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When infections occur in the body, stem cells in the blood often jump into action by multiplying and differentiating into mature immune cells that can fight off illness. But repeated infections and inflammation can deplete these cell populations, potentially leading to the development of serious blood conditions such as cancer. Now, a team of researchers led by biologists at the California Institute of Technology (Caltech) has found that, in mouse models, the molecule microRNA-146a (miR-146a) acts as a critical regulator and protector of blood-forming stem cells (called hematopoietic stem cells, or HSCs) during chronic inflammation, suggesting that a deficiency of miR-146a may be one important cause of blood cancers and bone marrow failure.
DNA-tethered nanorods link up like rungs on a ribbonlike ladder—a new mechanism for linear self-assembly that may be unique to the nanoscale. Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have discovered that DNA "linker" strands coax nano-sized rods to line up in way unlike any other spontaneous arrangement of rod-shaped objects. The arrangement-with the rods forming "rungs" on ladder-like ribbons linked by multiple DNA strands-results from the collective interactions of the flexible DNA tethers and may be unique to the nanoscale. The research, described in a paper published online in ACS Nano, a journal of the American Chemical Society, could result in the fabrication of new nanostructured materials with desired properties.
This image shows Matthias Hebrok, Ph.D., University of California, San Francisco. Raising hopes for cell-based therapies, UC San Francisco researchers have created the first functioning human thymus tissue from embryonic stem cells in the laboratory. The researchers showed that, in mice, the tissue can be used to foster the development of white blood cells the body needs to mount healthy immune responses and to prevent harmful autoimmune reactions.
May 9, 2013, New York, NY and San Diego, CA – A large, multi-institutional research team involved in the NIH Epigenome Roadmap Project has published a sweeping analysis in the current issue of the journal Cell of how genes are turned on and off to direct early human development. Led by Bing Ren of the Ludwig Institute for Cancer Research, Joseph Ecker of The Salk Institute for Biological Studies and James Thomson of the Morgridge Institute for Research, the scientists also describe novel genetic phenomena likely to play a pivotal role not only in the genesis of the embryo, but that of cancer as well. Their publicly available data, the result of more than four years of experimentation and analysis, will contribute significantly to virtually every subfield of the biomedical sciences.
Children born with rare, inherited conditions known as Congenital Disorders of Glycosylation, or CDG, have mutations in one of the many enzymes the body uses to decorate its proteins and cells with sugars. Properly diagnosing a child with CDG and pinpointing the exact sugar gene that's mutated can be a huge relief for parents—they better understand what they're dealing with and doctors can sometimes use that information to develop a therapeutic approach. Whole-exome sequencing, an abbreviated form of whole-genome sequencing, is increasingly used as a diagnostic for CDG.
A team of NIH scientists has developed a new tool to identify broadly neutralizing antibodies (bNAbs) capable of preventing infection by the majority of HIV strains found around the globe, an advance that could help speed HIV vaccine research. Scientists have long studied HIV-infected individuals whose blood shows powerful neutralization activity because understanding how HIV bNAbs develop and attack the virus can yield clues for HIV vaccine design. But until now, available methods for analyzing blood samples did not easily yield specific information about the HIV bNAbs present or the parts of the virus they targeted. In addition, determining where and how HIV bNAbs bind to the virus has been a laborious process involving several complicated techniques and relatively large quantities of blood from individual donors.
The U.S. Department of Energy Joint Genome Institute (DOE JGI) is among the world leaders in sequencing the genomes of microbes, focusing on their potential applications in the fields of bioenergy and environment. As a national user facility, the DOE JGI is also focused on developing tools that more cost-effectively enable the assembly and analysis of the sequence that it, as well as other genome centers, generates.
UCSF scientists controlled seizures in epileptic mice with a one-time transplantation of medial ganglionic eminence (MGE) cells, which inhibit signaling in overactive nerve circuits, into the hippocampus, a brain region associated with seizures, as well as with learning and memory. Other researchers had previously used different cell types in rodent cell transplantation experiments and failed to stop seizures.
A new study led by researchers from Harvard School of Public Health (HSPH) and the Wellcome Trust Sanger Institute in the UK has, for the first time, used genome sequencing technology to track the changes in a bacterial population following the introduction of a vaccine. The study follows how the population of pneumococcal bacteria changed following the introduction of the 'Prevnar' conjugate polysaccharide vaccine, which substantially reduced rates of pneumococcal disease across the U.S. The work demonstrates that the technology could be used in the future to monitor the effectiveness of vaccination or antibiotic use against different species of bacterial pathogens, and for characterizing new and emerging threats.
Endometrial tumors can be reclassified into distinct subtypes based partly on their genomic makeup and may respond to targeted drugs already being tested in clinical trials, according to a large-scale genomic analysis led by researchers at Memorial Sloan-Kettering Cancer Center and other centers within The Cancer Genome Atlas (TCGA) Research Network.
Mammalian females ovulate periodically over their reproductive lifetimes, placing significant demands on their ovaries for egg production. Whether mammals generate new eggs in adulthood using stem cells has been a source of scientific controversy. If true, these "germ-line stem cells" might allow novel treatments for infertility and other diseases. However, new research from Carnegie's Lei Lei and Allan Spradling demonstrates that adult mice do not use stem cells to produce new eggs. Their work is published by the Proceedings of the National Academy of Sciences the week of April 29.
Scientists in Mainz and Aachen have discovered a new mechanism that controls egg cell fertility and that might have future therapeutic potential. It was revealed by Professor Dr. Walter Stöcker of the Institute of Zoology at Johannes Gutenberg University Mainz (JGU) that the blood protein fetuin-B plays an important and previously unknown role in the fertilization of oocytes. Fetuin-B, first identified in the year 2000, is formed in the liver and secreted into the blood stream. During a joint research project with researchers at RWTH Aachen University headed by Professor Dr. Willi Jahnen-Dechent of the Helmholtz Institute for Biomedical Engineering, it was discovered that fetuin-B contributes to egg cell fertility by regulating the hardening of the protective zona pellucida of oocytes. The findings have recently been published in the scientific journal Developmental Cell.