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Washington: An international team of biomedical engineers has demonstrated for the first time that it is possible to grow healthy new bone reliably in one part of the body and use it to repair damaged bone at a different location. The research, which is based on a dramatic departure from the current practice in tissue engineering, is described in a paper titled "In vivo engineering of organs: The bone bioreactor" published online next week by the Proceedings of the National Academy of Science. "We have shown that we can grow predictable volumes of bone on demand," says V. Prasad Shastri, assistant professor of biomedical engineering at Vanderbilt University who led the effort. "And we did so by persuading the body to do what it already knows how to do." "This research has important implications not only for engineering bone, but for engineering tissues of any kind," adds co-author Robert S. Langer, Institute Professor at the Massachusetts Institute of Technology and a pioneer in the field of tissue engineering. "It has the potential for changing the way that tissue engineering is done in the future." The current approach currently used by orthopedic surgeons to repair serious bone breaks is to remove small pieces of bone from a patient's rib or hip and fuse them to the broken bone. They use the same method to fuse spinal vertebrae to treat serious spinal injuries and back pain. Although this works well at the repair site, the removal operation is extremely painful and can produce serious complications. If the new method is confirmed in clinical studies, it will become possible to grow new bone for all types of repairs instead of removing it from existing bones. For
people with serious bone disease, it may even be possible to grown replacement
bone at an early stage and freeze it so it can be used when it is needed,
says Prasad. Despite the fact that living bone is continually growing
and reshaping, the numerous attempts to coax it to grow bone outside
of the body--in vitro--have all failed. Recent attempts to stimulate
bone growth within the body--in vivo--have had limited success but have
proven to be extremely complex, expensive and unreliable. "The new bone
actually has comparable strength and mechanical properties to native
bone," says Molly Stevens, currently a reader at Imperial College in
the United Kingdom who did most of the research as a post-doctoral fellow
at MIT, "and since the harvested bone is fresh it integrates really
well at a recipient site." The scientists intend to proceed with the
large animal studies and clinical trials necessary to determine if the
procedure will work in humans and, if it does, to get it approved for
human treatment. At the same time, they hope to test the approach with
the liver and pancreas, which have outer layers similar to the periosteum. Grapefruit extract may heal stomach ulcers (Go To Top) London:
Polish researchers, after successfully using grapefruit's seed to
reduce the size of stomach ulcers in rats, have claimed that the fruit
extract can help heal stomach ulcers. Gastric ulcer is a break in the
normal tissue lining the stomach and includes symptoms such as abdominal
pain, nausea, indigestion, weight loss and fatigue. Jagiellonian researchers
found that grapefruit extract had strong antibacterial and antioxidant
properties, which calm the gastric tract and aid the healing process.
They induced gastric ulcers in rats, and applied graded doses of the
fruit extract to measure its effect. They looked at levels of gastric
secretion, which is one of the major causes of gastric ulcers. Rats
treated with GSE at 10 mg/kg experienced a 50 percent reduction in gastric
acid secretion, and a progressive decrease in the area of their ulcer.
The treatment also prompted a significant rise in blood flow at the
ulcer sites. But the beneficial effects were diminished in the presence
of drugs that inhibit two enzymes, which play a key role in maintaining
the health of the stomach lining. "Because grapefruit is acidic in nature,
people with ulcers might assume that they should not include the fruit
in their diet. However, this research suggests the exact opposite,"
the BBC quoted Lead researcher Dr Thomas Brzozowski as saying. 'Haldi' may hold the cure for cancer (Go To Top) Washington:
Curcumin, the pungent yellow spice found in both turmeric and curry
powders, blocks a key biological pathway needed for development of melanoma
and other cancers, say researchers from The University of Texas M. D.
