Tag Archives: virus

MRI That Can See Bacteria, Virus and Proteins

The researchers demonstrated this imaging at a resolution 100 million times finer than current MRI. The advance could lead to important medical applications and is powerful enough to see bacteria, viruses and proteins, say the researchers.

The researchers said it offered the ability to study complex 3D structures at the “nano” scale. The step forward was made possible by a technique called magnetic resonance force microscopy (MRFM), which relies on detecting very small magnetic forces.

In addition to its high resolution, MRFM has the further advantage that it is chemically specific, can “see” below surfaces and, unlike electron microscopy, does not destroy delicate biological materials.

Now, the IBM-led team has dramatically boosted the sensitivity of MRFM and combined it with an advanced 3D image reconstruction technique. This allowed them to demonstrate, for the first time, MRI on biological objects at the nanometre scale.

That is very cool.

One Sneeze, 150 Colds for Commuters

One sneeze, 150 colds for commuters

An analysis of the germs unleashed from a single commuter’s sneeze showed that within minutes they are being passed on via escalator handrails or seats on trains and underground carriages. At the busiest stations, one sneeze not smothered by a tissue or handkerchief will provide enough germs to infect another 150 commuters.
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A single sneeze expels 100,000 droplets of germs into the air at 90mph. Individual droplets get transferred to handles, rails and other areas frequently held or touched. Up to 10 per cent of all commuters will come into contact with an area infected by that one sneeze, Dr Henderson calculated.
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Researchers asked 1,300 workers about their health and found 99 per cent of commuters suffered at least one cold last winter. In contrast, just 58 per cent of those who work from home and 88 per cent of those who walk to work regularly caught a cold last winter.

It is amazing (or maybe not but I find it amazing) how well cold viruses have evolved to have us sneeze and send out personal virus jet packs to spread them all over and let them infect others. It is sad how impolite some people are as they go around potentially infecting hundreds of other people. Partially their ignorance of basic science may also be to blame for their behavior. It is too bad others have to suffer due to their bad manners and ignorance.

Common Cold Alters the Activity of Genes

Scientists Come Closer to Unlocking Secrets of Common Cold

Canadian and U.S. researchers have found that the human rhinovirus, long blamed for causing the common cold, doesn’t actually cause those annoying sniffles, sneezes, and coughs.

Instead, the ubiquitous virus alters the activity of genes in the body, which then results in the misery that afflicts most people every year or so, according to a study in the first November issue of the American Journal of Respiratory and Critical Care Medicine.
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Human rhinovirus (HRV) causes some 30 percent to 50 percent of common colds and can also worsen more serious conditions, such as asthma.
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A “microarray analysis” of DNA showed no genetic changes eight hours after infection. But, after two days, about 6,500 genes had been affected, either with heightened activity or dampened activity.

The genes most affected by the presence of the virus were ones that make antiviral proteins and pro-inflammatory chemicals that contribute to airway inflammation, the researchers said.

Read: Learning How Viruses Evade the Immune System – Gene Carnival – Black Raspberries Alter Hundreds of Genes Slowing Cancer – Study Finds No Measurable Benefit to Flu Shots

Nobel Prize in Physiology or Medicine 2008

photos of Harald zur Hausen, FranÃ§oise BarrÃ©-Sinoussi and Luc Montagnier

The Nobel Prize in Physiology or Medicine for 2008 with one half to Harald zur Hausen for his discovery of “human papilloma viruses causing cervical cancer” and the other half jointly to FranÃ§oise BarrÃ©-Sinoussi and Luc Montagnier for their discovery of “human immunodeficiency virus.”

Harald zur Hausen went against current dogma and postulated that oncogenic human papilloma virus (HPV) caused cervical cancer, the second most common cancer among women. He realized that HPV-DNA could exist in a non-productive state in the tumours, and should be detectable by specific searches for viral DNA. He found HPV to be a heterogeneous family of viruses. Only some HPV types cause cancer. His discovery has led to characterization of the natural history of HPV infection, an understanding of mechanisms of HPV-induced carcinogenesis and the development of prophylactic vaccines against HPV acquisition.

FranÃ§oise BarrÃ©-Sinoussi and Luc Montagnier discovered human immunodeficiency virus (HIV). Virus production was identified in lymphocytes from patients with enlarged lymph nodes in early stages of acquired immunodeficiency, and in blood from patients with late stage disease. They characterized this retrovirus as the first known human lentivirus based on its morphological, biochemical and immunological properties. HIV impaired the immune system because of massive virus replication and cell damage to lymphocytes. The discovery was one prerequisite for the current understanding of the biology of the disease and its antiretroviral treatment.

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8 Percent of the Human Genome is Old Virus Genes

In Our Genes, Old Fossils Take On New Roles

It turns out that about 8 percent of the human genome is made up of viruses that once attacked our ancestors. The viruses lost. What remains are the molecular equivalents of mounted trophies, insects preserved in genomic amber, DNA fossils.

