anonymous asked:

I've always asked myself why wizards don't use the reparo-spell for basically everything. It's like the most useful spell ever! The healers at St. Mungo's could all be replaced by some wizards who know their reparo, because if it can repair a broken pair of glasses, it should also be able to repair human cells, right? right?

I looked this up for you, anon:

“The Mending Charm was effective at repairing most materials. However, damage caused by certain rare, powerful curses was impossible to undo. […] The charm was suitable for use only on inanimate objects. Use on living beings was entirely proscribed. Serious scarring could result if it were cast on a person or animal in an attempt to heal wounds. […] This charm does not seem to work on objects of powerful and complex magic, such as Vanishing Cabinets and wands.” - x

So sadly, it’s not quite as easy. ^^

3D-printed human cells could “replace animal testing”

3D-printed human cells could replace the need for animal testing of new drugs within five years, according to a pioneering bio-printing expert at the 3D Printshow in London.

“It lends itself strongly to replace animal testing,” said bioengineering PhD student Alan Faulkner-Jones of Heriot Watt University in Edinburgh. “If it gets to be as accurate as it should be, there would be no need to test on animals.”

Can You Smell Yourself?

You might not be able to pick your fingerprint out of an inky lineup, but your brain knows what you smell like. For the first time, scientists have shown that people recognize their own scent based on their particular combination of major histocompatibility complex (MHC) proteins, molecules similar to those used by animals to choose their mates. The discovery suggests that humans can also exploit the molecules to differentiate between people.

“This is definitely new and exciting,” says Frank Zufall, a neurobiologist at Saarland University’s School of Medicine in Homburg, Germany, who was not involved in the work. “This type of experiment had never been done on humans before.”

MHC peptides are found on the surface of almost all cells in the human body, helping inform the immune system that the cells are ours. Because a given combination of MHC peptides—called an MHC type—is unique to a person, they can help the body recognize invading pathogens and foreign cells. Over the past 2 decades, scientists have discovered that the molecules also foster communication between animals, including mice and fish. Stickleback fish, for example, choose mates with different MHC types than their own. Then, in 1995, researchers conducted the now famous “sweaty T-shirt study,” which concluded that women prefer the smell of men who have different MHC genes than themselves. But no studies had shown a clear-cut physiological response to MHC proteins.

In the new work, Thomas Boehm, a biologist at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, Germany, and colleagues first tested whether women can recognize lab-made MHC proteins resembling their own. After showering, 22 women applied two different solutions to their armpits and decided which odor they liked better. The experiment was repeated two to six times for each participant. Women preferred to wear a synthetic scent containing their own MHC proteins, but only if they were nonsmokers and didn’t have a cold. The study did not determine which scents women preferred on other people, but past studies on perfume have shown that individuals prefer different smells on themselves than on others.

The researchers wanted to know whether the preferences were truly rooted in the brain’s response to the proteins. So next, they used functional magnetic resonance imaging to measure changes in the brains of 19 different women when they smelled the various solutions, in aerosol form puffed toward their noses. “Sure enough, there again was a clear difference between the response to self and non-self peptides,” Boehm says. “There was a particular region of the brain that was only activated by peptides resembling a person’s own MHC molecules.” The brain had a similar response to all non-self MHC combinations, suggesting that any preference for how other people smell is a preference for non-self, not for particular MHC types.

(Image: Getty)

Human Cells have Electric Fields as Powerful as Lighting Bolts

Human Cells have Electric Fields as Powerful as Lighting Bolts

Using newly developed voltage-sensitive nanoparticles, researchers have found that the previously unknown electric fields inside of cells are as strong, or stronger, as those produced in lightning bolts. Previously, it has only been possible to measure electric fields across cell membranes, not within the main bulk of cells, so scientists didn’t even know cells had an internal electric field.…

View On WordPress

Listening to Cells: Scientists probe human cells with high-frequency sound

Sound waves are widely used in medical imaging, such as when doctors take an ultrasound of a developing fetus. Now scientists have developed a way to use sound to probe tissue on a much tinier scale. Researchers from the University of Bordeaux in France deployed high-frequency sound waves to test the stiffness and viscosity of the nuclei of individual human cells. The scientists predict that the probe could eventually help answer questions such as how cells adhere to medical implants and why healthy cells turn cancerous.

“We have developed a new non-contact, non-invasive tool to measure the mechanical properties of cells at the sub-cell scale,” says Bertrand Audoin, a professor in the mechanics laboratory at the University of Bordeaux. “This can be useful to follow cell activity or identify cell disease.” The work will be presented at the 57th Annual Meeting of the Biophysical Society (BPS), held Feb. 2-6, 2013, in Philadelphia, Pa.

The technique that the research team used, called picosecond ultrasonics, was initially applied in the electronics industry in the mid-1980s as a way to measure the thickness of semiconductor chip layers. Audoin and his colleagues, in collaboration with a research group in biomaterials led by Marie-Christine Durrieu from the Institute of Chemistry & Biology of Membranes & Nano-objects at Bordeaux University, adapted picosecond ultrasonics to study living cells. They grew cells on a metal plate and then flashed the cell-metal interface with an ultra-short laser pulse to generate high-frequency sound waves. Another laser measured how the sound pulse propagated through the cells, giving the scientists clues about the mechanical properties of the individual cell components.

