Messenger RNA With FLASH

A study from the University of North Carolina at Chapel Hill has identified a key player in a molecular process essential for DNA replication within cells.

The new findings highlight a protein called FLASH, already shown to play a role in initiating apoptosis, or programmed cell death. Apoptosis is a normal biochemical response that occurs when a cell is damaged beyond repair after viral infection or accumulation of mutations that could lead to uncontrolled cellular proliferation, or cancer. Apoptosis is also crucial to the developing embryo through selective cell death, which allows proper differentiation of physical structures, such as fingers and toes.

According to senior study author Zbigniew Dominski, Ph.D., associate professor of biochemistry and biophysics at UNC, the new study demonstrates that FLASH is also required for the proper synthesis of histone messenger RNA, which gives rise to histone proteins.

Histones are the chief protein components of chromatin and act as a scaffold allowing packaging of DNA into a condensed form that fits inside the nucleus of a cell. As the DNA interacts with histones and with metabolic signals from within the cell, these proteins help regulate gene expression.

"Our study suggests for the first time that a potential link exists between the processes of histone messenger RNA formation and apoptosis," Dominski said. "FLASH is crucial for the production of histone messenger RNA, without which the cell can't make the histone proteins around which DNA is packaged."

The research is described in the Oct. 23, 2009 issue of the journal Molecular Cell.

For the study, Dominski adapted a laboratory system that reproduces in the test tube what normally occurs in the cell when FLASH participates in the biochemical cleavage event that results in mature histone messenger RNA. This enabled his team to explore what might occur when FLASH was added or removed.

"We could then figure out exactly what portion of FLASH would restore the protein's function in generating histone mRNAs and remarkably, only the first 100 or so amino acids are required. The remaining 2,000 amino acids of this large protein likely control other processes in the cell, including apoptosis and DNA replication," he explained.

Co-author William F. Marzluff, Ph.D., is distinguished professor of biochemistry and biophysics and executive associate dean for basic research in the UNC School of Medicine. He noted that FLASH is the first component found in this protein complex "that integrates or initiates many cellular functions DNA replication, apoptosis, histone production. Having this small piece of the puzzle makes it a lot easier to identify others."

Other UNC coauthors include Xiao-cui Yang, laboratory technician, and Yan Yan, undergraduate student, both from the Department of Biochemistry and Biophysics and the UNC Program in Molecular Biology and Biotechnology and Brandon D. Burch, graduate student in in genetics and molecular biology.

Funding for the study came from the National Institute of General and Medical Sciences, a component of the National Institutes of Health.

Source: University of North Carolina

New Molecules Created By University Of California Riverside Chemists Have Wide Applications

Researchers at the University of California, Riverside have successfully created in the laboratory a class of carbenes, highly reactive molecules, used to make catalysts - substances that facilitate chemical reactions. Until now, chemists believed these carbenes, called "abnormal N-heterocyclic carbenes" or aNHCs, were impossible to make.

Carbenes are made up of unusual carbon atoms and are usually unstable in nature. They attach themselves to metals to form metal-carbene complexes that serve as efficient catalysts used widely in the pharmaceutical industry.

The metal-carbene complexes are formed in two ways: (a) the complex is created in one step, without first preparing carbene independently, and (b) a metal and an independent carbene are brought together to make the complex.

Most often the metal used in a metal-carbene complex is rhodium, gold, platinum or palladium - all of which are very expensive and, in some cases, even toxic. To bring down the cost of catalysts, when possible, carbenes are used independently (without metals) in many chemical reactions.

Until now, aNHCs have been used as only metal-carbene complexes, never independently. Chemists had assumed that aNHCs cannot exist freely, which made them impossible to make.

Now UC Riverside's Guy Bertrand, a distinguished professor of chemistry, and colleagues have challenged that assumption by successfully creating aNHCs that are metal-free and can be used to make any desired complex.

