be added to measure pressure, temperature or electrical properties such as resistance.
People wearing the device receive electrotactile stimulation – a tingling sensation caused by a small voltage applied to the skin. The size of the voltage is controlled by the sensor and varies depending on the properties of the object being touched.
Surgical gloves are one potential application. Rogers, who worked with colleagues at Northwestern University in Evanston, Illinois, and Dalian University of Technology in China, says gloves fitted with the nanomembrane could sense the thickness or composition of tissue via its electrical properties. A surgeon could also whittle away at the tissue using a high-frequency alternating current supplied by a battery attached at the wrist and delivered via the nanomembrane itself, says Rogers.
Can bacteria fight brain cancer?
The thinking behind an approach that has caused trouble in California.
Last week, the Sacramento Bee reported that two neurosurgeons at the University of California, Davis, had been banned from research on humans after deliberately infecting three terminally ill cancer patients with pathogenic bacteria in an attempt to treat them. All three died, two showing complications from the infection. Nature explores what happened and the science behind it.
Building a human on a chip, organ by organ
Human “organs on chips” could be linked to make the ideal guinea pig, revolutionising the way drugs are tested and cancer is treated
Such organs on chips can be used to model how human organs function and respond to drugs, says Ingber. He thinks that they even have the potential to eliminate the use of animals in drug testing. “Animal testing is expensive and time-consuming, and animals are not always representative of humans.”
Still, Ingber points out that the chips can perform some roles that animal studies cannot. For instance, they could be personalised by building them from an individual’s own cells. In theory, a doctor could send tissue samples to a lab to test a potentially harmful therapy on such a chip before handing out a prescription. This would be especially useful for people with cancer, as the various therapies available can have very different effects on different people, Ingber says. “You could get a quick yes-or-no answer to whether a drug would work or not,” he says.
Personalised chips might also speed up clinical trials. “Someday it might be possible to shortcut clinical trials by using chips containing cells from different human populations that are known to respond differently to specific drug classes,” Ingber says.
Californian biotech firm Life Technologies is the first team to register for the $10 million (£6.4m) Archon Genomics X Prize, which will be a race to sequence the genomes of 100 centenarians.
The prize was first announced in 2006, and is a joint effort between the X Prize Foundation and geneticist J Craig Venter. It’s supposed to stimulate the development of less expensive sequencing technologies, and establish a clinical standard for DNA research.
Interested parties have until May 2013 to register. Late that year, in September, each team will have 30 days to sequence the genomes of 100 people, at a cost of $1,000 (£643) or less.
The DNA has been donated by 100 100 year old people from all over the world, to make the competition “scientifically valuable and more meaningful to the general public”. That way, the prize can double up as medical research into the science of healthy aging and longevity.
Life Technologies’ secret weapon is the Ion Proton Sequencer, which it describes as a “semiconductor device that enables chemical signals to be directly translated into digital information for the first time” — a bit like the CMOS imager in an iPhone, which turns photons into electrons.
"It would have cost $100 million and taken 33 years to meet this challenge when the competition was announced in 2006," said Jonathan Rothberg, CEO and founder of Life Technology’s Ion Torrent brand. "The Ion Proton sequencer is designed to sequence a human genome for $1,000 in just a few hours."
Source: Wired
New epilepsy gene identified; possible new treatment option
ScienceDaily (July 23, 2012) — New research conducted by neuroscientists from the Royal College of Surgeons in Ireland (RCSI) published in Nature Medicine has identified a new gene involved in epilepsy and could potentially provide a new treatment option for patients with epilepsy.
The research focussed on a new class of gene called a ‘microRNA’ which controls protein production inside cells. The research looked in detail at one particular microRNA called ‘microRNA-134’ and found that levels of microRNA-134 are much higher in the part of the brain that causes seizures in patients with epilepsy.
By using a new type of drug-like molecule called an antagomir which locks onto the ‘microRNA-134’ and removes it from the brain cell, the researchers found they could prevent epileptic seizures from occurring.
