jueves, 27 de febrero de 2014

Biomarked for Death—Four Blood Proteins Can Predict Early Demise

While you may appear to be healthy, you may be frailer than you know. You may even be at risk of death—from one disease or another—within the next five years. Would you want to know? You may now have the choice, thanks to researchers at the Estonian Genome Center and the Institute for Molecular Medicine, Finland.
These researchers have developed a screening technology. It looks for four biomarkers that have been associated with a risk of dying from any disease in the near future. Ordinarily, biomarkers are used to assess an individual’s risk of developing a specific condition. The new screening technology, however, is used to reveal general frailty, even in apparently healthy people. It reflects the risk for dying, whatever the ultimate cause—heart disease, cancer, or any other condition.
The biomarkers identified by the researchers are albumin, alpha-1-acid glycoprotein, citrate, and the size of very-low-density lipoprotein particles. Of these, albumin was the only one previously linked with mortality. All these molecules are normally present in everyone's blood—the amounts of these molecules are what matter. To assess the degree to which an individual’s biomarkers are imbalanced, the researchers found a way to compile a biomarker score.
The researchers found that individuals with a biomarker score in the top 20% had a risk of dying within five years that was 19 times greater than that of individuals with a score in the bottom 20% (288 versus 15 deaths). In addition, biomarker scores were still predictive of early death—that is, a death within the next five years—independent of well-known risk factors such as age, smoking, drinking, obesity, blood pressure, and cholesterol.
The researchers detailed their results February 25 in PLOS Medicine, in an article entitled “Biomarker Profiling by Nuclear Magnetic Resonance Spectroscopy for the Prediction of All-Cause Mortality: An Observational Study of 17,345 Persons.” To carry out their study, the researchers relied on technology that allowed them to screen blood samples for a wide range of blood biomarkers.
This technology, nuclear magnetic resonance (NMR) spectroscopy, screened for over 100 potential biomarkers in two cohorts of healthy people. The first cohort, investigated by Estonian members of the research team, consisted of 9,842 people. So astonished by what they found, the Estonian scientists asked their Finnish colleagues to repeat the experiment. The Finnish cohort, consisting of 7,503 people, produced the same result: Just four biomarkers are predictive of cardiovascular mortality, as well as death from cancer and other nonvascular diseases.
While the researchers emphasized that more studies would be needed before their findings could be implemented in clinical practice, they expressed optimism that their work could alert seemingly healthy people to the need for medical intervention. One of the study’s Finnish authors, Johnannes Kettunen, said, “We believe that in the future these measures can be used to identify people who appear healthy but in fact have serious underlying illnesses and guide them to proper treatment.”
In discussing their results, the authors of the PLOS Medicine story wrote, “In spite of [this study’s] limitations, the fact that the same four biomarkers are associated with a short-term risk of death from a variety of diseases does suggest that similar underlying mechanisms are taking place. This observation points to some potentially valuable areas of research to understand precisely what's contributing to the increased risk.”

