New cause of osteoporosis: Mutation in a miroRNA

 New cause of osteoporosis: Mutation in a miroRNA

del.icio.us Tags: DNA,osteoperosis,miroRNA

Science News

New Cause of Osteoporosis: Mutation in a miroRNA

ScienceDaily (Nov. 20, 2009) — Many biological processes are controlled by small molecules known as microRNAs, which work by suppressing the expression of specific sets of genes. Xiang-Hang Luo and colleagues, at Second Xiangya Hospital of Central South University, People's Republic of China, have now identified a previously unknown microRNA (miR-2861) as crucial to bone maintenance in mice and humans.

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Of clinical importance, expression of functional miR-2861 was absent in two related adolescents with primary osteoporosis.

Several lines of evidence determined the key role of miR-2861 in maintaining bone. First, miR-2861 promoted the in vitro development of a mouse stromal cell line into the cells responsible for bone formation. Second, in mice, in vivo silencing of miR-2861 inhibited bone formation and decreased bone mass. Last, analysis of ten patients with primary osteoporosis revealed two related adolescents in whom disease was caused by a mutation in the miR-2861 precursor (pre-miR-2861) that blocked expression of miR-2861.

These data led the authors to conclude that miR-2861 has an important role in controlling the generation of the cells responsible for bone formation and that defects in the processing of its precursor can cause osteoporosis.

The research appears in the Journal of Clinical Investigation.

New cause of osteoporosis: Mutation in a miroRNA

Small nanoparticles bring big improvement to medical imaging

Small nanoparticles bring big improvement to medical imaging

del.icio.us Tags: medical*imaging,cell*growth,nanoparticles

November 18, 2009 04:30 PM
Biotechnology
Previous article: Scientists unravel evolution of highly toxic box
If you're watching the complex processes in a living cell, it is easy to miss something important—especially if you are watching changes that take a long time to unfold and require high-spatial-resolution imaging. But new research* makes it possible to scrutinize activities that occur over hours or even days inside cells, potentially solving many of the mysteries associated with molecular-scale events occurring in these tiny living things.


A joint research team, working at the National Institute of Standards and Technology (NIST) and the National Institute of Allergy and Infectious Diseases (NIAID), has discovered a method of using nanoparticles to illuminate the cellular interior to reveal these slow processes. Nanoparticles, thousands of times smaller than a cell, have a variety of applications. One type of nanoparticle called a quantum dot glows when exposed to light. These semiconductor particles can be coated with organic materials, which are tailored to be attracted to specific proteins within the part of a cell a scientist wishes to examine.
"Quantum dots last longer than many organic dyes and fluorescent proteins that we previously used to illuminate the interiors of cells," says biophysicist Jeeseong Hwang, who led the team on the NIST side. "They also have the advantage of monitoring changes in cellular processes while most high-resolution techniques like electron microscopy only provide images of cellular processes frozen at one moment. Using quantum dots, we can now elucidate cellular processes involving the dynamic motions of proteins."
For their recent study, the team focused primarily on characterizing quantum dot properties, contrasting them with other imaging techniques. In one example, they employed quantum dots designed to target a specific type of human red blood cell protein that forms part of a network structure in the cell's inner membrane. When these proteins cluster together in a healthy cell, the network provides mechanical flexibility to the cell so it can squeeze through narrow capillaries and other tight spaces. But when the cell gets infected with the malaria parasite, the structure of the network protein changes.
"Because the clustering mechanism is not well understood, we decided to examine it with the dots," says NIAID biophysist Fuyuki Tokumasu. "We thought if we could develop a technique to visualize the clustering, we could learn something about the progress of a malaria infection, which has several distinct developmental stages."
The team's efforts revealed that as the membrane proteins bunch up, the quantum dots attached to them are induced to cluster themselves and glow more brightly, permitting scientists to watch as the clustering of proteins progresses. More broadly, the team found that when quantum dots attach themselves to other nanomaterials, the dots' optical properties change in unique ways in each case. They also found evidence that quantum dot optical properties are altered as the nanoscale environment changes, offering greater possibility of using quantum dots to sense the local biochemical environment inside cells.
"Some concerns remain over toxicity and other properties," Hwang says, "but altogether, our findings indicate that quantum dots could be a valuable tool to investigate dynamic cellular processes."
Small nanoparticles bring big improvement to medical imaging

Tongue Vision - Research on sensory substitution and brain plasticity

Tongue Vision - Research on sensory substitution and brain plasticity

del.icio.us Tags: tongue,sensory*perception,blind

Neuropsychology: The blind can walk thanks to an eye on the tongue

published in Forum Express
12 décembre 2007
'The only limits with this device are the ones set by the researcher': Daniel Chebat
“It’s the first time I make my way across a cluttered course of several meters without the help of my cane,” explains 35-year-old M.L. who has been blind since birth. He accomplished this thanks to a device mounted on his tongue, which creates a mental image of the space around him.

Tongue Vision - Research on sensory substitution and brain plasticity

New Computer Simulator Helps Design Military Strategies Based On Ants' Movements

New Computer Simulator Helps Design Military Strategies Based On Ants' Movements

del.icio.us Tags: Ants,Army,Strategy,troops,movement

New Computer Simulator Helps Design Military Strategies Based On Ants' Movements

ScienceDaily (Nov. 7, 2009) — A researcher at the University of Granada has designed a new system for the mobility of military troops within a battlefield based on the mechanisms used by ant colonies to move using a commercial video game.

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Matter & Energy

• Virtual Environment
• Weapons Technology

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Science & Society

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Reference

• Computer simulation
• User interface design
• Military aviation
• Cyber security standards

This work, developed at the department of Computer Architecture and Technology of the UGR, has designed several algorithms that permit to look for the best route path (this is, to find the better route to satisfy certain criteria) within a particular environment.
Specifically, this research work has developed a software that would allow the army troops to define the best path within a military battle field, considering that such path will be covered by a company and this must consider the security criteria (reaching their destination with the lower number of casualties) and speed (reaching their destination as quickly as possible).
To that end, the scientists have used the so called 'ant colony optimization algorithm (ACO)', a probabilistic technique used to solve optimization problems and inspired in the behaviors of ants to find trajectories from the colony to the food.

New Computer Simulator Helps Design Military Strategies Based On Ants' Movements