Stories tagged Cells
CT scan showing malignant mesothelioma tumor: a new drug is showing promise against several types of cancer.Courtesy Stevenfruitsmaak via Wikimedia CommonsWhen a cancer cell (a tumor) appears in a particular organ or area of a body, it somehow signals the body's immune system to back off and leave it alone. This allows the cancerous tumor to grow and eventually metastasize to the lymph nodes and other parts of the body. It's as if the cancer grants itself a sort of diplomatic immunity against the body's natural antibodies from interfering with its destructive undertakings.
Now, researchers have found a drug that switches off this "don't touch" warning and allows the cancer to be diminished or entirely destroyed. And it works for several types of cancers, including those affecting the brain, liver, colon, breast, ovary and prostate.
A protein called CD47 is present in human blood cells and prevents those cells from being attacked by the body's immune system. The protein attaches to the surface of the blood cells and signals to the immune system that the blood cells are "okay" and shouldn't be destroyed. About ten years ago, biologist Irving Weissman and researchers at Stanford University's School of Medicine noticed higher levels (up to 3x more) of the same "don't touch" protein were present in leukemia cells, a blood disorder. The surprised Weissman realized that the blood cancer was co-opting the body's own defense system to work against itself, thereby stopping any attacks on the cancer. This left the cancer unmolested and able to grow and spread. After further testing, Weissman and his colleagues subsequently discovered that CD47 levels in many other cancers were also higher than levels in normal cells.
"What we've shown is that CD47 isn't just important on leukemias and lymphomas, it's on every single human primary tumor that we tested.“
The Weissman lab has now developed a promising drug that switches off this "don't touch" signal in cancer cells giving the body's immune system the green light to go after them. The drug has been tested in the laboratory using petri dishes containing treated and untreated cancer molecules. Immune cells (macrophages) were present in each sample. In the untreated sample, the macrophages ignored the cancerous molecules, while they readily attacked those treated with the anti-CD47 drug. In later tests, a variety of human cancer tumors were placed into lab mice and left to grow for two weeks. After the tumors grabbed hold, they were treated with the anti-CD47 therapy and the tumors shrunk considerably or disappeared altogether.
"The microenvironment of a real tumor is quite a bit more complicated than the microenvironment of a transplanted tumor," Weissman said, "and it's possible that a real tumor has additional immune suppressing effects."
The biologist is confident that the research will eventually move into human clinical trials within the next two years.
SOURCES and LINKS
Sciencemag.org
Stanford news
Nature World News
What are antibodies
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Doubling up the double helix: The newly discovered quadruple helix in human DNA could lead to new treatments in cancer.Courtesy rijksbandradio (original image) via Flckr; graphic by author.By now most readers are aware of the double helix, the two intertwined ribbons of genetic information that make up our DNA.
Now researchers at University of Cambridge have announced the discovery of a quadruple helix in the human genome. The four-stranded genetic ribbons are termed G-quadruplexes because they contain high levels of the nucleotide guanine (the other 3 nucleotides are adenine, thymine, and cytosine – together they make up the G, A, T, and C elements of DNA; uracil (U) replaces thymine in RNA). G-quadruplexes mainly appear at the moment of cell replication, when cells divide and multiply. Researchers think this indicates that G-quadruplexes are an essential part of the replication process. The upsurge of G-quadrupleexes was detected using fluorescent biomarkers. The discovery could open up new avenues in the treatment of cancer
"The research indicates that quadruplexes are more likely to occur in genes of cells that are rapidly dividing, such as cancer cells,” said Shankar Balasubramanian, the study’s lead researcher. “For us, it strongly supports a new paradigm to be investigated -- using these four-stranded structures as targets for personalised treatments in the future."
Balasubramanian, a professor at the Department of Chemistry and Cambridge Research Institute, thinks synthetic molecules could one day be used to corral the G-quadruplexes and hinder the out-of-control cell division often prevalent in cancerous cells. In fact, the research team has already been successful in slowing down the replication process by using such molecules. During their experiments, when cell division was blocked, the number of G-quadruplexes decreased.
The research was published in Nature Chemistry. The 'quadruple helix' discovery comes 60 years after the discovery of the double helix in 1953, also at the University of Cambridge.
SOURCES and LINKS
Wired
Science Daily
Sniffing Out Cancer: Amherst chemists develop a way to "smell" cancer cells.Courtesy Jeremie63Chemists from the University of Massachusetts Amherst have developed a way to quickly and accurately detect and identify metastatic cancer cells in living tissue, in much the same way that your nose can detect and identify certain odors.
The smell of a rose, for example, is a unique pattern of molecules, which activates a certain set of receptors in your nose. When these specific receptors are triggered, your brain immediately recognizes it as a rose.
