"Our study showed how arsenic directly targets these proteins and
kills them," lead researcher Zhang Xiaowei at the State Key Laboratory
of Medical Genomics in Shanghai, China, told Reuters.
"Unlike chemotherapy, the side effects of arsenic (in treating acute
promyelocytic leukemia) are very low. There is no hair loss or
suppression of bone marrow (function). We are interested in finding
out how arsenic can be used in other cancers," Zhang said by
Well known for its toxicity, arsenic was regarded in the past as the
king among poisons because its symptoms are like those of cholera and
can often go undetected.
In China, however, it has long served a dual purpose. Apart from
intentional poisoning, it has been used for at least 2,000 years in
traditional Chinese medicine.
In 1992, a group of Chinese doctors reported how they used arsenic to
treat acute promyelocytic leukemia (APL), a blood and bone marrow
cancer that has surprisingly high cure rates of over 90 percent in
However, the actual workings of arsenic and how it interacts with
cancer tissues has never been clear -- until Zhang and his colleagues
used modern technology to find out.
In a paper published in the journal Science, Zhang and his team, which
includes Health Minister Chen Zhu, described how they used modern
equipment and saw how arsenic attacked specific proteins that would
otherwise be keeping the cancer alive and well.
"This shows how Western technology can be used to find out about the
mysteries of Chinese medicine," Zhang said.
"Although many countries are now using arsenic to treat APL, some
countries are resistant to the idea. It depends a lot on whether
doctors recommend it and whether patients accept it."
In APL, there is a drop in the production of normal red blood cells
and platelets, resulting in anemia and thrombocytopenia. The bone
marrow is unable to produce healthy red blood cells. Until the 1970s,
APL was 100 percent fatal and there was no effective treatment.
"The clinical result of arsenic in treating APL is well-established.
More than 90 percent of APL patients in China have (at least) five
years of disease-free survival," Zhang said.
In a separate commentary in Science, Scott Kogan at the University of
California San Francisco Cancer Center wrote that proper case
selection and combination therapy with arsenic may lead to improved
outcomes for treating not only promyelocytic leukemia, but other
diseases as well.
"If so, an ancient medicine, revived through careful clinical and
biological studies in modern times, will have an even greater impact
on human health," wrote Kogan, who was not linked to the Chinese
(Editing by Chris Lewis and Sugita Katyal)
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Man Is A Herbivore!
DEAD PEOPLE WALKING
"Arsenic adsorption to iron"
"Iron-adsorbing agent Chitosan"
Factors Influencing Arsenite Removal by Zero-Valent Iron
J. Envir. Engrg. Volume 132, Issue 11, pp. 1459-1469
Xueyuan Yu,1 Christopher Amrhein,2 Yiqiang Zhang,3 and Mark R.
1San Diego Regional Water Quality Control Board, 9174 Sky Park Court,
San Diego, CA 92123-4340. E-mail: he...@waterboards.ca.gov
2Professor, Dept. of Environmental Sciences, Univ. of California,
Riverside, Riverside, CA 92521. E-mail: christoph...@ucr.edu
3Postgraduate Researcher, Dept. of Environmental Sciences, Univ. of
Riverside, Riverside, CA 92521. E-mail: yiqian...@ucr.edu
4Associate Dean for Research and Graduate Education, Bourns College of
Univ. of California, Riverside, Riverside, CA 92521 (corresponding
The effects of pH, alkalinity, and mass transfer efficiency on the
of arsenite [As(III)] by zero-valent iron (ZVI) were evaluated in this
The optimum pH range for removal of As(III) was found to be between
7 and 8.
As(III) removal varied with salinity, pH, alkalinity conditions, and
Degradation of As(III) removal performance was observed only under
conditions of high alkalinity and arsenic concentrations [alkalinity
CaCO3/L and 2.9 mg/L As(III)].
A strong correlation between As(III) removal and increasing Reynolds
number in batch testing suggests that mass transfer efficiency plays
important role in the removal of As(III) by ZVI.
