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A new study has identified a set of unique cells within the adult tendon that have stem cell traits including the capacity to proliferate and self-renew, offering hope for the treatment of tendon injuries caused by overuse and trauma.“Clinically, tendon injury is a difficult one to treat, not only for athletes but for patients who suffer from tendinopathy such as tendon rupture or ectopic ossification,” Nature quoted Songtao Shi from the University of Southern California (USC) School of Dentistry, as saying.

“This research demonstrates that we can use stem cells to repair tendons. We now know how to collect them from tissue and how to control their formation into tendon cells,” Shi added.

Prior to this research, little was known about the cellular makeup of tendons and its originators.

By looking at tendons at the molecular level, the study team discovered a unique cell population called tendon stem/progenitor cells (TSPCs) in both mice and adult human that structure into tendon cells in a particular molecular environment.

The results of the research will be published in the October 2007 issue of the journal Nature Medicine. (ANI)

Scientists have identified a way to develop a vaccine against Chlamydia trachomatis, the most prevalent sexually transmitted bacterial infection in the world.Boffins identified plasmid-deficient derivatives of the Chlamydia trachomatis strains that when investigated in an animal model of genital tract infection, failed to cause disease.

The researchers now believe that this may serve as a vaccine against the disease.

The research was led by Toni Darville, MD, chief of the Division of Pediatric Infectious Diseases along with other scientists at Children’s Hospital of Pittsburgh of UPMC. The results of the study are published in the Sept. 15 issue of the Journal of Immunology.

“This finding represents a major step forward in our work to eventually develop a vaccine against chlamydial disease,” said Dr. Darville, senior author of the study and also a professor of pediatrics and microbiology/immunology at the University of Pittsburgh School of Medicine.

“If we can identify plasmid-deficient derivatives of the C. trachomatis strains that infect humans, they would have the potential to serve as a vaccine against this disease.”

Symptoms of the infection are usually mild or absent, so, it can damage a woman’s reproductive organs and cause irreversible damage, including infertility, before a woman ever recognizes a problem.

In this study, a plasmid-deficient strain derived from Chlamydia muridarum was introduced to mice. The mice became infected but did not develop the trademark signs of chlamydial disease, particularly damage to the oviduct, the tube that carries eggs from the ovaries, according to Catherine M. O’Connell, PhD, a researcher in Dr. Darville’s laboratory and first author of the study.

“Not only did the mice not develop oviduct scarring after infection with the plasmid-deficient strain, we also found that the mice previously infected with these strains were protected against oviduct disease when later infected with fully virulent C. muridarum,” Dr. O’Connell said.

Chemists at Rice University say that they have devised a technique to create tiny spheres comprising of dozens of molecules of the anti-cancer drug paclitaxel by using gold nanoparticles.The investigators claim that the tiny balls they have created are many times smaller than a living cell that literally bristles with the drug sold under the brand name Taxol, which prevents cancer cells from dividing by jamming their inner works.

“Paclitaxel is one of the most effective anti-cancer drugs, and many researchers are exploring how to deliver much more of the drug directly to cancer cells,” said lead researcher Eugene Zubarev, the Norman Hackerman-Welch Young Investigator and assistant professor of chemistry at Rice.

“We looked for an approach that would clear the major hurdles people have encountered — solubility, drug efficacy, bioavailability and uniform dispersion — and our initial results look very promising,” he added.

Paclitaxel-used to treat breast, ovarian and other cancers-slows down the growth of tumours in some patients by decelerating the process of cancer cells’ division. But since the drug works on all cells, it also tends to inhibit the division of healthy cells.

The researchers say that it is due to this problem with paclitaxel use that patients undergoing chemotherapy sometimes suffer side effects like hair loss and suppressed immune function.

“Ideally, we’d like to deliver more of the drug directly to the cancer cells and reduce the side effects of chemotherapy. In addition, we’d like to improve the effectiveness of the drug, perhaps by increasing its ability to stay bound to microtubules within the cell,” Zubarev said.

He worked with graduate student Jacob Gibson to develop the new drug delivery system that centres on a tiny ball of gold, barely wider than a strand of DNA.

The researchers first designed a chemical “wrapper” to shroud the drug’s key, located on the face of each bristle, in order to protect it from any chemical reactions. With the wrapped version of the drug, they undertook a series of reactions to attach the drug to linker molecules that were attached to the ball.

In the final step of the reaction, the researchers dissolved the wrapper to restore the drug’s key.

“We are already working on follow-up studies to determine the potency of the paclitaxel-loaded nanoparticles. Since each ball is loaded with a uniform number of drug molecules, we expect it will be relatively easy to compare the effectiveness of the nanoparticles with the effectiveness of generally administered paclitaxel,” Zubarev said.

The research has been reported in the Journal of the American Chemical Society.