Similarly, each type of cancer has a unique pattern to the proteins that make up its cells. The Amherst chemists just needed a "nose" to recognize these patterns. What they came up with was an array of gold nanoparticle sensors, coupled with green fluorescent proteins (GFP). The researchers took healthy tissue and tumor samples from mice, and trained the nanoparticle-GFP sensors to recognize the bad cells, and for the GFP to fluoresce in the presence of metastatic tissues.
This method is really sensitive to subtle differences, it's quick (can detect cancer cells within minutes), it can differentiate between types of cancers, and is minimally invasive. The researchers haven't tested this method on human tissue samples yet, but it holds some exciting potential.
Vision evolution: The compound eye of a 390 million-year-old trilobite, Phacops rana milleri.Courtesy Striving to a goalSomewhere, deep in the recesses of animal evolution, a mass of molecules known as opsin mutated from a run-of-the-mill protein into a detector protein with great vision. Not vision in the figurative way, but vision in the literal way. Opsin is the protein in the photopigments of your eye that interacts with light, and allows you to see all the wonderful things visible in the universe. If you’re reading this post, you have the opsins in your eyes to thank.
Here’s how it works. When a particle or wave of light (a photon) enters your eye, the light sensitive opsin traps it using a small chromophore molecule in it architecture called retinal. Normally, retinal’s tail is all twisted and bent, tensed up, and waiting for something to happen. That’s just the way retinal is when it’s chilling out. But when a photon hits it, the light particle interrupts retinal’s naptime, and the molecule reacts by straightening out its tail. The tail’s movement starts a chain reaction of sorts activating the opsin, which in turn, activates a nearby nerve that shoots out a signal that your brain perceives as light.
Three types of opsin can exist in the eye: R-opsins (rhabdomeric), C-opsins (ciliary, and Go/RGR-opsins (Go-coupled/retinal G protein-coupled receptor). The R and C opsins, depending what type of animal you are (e.g. vertebrate or jellyfish), are used for detecting light. Go/RGR-opsins don’t detect light but are used instead to help regenerate retinal cells and regulate an animal’s inner clock or biological rhythms. Scientists have known about opsins since the 19th century, but haven’t known much on how they evolved, or how they became designated light detectors.
In a recent study published in the journal PNAS, Roberto Feuda of the Department of Biology, National University of Ireland Maynooth, and colleagues reported on their detailed examination of the genetic trail of opsins in all kinds of animal life, from sponges and jellyfish to reptiles, birds and mammals. And while their results warrant further study, they did add new knowledge to our understanding how the eye evolved.
The study negated a long-held idea among scientists that only certain light-designated opsins were present in certain animal types. Generally, C-opsins were thought to be present only in vertebrates, and R-opsins only in invertebrates. But the study showed otherwise. It postulated that all three forms of opsins probably existed in the earliest common ancestor right from the beginning. Later, somewhere along their respective evolutionary lines each group designated the C or R opsins for light detection. The leftover opsins (whether C or R) were used for other non-visual purposes such as setting biological rhythms.
It also pushed the origins of light-sensitive organs back a couple hundred million years from about half a billion years ago to three-quarters of a billion years ago, a time not long after sponges had diverged from other animals and before they split into Bilateria and Cnidaria. Within that evolutionary timeline opsins were found in the gene sequence of the tiny and transparent shape-shifting microorganisms called placozoa. However, because the genome lacks a critical retinal-binding amino acid - lysine 296– it’s unlikely these opsins were able to detect light. (It should be noted that placozoan phylogeny is still under debate). But somewhere along the evolutionary line, these non-visual opsins mutated into a light sensing protein. After just two more gene duplications the three opsins, R, C, and Go/RGR we find in our eye’s photopigments today, were already present in the genome.
Why or when opsins developed into part of the eye’s photopigment is anyone’s guess. This research doesn’t solve all the mysteries surrounding them, particularly their non-visual functions but it does fill in some of the gaps in our understanding of key components of vision evolution.
SOURCES
The Conversation article
Scientific American article
Intro to phyologeny
Evolution timeline from 1882: This caricature of Darwin's theory appeared in the 1882 Punch Almanac. The recent evolution timeline created by Kyrk and Sezen is a bit of an improvement.Courtesy Public domain via Wikipedia This cool evolution timeline is really fascinating and fun to mess around with. I'm guessing Charles Darwin would agree it's a vast improvement over the one that appeared in Punch Almanac in1882 when he was still alive (see image at right). This new one was created by John Kyrk, a biology-trained artist in San Francisco in collaboration with Dr. Uzay Sezen, a plant biologist from the University of Georgia. The timeline is available in several languages and would be very useful in a classroom setting when studying evolution and paleontology.