The thousands of human endogenous retroviruses, or HERVs, sketch a history of rough times during the 550 million years of vertebrate evolution. The best-preserved one, HERV-K113, probably arrived less than 200,000 years ago, long after human beings and chimpanzees diverged from a common ancestor.

But these retroviruses are more than just curiosities. They are some of the most important enemies we ever had. They helped mold the immune system that is one of the evolutionary marvels of life on Earth.

I must say there is tons of amazing stuff I learn about but I still find retroviruses amazing.

Viruses and What is Life

Viruses are generally considered not to be alive (they must use a host cell of something else to reproduce). However, defining exactly what life is, is not as easy as you might think.

The debate about what counts as a living thing is fuelled today by the discovery of the first virus that is able to fall “ill” by being infected with another virus.
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the discovery of a giant virus that itself falls ill through infection by another virus seems to suggest they too are alive, highlighting how there is no watertight definition of what exactly scientists mean when they refer to something as “living”.

“There’s no doubt, this is a living organism,” the journal Nature is told by Prof Jean-Michel Claverie, director of the Mediterranean Institute of Microbiology in Marseilles, part of France’s basic-research agency CNRS. “The fact that it can get sick makes it more alive.”

Learning How Viruses Evade the Immune System

photo of Naama Elefant

MicroRNA genes are a class of very tiny genes found in a variety of organisms. First discovered in 1993 and at the time considered relatively unimportant, they are now recognized as major players in diverse biological processes.

MicroRNAs are important regulators of protein production. Proteins, the building blocks of the cell, must be produced precisely at the right time and place. MicroRNAs specifically latch on to other genes (their targets) and inhibit the production of the protein products of these genes. Hundreds of microRNAs have already been discovered, but the identity of their target genes remains mostly unknown and presents a great challenge in the field.

Elefant developed a computer algorithm that predicts the targets of microRNAs. Her algorithm, named RepTar, searches the thousands of genes in the human genome and through sequence, structural and physical considerations detects matches to hundreds of microRNAs.

For her work in this field, Naama Elefant, a student of Prof. Hanah Margalit of the Faculty of Medicine at the Hebrew University and an Azrieli fellow, was named one of this year’s winners of the Barenholz Prizes for Creativity and Originality in Applied Computer Science and Computational Biology. This discovery also was declared by the magazine Nature Medicine as ”one of the ten notable advances of the year 2007.”
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Finding the Host Genes Viruses Require

Flu-infected fly cells reveal dependencies of the virus

The new study is important because it demonstrates a rapid-fire technique for identifying host factors such as proteins and carbohydrates that a virus commandeers to successfully infect a cell. By exposing the virus’s dependencies, the Wisconsin team has uncovered a target-rich environment for influenza drug developers.
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By working in fly cells, the Wisconsin team was able to deploy a technique to rapidly and selectively silence thousands of genes to see which were used by the flu virus. Screening a library of some 13,000 genes, the group identified more than 100 whose suppression in fly cells hindered the virus’s ability to successfully take over the cell and make new viruses.

Alligator Blood Provides Strong Resistance to Bacteria and Viruses

Gator Blood May Be New Source of Antibiotics

The study authors, from McNeese State University and Louisiana State University, said their research is the first to take an in-depth look at alligator blood’s prospects as an antibiotic source. According to the researchers, alligators can automatically fight germs such as bacteria and viruses without having been exposed to them before launching a defense.

For the study, the researchers extracted proteins known as peptides from white cells in alligator blood. As in humans, white cells are part of the alligator’s immune system. The researchers then exposed various types of bacteria to the protein extracts and watched to see what happened.

In laboratory tests, tiny amounts of these protein extracts killed a so-called “superbug” called methicillin-resistant Staphylococcus aureus, or MRSA. The bacteria has made headlines in recent years because of its killing power in hospitals and its spread among athletes and others outside of hospitals.

The extracts also killed six of eight strains of a fungus known as Candida albicans, which causes a condition known as thrush, and other diseases that can kill people with weakened immune systems.

Bacteriophages: The Most Common Life-Like Form on Earth

There are more bacteriophages on Earth than any other life-like form. These small viruses are not clearly a form of life, since when not attached to bacteria they are completely dormant. Bacteriophages attack and eat bacteria and have likely been doing so for over 3 billion years. Although initially discovered early last century, the tremendous abundance of phages was realized more recently when it was found that a single drop of common seawater typically contains millions of them. Extrapolating, phages are likely to be at least a billion billion times more numerous than humans. Pictured above is an electron micrograph of over a dozen bacteriophages attached to a single bacterium. Phages are very small — it would take about a million of them laid end-to-end to span even one millimeter. The ability to kill bacteria makes phages a potential ally against bacteria that cause human disease, although bacteriophages are not yet well enough understood to be in wide spread medical use.

Photo credit: Wikipedia Electron micrograph of bacteriophages attached to a bacterial cell. These viruses have the size and shape of coliphage T1.; Insert: Mike Jones