An asteroid the size of an aircraft carrier has flown by Earth in the closest encounter by a massive space rock in more than 30 years. The asteroid, named 2005 YU55, came within about 325,000 kilometers of the planet Tuesday evening (at 2328 UTC).  The U.S. space agency, NASA, said there was no chance that the spherical rock would collide with Earth or the moon.  The asteroid was traveling at more than 46,670 kilometers per hour.  It passed closer to Earth than the moon. The last time an object the size of the asteroid traveled so near to Earth was in 1976.  Scientists say it will be 2028 before another space object this large will fly by the planet. A scientist at the University of Arizona discovered the YU55 asteroid in 2005.   NASA scientists planned to bounce radio waves off the asteroid and analyze the radar echoes.  Those images should reveal details about the rock’s surface features. YU55 is about 400 meters in diameter.  Scientists believe it has been passing by Earth for thousands of years.  It is one of about 8,500 near-Earth objects that NASA has catalogued. Some information for this report was provided by AP and AFP.

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Doctor Katarzyna Koziol (unseen) injects sperm directly into an egg during in vitro fertilization (IVF) procedure called Intracytoplasmic Sperm Injection (ICSI) at Novum clinic in Warsaw October 26, 2010. Credit: Reuters/Kacper Pempel LONDON | Fri Aug 19, 2011 11:30am EDT LONDON (Reuters) – Scientists have uncovered exactly how a human egg captures an incoming sperm to begin the process of fertilization and say their discovery could in future help couples who suffer from infertility. In a study in the journal Science, an international team of researchers found that a specific kind of sugar molecule makes the outer coat of the egg “sticky,” helping the egg and sperm bind together. “The details we’ve discovered here fill in a huge gap in our knowledge of fertility and we hope they will ultimately help many of those people who currently cannot conceive,” said Anne Dell of Imperial College London, who worked on the study with scientists from the universities of Missouri and Hong Kong, and the Academia Sinica in Taiwan. The World Health Organization estimates that infertility affects up to 15 percent of reproductive-aged couples around the world and almost one in every seven couples in Britain has problems conceiving a child for various reasons, many of which remain unexplained by medical science. Scientists already know that a sperm “recognizes” an egg when proteins on the head of the sperm meet and match a series of specific sugars in the egg’s outer coating. Once a successful match has been made, the outside surfaces of the sperm and egg bind together before they merge and the sperm delivers its DNA to the inside, fertilizing the egg. In this new study, the researchers used ultra-sensitive mass-spectrometric imaging technology to assess which molecules were most likely to be key in the binding process. They found that a sugar chain known as the sialyl-lewis-x sequence (SLeX) is abundant on the surface of the human egg, and after experimenting with a range of synthesized sugars in the laboratory they found that it is SLeX that specifically binds sperm to an egg. To make sure, they then tested their findings using the outer coats of unfertilized “non-living” human eggs. Dell said the research was enormously difficult “because human eggs are very tiny — about the size of a full stop — so we didn’t have much material to work with.” Poh-Choo Pang, also from Imperial and who worked on the study, said that although clinical treatments derived from this discovery are a long way off, it could open up new possibilities for understanding fertility problems faced by many couples. The researchers said they now want to use the findings of this work to further investigate the proteins on the head of a sperm that enable it to recognize an egg. SOURCE: bit.ly/mQSHLd Science, online August 18, 2011.

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Mari, a 3 year-old leukaemia patient, stands next to her IV drip at the corridor of the onco-hematology department of the Iashvili Central Children’s Hospital in Tbilisi April 7, 2011. Credit: Reuters/David Mdzinarishvili By Deena Beasley LOS ANGELES | Wed Aug 10, 2011 2:40pm EDT LOS ANGELES (Reuters) – Scientists for the first time have used gene therapy to successfully destroy cancer tumors in patients with advanced disease — a goal that has taken 20 years to achieve. Researchers at the University of Pennsylvania engineered patients’ own pathogen-fighting T-cells to target a molecule found on the surface of leukemia cells. The altered T-cells were grown outside of the body and infused back into patients suffering from late-stage chronic lymphocytic leukemia (CLL), which affects the blood and bone marrow and is the most common form of leukemia. Two participants in the Phase I trial have been in remission for up to a year. A third had a strong anti-tumor response, and his cancer remains in check. The research group plans to treat four more patients with CLL before moving into a larger Phase II trial. “We put a key onto the surface of the T-cells that fits into a lock that only the cancer cells have,” said Dr. Michael Kalos, director of translational and correlative studies at the University of Pennsylvania’s Perelman School of Medicine and an investigator on the study. The results provide “a tumor-attack roadmap for the treatment of other cancers,” including those of the lung and ovaries as well as myeloma and melanoma, researchers said. The findings were published simultaneously Wednesday in the New England Journal of Medicine and Science Translational Medicine. Kalos said past efforts to use the technique, known as “adoptive T-cell transfer,” failed either because the T-cell response was too weak or proved too toxic for normal tissue. NEW METHODOLOGY The technique differs from other cancer therapies designed to harness the body’s own immune system to fight tumors — such as therapeutic cancer vaccines. “We are saying forget about stimulating an immune response. We are going to give you an immune response,” Kalos said. The treatment appears safe, but researchers said more study was needed. The leukemia patients in the Phase I trial had to be treated with an immunity-boosting drug since the targeted molecule, CD-19, is also present on certain normal immune-system cells. To deliver the gene therapy, the researchers used a virus that can only infect cells once. It was used to carry a chimeric antigen receptor targeting CD-19 coupled with receptors for two other components of T-cell activity. About two weeks after the gene therapy, patients began to experience “tumor lysis syndrome” — chills, nausea and fever — caused by the break-down products of dying cancer cells. The engineered T-cells were detected in patients’ blood for several months afterward, and a portion of them turned into “memory T-cells,” which could provide ongoing protection against cancer recurrence, researchers surmised. Dr. Walter Urba of the Providence Cancer Center in Portland Oregon cautioned that continued presence of activated T-cells and memory cells might be more of a problem in other types of cancer where toxic effects on normal tissue could be more severe. In addition, the long-term viability of the treatment is still unknown. “One of the big questions is … will those persistent T-cells continue to work and prevent that tumor from coming back,” said Urba, who was not involved in the study. All of the funding for the University of Pennsylvania’s gene therapy work has come from the academic community, but the work is expensive. “We are looking for corporate partners as we head into Phase II trials,” Kalos said. Further study will show whether the latest results “reflect an authentic advance toward a clinically applicable and effective therapy or yet another promising lead that runs into a barrier that cannot be easily overcome,” Urba said in an NEJM editorial. (Reporting by Deena Beasley; Editing by Paul Simao)

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