The site is interactive and follows the evolution of our universe from the Big Bang to the present. You start it by clicking and sliding the red pyramid on the right. As you scroll across the timeline, various events in the history of the Universe, Solar System and ultimately, the Earth show up on the screen. All along, links also appear that either explain concepts or show examples of them. In the upper left hand corner is a menu linking you to several corollary Flash animations by Kyrk explaining cell biology and how RNA, DNA, cells, water, and other basic elements of life (including viruses) operate. Kyrk thinks animated illustrations are very useful in teaching and remembering ideas and concepts.
All the phases of Earth’s formation and development are covered in the evolution timeline, including the Late Heavy Bombardment, Snowball Earth, Cambrian Explosion, stromatolites, photosynthesis and iron formation. Once life begins to rise up, your computer screen will run amok with Earth’s diverse species populations from the one-celled animals, trilobites and fish to amphibians, reptiles, dinosaurs and mammals – the whole shooting match. All the major extinction events are shown, too.
The site also contains a link to this YouTube video version of someone else working the timeline so you can just sit back and watch how it happens, But I recommend working the interactive page yourself. A lot more happens and is available than the video allows you to see. Note that you’ll need Flash for it to run on your computer.
I wonder how Darwin would have reacted if he were able to see his theory illustrated in this way?
SOURCES
Evolution Timeline
The man behind the video: Drew Berry is a biomedical animator who is responsible for the fascinating scenes in Bjork's music video.Courtesy John D. & Catherine T. MacArther FoundationIn the same vein as this Buzz post, here is another interesting blend of art and science. Bjork teams up with a biomedical animator to create a music video for her song "Hollow."
The animation is a mesmerizing, slightly creepy exercise of scale: it takes you down to the nanoscale, where you watch DNA replicate, then all the way back out to the macroscale, when you zoom out of Bjork's forehead. Interesting, indeed.
Zombies are not real right now because it is impossible. Well, until a scientist screws up. In the movies zombies are people that get infected from a source, it is unlikely that it will happen in our lifetime, but scientifically it will be brains( how ironic ), not bronze that prevails over this threat of zombies. The virus would most likely be like the T virus in Resident Evil, but we probably will never know. What do you think??? I was reading a article from the CDC and they say that it might be possible for a zombie apocalypse to happen! How do you think you would prepare for this??? Well we don't know. We honestly don't. Scientifically we would never truly be ready. And for an Awnser I don't want, "my dad has a gun"!!! Actual science reasons here. Heck, it might be a parasite for all we know, then again, your mom or dad may get it first( that would suck! ), or your sister, or brother. We will never know until we realize that nothing is impossible in science. Scientifically I should say, ELECTRICITY would go down first! Then GAS would eventually run out. Cities would be safe most of the time, because all the people would go out to the country.
Then all the people left would be in shock, and/or, injured and extremely prejudiced, but some will still be sane, like me, I know how to keep alive in a Z.A. but some people would not, but, scientifically someone will be smart and start remaking our civilization, but who knows maybe we will all die? You never know how things will turn out. What are your comments??? I would love to hear them.
EDITED BY LIZA, 11/1/2011: Hey, Buzzketeers! Still need a post-Halloween zombie fix, like ZombieDestroyer here? Head on over to the zombies page. You'll find out about a new zombie-fighting weapon, a real-life zombie-making parasite, and a very long-running thread about whether or not a zombie apocalypse is possible. (And if you feel a need to argue zombie-fighting strategies or likelihood, take it over to that last thread and keep it science-y, y'all!)
Publication Party for "Fool Me Twice: Fighting the Assault on Science in America" by Shawn Lawrence Otto
You are Cordially Invited
Publication Party, Public Reading, and Book Signing Event
for
FOOL ME TWICE: Fighting the Assault on Science in America
by
SHAWN LAWRENCE OTTO
Introduction by Don Shelby
Emcee Jim Lenfestey
"A gripping analysis of America's anti-science crisis."
—Starred Kirkus Review
“In this incredible book, Otto explores the devaluation of science in America.”
—Starred Publishers Weekly Review
You know you want to read it. Click here for more infoCourtesy Shawn Lawerence Otto
Tuesday October 18, 2011 at 7PM
Target Performance Hall, Open Book
1011 Washington Avenue South, Minneapolis
(click here for directions and free parking)
This event is free and open to the public
sponsored by
the Loft Literary Center
the Science Museum of Minnesota
no reservation required, but click here to RSVP to help us plan
Beer, wine and light refreshments served
Books for sale at the event
Free book by drawing. To qualify: A) post about the event on Facebook B) tweet at the event with hashtag #FoolMeTwice and mention @ShawnOtto
R/V Hespérides, docked at Aloha Tower in Honolulu, Hawai`iCourtesy C-MOREHow would you like to be aboard a ship, circumnavigating the globe, collecting samples from the world’s ocean?
