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Archive - Oct 2013

Date

October 8th

“Zone in with Zon”—Nanomedicine Used to Target Breast Cancer Tumors

Dr. Gerald Zon’s latest “Zone in with Zon” blog post, dated October 7, 2013, and published by TriLink BioTechnologies of San Diego, reviews some of the latest advances in breast cancer research in recognition of October as National Breast Cancer Awareness Month. Dr. Zon begins with an outline of some of the grim statistics about the deadly impact of breast cancer today and then goes on to describe existing treatments and a number of exciting and promising new therapeutic approaches that are being developed. Statistics from the NIH predict 232,340 new breast cancer cases and 39,620 deaths in 2013 in the U.S., Dr. Zon said. Nevertheless, in women diagnosed with breast cancer in the period of 1999 through 2006, the 5-year survival rate was 90%, which represents a significant improvement since the mid-1970s and is attributed to more screening and improved treatments. Among these treatments are tamoxifen and another selective estrogen receptor modulator (SERM), raloxifene, which have been approved by the FDA, and the monoclonal antibody trastuzumab, which is an accepted treatment for breast cancers that overproduce a protein called human epidermal growth factor receptor 2, or HER2. Dr. Zon also provided a description of cancer research expert Esther H. Chang, M.D., Ph.D., who has made significant achievements in specifically targeting tumors using antibody-fragment-tagged liposomal nanoparticles. Dr. Zon noted that Dr. Chang has referred to this process as involving “tiny little Fed Ex trucks.” Dr. Zon noted that tumor-targeted nanomedicine delivery of the p53 gene (SGT-53) has already successfully completed Phase I safety trials. He went on to note that nanomedicine researchers are currently seeking to develop a number of revolutionary tools.

2013 Chemistry Nobel Prize Awarded for Computer Modeling of Chemical Reactions

The Royal Swedish Academy of Sciences has decided, on October 9, 2013, to award the Nobel Prize in Chemistry for 2013 to Martin Karplus, Université de Strasbourg, France and Harvard University, Cambridge, MA, USA; Michael Levitt, Stanford University School of Medicine, Stanford, CA, USA; and Arieh Warshel, University of Southern California, Los Angeles, CA, USA “for the development of multiscale models for complex chemical systems.” Chemists once created models of molecules using plastic balls and sticks. Today, the modelling is carried out in computers. In the 1970s, Martin Karplus, Michael Levitt, and Arieh Warshel laid the foundation for the powerful programs that are used to understand and predict chemical processes. Computer models mirroring real life have become crucial for most advances made in chemistry today. Chemical reactions occur at lightning speed. In a fraction of a millisecond, electrons jump from one atomic nucleus to the other. Classical chemistry has a hard time keeping up; it is virtually impossible to experimentally map every little step in a chemical process. Aided by the methods now awarded with the Nobel Prize in Chemistry, scientists let computers unveil chemical processes, such as a catalyst’s purification of exhaust fumes or the photosynthesis in green leaves. The work of Karplus, Levitt, and Warshel is ground-breaking in that they managed to make Newton’s classical physics work side-by-side with the fundamentally different quantum physics. Previously, chemists had to choose to use one or the other. The strength of classical physics was that calculations were simple and could be used to model really large molecules. Its weakness was that it offered no way to simulate chemical reactions. For that purpose, chemists instead had to use quantum physics.

October 7th

2013 Medicine Nobel Prize Awarded for Discovery of Machinery Regulating Vesicular Traffic

The Nobel Assembly at Karolinska Institute in Sweden decided on October 7, 2013 to award the 2013 Nobel Prize in Physiology or Medicine jointly to James E. Rothman, Randy W.Schekman, and Thomas C. Südhof for their discoveries of the machinery regulating vesicle traffic, a major transport system in our cells. The 2013 Nobel Prize honours three scientists who have solved the mystery of how the cell organizes its transport system. Each cell is a factory that produces and exports molecules. For instance, insulin is manufactured and released into the blood and chemical signals called neurotransmitters are sent from one nerve cell to another. These molecules are transported around the cell in small packages called vesicles. The three Nobel Laureates have discovered the molecular principles that govern how this cargo is delivered to the right place at the right time in the cell. Randy Schekman discovered a set of genes that were required for vesicle traffic. James Rothman unravelled protein machinery that allows vesicles to fuse with their targets to permit transfer of cargo. Thomas Südhof revealed how signals instruct vesicles to release their cargo with precision. Through their discoveries, Rothman, Schekman, and Südhof have revealed the exquisitely precise control system for the transport and delivery of cellular cargo. Disturbances in this system have deleterious effects and contribute to conditions such as neurological diseases, diabetes, and immunological disorders. In a large and busy port, systems are required to ensure that the correct cargo is shipped to the correct destination at the right time.

October 6th

Gene Activity and Transcript Patterns Visualized for First Time in Thousands of Single Cells

Biologists of the University of Zurich have developed a method to visualize the activity of genes in single cells. The method is so efficient that, for the first time, a thousand genes can be studied in parallel in ten thousand single human cells. Applications lie in fields of basic research and medical diagnostics. The new method shows that the activity of genes and the spatial organization of the resulting transcript molecules, strongly vary between single cells. Whenever cells activate a gene, they produce gene-specific transcript molecules, which make the function of the gene available to the cell. The measurement of gene activity is a routine activity in medical diagnostics, especially in cancer medicine. Today's technologies determine the activity of genes by measuring the amount of transcript molecules. However, these technologies can neither measure the amount of transcript molecules of one thousand genes in ten thousand single cells, nor the spatial organization of transcript molecules within a single cell. The fully automated procedure, developed by biologists of the University of Zurich under the supervision of Professor Lucas Pelkmans, allows, for the first time, a parallel measurement of the amount and spatial organization of single transcript molecules in ten thousands single cells. The results, which were published online on October 6, 2013 in Nature Methods, provide completely novel insights into the variability of gene activity of single cells. The method developed by Dr. Pelkmans' Ph.D. students Nico Battich and Thomas Stoeger is based upon the combination of robots, an automated fluorescence microscope, and a supercomputer. "When genes become active, specific transcript molecules are produced. We can stain them with the help of a robot," explains Stoeger.

October 3rd

Toxoplasma Infection of Mice May Permanently Eliminate Their Fear of Cats

The toxoplasma parasite can be deadly, causing spontaneous abortion in pregnant women or killing immune-compromised patients, but it has even stranger effects in mice. Infected mice lose their fear of cats, which is good for both cats and the parasite, because the cat gets an easy meal and the parasite gets into the cat’s intestinal tract, the only place it can sexually reproduce and continue its cycle of infection. New research by graduate student Wendy Ingram at the University of California, Berkeley, reveals a scary twist to this scenario: the parasite’s effect seem to be permanent. The fearless behavior in mice persists long after the mouse recovers from the flu-like symptoms of toxoplasmosis, and for months after the parasitic infection is cleared from the body, according to research published today online on September 18, 2013 in the open-accessjournal PLOS ONE. “Even when the parasite is cleared and it’s no longer in the brains of the animals, some kind of permanent long-term behavior change has occurred, even though we don’t know what the actual mechanism is,” Ingram said. She speculated that the parasite could damage the smell center of the brain so that the odor of cat urine can’t be detected. The parasite could also directly alter neurons involved in memory and learning, or it could trigger a damaging host response, as in many human autoimmune diseases. Ingram became interested in the protozoan parasite, Toxoplasma gondii, after reading about its behavior-altering effects in mice and rats and possible implications for its common host, the domesticated cat, and even humans. One third of people around the world have been infected with toxoplasma and probably have dormant cysts in their brains.