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Thursday, May 5, 2016

Human Embryo Implantation Model in Lab Dish

Scientists based at The Rockefeller University have created an experimental system that models the implantation of a human embryo. The new system, an adaptation of one used to recapitulate the implantation of a mouse embryo, provides an attachment substrate, surrounds the blastocyst with just the right chemical environment, and provides scaffolding that accommodates the morphological movements that are particular to human embryos. For example, a human blastocyst undergoing implantation assumes a disk-like shape, whereas the mouse blastocyst is oblong.


The in vitro system has been used to show molecular and cellular processes in human development that occur up to day 14 after fertilization. The system, which has experimentally replicated implantation outside of the uterus for the first time, promises to expand scientists’ ability to answer basic questions about our own development, as well as to understand early pregnancy loss.

Details of the work appeared May 4 in the journal Nature, in an article entitled, “Self-Organization of theIn Vitro Attached Human Embryo.” The article paid particular attention to postimplantation development of the human embryo, a process that remains mysterious.



Source: genengnews

The mechanisms and functions of spontaneous neurotransmitter release

Fast synaptic communication in the brain requires synchronous vesicle fusion that is evoked by action potential-induced Ca2+ influx. However, synaptic terminals also release neurotransmitters by spontaneous vesicle fusion, which is independent of presynaptic action potentials. A functional role for spontaneous neurotransmitter release events in the regulation of synaptic plasticity and homeostasis, as well as the regulation of certain behaviours, has been reported. In addition, there is evidence that the presynaptic mechanisms underlying spontaneous release of neurotransmitters and their postsynaptic targets are segregated from those of evoked neurotransmission. These findings challenge current assumptions about neuronal signalling and neurotransmission, as they indicate that spontaneous neurotransmission has an autonomous role in interneuronal communication that is distinct from that of evoked release.

Key points
  • Synaptic terminals can release neurotransmitter by spontaneous vesicle fusion that is independent of presynaptic action potentials.
  • The traditional view of spontaneous neurotransmitter release suggests that spontaneous events occur randomly in the absence of stimuli owing to low-probability conformational changes in the vesicle fusion machinery.
  • Recent studies have identified key distinctions between the synaptic vesicle fusion machineries that perform spontaneous versus evoked neurotransmitter release.
  • In mammalian hippocampal synapses and at the Drosophila melanogaster neuromuscular junction, spontaneous and evoked neurotransmitter release events show some spatial segregation and activate distinct populations of postsynaptic receptors.
  • Segregation of spontaneous neurotransmission enables selective neuromodulation that is independent of evoked release.
  • In mammalian hippocampal synapses and at the D. melanogaster neuromuscular junction, spontaneous release events activate specific postsynaptic signal transduction cascades that maintain synaptic efficacy or regulate structural plasticity and synaptic development.
  • Novel strategies that selectively target spontaneous release events are needed to address whether spontaneous release can signal independently during ongoing activity in intact neuronal circuits.
  • Introduction
Introduction
Our current insights into the mechanisms underlying synaptic transmission originate from experiments that were conducted in the 1950s by Bernard Katz and colleagues. A key aspect of these studies was the discovery of spontaneous neurotransmitter release events, which seemed to occur in discrete 'quantal' packets. This fundamental observation enabled the complex and seemingly intractable nature of action potential-evoked neurotransmission to be analyzed and understood on the basis of its unitary components. Although the original work solely relied on electrophysiological analysis, later studies that used electron microscopy provided visual validation of the hypothesis that neurotransmission occurs through fusion of discrete synaptic vesicles that contain neurotransmitters with the presynaptic plasma membrane.


Figure 3: Segregation of spontaneous and evoked neurotransmission.

Vitamin D Could Repair Nerve Damage in Multiple Sclerosis

A protein activated by vitamin D could be involved in repairing damage to myelin in people with multiple sclerosis (MS), according to new research from the University of Cambridge. The study, published today in the Journal of Cell Biology, offers significant evidence that vitamin D could be a possible treatment for MS in the future.

Researchers, from the MS Society Cambridge Centre for Myelin Repair, identified that the ‘vitamin D receptor’ protein pairs with an existing protein, called the RXR gamma receptor, already known to be involved in the repair of myelin, the protective sheath surrounding nerve fibres.

By adding vitamin D to brain stem cells where the proteins were present, they found the production rate of oligodendrocytes (myelin making cells) increased by 80%. When they blocked the vitamin D receptor to stop it from working, the RXR gamma protein alone was unable to stimulate the production of oligodendrocytes.


Neuron with oligodendrocyte and myelin sheath (edited)

Wednesday, May 4, 2016

Neurodegenerative disease damage reversed in fruit flies

Alzheimer's and Parkinson's symptoms have been reversed in fruit flies following treatment with a drug-like chemical, says research published in the Proceedings of the National Academy of Sciences.

The discovery, which centers around the protection of brain cells, could be a turning point in the fight against neurodegenerative disease, say the authors.

Neurodegenerative diseases occur when groups of nerve cells in the brain die, making it difficult for a person to move and to think.

According to Claire Bale, of Parkinson's UK, the symptoms of Parkinson's tend not to appear until 70 percent of nerve cells in the brain have already been lost.

Unfortunately, current treatments are only able to tackle the symptoms of the condition - they cannot slow or stop the degeneration of these cells.


Scientists are making progressing in techniques to protect nerve cells.

New gene testing method can identify mutations, prioritize variants in breast and ovarian cancer genes

A research team led by an award-winning genomicist at Western University has developed a new method for identifying mutations and prioritizing variants in breast and ovarian cancer genes, which will not only reduce the number of possible variants for doctors to investigate, but also increase the number of patients that are properly diagnosed.