"Many chemical species are believed to be unstable because they do not obey the rules we learned at school, and consequently nobody tries to make them," said Bertrand, who led the research project. "The role of scientists, however, is to challenge former hypotheses. That is just what we did in the case of the aNHCs, and we were successful.

"The aNHCs are stable at room temperature both in the solid state and in solution, which means their application as metal-free catalysts is extremely wide, greatly benefiting industry by making possible scores of new chemical reactions."

Results of the study appear in the Oct. 23 issue of Science.

"This study, reporting the synthesis and characterization of an entirely different class of metal-free NHCs, could open new horizons and have a huge impact on the field of catalysis," said John Schwab, who oversees organic synthesis grants at the National Institutes of Health's National Institute of General Medical Sciences. "The potential applications to drug discovery and manufacture are exciting, since catalytic processes can help keep costs in check and be environmentally friendly, to boot."

Bertrand is interested in making aNHCs commercially available. "We hope many chemists in the world will use these carbenes and find some new applications," he said.

The UCR Office of Technology Commercialization has filed a patent application on the technology and is currently seeking partners in industry interested in developing the technology commercially.

An internationally renowned scientist, Bertrand came to UCR in 2001 from France's national research agency, the Centre National de la Recherche Scientifique (CNRS). He is the director of the UCR-CNRS Joint Research Chemistry Laboratory.

A recipient of numerous awards and honors, most recently he won the 2009-2010 Sir Ronald Nyholm Prize for his seminal research on the chemistry of phosphorus-phosphorus bonds and the chemistry of stable carbenes and their complexes.

He is a recipient of the Japanese Society for Promotion of Science Award, the French-German Humboldt Award, and the International Council on Main Group Chemistry Award. He is a fellow of the American Association for the Advancement of Sciences, and a member of the French Academy of Sciences, the European Academy of Sciences, Academia Europea, and Academies des Technologies.

He has authored more than 300 scholarly papers and holds 35 patents.

Bertrand was joined in the research by Eugenia Aldeco-Perez, Amos J. Rosenthal, and Bruno Donnadieu of UCR; and Gernot Frenking and Pattiyil Parameswaran of Phillips-Universitat Marburg, Germany.

The research project was funded by the National Institutes of Health. The National Council for Science and Technology (CONACYT), Mexico, provided Aldeco-Perez, the first author of the research paper, with financial support.

Source:
Iqbal Pittalwala
University of California - Riverside

Stacks Of Filter Paper Provide A Realistic, Easy-to-use Medium For Growing Cells

An insight from the labs of Harvard chemist George Whitesides and cell biologist Don Ingber is likely to make a fundamental shift in how biologists grow and study cells – and it's as cheap and simple as reaching for a paper towel.

Ratmir Derda, a postdoctoral student co-mentored by Whitesides and Ingber at Harvard's new Wyss Institute for Biologically Inspired Engineering, has realized that by growing cells on several sheets of uncoated paper, he can solve a problem that has bedeviled biologists for years: how to easily grow and study cells that mimic the three-dimensionality of real tissue.

This work will simplify creation of realistic, three-dimensional models of normal or cancerous tissue -- potentially making it faster and easier to find drugs that fight cancer and other diseases.

"This research has the potential to become a standard laboratory tool, alongside the Petri dish, in laboratories that work with cells," said George M. Whitesides, the Woodford L. and Ann A. Flowers University Professor at Harvard University and a founding faculty member of the Wyss Institute. "Filter paper and other kinds of paper are readily available, and the technique is both very flexible in what it can do, and very convenient to use."

Now, researchers grow cells in a Petri dish, creating a thin, two-dimensional layer of cells. If they want to do a better job of mimicking real tissue, they culture the cells in a gel. But because cells in different locations get vastly different amounts of oxygen and food, these cultures fail to mimic real tissues. And studying the cells from different parts of these gels without destroying the 3D culture is tricky.