“The higher the frequency of sound you create, the smaller the wavelength, which means the smaller the objects you can probe” says Audoin. “We use gigahertz waves, so we can probe objects on the order of a hundred nanometers.” For comparison, a cell’s nucleus is about 10,000 nanometers wide.

The team faced challenges in applying picosecond ultrasonics to study biological systems. One challenge was the fluid-like material properties of the cell. “The light scattering process we use to detect the mechanical properties of the cell is much weaker than for solids,” says Audoin. “We had to improve the signal to noise ratio without using a high-powered laser that would damage the cell.” The team also faced the challenge of natural cell variation. “If you probe silicon, you do it once and it’s finished,” says Audoin. “If you probe the nucleus you have to do it hundreds of times and look at the statistics.”

The team developed methods to overcome these challenges by testing their techniques on polymer capsules and plant cells before moving on to human cells. In the coming years the team envisions studying cancer cells with sound. “A cancerous tissue is stiffer than a healthy tissue,” notes Audoin. “If you can measure the rigidity of the cells while you provide different drugs, you can test if you are able to stop the cancer at the cell scale.”

(Photo: Image courtesy of UCSD Jacobs)

Scientists solve decades-old cell biology puzzle

Researchers at EMBL Heidelberg have solved a question that has puzzled cell biologists for decades – how does the protein machine that allows cells to swallow up molecules during endocytosis function?

In the first model, the clathrin lattice, or coat, first assembles as a flat structure, and then bends, essentially wrapping around the forming vesicle. In the second model, scientists suggest that clathrin assembles directly, assuming the shape of the membrane as it is drawn inwards.

Although the second model has been more generally accepted, a new paper published today in Science, shows that, in fact, the first explanation is more accurate. In their experiments, the team at EMBL Heidelberg used human cell lines in which the sites where endocytosis was taking place had been tagged with a fluorescent marker.EMBL post-doctoral researcher, Ori Avinoam, then used 3D electron microscopy to take pictures of these sites and analysed them to understand how they changed shape over time.

By analysing the images computationally, the research team was able to demonstrate that the surface area of the clathrin coat does not change during endocytosis, only its curvature changes as it draws the cell membrane inwards.

More information: “Endocytic sites mature by continuous bending and remodeling of the clathrin coat” Science 19 June 2015:  Vol. 348 no. 6241 pp. 1369-1372 DOI: 10.1126/science.aaa9555

Clathrin proteins involved in endocytosis form a lattice that can dramatically change its shape to form the vesicle. Credit: Ori Avinoam/EMBL      

VIDEO: Fully functioning artificial neuron uses organic bioelectronics to act like human nerve cell

Scientists at Sweden’s Karolinska Institutet have managed to build a fully functional neuron by using organic bioelectronics. This artificial neuron contain no ‘living’ parts, but is capable of mimicking the function of a human nerve cell and communicate in the same way as our own neurons do.

Neurons are isolated from each other and communicate with the help of chemical signals, commonly called neurotransmitters or signal substances.


Ref:  An organic electronic biomimetic neuron enables auto-regulated neuromodulation.  Biosensors and Bioelectronics (September 2015) | DOI:10.1016/j.bios.2015.04.058

Segregation, Science and $

This book is on my daughter’s university reading list–she is studying nursing–and when she told me a bit about it, I downloaded the audio format from my library.  I doubt that I would have discovered this book otherwise.  It’s the true story of a 1950s African American female cancer patient whose cells are still alive in labs around the world, whose cells were used to test the polio vaccine, to gain information about gene mapping, viruses and cloning, whose cells are bought and sold and have made perhaps millions of dollars. Yet Henrietta Lacks is buried in an unmarked grave near the house where she was born, former slave quarters in Lackstown, Virginia.  And her surviving family cannot afford health care.  

Rebeca Skloot’s detective skills provide details that make both the lab and the home vivid and real to the reader.  We learn about the Johns Hopkins ward for “negroes” where Henrietta received treatment for cancer and where cervical tissue was removed from her, later to gain immortality. We learn about Dr. Gey’s innovative and ultimately successful efforts to design a culture that would enable human cells to stay alive as well as how to transport them via air, train and U.S. mail. Unwittingly, he pioneered processes, equipment and protocols that would pave the way for the hugely profitable bio-medical corporations that exist today. We learn about the physical and sexual abuse Henrietta’s children received after her death at the hands of yet another “cousin”.

Most poignant for me were the conversations with Henrietta’s daughter, Deborah.  Questions about the mother she couldn’t remember–Deborah was 4 when her mother died–what she was like, what happened to her eldest daughter Elsie, and why nobody told them about the “immortal cells”, bring Henrietta Lacks’ story back to the scale of a single human.

Cell biology, virology, medical practices of the early 1950s, segregation, poverty,tobacco farming, slave owning, Turners Station (one of the first African-American communities in Baltimore County) are some of the topics this book explores. It is an important book on so many levels. I am grateful to Rebecca Skloot for telling this story, so relevant to our time, with objectivity and skill.

9 out of 10.