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Archives for : febbraio2014

Genetically modified purple tomatoes heading for shops

See on Scoop.itCuriosopernatura

The prospect of genetically modified (GM) purple tomatoes reaching the shelves has come a step closer. Their dark pigment is intended to give tomatoes the same potential health benefits as fruit such as blueberries.

 

Developed in Britain, large-scale production is now under way in Canada with the first 1,200 liters of purple tomato juice ready for shipping. The pigment, known as anthocyanin, is an antioxidant which studies on animals show could help fight cancer.

Scientists say the new tomatoes could improve the nutritional value of everything from ketchup to pizza topping. The tomatoes were developed at the John Innes Centre in Norwich where Prof Cathie Martin hopes the first delivery of large quantities of juice will allow researchers to investigate its potential.

“With these purple tomatoes you can get the same compounds that are present in blueberries and cranberries that give them their health benefits – but you can apply them to foods that people actually eat in significant amounts and are reasonably affordable,” she said.

 

The tomatoes are part of a new generation of GM plants designed to appeal to consumers – the first types were aimed specifically at farmers as new tools in agriculture. The purple pigment is the result of the transfer of a gene from a snapdragon plant – the modification triggers a process within the tomato plant allowing the anthocyanin to develop.

 

Although the invention is British, Prof Martin says European Union restrictions on GM encouraged her to look abroad to develop the technology. Canadian regulations are seen as more supportive of GM and that led to a deal with an Ontario company, New Energy Farms, which is now producing enough purple tomatoes in a 465 square meter (5,000sq ft) greenhouse to make 2,000 liters (440 gallons) of juice. The first 1,200 liters are due to be shipped to Norwich shortly – and because all the seeds will have been removed, there is no genetic material to risk any contamination.


See on www.bbc.co.uk

Chemical imaging brings cancer tissue analysis into the digital age

See on Scoop.itAmazing Science

Imperial College London researchers have developed a new method for analyzing biological samples based on their chemical makeup that could transform the way medical scientists examine diseased tissue.

When tests are carried out on a patient’s tissue today, such as looking for cancer, the test has to be interpreted by a histology specialist, which can take weeks to get a full result.

Scientists have proposed using mass spectrometry imaging (MSI), which uses technologies that reveal how hundreds or thousands of chemical components are distributed in a tissue sample. But currently proposed MSI workflows are subject to several limitations, including nonoptimized raw data preprocessing, imprecise image coregistration, and limited pattern recognition capabilities.

In PNAS, the Imperial College London researchers have now outlined a comprehensive new strategy for effectively processing MSI data and building a database of tissue types. In MSI, a beam moves across the surface of a sample, producing a pixelated image. Each pixel contains data on thousands of chemicals present in that part of the sample. By analyzing many samples and comparing them to the results of traditional histological analysis, a computer can learn to identify different types of tissue.


A single test taking a few hours can provide much more detailed information than standard histological tests, for example showing not just if a tissue is cancerous, what the type and sub-type of cancer, which can be important for choosing the best treatment. The technology can also be applied in research to offer new insights into cancer biology.

According to Kirill Veselkov, M.D., corresponding author of the study from the Department of Surgery and Cancer at Imperial College London, “MSI is an extremely promising technology, but the analysis required to provide information that doctors or scientists can interpret easily is very complex. This work overcomes some of the obstacles to translating MSI’s potential into the clinic. It’s the first step towards creating the next generation of fully automated histological analysis.”

The technology will also be useful in drug development. To study where a new drug is absorbed in the body, pharmaceutical scientists attach a radioactive label to the drug molecule, then look at where the radiation can be detected in a laboratory animal. If the label is detached when the drug is processed in the body, it is impossible to determine how and where the drug has been metabolized. MSI would allow researchers to look for the drug and any metabolic products in the body, without using radioactive labels.


See on www.kurzweilai.net

H1N-What? Wading Through the Alphabet Soup of Flu Virus Names

See on Scoop.itVirology News


Muddled about all the new flu viruses?

It’s hard to keep up with the changing names in the news. H1Nwhat? Bird flu. Pig flu. MERS. SARS. Here …


Ed Rybicki‘s insight:

Great post on flu.