By growing the cells in a thin layer of gel supported by paper, and then stacking those pieces of paper, the scientists showed they could recreate the benefits of two-dimensional research – where cells receive a uniform amount of oxygen and food -- while also closely mimicking real tissue. In this case, they engineered a 3D tumor on paper that exhibited behaviors similar to a cancer in the body.

Stacking multiple cell-containing sheets also allows researchers to examine the interior of a large cell cluster, either cultured on a dish or grown in vivo, simply by peeling the layers apart, without disturbing the properties of the cells. Isolating cells grown with other 3D culture techniques requires either performing complex laser-assisted surgery on the tumor sections or destroying the architecture of the tissue and then sorting the cells.

Derda said he had the initial insight that led to this study when he heard a colleague complain that he couldn't use paper to filter blood, because the erythrocytes, which give blood their red color, are sometimes trapped in the paper and sometimes go through it. Derda, who developed and used peptide arrays for stem cell research in his Ph.D. work, thought he might be able to use this trapping property for high-throughput screening. When he discussed that insight with Whitesides, the older chemist suggested Derda try stacking the pages instead.

Fellow postdoctoral student Anna Laromaine helped Derda figure out how to clip multiple layers of paper together while submerged in the gel, allowing the first multi-layer cell culture to grow. When he gingerly pulled the sheets of paper apart and analyzed the distribution of cells in different layers, he realized the versatility of paper as a growing medium and its potential to mimic any three-dimensional tissue.

"The best thing about this approach is that it can be used by everyone," Derda said. "Paper is nearly free, it's all over the place and you don't have to know anything other than how to dip."

The work was supported by funds from the Wyss Institute, National Institutes of Health, Vertex Inc., DoD Breast Cancer Innovator Award, the Fulbright-Generalitat de Catalunya, and the American Heart Association.

In addition to Derda, Whitesides and Ingber, the founding director of the Wyss Institute, a faculty member at Harvard's Medical School and its School of Engineering and Applied Sciences, and a researcher at Children's Hospital Boston, the paper's other authors are: Akiko Mammoto and Tadanori Mammoto of Ingber's lab, and Laromaine and Sindy K. Y. Tang of Whitesides' lab.

Reference:

Akiko Mammoto et al. Paper-Supported Three-Dimensional Cell Culture for Tissue-Based Bioassays. Proceedings of the National Academy of Sciences, October 19, 2009

Scientists Identify Specific Markers That Trigger Aggressiveness Of Liver Cancer

Hepatocellular carcinoma (HCC) or primary liver cancer forms in the epithelial tissue of the liver and is most commonly caused by the hepatitis B virus (HBV) or hepatitis C virus (HCV). In the U.S., the National Cancer Institute (NCI) estimates that 15,000 men and 6,000 women are diagnosed with HCC each year. Worldwide, HCC accounts for 632,000 cases with the highest regions being Western Pacific and Africa according to a 2004 World Health Organization (WHO) report.

Researchers from Taipei Veterans General Hospital investigated the molecular mechanisms of HCC, one of the most common tumors found in Taiwan and largely caused by the high prevalence (15%-20%) of HBV in the country. The study, funded in part by a grant from the National Science Council, is the first to provide a comprehensive profile of multiple Epithelial-Mesenchymal Transition (EMT) markers and to demonstrate that Snail and Twist, but not Slug, are the major inducers of EMT in HCC. Results of the study are published in the November issue of Hepatology, a journal of the American Association for the Study of Liver Diseases.

EMT is critical in the development of invasiveness and metastatic potential of human cancers, and described as process where epithelial cells no longer adhere to one another, taking on fibroblastic properties. The EMT process is initiated by suppression of E-cadherin function through the major EMT regulators (Snail, Slug, and Twist). E-cadherin (calcium dependent adhesion molecules) is a type of protein found in the epithelial cells that ensure tissue cells bind together. When E-cadherin function is lost, cancer is able to progress and metastasize.