A new study by researchers at the University of California, Los Angeles (UCLA) have identified a distinct pattern of gene expression in immune cells from people who experience chronically high levels of loneliness.The researchers say that their findings link social isolation to alterations in the activity of genes that drive inflammation, the first response of the immune system.

According to them, their study provides a molecular framework for understanding why social factors are linked to an increased risk of heart disease, viral infections and cancer.

Previous studies had shown that lonely people suffered from higher mortality than others. The researchers are now trying to determine whether this risk is an outcome of reduced social resources like physical or economic assistance or of the biological impact of social isolation on the function of the human body.

“What this study shows is that the biological impact of social isolation reaches down into some of our most basic internal processes the activity of our genes.” said Steve Cole, an associate professor of medicine in the division of Hematology-Oncology at the David Geffen School of Medicine, and a member of the UCLA Cousins Center for Psychoneuroimmunology.

“We found that changes in immune cell gene expression were specifically linked to the subjective experience of social distance. The differences we observed were independent of other known risk factors, such as health status, age, weight, and medication use. The changes were even independent of the objective size of a person’s social network,” said Cole, who is also a member of the Jonsson Comprehensive Cancer Center.

Working with collaborators from the University of Chicago, Cole and his colleagues used DNA micro-arrays to survey the activity of all known human genes in white blood cells from 14 individuals in the Chicago Health, Aging, and Social Relations Study.

The researchers say that six participants scored in the top 15 per cent of the UCLA Loneliness Scale, a widely used measure of loneliness that was developed in the 1970s. Other study subjects scored in the bottom 15 per cent, they add.

It was observed that 209 gene transcripts (the first step in the making of a protein) were differentially expressed between the two groups, with 78 being overexpressed and 131 underexpressed.

“Leukocyte (white blood cell) gene expression appears to be remodelled in chronically lonely individuals,” said Cole.

He said that genes overexpressed in lonely individuals included many involved in immune system activation and inflammation, but certain genes involved in antiviral responses and antibody production were underexpressed.

“These findings provide molecular targets for our efforts to block the adverse health effects of social isolation,” said Cole.

“We found that what counts at the level of gene expression is not how many people you know, it’s how many you feel really close to over time,” he added.

He said that the transcriptional fingerprint identified by his team might become useful as a ‘biomarker’ to monitor interventions designed to reduce the impact of loneliness on health in future.

The study has been published in the journal Genome Biology.

A new study by researchers at the University of California, Los Angeles (UCLA) have identified a distinct pattern of gene expression in immune cells from people who experience chronically high levels of loneliness.The researchers say that their findings link social isolation to alterations in the activity of genes that drive inflammation, the first response of the immune system.

According to them, their study provides a molecular framework for understanding why social factors are linked to an increased risk of heart disease, viral infections and cancer.

Previous studies had shown that lonely people suffered from higher mortality than others. The researchers are now trying to determine whether this risk is an outcome of reduced social resources like physical or economic assistance or of the biological impact of social isolation on the function of the human body.

“What this study shows is that the biological impact of social isolation reaches down into some of our most basic internal processes the activity of our genes.” said Steve Cole, an associate professor of medicine in the division of Hematology-Oncology at the David Geffen School of Medicine, and a member of the UCLA Cousins Center for Psychoneuroimmunology.

“We found that changes in immune cell gene expression were specifically linked to the subjective experience of social distance. The differences we observed were independent of other known risk factors, such as health status, age, weight, and medication use. The changes were even independent of the objective size of a person’s social network,” said Cole, who is also a member of the Jonsson Comprehensive Cancer Center.

Working with collaborators from the University of Chicago, Cole and his colleagues used DNA micro-arrays to survey the activity of all known human genes in white blood cells from 14 individuals in the Chicago Health, Aging, and Social Relations Study.

The researchers say that six participants scored in the top 15 per cent of the UCLA Loneliness Scale, a widely used measure of loneliness that was developed in the 1970s. Other study subjects scored in the bottom 15 per cent, they add.

It was observed that 209 gene transcripts (the first step in the making of a protein) were differentially expressed between the two groups, with 78 being overexpressed and 131 underexpressed.

“Leukocyte (white blood cell) gene expression appears to be remodelled in chronically lonely individuals,” said Cole.

He said that genes overexpressed in lonely individuals included many involved in immune system activation and inflammation, but certain genes involved in antiviral responses and antibody production were underexpressed.

“These findings provide molecular targets for our efforts to block the adverse health effects of social isolation,” said Cole.

“We found that what counts at the level of gene expression is not how many people you know, it’s how many you feel really close to over time,” he added.

He said that the transcriptional fingerprint identified by his team might become useful as a ‘biomarker’ to monitor interventions designed to reduce the impact of loneliness on health in future.

The study has been published in the journal Genome Biology.