Professor David Henshall, Department of Physiology & Medical Physics, RCSI and senior author on the paper said ‘We have been looking to find what goes wrong inside brain cells to trigger epilepsy. Our research has discovered a completely new gene linked to epilepsy and it shows how we can target this gene using drug-like molecules to reduce the brain’s susceptibility to seizures and the frequency in which they occur.”
Dr Eva Jimenez-Mateos, Department of Physiology & Medical Physics, RCSI and first author on the paper said “Our research found that the antagomir drug protects the brain cells from toxic effects of prolonged seizures and the effects of the treatment can last up to one month.”
Epilepsy affects 37,000 in Ireland alone. For every two out of three people with epilepsy their seizures are controlled by medication, but one in three patients continues to have seizures despite being prescribed medication. This study could potentially offer new treatment methods for patients.
The research was supported by a grant from Science Foundation Ireland (SFI). Researchers in the Department of Physiology & Medical Physics and Molecular & Cellular Therapeutics, RCSI, clinicians at Beaumont Hospital and experts in brain structure from the Cajal Institute in Madrid were involved in the study.
Source: Science Daily
Researchers identify mechanisms that allow embryonic stem cells to become any cell in the human body
July 18, 2012
(Phys.org) — New research at the Hebrew University of Jerusalem sheds light on pluripotency—the ability of embryonic stem cells to renew themselves indefinitely and to differentiate into all types of mature cells. Solving this problem, which is a major challenge in modern biology, could expedite the use of embryonic stem cells in cell therapy and regenerative medicine. If scientists can replicate the mechanisms that make pluripotency possible, they could create cells in the laboratory which could be implanted in humans to cure diseases characterized by cell death, such as Alzheimer’s, Parkinson’s, diabetes and other degenerative diseases.
To shed light on these processes, researchers in the lab of Dr. Eran Meshorer, in the Department of Genetics at the Hebrew University’s Alexander Silberman Institute of Life Sciences, are combining molecular, microscopic and genomic approaches. Meshorer’s team is focusing on epigenetic pathways—which cause biological changes without a corresponding change in the DNA sequence—that are specific to embryonic stem cells.
The molecular basis for epigenetic mechanisms is chromatin, which is comprised of a cell’s DNA and structural and regulatory proteins. In groundbreaking research performed by Shai Melcer, a PhD student in the Meshorer lab, the mechanisms which support an “open” chromatin conformation in embryonic stem cells were examined. The researchers found that chromatin is less condensed in embryonic stem cells, allowing them the flexibility or “functional plasticity” to turn into any kind of cell.
A distinct pattern of chemical modifications of chromatin structural proteins (referred to as the acetylation and methylation of histones) enables a looser chromatin configuration in embryonic stem cells. During the early stages of differentiation, this pattern changes to facilitate chromatin compaction.
But even more interestingly, the authors found that a nuclear lamina protein, lamin A, is also a part of the secret. In all differentiated cell types, lamin A binds compacted domains of chromatin and anchors them to the cell’s nuclear envelope. Lamin A is absent from embryonic stem cells and this may enable the freer, more dynamic chromatin state in the cell nucleus. The authors believe that chromatin plasticity is tantamount to functional plasticity since chromatin is made up of DNA that includes all genes and codes for all proteins in any living cell. Understanding the mechanisms that regulate chromatin function will enable intelligent manipulations of embryonic stem cells in the future.
"If we can apply this new understanding about the mechanisms that give embryonic stem cells their plasticity, then we can increase or decrease the dynamics of the proteins that bind DNA and thereby increase or decrease the cells’ differentiation potential," concludes Dr. Meshorer. “This could expedite the use of embryonic stem cells in cell therapy and regenerative medicine, by enabling the creation of cells in the laboratory which could be implanted in humans to cure diseases characterized by cell death, such as Alzheimer’s, Parkinson’s, diabetes and other degenerative diseases.”
Source: PHYS.ORG