Professor Jaw-Ching Wu and colleagues obtained samples of primary HCC with adjacent non-tumorous liver tissues from 123 patients who had hepatic resection surgery between 1990 and 2002 at Taipei Veterans General Hospital. Reduced E-cadherin function was observed in 60.2% of patients. "We found a significant decrease in cancer-free intervals and overall survival for those patients who had a reduction in E-cadherin function," explained Dr. Wu. A downregulated expression of E-cadherin was also associated with large tumor size and multi-nodular tumors.

Results show that co-expression Snail and Twist (transcription factors or proteins that control when genes are switched on or off) indicates the worst prognosis for HCC patients. "Our research is the first to prove that the two proteins (Snail and Twist) work independently, but together promote EMT," noted Dr. Wu.

According to the study, overexpression of Twist is correlated with HCV-related HCC, partially explaining the highly invasive behavior and poor prognosis for patients with this form of liver cancer. Dr Wu added, "Our results provide essential information for determining HCC prognosis in patients and identifies possible new treatments for future HCC management."

Reference

1. Yang et al. Comprehensive analysis of the independent effect of twist and snail in promoting metastasis of hepatocellular carcinoma. Hepatology, 2009; DOI: 10.1002/hep.23221
2. Gianluigi Giannelli. The Epithelial Mesenchymal Transition: fact or fiction in cancer? Hepatology;, Published Online: October 29, 2009 DOI: 10.1002/hep.23329

High-Speed Test To Improve Pathogen Decontamination Developed

A chemist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., has developed a technology intended to rapidly assess any presence of microbial life on spacecraft. This new method may also help the military test for disease-causing bacteria, such as a causative agent for anthrax, and may also be useful in the medical, pharmaceutical and other fields.

Adrian Ponce, the deputy manager for JPL's planetary science section, devised the new microscope-based method, which has the potential to quickly validate -- from days to minutes -- a spacecraft's cleanliness.

NASA adheres to international protocols by striving to ensure that spacecraft don't harbor life from Earth that could contaminate other planets or moons and skew science research. Microbes known as bacterial endospores can withstand extreme temperatures, ultraviolet rays and chemical treatments, and have been known to survive in space for six years. This resilience makes them important indicators for cleanliness and biodefense, Ponce said.

"Bacterial endospores are the toughest form of life on Earth," Ponce explained. "Therefore, if one can show that all spores are killed, then less-resistant, disease-causing organisms will also be dead."

The new technology works by looking for dipicolinic acid -- a major component of endospores and evidence of endospore growth -- by first applying terbium to a dime-sized area. Terbium is a chemical element used to generate the color green on television screens. That area is then illuminated under an ultraviolet lamp. Within minutes, one can see through a microscope aided by a digital camera whether live endospores are present. That's because they will literally glow: The terbium will show the endospores as bright green spots.

Ponce co-authored a paper on the new technology, called Germinable Endospore Biodosimetry, along with Pun To Young, a post-doctoral student at the California Institute of Technology in Pasadena, in the journal Applied and Environmental Microbiology. The research was also highlighted in Microbe, a magazine of the American Society for Microbiology.

The technology has piqued the interest of the U.S. Department of Homeland Security. The federal agency is funding development of a portable instrument based on Ponce's research that could quickly check for decontamination of pathogens after a biological attack. Ponce is working with the Department of Homeland Security and Advance Space Monitor, a company based in Falls River, Mass., to develop the instrument, which they plan to have ready for use by 2011. JPL and Caltech licensed the technology to Advance Space Monitor.

"As part of the Department of Homeland Security Science and Technology Directorate's near-term bioassays effort, the technology could enable the rapid assessment of facility sterilization. This could significantly reduce the time and cost of building restoration following a bio-contamination event," said James Anthony, chemical and biological research and development program manager at the Dept. of Homeland Security. A bioassay is an assessment of whether certain biological material is present on a surface being tested.

