Human stem cells help regenerate liver function in mice

ANI | Jul 28, 2013, 04.51 PM IST
READ MORE Stem Cells|liver function in mice|human stem cells
Human stem cells help regenerate liver function in mice
WASHINGTON: Researchers transplanted derived functional hepatocytes from human stem cells into mice suffering from acute liver injury, and found that these liver cells functioned normally and raised survival of the treated animals.

Massoud Vosough and co-authors demonstrate a large-scale, integrated manufacturing strategy for generating functional hepatocytes in a single suspension culture grown in a scalable stirred bioreactor.

In the article 'Generation of Functional Hepatocyte-Like Cells from Human Pluripotent stem cells in a Scalable Suspension Culture' the authors describe the method used for scale-up, differentiation of the pluripotent stem cells into liver cells, and characterization and purification of the hepatocytes based on their physiological properties and the expression of liver cell biomarkers.

David C Hay, MRC Centre for Regenerative Medicine, University of Edinburgh, UK, comments on the importance of Vosough and others' contribution to the scientific literature in his editorial in Stem Cells and Development entitled 'Rapid and Scalable Human Stem Cell Differentiation: Now in 3D.'

The researchers 'developed a system for mass manufacture of stem cell derived hepatocytes in numbers that would be useful for clinical application,' creating possibilities for future 'immune matched cell based therapies,' Hays said.

Such approaches could be used to correct mutated genes in stem cell populations prior to differentiation and transplantation, he adds.

The findings have been published in Stem Cells and Development.
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E-psychiatry software to treat patients in remote, disaster-hit areas

, TNN | Jul 27, 2013, 03.58 AM IST
READ MORE Tata Consultancy Services|diabetes|PGIMER|ICMR
CHANDIGARH: Following Uttarakhand-like disasters, where it is sometimes not possible to reach the interiors and provide timely psychological assistance, an e-psychiatry software, jointly developed by PGIMER and Tata Consultancy Services (TCS), is all set to take off at the primary hospitals in remote regions of Bilaspur (Himachal), Srinagar (J&K) and Uttarakhand.

Gradually this will expand to other regions of the country. "After successfully passing a three-year field trial in these remote areas, the software has been developed to detect, diagnose and treat mental disorders, which even a non-medico can use," said Savita Malhotra, main investigator of the project at the department of psychiatry, PGIMER.

The project has been funded by the department of science and technology, and the Indian Council of Medical Research ( ICMR). Using the e-psychiatry, total 1,000 patients have been already assessed to check the reliability factor.

The software can be used as a diagnostic and treatment tool by social workers (non-medicos), who can assess the mental disease using a set of validated questionnaires fed into the software. The technology also generates a database of patients' history and alerts the user if there is a case of diabetes or hypertension or pregnancy.

The software includes comprehensive management of 18 psychiatric disorders each in adults, children and adolescents. Explaining about how the tool works, Malhotra said, "Questions are asked from the patient. These questions are fed into the software. After the screening questionnaire is answered, only those modules open for which the patient seems likely to suffer from. For instance, if its schizophrenia, modules which have symptoms close to this disease will open. Finally, after a few responses, which are automated, the diagnosis is confirmed."

Once the disease is diagnosed, treatment is generated on the basis of assessment and few scales, which the software responds to. "Currently, the application is at the secondary level health care. We are now working on to make it useful for primary level health care. Gradually, it will be incorporated in the mobile phones and used by the households," said Malhotra.

According to the WHO, 65 persons per 1,000 suffer from mental disorders. For every one lakh patients there are only 0.2 psychiatrists in India.
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Scientists produce false memories in mice

TNN | Jul 26, 2013, 02.51 PM IST
READ MORE Scientists produce false memories|Professor Susumu Tonegawa|false memories in mice
Scientists produce false memories in mice
The study also provides further evidence that memories are stored in networks of neurons that form memory traces for each experience we have.
WASHINGTON: Scientists have pulled off the plot of Inception — with mice!

Researchers have successfully implanted false memories of an event that never actually took place into a mice brain, showing it is possible to create inaccurate recollections of the past.
Massachusetts Institute of Technology (MIT) scientists have shown that they can plant false memories in the brains of mice.

They also found that many of the neurological traces of these memories are identical in nature to those of authentic memories.

"Whether it's a false or genuine memory, the brain's neural mechanism underlying the recall of the memory is the same," said Professor Susumu Tonegawa, senior author of the paper published in journal Science.

The study also provides further evidence that memories are stored in networks of neurons that form memory traces for each experience we have — a phenomenon that Tonegawa's lab first demonstrated last year.

Neuroscientists have long sought the location of these memory traces, also called engrams. In the pair of studies, Tonegawa and colleagues showed that they could identify the cells that make up part of an engram for a specific memory and reactivate it using a technology called optogenetics.

Episodic memories — memories of experiences — are made of associations of several elements, including objects, space and time. These associations are encoded by chemical and physical changes in neurons, as well as by modifications to the connections between the neurons.

Where these engrams reside in the brain has been a longstanding question in neuroscience.

Tonegawa's lab turned to optogenetics, a new technology that allows cells to be selectively turned on or off using light.

The researchers engineered mouse hippocampal cells to express the gene for channelrhodopsin, a protein that activates neurons when stimulated by light.

They also modified the gene so that channelrhodopsin would be produced whenever the c-fos gene, necessary for memory formation, was turned on.

In last year's study, the researchers conditioned these mice to fear a particular chamber by delivering a mild electric shock.

As this memory was formed, the c-fos gene was turned on, along with the engineered channelrhodopsin gene. This way, cells encoding the memory trace were "labelled" with light-sensitive proteins, researchers said.

The next day, when the mice were put in a different chamber they had never seen before, they behaved normally.

However, when the researchers delivered a pulse of light to the hippocampus, stimulating the memory cells labelled with channelrhodopsin, the mice froze in fear as the previous day's memory was reactivated.
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