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Archive - Aug 9, 2013

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New Treatment for Brittle Bone Disease Found

A new treatment for children with brittle bone disease has been developed by scientists at the University of Sheffield and Sheffield Children’s Hospital. The study of the new treatment for children with the fragile bone disease osteogenesis imperfecta was published online on August 6, 2013 in The Lancet. This is the first study to clearly demonstrate that the use of the medicine risedronate can not only reduce the risk of fracture in children with brittle bones but also have rapid action - the curves for fracture risk begin to diverge after only six weeks of treatment. Dr. Nick Bishop, Professor of Pediatric Bone Disease at the University of Sheffield, said: “We wanted to show that the use of risedronate could significantly impact on children's lives by reducing fracture rates - and it did. The fact that this medicine can be given by mouth at home (other similar medicines are given by a drip in hospital) makes it family-friendly.” The study, funded by the Alliance for Better Bone Health, trialled children with osteogenesis imperfecta aged 4-15 years and showed that oral risedronate reduced the risk of first and recurrent clinical fractures and that the drug was generally well tolerated. For more information about osteogenesis imperfecta, visit the Brittle Bone Society (http://www.brittlebone.org/). [Press release] [The Lancet abstract]

Genetics of Planktonic Fossils May Shed New Light on Evolutionary Processes

An evolutionary ecologist at the University of Southampton in the UK, is using 'grains of sand' to understand more about the process of evolution. Dr. Thomas Ezard is using the fossils of microscopic aquatic creatures called planktonic foraminifera, often less than a millimeter in size, which can be found in all of the world's oceans. The remains of their shells now resemble grains of sand to the naked eye and date back hundreds of millions of years. A new paper by Dr. Ezard, published online on August 9, 2013 in an open-access article in the journal Methods in Ecology & Evolution, opens the debate on the best way to understand how new species come into existence (speciation). The debate concerns whether fossil records such as those of the planktonic foraminifera, contain useful evidence of speciation over and above the molecular study of evolution. Molecular evolution traditionally uses evidence from species that are alive today to determine what their ancestors may have looked like, whereas this new research promotes the importance of using fossil records in conjunction with the molecular models. Dr. Ezard, from Biological Sciences and the Institute for Life Sciences at Southampton, says: "Because planktonic foraminifera have been around for many millions of years and rocks containing groups of their species can be dated precisely, we can use their fossils to see evidence of how species evolve over time. We can also see how differences between individual members of species develop and, in theory, how a new species comes into existence. The controversial hypothesis we test is that the processes leading to a new species coming into existence provoke a short, sharp burst of rapid genetic change.

Successful Treatment of Triple Negative Breast Cancer by Modulating OGF-OGFr Axis

Researchers at The Pennsylvania State University College of Medicine, led by Dr. Ian S. Zagon, have discovered that a novel biological pathway, the OGF-OGFr (opioid growth factor-opioid growth factor receptor) axis, can be modulated in human triple-negative breast cancer cells to inhibit cancer proliferation. According to BreastCancer.org, 1 in 8 women in the U.S. will develop invasive breast cancer and more than 39,000 deaths occur annually. Approximately 15 to 20% of all breast cancers are designated as triple-negative meaning that the cancer cells lack estrogen and progesterone receptors, and do not overexpress human epidermal growth factor receptor (HER-2), thereby limiting responsiveness to approved therapy. In the June 2013 issue of Experimental Biology and Medicine, Dr. Zagon and colleagues demonstrate that exposure of human breast cancer cell lines to OGF in vitro repressed growth within 24 hours in a receptor-mediated and reversible manner. Treatment with low dosages of the opioid antagonist naltrexone (LDN) provoked a compensatory elevation in endogenous opioids (i.e., OGF) and receptors that interact for 18-20 hours daily following receptor blockade to elicit a robust inhibition of cell proliferation. Because OGF is an endogenous neuropeptide, there are minimal or no side effects. The mechanism of action for OGF is upregulation of the p21 cyclin-dependent inhibitory kinase pathway that delays passage through the cell cycle. OGF also confers some level of protection against paclitaxel treatment, a standard breast cancer therapy. A dosage of 10(-8) M paclitaxel given alone caused marked apoptosis, but resulted in 60% less cell death when given in the presence of OGF. In patients, paclitaxel often is accompanied by side effects that reduce compliance.

Whole-Genome Sequencing Reveals Mysteries of the Endangered Chinese Alligator

In a study published online on August 6, 2013 in an open-access article in Cell Research, Chinese scientists from Zhejiang University and BGI have completed the genome sequencing and analysis of the endangered Chinese alligator (Alligator sinensis). This is the first published crocodilian genome, providing a good explanation of how terrestrial-style reptiles adapt to aquatic environments and temperature-dependent sex determination (TSD). The Chinese alligator is a member of the alligator family that lives in China. It is critically endangered with a population of ~100 wild and ~10,000 captive individuals in Zhejiang and Anhui Provinces. Great efforts have been put into uncovering the mysteries of this species because of its unique features that allow the animals to be be adapted for living in both water and land habitats. In this study, researchers collected a Chinese alligator sample from Changxing Yinjiabian Chinese Alligator Nature Reserve (Zhejiang Province, China) and sequenced its genome using a whole-genome shotgun strategy. The genomic data yielded a draft sequence of Chinese alligator with the size of 2.3 Gb, and a total of 22,200 genes were predicted. The genomic data provides strong evidence from the DNA level to illustrate why the Chinese alligator can hold its breath under water for long periods of time, such as the duplication of the bicarbonate-binding hemoglobin gene, positively selected energy metabolism, and others. Researchers further identified the genetic signatures of the powerful sensory system and immune system of the Chinese alligator. All the results presented evidence for co-evolution of multiple systems specific to the back-to-the water transition. Chinese alligator exhibits TSD, and does not possess sex chromosomes. The absence of sex chromosomes is another interesting feature.