Anthony added that the technology could also be used in bio-containment facilities that have regularly scheduled decontamination requirements and rapidly reactivate important bio-defense research facilities.

Besides outer space and defense purposes, this new technology might also be applied in hospitals, child-care centers, dentists' offices and nursing homes.

"Given all the problems with hospital-acquired infections, assessing the sterility and hygiene of medical equipment and surfaces is becoming increasingly important," said Ponce.

Funding for Ponce's project was provided by NASA's Astrobiology Science and Instrument Development Program and Mars Technology Program, and the U.S. Department of Homeland Security's Chemical and Biological Research and Development division.

Courtesy: ScienceDaily

Chromosomal Test By Molecular Biologists Determines Cancer Spread

A new biopsy test, created by molecular biologists, can tell ocular melanoma patients if theirs is the kind that will spread. Using very thin needles, surgeons collect cells from tumors and analyze them. If tumors are missing a copy of chromosome three, patients are at high risk of having their cancer spread. While there's no cure for ocular melanoma, patients who are at higher risk can be followed more closely and put on experimental treatments.

Ocular melanoma, or eye cancer, is a serious disease that affects about 2,000 Americans each year. Roughly half of patients will die from the cancer because their tumor spreads to other areas of the body. Now, a new test can tell patients if they're looking at life ... or death.

Just like everyone, Susan Izanstark-Rosenthal relies on her eyes every second of every day. "I'm an attorney, and I read and write all day long," she says.

But about a year ago, she didn't know if she'd be able to see out of her left eye ever again. Rosenthal was diagnosed with ocular melanoma. Surgery followed.

"It was very scary, and I didn't know when I woke up if I'd be able to see in the other eye," she says. Even scarier -- she found out she could die if her cancer spread. Ocular oncologist Tara Young, says a new biopsy test can tell patients if their tumor is the kind that will spread.

"It represents the first step that we've been able to make in a long time with this cancer," Young, of the Jules Stein Eye Institute at UCLA, tells DBIS.

Using very thin needles, surgeons collect cells from tumors and analyze them. If tumors are missing a copy of chromosome three, patients are at high risk of having their cancer spread. If tumors are normal, they have a very low risk.

"If someone could tell you that you were gonna go and die of your cancer, I think that most people want that information and that knowledge, so that they can just take a little bit more control over their lives," Young says.

Only a handful of medical centers across the country are performing the eye biopsy technique. While there's no cure for ocular melanoma, patients who are at higher risk can be followed more closely and put on experimental treatments. She says so far, all of her patients have wanted to know the results of their biopsy.

Rosenthal wasn't missing a copy. It's a great relief for her -- and her daughter. "It's given me, once again, a reminder that you need to appreciate every day and be very grateful for what you have," Rosenthal says.

BACKGROUND: The Jules Stein Eye Institute at the University of California, Los Angeles, is the first center in the country to practice analyzing rare eye cancers at a level as small as a molecule. The new biopsy technique looks for a certain chromosome within the tumor that can predict which tumors have a high risk of spreading. Physicians can determine this earlier, and thereby recommend much more aggressive treatment, resulting in longer survival rates for their patients. Since 2005, JSEI has performed more than 70 procedures.

ABOUT THE DISEASE: Ocular melanoma -- eye cancer -- is a particularly rare and aggressive form of cancer that attacks the pigment cells in the retina. There are essentially two types of intraocular melanoma: low-grade tumors, which grow slowly and rarely metastasize, and high-grade tumors, which grow more quickly and metastasize at a very early stage. Once a tumor metastasizes, the cancer spreads quickly to the liver and other organs, and a patient has only 6 to 12 months to live in most cases, although some can survive for as long as 5 years. The National Eye Institute reports some 2000 newly diagnosed cases of ocular melanoma per year in the US and Canada's roughly seven in one million people. It affects people of all ages and races, and is not hereditary. Ocular melanoma kills nearly half of those who develop it

