A University of Colorado at Boulder-led study shows that specific types of stem cells transplanted into the leg muscles of mice prevented the loss of muscle function and mass that normally occurs with aging, a finding with potential uses in treating humans with chronic, degenerative muscle diseases.
The experiments showed that when young host mice with limb muscle injuries were injected with muscle stem cells from young donor mice, the cells not only repaired the injury within days, they caused the treated muscle to double in mass and sustain itself through the lifetime of the transplanted mice. “This was a very exciting and unexpected result,” said Professor Bradley Olwin of CU-Boulder’s molecular, cellular and developmental biology department, the study’s corresponding author. (more…)
COLUMBUS, Ohio – Depression appears to be associated with a molecular-level disturbance in the body’s 24-hour clock, new research suggests.
Scientists examined genes that regulate circadian rhythm in people with and without a history of depression. As a group, those with a history of depression had a higher level of activity of the so-called Clock gene, which has a role in regulating circadian rhythm, than did people with no mood disorders.
Higher expression levels of this gene suggest something is amiss in the body’s 24-hour biological and behavioral cycle, which could affect sleep patterns and other physiological functions governed by circadian rhythm. Sleep disturbance is a common symptom of depression.(more…)
*Initial science results on comet released from University of Maryland, much more to come UMD scientists say.*
Jets Galore. This enhanced image, one of the closest taken of comet Hartley 2. Image credit: University of Maryland
COLLEGE PARK, Md. – One of the biggest comet findings coming out of the amazing images and data taken by the University of Maryland-ledEPOXI mission as it zipped past comet Hartley 2 last week is that dry ice is the ‘jet’ fuel for this comet and perhaps many others.
Images from the flyby show spectacular jets of gas and particles bursting from many distinct spots on the surface of the comet. This is the first time images of a comet have been sharp enough to allow scientists to link jets of dust and gas with specific surface features. Analysis of the spectral signatures of the materials coming from the jets shows primarily CO2 gas (carbon dioxide) and particles of dust and ice.
“Previously it was thought that water vapor from water ice was the propulsive force behind jets of material coming off of the body, or nucleus, of the comet,” said University of Maryland Astronomy Professor Jessica Sunshine, who is deputy principal investigator for the EPOXI mission. “We now have unambiguous evidence that solar heating of subsurface frozen carbon dioxide (dry ice), directly to a gas, a process known as sublimation, is powering the many jets of material coming from the comet. This is a finding that only could have been made by traveling to a comet, because ground based telescopes can’t detect CO2 and current space telescopes aren’t tuned to look for this gas,” Sunshine said.(more…)
Hybrid Cardiac Procedure. Schematic of the heart showing the minimally-invasive approaches to allow access to the surface of the heart (the blue and red areas) during this hybrid cardiac procedure. Image credit: University of California
New techniques now being used at UCLA allow doctors to more precisely target certain areas of the heart to stop ventricular arrhythmias — serious abnormal rhythms in the heart’s lower chambers — in high-risk patients.
Generally, arrhythmias can be controlled by medications, and sometimes defibrillators. But a potentially life-threatening, recurrent arrhythmia known as a ventricular tachycardia, which originates in one of the heart’s two ventricles, can produce a fast heart beat that requires other interventions, such as catheter ablation, in which the precise focus area of the arrhythmia must be controlled.
Cardiologists will often use catheter ablation once medications and other therapies have failed. The procedure involves the insertion of a tiny, metal-tipped catheter through a vein in the groin or neck to reach the inside of the heart. Prior to the procedure, electrical tests are conducted on the heart to identify and map the exact site of the arrhythmia’s origin.(more…)
ANN ARBOR, Mich.—Kids who are deficient in vitamin D accumulated fat around the waist and gained weight more rapidly than kids who got enough vitamin D, a new University of Michigan study suggests.
Vitamin D, which is primarily provided to the body by the sun, has been a hot topic in the U.S. lately. The federal standards for vitamin D intake have come under fire by public health professionals as being much too low, and disagreement continues over the proper amount of vitamin D necessary for optimal health. (more…)
*Pregnant women whose sisters had condition are 17 times more likely to have it*
Approximately 60,000 pregnant women are hospitalized each year due to hyperemesis gravidarum (HG), an extreme form of nausea and vomiting that endangers their lives and often forces them to reluctantly terminate their pregnancies.
And for women with sisters, mothers and grandmothers on either side of the family who have experienced extreme morning sickness during pregnancy, the risk of HG may be heightened, according to a new study led by researchers from UCLA and the University of Southern California.(more…)
A model representation of telomerase's RNA "core domain," determined by Juli Feigon, Qi Zhang and colleagues in Feigon's UCLA laboratory. Image credit: Juli Feigon, UCLA Chemistry and Biochemistry/PNAS
Telomerase is an enzyme that maintains the DNA at the ends of our chromosomes, known as telomeres. In the absence of telomerase activity, every time our cells divide, our telomeres get shorter. This is part of the natural aging process, as most cells in the human body do not have much active telomerase. Eventually, these DNA-containing telomeres, which act as protective caps at the ends of chromosomes, become so short that the cells die.
But in some cells, such as cancer cells, telomerase, which is composed of RNA and proteins, is highly active and adds telomere DNA, preventing telomere shortening and extending the life of the cell.
UCLA biochemists have now produced a three-dimensional structural model of the RNA “core domain” of the telomerase enzyme. Because telomerase plays a surprisingly important role in cancer and aging, understanding its structure could lead to new approaches for treating disease, the researchers say.(more…)
*Petunias show that the mechanisms behind inbreeding prevention are similar to immune response*
About the image: The female part of the petunia flower secretes an enzyme that is designed to deter pollen tube growth, thereby preventing fertilization. However, in the cases that the pollen has come from a genetically different plant, the pollen produces its own protein that combats the pistil’s enzyme. With the enzyme out of the way, the pollen tube can keep growing and fertilization can occur. Image credit: Zina Deretsky, National Science Foundation
Inbreeding is a bad strategy for any organism, producing weak and problematic offspring. So imagine the challenge of inbreeding prevention in a plant where male and female sexual organs grow right next to each other! Such is the genetic conundrum faced by the petunia. (more…)