Tomado de genengnews.com

martes, 25 de febrero de 2014

MIT Team Develops Urine Test for Cancer


Scientists at MIT say they have developed a simple, cheap paper test that could be used to improve cancer diagnosis rates and help people get treated earlier. The diagnostic, which works much like a pregnancy test, reportedly could reveal within minutes, based on a urine sample, whether a person has cancer. This approach has helped detect infectious diseases, and the new technology allows noncommunicable diseases to be detected using the same strategy.
The technique, developed by MIT professor and Howard Hughes Medical Institute investigator Sangeeta Bhatia, Ph.D., relies on nanoparticles that interact with tumor proteases, each of which can trigger release of hundreds of biomarkers that are then detectable in a patient's urine.
“When we invented this new class of synthetic biomarker, we used a highly specialized instrument to do the analysis,” said Dr. Bhatia. “For the developing world, we thought it would be exciting to adapt it instead to a paper test that could be performed on unprocessed samples in a rural setting, without the need for any specialized equipment. The simple readout could even be transmitted to a remote caregiver by a picture on a mobile phone.”
Dr. Bhatia, who is also a member of MIT's Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science, is the senior author of a paper (“Point-of-care diagnostics for noncommunicable diseases using synthetic urinary biomarkers and paper microfluidics”) describing the particles in Proceedings of the National Academy of Sciences.
In 2012, Dr. Bhatia and colleagues introduced the concept of a synthetic biomarker technology to amplify signals from tumor proteins that would be hard to detect on their own. These proteins, known as matrix metalloproteinases (MMPs), help cancer cells escape their original locations by cutting through proteins of the extracellular matrix, which normally holds cells in place.
The MIT nanoparticles are coated with peptides targeted by different MMPs. These particles congregate at tumor sites, where MMPs cleave hundreds of peptides, which accumulate in the kidneys and are excreted in the urine.
In the original version of the technology, these peptides were detected using a mass spectrometer. However, these instruments are not readily available in the developing world, so the researchers adapted the particles so they could be analyzed on paper, using a lateral flow assay.
“We describe the design of exogenous agents that serve as synthetic biomarkers for NCDs [noncommunicable diseases] by producing urinary signals that can be quantified by a companion paper test. These synthetic biomarkers are composed of nanoparticles conjugated to ligand-encoded reporters via protease-sensitive peptide substrates,” wrote the investigators. “Upon delivery, the nanoparticles passively target diseased sites…where up-regulated proteases cleave the peptide substrates and release reporters that are cleared into urine. The reporters are engineered for detection by sandwich immunoassays, and we demonstrate their quantification directly from unmodified urine.”
In tests in mice, the researchers were able to accurately identify colon tumors as well as blood clots. Dr. Bhatia says these tests represent the first step toward a diagnostic device that could someday be useful in human patients.
  • Tomado de genengnews.com

Marijuana may protect the immune system against SIV and slow disease progression

New evidence that chronic intake of THC, the primary psychoactive ingredient in marijuana, can protect critical immune tissue in the gut from the damaging effects of HIVinfection is reported in AIDS Research and Human Retroviruses, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available on the AIDS Research and Human Retroviruses website.
Patricia Molina and coauthors from Louisiana State University Health Sciences Center, New Orleans, report that chronic THC administration was associated with greater survival of T cell populations and reduced overall cell death in the gut in monkeys, which is known to be a key target for simian immunodeficiency virus (HIV) replication and infection-related inflammation. The researchers present their findings in the article "Modulation of Gut-Specific Mechanisms by Chronic-9-Tetrahydrocannabinol Administration in Male Rhesus Macaques Infected with Simian Immunodeficiency Virus: A Systems Biology Analysis." This report provides mechanistic insights into their previous observation that THC administration attenuates disease progression in SIV infected macaques (AIDS Research and Human Retroviruses 2011; 27: 585-592).
"To better treat HIV infection, we need a better understanding of how it causes the disease we call AIDS. We also need alternative approaches to treatment," says Thomas Hope, PhD, Editor-in-Chief of AIDS Research and Human Retroviruses and Professor of Cell and Molecular Biology at the Feinberg School of Medicine, Northwestern University, Chicago, IL. "This study is important because it begins to explain how THC can influence disease progression in SIV-infected macaques. It also reveals a new way to slow disease progression."
Referencia:Modulation of Gut-Specific Mechanisms by Chronic Δ9-Tetrahydrocannabinol Administration in Male Rhesus Macaques Infected with Simian Immunodeficiency Virus: A Systems Biology Analysis, Authors: Molina, Patricia E., Amedee, Angela M., Le Capitaine, Nicole J., Zabaleta, Jovanny, Mohan, Mahesh, Winsauer, Peter J., Vande Stouwe, Curtis, McGoey, Robin R., Auten, Matthew W., LaMotte, Lynn, Chandra, Lawrance C., and Birke, Leslie L., AIDS Research and Human Retroviruses. doi:10.1089/aid.2013.0182
Tomado de:medicalnewstoday.com

viernes, 7 de febrero de 2014

TOMA DE MUESTRA : SANGRE ARTERIAL

VIDEO SOBRE LA TOMA DE MUESTRA DE
 SANGRE  ARTERIAL





Tomado de MedicineUpToDate