IT'S ALL IN THE GENES: Doctors understand very little about the molecular changes that result in this aggressive behavior, but they now know that patients who are missing one copy of chromosome 3 in their tumor tissue are more likely to have highly aggressive cancers. For the first time, UCLA surgeons have demonstrated that it is feasible and safe to perform a biopsy on a living eye. They use an ultra-fine needle to collect cells from the cancer before surgery and send the sample to the lab for culture. After growing the tumor cells, a geneticist analyzes them to determine which are missing a copy of chromosome 3. This genetic marker tells them which patients require more aggressive treatment for their cancer.

WHAT ARE CHROMOSOMES? A chromosome is a single large macromolecule of DNA, and constitutes a physically organized form of DNA in a cell. It is a very long, continuous piece of DNA (a single DNA molecule), which contains many genes, regulatory elements and other intervening nucleotide sequences. A broader definition of "chromosome" also includes the DNA-bound proteins which serve to package and manage the DNA. The word chromosome comes from the Greek chroma ('color') and soma ('body') due to its capacity to be stained very strongly with dyes.

Courtesy:ScienceDaily

Chemical Engineers Call On Nanoparticles To Combat Polluted Groundwater

Chemical engineers created nanoparticles out of gold and palladium to break down pollutants in groundwater. Adding the particles to groundwater converts dangerous contaminants like trichloroethylene into non-toxic compounds.

He's just 37 years old, but he's already making a difference in the world! A young engineer is creating small solutions to big problems.

We've seen it in the movies -- polluted drinking water is a health and environmental concern. In fact, right now, 30 states need to clean up their groundwater. "They've been designated by the EPA as being highly contaminated, and they've got to do something about the contaminated water," Michael Wong, Ph.D., a chemical engineer at Rice University in Houston, told Ivanhoe.

Dr. Wong is one of Smithsonian Magazine's America's Young Innovators … and for good reason. He's trying to come up with a way to use nanoparticles to clean up our water. "Water is not just H2O. Water has all sorts of stuff in it and the stuff we don't want, those are the things that can really hurt you," Dr. Wong explains.

He's using nanoparticles made out of gold and palladium -- a metal related to platinum -- to get rid of chemicals. One of the most common pollutants in United States groundwater is trichloroethylene, or TCE, a solvent used to degrease metals. And it can cause cancer.

"Our idea was, let's go ahead and break it down -- break it down into something that's safer," Dr. Wong says. "Safer chemicals that won't hurt your body and hurt the animals and the fish and what not."

Wong uses nanoparticles -- ten thousand times smaller than a human hair -- and hydrogen to break TCE into something non-toxic. "We are going to pump water through this guy here and the water is being pumped from the bottom up," Dr. Wong explains.

Glass beads will help to hold the nanoparticles in place. "Then clean water comes out," Dr. Wong says. Dr. Wong plans to test it at military sites first -- then move onto industrial sites and dry cleaning businesses. "I'd like to see our reactor do a really good job of getting rid of some of the contaminants," Dr. Wong says. Possibly, making our water and environment cleaner in the future. Dr. Wong says his reactor will be more efficient and cost less than the carbon reactors being used now.

WHAT IS HAZARDOUS WASTE? In the U.S., hazardous waste is defined as any discarded solid or liquid that is highly corrosive, toxic, reactive enough to release toxic fumes, or easily ignited. It can include solvents, pesticides, and spilled chemicals -- including acids, ammonia, chlorine bleach and other industrial cleaning agents -- as well as most heavy metals. Long-term exposure to hazardous waste can lead to chronic respiratory diseases such as asthma, damaged liver and kidneys, or cancer. Poisoning and chemical burns can result from contact with even small amounts of toxic chemical waste. Even brief exposure can cause headaches, dizziness, and nausea.