A diffusion-limited adsorption model was used to describe the removal
As(III) as the result of adsorption to precipitated iron oxides
After an initial period of As(III) rapid adsorption to surface rusts
during manufacturing and exposure to air, As(III) removal rate is most
controlled by the rate of iron corrosion and the diffusion of As(III)
adsorption sites in ZVI/iron oxides.
History: Submitted 19 January 2005; accepted 17 March 2006
First evidence that chitosan could repair spinal damage
April 16, 2010 Spinal injuries are some of the most debilitating that
anyone can suffer. However, Richard Borgens and his team from the
Center for Paralysis Research at the Purdue School of Veterinary
Medicine can now offer spinal cord damage sufferers some hope. They
publish their discovery in the Journal of Experimental Biology that
chitosan, a sugar, can target and repair damaged spinal cord nerve
membranes and restore nerve function.
Richard Borgens and his colleagues from the Center for Paralysis
Research at the Purdue School of Veterinary Medicine have a strong
record of inventing therapies for treating nerve damage. From Ampyra,
which improves walking in multiple sclerosis patients to a spinal
simulator for spinal injury victims, Borgens has had a hand in
developing therapies that directly impact patients and their quality
Another therapy that is currently undergoing testing is the use of
polyethylene glycol (PEG) to seal and repair damaged spinal cord
cells. By repairing the damaged membranes of nerve cells, Borgens and
his team can restore the spinal cord's ability to transmit signals to
the brain. However, there is one possible clinical drawback: PEG's
breakdown products are potentially toxic. Is there a biodegradable
toxic compound that is equally effective at targeting and repairing
damaged nerve membranes?
Borgens teamed up with physiologist Riyi Shi and chemist Youngnam
who pointed out that some sugars are capable of targeting damaged
membranes. Could they find a sugar that restored spinal cord activity
as effectively as PEG? Borgens and his team publish their discovery
that chitosan can repair damaged nerve cell membranes in The Journal
of Experimental Biology on 16 April 2010.
Having initially tested mannose and found that it did not repair
spinal cord nerve membranes, Cho decided to test a modified form of
chitin, one of the most common sugars that is found in crustacean
shells. Converting chitin into chitosan, Cho isolated a segment of
guinea pig spinal cord, compressed a section, applied the modified
chitin and then added a fluorescent dye that could only enter the
cells through damaged membranes. If the chitosan repaired the crushed
membranes then the spinal cord tissue would be unstained, but if the
chitosan had failed, the spinal cord neurons would be flooded with
fluorescent dye. Viewing a section of the spinal cord under the
microscope, Cho was amazed to see that the spinal cord was completely
dark. None of the dye had entered the nerve cells. Chitosan had
repaired the damaged cell membranes.
Next Cho tested whether a dose of chitosan could prevent large
molecules from leaking from damaged spinal cord cells. Testing for
presence of the colossal enzyme lactate dehydrogenase (LDH), Borgens
admits he was amazed to see that levels of LDH leakage from chitosan
treated spinal cord were lower than from undamaged spinal cords. Not
only had the sugar repaired membranes at the compression site but
at other sites where the cell membranes were broken due to handling.
And when the duo tested for the presence of harmful reactive oxygen
species (ROS), released when ATP generating mitochondria are damaged,
they found that ROS levels also fell after applying chitosan to the
damaged tissue: chitosan probably repairs mitochondrial membranes as
well as the nerve cell membranes.
But could chitosan restore the spinal cord's ability to transmit
electrical signals to the brain through a damaged region? Measuring
the brain's response to nerve signals generated in a guinea pig's
leg, the duo saw that the signals were unable to reach the brain
through a damaged spinal cord. However, 30·min after injecting
chitosan into the rodents, the signals miraculously returned to the
animals' brains. Chitosan was able to repair the damaged spinal cord
so that it could carry signals from the animal's body to its brain.
Borgens is extremely excited by this discovery that chitosan is able
to locate and repair damaged spinal cord tissue and is even more
enthusiastic by the prospect that nanoparticles of chitosan could
target delivery of neuroprotective drugs directly to the site of
injury 'giving us a dual bang for our buck,' says Borgens.