That’s exactly what Spanish oceanographers are doing on their Malaspina Expedition aboard the Research Vessel, R/V Hespérides. Scientists and crew left southern Spain in December, reached New Zealand in mid-April, and recently arrived in Hawai`i. The expedition's primary goals are to:
- build upon the historic 1789-1794 Malaspina expedition to promote interest in marine sciences among the Spanish public, particularly the nation’s youth
- collect oceanographic and atmospheric data -- chemical, physical and biological – that will help evaluate the impact of global change
- explore the variety of marine life, including microbes, especially those living in the deep sea
CTD: As this oceanographic instrument is lowered over the side of a ship, each gray Niskin “bottle” can be electronically triggered to collect a seawater sample from a different ocean depth.Courtesy C-MOREIn connection with the latter two goals, the Malaspina scientists met with their colleagues at the Center for Microbial Oceanography: Research and Education (C-MORE). The two groups of scientists are working together. "We can exchange data on the local effects, what's happening around the Hawaiian Islands, and they can tell us what's happening in the middle of the Pacific," said Dr. Dave Karl, University of Hawai`i oceanography professor and Director of C-MORE.
The Malaspina-C-MORE partnership is the kind of cooperation that can help solve environmental problems which stretch beyond an individual nation’s borders. The R/V Hespérides has now left Honolulu on its way to Panama and Colombia. From there, the scientists expect to complete their ocean sampling through the Atlantic Ocean and return to Spain by July. Buen viaje!
the ocean's 5 major gyresCourtesy NOAAWe often talk about the ocean ecosystem. And, indeed, there is really just one, world-wide ocean, since all oceans are connected. An Indian Ocean earthquake sends tsunami waves to distant coasts. Whitecaps look as white anywhere in the world. The ocean swirls in similar patterns.
However, oceanographers do find differences from place to place. For example, let’s take a closer look at the chemistry of two swirls, or gyres as they’re more properly called. Scientists have found a micro difference between the North Atlantic Gyre and the North Pacific Gyre. The Atlantic generally has really low levels of phosphorus, measurably lower than the North Pacific Gyre.
the element phosphorus among its neighbors in the Periodic Table of the ElementsCourtesy modified from WikipediaPhosphorus is a very important element in living things. For example, it’s a necessary ingredient in ATP (adenosine tri-phosphate), the energy molecule used by all forms of life. Phosphorus is picked up from seawater by bacteria. All other marine life depends upon these bacteria, either directly or indirectly, for P. Therefore, if you’re bacteria living in the impoverished North Atlantic Gyre, you’d better be really good at getting phosphorus.
And they are!
Oceanographers at the Center for Microbial Oceanography: Research and Education (C-MORE) at the University of Hawai`i have made an important discovery. C-MORE scientists Sallie Chisholm, based at the Massachusetts Institute of Technology and her former graduate student Maureen Coleman, now a scientist at the California Institute of Technology, have been studying two species of oceanic bacteria. Prochlorococcus is an autotrophic bacterium that photosynthesizes its own food; Pelagibacter, is a heterotrophic bacterium that consumes food molecules made by others.
Pacific HOT and Atlantic BATS Stations: Microbial samples were collected at each location.Courtesy C-MOREDrs. Chisholm and Coleman took samples of these two kinds of bacteria from both the Atlantic and Pacific Ocean. The Atlantic samples were collected by the Bermuda Atlantic Time-Series (BATS) program. The Pacific samples were collected in the North Pacific Gyre (about 90 miles north of Honolulu) by the Hawai`i Ocean Time-Series (HOT) program. The scientists discovered surprising differences in the genetic code of the bacteria between the two locations:
- First of all, the Atlantic populations of both bacterial species have more phosphorus-related genes compared to their Pacific cousins. (Picture Atlantic microbes in Superman outfits with a big "P" on their chests!)
- Secondly, in the Atlantic, Prochlorococcus has different kinds of P-related genes compared to Pelagibacter. Perhaps this means the two microbial species have evolved over time to use different phosphorus sources, to avoid competing with one another for this limited resource.
Drs. Chisholm and Coleman have discovered important micro differences between bacteria of the same species in two oceanic gyres. Now we can better understand how these microbes are working to recycle an important nutrient beneath the whitecaps.
Reference: October 11, 2010 issue of the Proceedings of the National Academy of Sciences