WHERE THAT GLASS OF WATER COMES FROM: Drinking water can come from either ground water sources, via wells, or surface water sources, such as rivers, lakes and streams. Most U.S. water systems in small and rural areas use a ground water source, while large metropolitan areas tend to rely on surface water. Causes of contamination can range from agricultural runoff to improper use of household chemicals.

SECONDARY STANDARDS: Even if your tap water meets the EPA's basic requirement for safe drinking water, some people still object to the taste, smell or appearance of their water. These are aesthetic concerns, however, and therefore fall under the EPA's voluntary secondary standards. Some tap water is drinkable, but may be temporarily clouded because of air bubbles, or have a chlorine taste. A bleachy taste can be improved by letting the water stand exposed to the air for a while.

Courtesy:ScienceDaily

A Biochemist Explains The Chemistry Of Cooking

A biochemist and cook explains that cooking is all about chemistry and knowing some facts can help chefs understand why recipes go wrong. Because cooking is essentially a series of chemical reactions, it is helpful to know some basics. For example, plunging asparagus into boiling water causes the cells to pop and result in a brighter green. Longer cooking, however, causes the plant's cell walls to shrink and releases an acid. This turns the asparagus an unappetizing shade of grey.

You love to cook, but have you whipped up some disasters? Even the best recipes can sometimes go terribly wrong. A nationally recognized scientist and chef says knowing a little chemistry could help.

Long before she was a cook, Shirley Corriher was a biochemist. She says science is the key to understanding what goes right and wrong in the kitchen.

"Cooking is chemistry," said Corriher. "It's essentially chemical reactions."

This kind of chemistry happens when you put chopped red cabbage into a hot pan. Heat breaks down the red anthocyanine pigment, changing it from an acid to alkaline and causing the color change. Add some vinegar to increase the acidity, and the cabbage is red again. Baking soda will change it back to blue.

Cooking vegetables like asparagus causes a different kind of reaction when tiny air cells on the surface hit boiling water.

"If we plunge them into boiling water, we pop these cells, and they suddenly become much brighter green," Corriher said.

Longer cooking is not so good. It causes the plant's cell walls to shrink and release acid.

"So as it starts gushing out of the cells, and with acid in the water, it turns cooked green vegetables into [a] yucky army drab," Corriher said.

And that pretty fruit bowl on your counter? "Literally, overnight you can go from [a] nice green banana to an overripe banana," Corriher said.

The culprit here is ethylene gas. Given off by apples and even the bananas themselves, it can ruin your perfect fruit bowl -- but put an apple in a paper bag with an unripe avocado, and ethylene gas will work for you overnight.

"We use this as a quick way to ripen," Corriher said. Corriher says understanding a little chemistry can help any cook.

"You may still mess up, but you know why," she said. When it works, this kind of chemistry can be downright delicious.

WHAT ARE ACIDS AND BASES? An acid is defined as a solution with more positive hydrogen ions than negative hydroxyl ions, which are made of one atom of oxygen and one of hydrogen. Acidity and basicity are measured on a scale called the pH scale. The value of freshly distilled water is seven, which indicates a neutral solution. A value of less than seven indicates an acid, and a value of more than seven indicates a base. Common acids include lemon juice and coffee, while common bases include ammonia and bleach.

WHY DOES FOOD SPOIL? Processing and improper storage practices can expose food items to heat or oxygen, which causes deterioration. In ancient times, salt was used to cure meats and fish to preserve them longer, while sugar was added to fruits to prevent spoilage. Certain herbs, spices and vinegar can also be used as preservatives, along with anti-oxidants, most notably Vitamins C and E. In processed foods, certain FDA-approved chemical additives also help extend shelf life.

DNA Test Could Be Key To Targeting Treatments For Head And Neck Cancer

It is estimated that more than 7,000 people are diagnosed with head and neck cancer each year in the UK and approximately 3,500 cases result in death. These cancers include tumours of the mouth, lips, throat and voice-box, and some have been linked to the sexually transmitted infection, HPV-16. Scientists at Liverpool analysed the DNA of more than 90 cancerous tissue samples to look for genes that indicated infection.

