Genetically engineered commensal bacteria help researchers detect cancer metastases in mouse livers.
The technique: Researchers at MIT and the University of California, San Diego, have programmed a probiotic Escherichia coli strain to detect cancer metastases in the liver. The team used these bacteria, described this week (May 27) in Science Translational Medicine, to detect cancer in mice.
“There are so many bacteria in our own bodies,” said lead author Tal Danino, a postdoc in Sangeeta Bhatia’s lab at MIT. “In some ways, they are a very natural delivery vehicle for agents for diagnosis.”
The new diagnostic technique takes advantage of an old finding: bacteria thrive in tumors. Tumors are filled with nutrients released from dying cells and relatively free of immune cells. So the researchers fed the engineered E. coli to mice and found that the bacteria indeed homed to liver tumors and multiplied.
The gastrointestinal tract is connected to the liver through the portal vein system, Danino explained. “If you orally deliver bacteria, a lot of them will end up in the liver.”
(Emmy) Noether’s Theorem may be the most important theoretical result in modern physics.
Recommended read !!
By 1915, any list of the world’s greatest living mathematicians included the name David Hilbert. And though Hilbert previously devoted his career to logic and pure mathematics, he, like many other critical thinkers at the time, eventually became obsessed with a bit of theoretical physics.
With World War I raging on throughout Europe, Hilbert could be found sitting in his office at the great university at Göttingen trying and trying again to understand one idea—Einstein’s new theory of gravity.
Göttingen served as the center of mathematics for the Western world by this point, and Hilbert stood as one of its most notorious thinkers. He was a prominent leader for the minority of mathematicians who preferred a symbolic, axiomatic development in contrast to a more concrete style that emphasized the construction of particular solutions. Many of his peers recoiled from these modern methods, one even calling them “theology.” But Hilbert eventually won over most critics through the power and fruitfulness of his research.
For Hilbert, his rigorous approach to mathematics stood out quite a bit from the common practice of scientists, causing him some consternation. “Physics is much too hard for physicists,” he famously quipped. So wanting to know more, he invited Einstein to Göttingen to lecture about gravity for a week.
The advent of cheap genetic sequencing has given birth to a burgeoning ancestry industry. But before you pay to spit in a tube, let me give you a few facts for free
Sometimes I get asked if I’m related to the great physicist Ernest Rutherford. His discoveries about the atomic nucleus gave birth to physics in the 20th century. He is the father of nuclear physics, with labs and atoms named after him.
I’m not related to him. I can reveal however that I am a direct descendent of someone of similar greatness: Charlemagne, Carolingian King of the Franks, Holy Roman Emperor, the great European conciliator. Quelle surprise!
But we are all special, which means none of us are. If you’re vaguely of European extraction, you are also the fruits of Charlemagne’s prodigious loins. A fecund ruler, he sired at least 18 children by motley wives and concubines, including Charles the Younger, Pippin the Hunchback, Drogo of Metz, Hruodrud, Ruodhaid, and not forgetting Hugh.
Antibodies are the workhorses of biological experiments, but they are littering the field with false findings. A few evangelists are pushing for change
In 2006, things were looking pretty good for David Rimm, a pathologist at Yale University in New Haven, Connecticut. He had developed a test to guide effective treatment of the skin cancer melanoma, and it promised to save lives. It relied on antibodies — large, Y-shaped proteins that bind to specified biomolecules and can be used to flag their presence in a sample. Rimm had found a combination of antibodies that, when used to ‘stain’ tumour biopsies, produced a pattern that indicated whether the patient would need to take certain harsh drugs to prevent a relapse after surgery. He had secured more than US$2 million in funding to move the test towards the clinic.
Researchers develop a CRISPR-based, two-phage system that sensitizes resistant bacteria to antibiotics and selectively kills any remaining drug-resistant bugs.
Using bacteriophages to deliver a specificCRISPR/Cas system into antibiotic-resistant bacteria can sensitize the microbes to the drugs, according to a study published this week (May 18) in PNAS. The approach, developed by Udi Qimron of Tel Aviv University and his colleagues, is a modified version of phage therapy that does not require the delivery of phages to infected tissues and could help offset the pressure on bacterial populations to evolve drug resistance, according to the team.
Unlike classic phage therapy, which uses one or more types of phages to infect and lyse specific bacterial strains, the crux of this new approach is using these specialized viruses to supply CRISPR/Cas to rid bacteria of antibiotic-resistance plasmids in the environment before the microbes are able to infect a host. Each phage is specific to a bacterial species or strain and, using CRISPR, researchers can target a specific bacterial sequence.
Drug manufacturers have begun amassing enormous troves of human DNA in hopes of significantly shortening the time it takes to identify new drug candidates, a move some say is transforming the development of medicines.
The efforts will help researchers identify rare genetic mutations by scanning large databases of volunteers who agree to have their DNA sequenced and to provide access to detailed medical records.
It is made possible by the dramatically lower cost of genetic sequencing — it took government-funded scientists $3 billion and 13 years to sequence the first human genome by 2003. As of last year, the cost was closer to $1,500 per genome, down from $20,000 five years ago.
Updated classics and new techniques help microbiologists get up close and quantitative
Ever since Antonie van Leeuwenhoek espied the cavorting, swiftly swimming tiny critters he called animalcules through a small sphere of glass held in a metal frame, microscopes have figured into microbiological advances.
The stunning diversity of microbes, whether harvested from the human gut or scraped from the ocean floor, has increasingly led researchers to explore microbial behavior. As research entered the age of DNA, microscopes fell out of favor, and gaps in understanding the twitching, swimming, or creeping movements of microbes individually and as a colony have persisted.
Studying bacterial behavior requires techniques to view, track, and analyze these organisms in motion. Today, this involves new tools, such as genetically encoded fluorescent reporters, and improvements on old ones, such as quantitative methods for analyzing the complex swirls and spirals of bacterial colonies growing on agar plates. Even microscopes have made a comeback over the past two decades, thanks to the advent of small, relatively inexpensive cameras and increasingly sophisticated image-analysis programs, explains biologist Nicolas Biais of Brooklyn College.
The Scientist sought out some creative solutions for studying microbes on the move, en masse or one by one.