These potentially game-changing technologies, developed by Peter Rogan, PhD, students and his collaborators from Western's Schulich School of Medicine & Dentistry, reveal gene variants that were missed by conventional genetic testing.

Their method, described in BMC Medical Genomics, was first applied to 102 individuals at risk or with a diagnosis of inherited breast cancer. The team also studied 287 women with no known mutations for an article published in Human Mutation.

Rogan, Canada Research Chair in Genome Bioinformatics, says that 16 to 20 per cent of women in southwestern Ontario, who have their BRCA genes tested for breast and/or ovarian cancer risk, carry disease-causing gene variants that are well-understood by clinicians and genetic counselors. If a patient tests positive for an abnormal BRCA1 or BRCA2 gene and have never had breast cancer, there is a much higher-than-average risk of developing the deadly disease.


Source: azonano

A novel device claims to be an 'off switch' for painful menstruation.

It’s estimated that nine out of 10 women suffer from period pain each month, and an unfortunate 10 percent of those will get it so bad, they could be incapacitated for up to three days. 

Other than using contraceptives to skip their period altogether (just like astronauts do), menstruating women have precious few options to beat this thing and get on with their lives. Some over-the-counter pain-killers and a strategically placed hot water bottle is about it.

But there’s another option behind secret door #3, and early reports are saying this thing actually works. Dubbed Livia, this new medical device claims to be an"off switch for menstrual pain".

Okay, so first thing’s first: how does this supposed 'miracle cure' actually work? 

As the Livia website explains, the device comes with two electrodes, which you need to place on the painful areas on your abdomen. Switch the device on, and these electrodes will start delivering imperceptible electric pulses to your nerves, which will settle the pain.



Source: sciencealert

Fasting no longer necessary before cholesterol test

For the first time, a team of international experts recommends that most people do not need to fast before having their cholesterol and triglyceride levels tested.

Fasting is a problem for many patients, they explain, and note the latest research shows that cholesterol and triglyceride levels are similar whether people fast or not.

The experts represent the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) joint consensus initiative.

They refer to new research from Denmark, Canada, and the United States that included over 300,000 people and found it is not necessary to have an empty stomach to check cholesterol levels.

Apart from Denmark, all countries require that patients fast for at least 8 hours before checking their cholesterol and triglyceride levels - referred to as "lipid profile." In Denmark, non-fasting blood sampling has been in use since 2009.


Researchers say fasting before a cholesterol test is unnecessary.

We could be close enough to the stem cell revolution!

Stem cell therapy has been in use for many years, but with only limited reach. As such the oft bandied stem cell revolution has still yet to arrive. Steve Buckwell and Chris Coe explain why this is set to change and why now is the perfect time for its potential to be achieved. 

The stem cell revolution as it’s often referred to is now already in its third decade. But like the paper free office, is it just one of those envisaged futures that never seem to really happen? Embryonic stem cells were first isolated 18 years ago, but stem cell therapies have been slowed by high production costs, batch-to-batch variability and limited seed material. But we still believe the revolution will kick off some time in the second half of this decade. This is why.

Firstly the early ethical issues have, in many cases been overcome, with adult stem cells showing promise in the clinic but not requiring the embryo exploitation and destruction that made embryonic stem cell research so controversial in the years after 1998. Secondly, there is now substantial mid-stage clinical evidence that stem cells work in areas of unmet medical need, much of which has only become evident in the last five years.

There are various stem cell products in development that work allogeneically, meaning that the patient receives stem cells sourced from someone else’s body. As a general rule, allogeneic therapies are quite cost effective because they have the potential to be ‘off-the-shelf’, whereas autologous therapies (use of the patient’s own cells) can be considerably more expensive.



Source: labnews

Tuesday, May 3, 2016

Novel test can detect any virus

Scientists have designed a test that can detect not only any known virus type and subtype but also virus outbreaks.

A research team led by the Washington University School of Medicine in St Louis (WUSTL) condensed nearly 1 billion base pairs of viral DNA sequences to create a test that they call ViroCap.

“With this test, you don’t have to know what you’re looking for. It casts a broad net and can efficiently detect viruses that are present at very low levels. We think the test will be especially useful in situations where a diagnosis remains elusive after standard testing or in situations in which the cause of a disease outbreak is unknown,” said research associate Professor Gregory Storch.

To develop the test, the researchers targeted unique stretches of DNA or RNA from every known group of viruses that infects vertebrates – including 2 million unique stretches of genetic material. The stretches of material were used as probes which can pluck out viruses from a sample and find a genetic match. The matched viral material was then analyzed by high-throughput genetic sequencing.


New test can detect any virus that infects vertebrates
Source: labnews

Insights on the Growing Fingerprint Challenge

Although some fingerprint analysis is new, the concept—using fingerprints for identification—started centuries ago.

The Future of Identifying People Will Require More Than One Method

Standing in the immigration line at the Indira Gandhi International Airport in Delhi, India, I watch person after person be fingerprinted. First, you put your left four fingers on a digital pad, then your right four, and finally both thumbs at once. If all goes smoothly, the Indian government collects all ten fingerprints for everyone entering the country. It’s not as easy as it sounds, even from the start. More than one person is asked to try again and again. So obtaining a print can be as difficult as analyzing one.

Although some fingerprint analysis is new, the concept— using fingerprints for identification—started centuries ago. Thousands of years ago in Babylon, a fingerprint served as a signature of sorts on business papers. Finally, in 1880, British surgeon Henry Faulds described using fingerprints to identify people; he gets credit for the first use of this technology of lifting a print from an alcohol bottle.



Source: labmanager
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