The team found that nearly two thirds of tonsil tumour samples showed evidence of the HPV-16 gene. It is thought that chemical alterations in the virus's DNA trigger the production of proteins that can alter the rate at which cells grow and repair. This strongly increases the possibility of subsequent cancer development. Recent studies have found, however, that patients who have the HPV infection when they are diagnosed with cancer, respond better to chemotherapy or radiation therapy than those that do not have the infection. The work will be presented at the National Cancer Research Institute's (NCRI) Cancer Conference in Birmingham.

Mr Richard Shaw, from the School of Cancer Studies, explains: "Recent evidence demonstrates the possible involvement of HPV in the development of tonsil cancer, particularly in non-smokers. Interestingly, the treatment efficiency of chemotherapy and radiation, seems to differ between HPV positive and negative cases. We also need to find out why only a small percentage of people with this common infection develop this cancer. Our study, however, gives us a new lead towards a risk marker.

"It is thought that HPV interacts in the cell with genes controlling the chemical modification of DNA, which affects gene expression and tumour behaviour. Our study shows that HPV may be a trigger of tonsil cancer, independent of the known common causes, such as smoking or drinking. The work also suggests that a DNA test to determine the activity of HPV, could be used to identify the most effective treatment for each individual patient.

"Liverpool has the largest centralised head and neck oncology practice in the UK and our data show a doubling in the rate of non-drinkers and non-smokers presenting with tonsil cancer. As head and neck cancer is one of the cornerstones of the new CR-UK Cancer Centre in Liverpool, we are pleased to be making real progress in this area of research."

Researchers are now working to develop a clinical trial for a therapeutic HPV vaccine in head and neck cancer.

The study, supported by the Royal College of Surgeons, is presented at the NCRI Cancer Conference on Monday, 5 October.

Nobel Prize In Chemistry: What Ribosomes Look Like And How They Functions At Atomic Level

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry for 2009 jointly to Venkatraman Ramakrishnan, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom; Thomas A. Steitz, Yale University, New Haven, CT, USA; and Ada E. Yonath, Weizmann Institute of Science, Rehovot, Israel, "for studies of the structure and function of the ribosome".

The ribosome translates the DNA code into life

The Nobel Prize in Chemistry for 2009 awards studies of one of life's core processes: the ribosome's translation of DNA information into life. Ribosomes produce proteins, which in turn control the chemistry in all living organisms. As ribosomes are crucial to life, they are also a major target for new antibiotics.

This year's Nobel Prize in Chemistry awards Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath for having showed what the ribosome looks like and how it functions at the atomic level. All three have used a method called X-ray crystallography to map the position for each and every one of the hundreds of thousands of atoms that make up the ribosome.

Inside every cell in all organisms, there are DNA molecules. They contain the blueprints for how a human being, a plant or a bacterium, looks and functions. But the DNA molecule is passive. If there was nothing else, there would be no life.

The blueprints become transformed into living matter through the work of ribosomes. Based upon the information in DNA, ribosomes make proteins: oxygen-transporting haemoglobin, antibodies of the immune system, hormones such as insulin, the collagen of the skin, or enzymes that break down sugar. There are tens of thousands of proteins in the body and they all have different forms and functions. They build and control life at the chemical level.

An understanding of the ribosome's innermost workings is important for a scientific understanding of life. This knowledge can be put to a practical and immediate use; many of today's antibiotics cure various diseases by blocking the function of bacterial ribosomes. Without functional ribosomes, bacteria cannot survive. This is why ribosomes are such an important target for new antibiotics.

This year's three Laureates have all generated 3D models that show how different antibiotics bind to the ribosome. These models are now used by scientists in order to develop new antibiotics, directly assisting the saving of lives and decreasing humanity's suffering.

Courtesy: Sciencedaily