human-cells

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The Effects of Alcohol on Spiders: What Happens to Web Construction After Spiders Consume Alcohol?
Victor E. Cross

Spiders tended to spin the new webs more quickly after vodka consumption as well as to rip holes in the webs.It is concluded that the alcohol affected not only the ability of the spider to spin the species’ characteristic web, but also that the speed of construction affected the precision of the rays and cells.

In humans, alcohol causes relaxation, lowered inhibitions, loss of body control, and reduced muscular coordination.

The webs spun by the spiders after vodka consumption were asymmetrical, had fewer support rays, fewer cells, and the cells that were present were larger and irregularly spaced. Additionally, spiders were observed tearing large holes in their webs and also clasping each other (presumably mating).

The similarity of behaviors leads to the conclusion that the orb weaver spiders are affected by vodka in many of the same ways that humans are affected.

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)

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)

First almost fully-formed human brain grown in lab

An almost fully-formed human brain has been grown in a lab for the first time, claim scientists from Ohio State University. The team behind the feat hope the brain could transform our understanding of neurological disease.

Though not conscious the miniature brain, which resembles that of a five-week-old foetus, could potentially be useful for scientists who want to study the progression of developmental diseases. It could also be used to test drugs for conditions such as Alzheimer’s and Parkinson’s, since the regions they affect are in place during an early stage of brain development.

The brain, which is about the size of a pencil eraser, is engineered from adult human skin cells and is the most complete human brain model yet developed, claimed Rene Anand of Ohio State University, Columbus, who presented the work today at the Military Health System Research Symposium in Fort Lauderdale, Florida.

Previous attempts at growing whole brains have at best achieved mini-organs that resemble those of nine-week-old foetuses, although these “cerebral organoids” were not complete and only contained certain aspects of the brain. “We have grown the entire brain from the get-go,” said Anand.

Anand and his colleagues claim to have reproduced 99% of the brain’s diverse cell types and genes. They say their brain also contains a spinal cord, signalling circuitry and even a retina.

The ethical concerns were non-existent, said Anand. “We don’t have any sensory stimuli entering the brain. This brain is not thinking in any way.”

Anand claims to have created the brain by converting adult skin cells into pluripotent cells: stem cells that can be programmed to become any tissue in the body. These were then grown in a specialised environment that persuaded the stem cells to grow into all the different components of the brain and central nervous system.

According to Anand, it takes about 12 weeks to create a brain that resembles the maturity of a five-week-old foetus. To go further would require a network of blood vessels that the team cannot yet produce. “We’d need an artificial heart to help the brain grow further in development,” said Anand.

Several researchers said it was hard to judge the quality of the work without access to more data, which Anand is keeping under wraps due to a pending patent on the technique. Many were uncomfortable that the team had released information to the press without the science having gone through peer review.

Zameel Cader, a consultant neurologist at the John Radcliffe Hospital, Oxford, said that while the work sounds very exciting, it’s not yet possible to judge its impact. “When someone makes such an extraordinary claim as this, you have to be cautious until they are willing to reveal their data.”

If the team’s claims prove true, the technique could revolutionise personalised medicine. “If you have an inherited disease, for example, you could give us a sample of skin cells, we could make a brain and then ask what’s going on,” said Anand.

You could also test the effect of different environmental toxins on the growing brain, he added. “We can look at the expression of every gene in the human genome at every step of the development process and see how they change with different toxins. Maybe then we’ll be able to say ‘holy cow, this one isn’t good for you.’”

For now, the team say they are focusing on using the brain for military research, to understand the effect of post traumatic stress disorder and traumatic brain injuries.

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Image:  The tiny brain, which resembles that of a five-week-old foetus, is not conscious. Ohio State University

Human Cells have Electric Fields as Powerful as Lighting Bolts

Human Cells have Electric Fields as Powerful as Lighting Bolts

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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.…

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Segregation, Science and $

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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.

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Virus.