More information: Cho, Y., Shi, R. and Borgens, R. B. (2010).
produces potent neuroprotection and physiological recovery following
traumatic spinal cord injury. J. Exp. Biol. 213, 1513-1520.
Provided by The Company of Biologists
"May be a suitable iron-adsorbing agent in biological systems."
Evaluation of Chitosan As a Potential Medical Iron (III) Ion
Turk J Med Sci
30 (2000) 341-348© TÜBŒTAK341
Chitosan, a derivative of the natural polysaccharide chitin, is known
for its biocompatibility and metal-binding capacity.
The aim of this study was to combine these two properties of chitosan
and investigate its potential as a new iron (III) ion (ferric ion)
The development of a safe and orally active iron chelating agent is
especially important for the treatment of thalassemics.
In this study, the physicochemical parameters affecting the ability
chitosan flakes to adsorb iron (III)ions were studied by
The results showed that the iron(III) adsorption capacity of chitosan
increases with the amount of chitosan, degree of deacetylation of
chitosan, concentration of ferric ions in solution and with the pH of
The amount of ferric ions that adsorb on the polymer increases with
time until an equilibrium is reached between adsorbed iron (III) ions
and those in solution.
Preliminary in vitro results obtained in human blood serum indicate
that chitosan is capable of adsorbing iron (III) ions in the body
fluid medium and may be a suitable iron-adsorbing agent in biological
Key Words: chitin, chitosan, iron-chelation
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Man Is A Herbivore!
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> Tan Ee Lyn
> Fri Apr 9, 2010 1:37am
> EDT SINGAPORE (Reuters) - Scientists in China have demonstrated howarsenic-- a favorite murder weapon in the Middle Ages -- destroys
> deadly blood cancer by targeting and killing specific proteins that
> keep the cancer alive.
> "Our study showed howarsenicdirectly targets these proteins and
> kills them," lead researcher Zhang Xiaowei at the State Key Laboratory
> of Medical Genomics in Shanghai, China, told Reuters.
> "Unlike chemotherapy, the side effects ofarsenic(in treating acute
> promyelocytic leukemia) are very low. There is no hair loss or
> suppression of bone marrow (function). We are interested in finding
> out howarseniccan be used in other cancers," Zhang said by
> Well known for its toxicity,arsenicwas regarded in the past as the
> king among poisons because its symptoms are like those of cholera and
> can often go undetected.
> In China, however, it has long served a dual purpose. Apart from
> intentional poisoning, it has been used for at least 2,000 years in
> traditional Chinese medicine.
> In 1992, a group of Chinese doctors reported how they usedarsenicto
> treat acute promyelocytic leukemia (APL), a blood and bone marrow
> cancer that has surprisingly high cure rates of over 90 percent in
> However, the actual workings ofarsenicand how it interacts with
> cancer tissues has never been clear -- until Zhang and his colleagues
> used modern technology to find out.
> In a paper published in the journal Science, Zhang and his team, which
> includes Health Minister Chen Zhu, described how they used modern
> equipment and saw howarsenicattacked specific proteins that would
> otherwise be keeping the cancer alive and well.
> "This shows how Western technology can be used to find out about the
> mysteries of Chinese medicine," Zhang said.
> "Although many countries are now usingarsenicto treat APL, some
> countries are resistant to the idea. It depends a lot on whether
> doctors recommend it and whether patients accept it."
> In APL, there is a drop in the production of normal red blood cells
> and platelets, resulting in anemia and thrombocytopenia. The bone
> marrow is unable to produce healthy red blood cells. Until the 1970s,
> APL was 100 percent fatal and there was no effective treatment.
> "The clinical result ofarsenicin treating APL is well-established.
> More than 90 percent of APL patients in China have (at least) five
> years of disease-free survival," Zhang said.
> In a separate commentary in Science, Scott Kogan at the University of
> California San Francisco Cancer Center wrote that proper case
> selection and combination therapy witharsenicmay lead to improved