Anderson Cancer Centre. The study shows how curcumin stops laboratory
strains of melanoma from proliferating and pushes the cancer cells to
commit suicide. The study is the latest to suggest that curcumin has
potent anticancer powers, say the researchers. "The antioxidant, anti-inflammatory
and anti-carcinogenic properties of curcumin derived from turmeric are
undergoing intense research here and at other places worldwide," said
one of the study's authors, Bharat B. Aggarwal, Ph.D., professor of
cancer medicine in the Department of Experimental Therapeutics. While
researchers had thought curcumin primarily has anti- inflammatory properties,
the growing realization that cancer can result from inflammation has
spurred mounting interest in the spice as an anti-cancer agent, Aggarwal
says. He adds that another fact has generated further excitement: "The
incidence of the top four cancers in the U.S. - colon, breast, prostate,
and lung - is ten times lower in India," he says. He said that an ability
to suppress numerous biological routes to cancer development is important
if an agent is to be effective. "Cells look at everything in a global
way, and inhibiting just one pathway will not be effective," says Aggarwal. Early screening reduces prostate cancer mortality rate (Go To Top) Washington:
Early screening of prostate cancer in men may reduce their risk
of death from prostate cancer by as much as 35 per cent, researchers
from the University of Toronto have found. "Early screening with the
prostate specific antigen (PSA) is quite controversial. There are many
arguments both for and against the efficacy of this form of early screening,"
says Vivek Goel, professor of public health sciences and health policy
management and evaluation at University of Torronto and one of the senior
authors of the study. "Our study shows a fairly significant benefit,
and this benefit is demonstrated even among men who were not screened
regularly as part of a screening program. There may be greater benefit
from an organized screening program," he added. Published in the August
issue of the Journal of Urology, Goel and Jacek Kopec, a professor at
the University of British Columbia, did much of this work while both
were part of U of T's public health sciences department. The researchers
conducted a population-based case control study in the Greater Toronto
Area of 236 men with advanced metastatic prostate cancer and a control
group of 462 men who did not have metastatic prostate cancer. They found
that PSA screening of asymptomatic men reduced their risk of metastatic
prostate cancer by 35 per cent. "Just by chance alone you're going to
be picking up some of those prostate cancers, and those people wind
up getting labeled as prostate cancer patients," states Goel. "They
get treatments for it, surgery, radiation, chemotherapy, hormonal therapy
- all of which have side effects - not to mention the anxiety and angst
associated with having prostate cancer as a label. But the reality also
is that they may never have actually died of the prostate cancer because
it was so localized." Asprin therapy strongly recommended for heart patients (Go To Top) London:
A new study published in the July 1, 2005, issue of the American
Journal of Health-System Pharmacy is urging health care providers to
recognize, that despite decades of evidence that aspirin can prevent
heart attacks, some patients are still not receiving this simple and
cost-effective therapy. It is titled The newly revised "ASHP Therapeutic
Position Statement on the Daily Use of Aspirin for Preventing Cardiovascular
Events" and affirms that daily use of aspirin, in combination with other
effective drug therapies and modifying controllable risk factors, can
prevent first and subsequent heart attacks. "A daily aspirin is simple,
inexpensive, and very effective, yet not all eligible patients are receiving
this therapy. That means we are missing opportunities to help patients
avoid the devastating effects of heart attacks." ASHP President Jill
E. Martin said. The therapeutic position statement acknowledges the
importance of assessing a patient's risk for bleeding, which can be
a serious adverse effect of taking aspirin. "Pharmacists are uniquely
positioned to help patients reduce their risk factors. The best way
to reduce the chance of a heart attack is to combine aspirin therapy
with changing controllable risk factors, such as obesity, smoking, high
cholesterol, and high blood pressure," Martin added. Nanotubes to heal broken bones (Go To Top) Washington:
Scientists have shown for the first time that carbon nanotubes make
an ideal scaffold for the growth of bone tissue. The new technique could
change the way doctors treat broken bones, allowing them to simply inject
a solution of nanotubes into a fracture to promote healing. The report
appears in the June 14 issue of the American Chemical Society's journal
Chemistry of Materials. ACS is the world's largest scientific society.