See on blogs.scientificamerican.com

Retina cells 3D printed for the first time

See on Scoop.itAmazing Science

The ability to arrange cells into highly defined patterns and structures has recently elevated the use of 3D printing in the biomedical sciences to create cell-based structures for use in regenerative medicine.


A group of researchers from the UK have used 3-D biomedical printing to successfully print new eye cells, making it the first time the technology has been used successfully to print mature central nervous system cells. The breakthrough could lead to the production of artificial tissue grafts made from the variety of cells found in the human retina and may aid in the search to cure blindness.


Experts at the University of Cambridge printed two types of cells – ganglion cells and glial cells – derived from adult rat retinas. Ganglion cells transmit information from the eye to parts of the brain, while glial cells provide support and protection for neurons.


Co-authors of the study Professor Keith Martin and Dr Barbara Lorber, from the John van Geest Centre for Brain Repair, University of Cambridge, said: “The loss of nerve cells in the retina is a feature of many blinding eye diseases. The retina is an exquisitely organised structure where the precise arrangement of cells in relation to one another is critical for effective visual function”.


In their study, the researchers used a single nozzle piezoelectric inkjet printer that ejected the cells through a sub-millimetre diameter nozzle when a specific electrical pulse was applied. The driving waveform was defined by a PC-driven generator. “We plan to extend this study to print other cells of the retina and to investigate if light-sensitive photoreceptors can be successfully printed using inkjet technology. In addition, we would like to further develop our printing process to be suitable for commercial, multi-nozzle print heads,” Professor Martin concluded. His goal is to make living tissues using multiple nozzles so that different types of cells could be printed from different nozzles at the same time.


The study has been detailed in a paper published in Biofabrication.



See on www.imaginethat-3d.com

Black Death Left a Mark on Human Genome

See on Scoop.itCuriosopernatura

There have been multiple plagues throughout history around the world, but none have been so deadly as the Black Death, which killed an estimated one in every four Europeans, and so exerted very strong selection. The Black Death didn’t just wipe out millions of Europeans during the 14th century. It left a mark on the human genome, favoring those who carried certain immune system genes, according to a new study. Those changes may help explain why Europeans respond differently from other people to some diseases and have different susceptibilities to autoimmune disorders.

Geneticists know that human populations evolve in the face of disease. Certain versions of our genes help us fight infections better than others, and people who carry those genes tend to have more children than those who don’t. So the beneficial genetic versions persist, while other versions tend to disappear as those carrying them die. This weeding-out of all but the best genes is called positive selection. But researchers have trouble pinpointing positively selected genes in humans, as many genes vary from one individual to the next.

Genetically, the Rroma gypsies in Romania are still quite similar to the northwestern Indians, even though they have lived side by side with the Romanians for a millennium, the team found. But there were 20 genes in the Rroma and the Romanians that had changes that were not seen in the Indians’ versions of those genes, Netea and his colleagues report online today in the Proceedings of the National Academy of Sciences. These genes “were positively selected for in the Romanians and in the gypsies but not in the Indians,” Netea explains. “It’s a very strong signal.”

Those genes included one for skin pigmentation, one involved in inflammation, and one associated with susceptibility to autoimmune diseases such as rheumatoid arthritis. But the ones Netea and Bertranpetit were most excited about were a cluster of three immune system genes found on chromosome 4. These genes code for toll-like receptors, proteins which latch on to harmful bacteria in the body and launch a defensive response. “We knew they must be important for host defense,” Netea says.

 

What events in history might have favored these versions of the genes in gypsies and Romanians, but not in Indians? Netea and his colleagues tested the ability of the toll-like receptors to react to Yersinia pestis, the bacterium that caused the Black Death. They found that the strength of the immune response varied depending on the exact sequence of the toll-like receptor genes.

Netea and Bertranpetit propose that the Rroma and European Romanians came to have the same versions of these immune system genes because of the evolutionary pressure exerted by Y. pestis. Other Europeans, whose ancestors also faced and survived the Black Death, carried similar changes in the toll-like receptor genes. But people from China and Africa—two other places the Black Death did not reach—did not have these changes. The similarities in the other genes were likely caused by other conditions experienced by Rroma and Europeans, but not Indians.


See on news.sciencemag.org

Plant pest destruction goes viral

See on Scoop.itVirology News


Fusion of a viral coat protein to an insect-specific neurotoxin delivers the molecule into aphids where it is insecticidal.


See on www.nature.com

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