The success of a bone graft depends on the ability of the scaffold to
assist the natural healing process. Artificial bone scaffolds have been
made from a wide variety of materials, such as polymers or peptide fibers,
but they have a number of drawbacks, including low strength and the
potential for rejection in the body. "Compared with these scaffolds,
the high mechanical strength, excellent flexibility and low density
of carbon nanotubes make them ideal for the production of lightweight,
high-strength materials such as bone," says Robert Haddon, Ph.D., a
chemist at the University of California, Riverside, and lead author
of the paper. Single-walled carbon nanotubes are a naturally occurring
form of carbon, like graphite or diamond, where the atoms are arranged
like a rolled-up tube of chicken wire. They are among the strongest
known materials in the world. Bone tissue is a natural composite of
collagen fibers and hydroxyapatite crystals. Haddon and his coworkers
have demonstrated for the first time that nanotubes can mimic the role
of collagen as the scaffold for growth of hydroxyapatite in bone. "This
research is particularly notable in the sense that it points the way
to a possible new direction for carbon nanotube applications, in the
medical treatment of broken bones," says Leonard Interrante, Ph.D.,
editor of Chemistry of Materials and a professor in the department of
chemistry and chemical biology at Rensselaer Polytechnic Institute in
Troy, N.Y. "This type of research is an example of how chemistry is
being used everyday, world-wide, to develop materials that will improve
peoples' lives." The researchers expect that nanotubes will improve
the strength and flexibility of artificial bone materials, leading to
a new type of bone graft for fractures that may also be important in
the treatment of bone-thinning diseases such as osteoporosis. The new
technique may someday give doctors the ability to inject a solution
of nanotubes into a bone fracture, and then wait for the new tissue
to grow and heal. Earth's oceans may turn to acid by 2100 (Go To Top) Washington:
A new study has revealed that oceans around the world are fast turning
into acidic water bodies. The study conducted by Dr Ken Caldeira from
the Carnegie Institution's Department of Global Ecology in Stanford,
California says that human activities are producing so much carbon dioxide
that under the present circumstances the world's oceans are all going
to turn acidic by 2100 and severely threaten marine life. "If Carbon
dioxide from human activities continues to rise, the oceans will become
so acidic by 2100 it could threaten marine life in ways we can't anticipate,"
the report issued by the Royal Society, UK quoted Caldeira co-author
of the report as saying. Scientists further said that the oceans were
an important part of the ecological system and helped in slowing global
warming. Marine plants, they said, soaked up carbon dioxide and converted
it into food during photosynthesis. Organisms also used it to make their
skeletons and shells, which eventually formed sediments. Scientists
said that with the explosion of fossil-fuel burning over the past 200
years, more than one third of the green house gases generated by humans
had been absorbed into the oceans. They however, said that too much
of carbon dioxide into the water would disrupt the ecological balance
in the oceans. Carbon dioxide upon dissolving into the water produced
carbonic acid, which corroded the shells of marine organisms and interfered
with the oxygen supply in the marine environment, the study said. This,
they said would also interrupt the process of shell and coral formation
and adversely affect other organisms dependent upon corals and shellfish,
adding that the acidity could also negatively impact other calcifying
organisms, such as phytoplankton and zooplankton, which form the base
of the food chain in the oceans. "We can predict the magnitude of the
acidification based on the evidence that has been collected from the
ocean's surface, the geological and historical record, ocean circulation
models, and what's known about ocean chemistry. What we can't predict
is just what acidic oceans mean to ocean ecology and to Earth's climate.
International and governmental bodies must focus on this area before
it's too late," added Caldiera. They further said that in the past 200
years, the pH value of surface seawater has declined by 0.1 units, which
is a 30 increase in hydrogen ions, adding that if carbon dioxide emissions
continued, there would be another drop in pH by .5 units by 2100, something
that has not existed for millions of years. References: India Travel Times, News, Hotels, Airlines, Indian, Tourism, Tourist, Tour, Ayurveda, Yoga, Hotel |
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