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Smokers ‘use E-cigarettes to quit smoking’

May 4, 2010 By vani Leave a Comment

Washington, May 4 (ANI): Electronic cigarettes, or ”E-cigarettes”, are generally used to kick the butt, say researchers.

Writing in the open access journal BMC Public Health, the researchers polled 81 users and former users of the devices, finding that although the majority was happy with them, several concerns remain unaddressed.

Jean-François Etter, from the University of Geneva, Switzerland, carried out the research. He said, “Currently, there is a difficult balance between the need to protect consumers and the possibility now being offered to smokers to use a new, acceptable and potentially effective device to stop smoking. Given the enormous burden of disease and death caused by tobacco smoking, there is an urgent need for research into the toxicity, efficacy and public health impact of e-cigarettes”.

Almost all of the respondents (95 percent) had found e-cigarettes at least somewhat helpful to stop smoking. However, users were concerned about potential toxicity.

Poor quality, lack of reliability and frequent failures were also mentioned by several of the people surveyed.

Etter said, “Although users” comments were generally positive, many were concerned about safety and toxicity, and questioned why no study has yet investigated these aspects. Several respondents were also concerned about the future legal status of e-cigarettes, and that they may possibly be banned. Very few studies have investigated these devices and research is now urgently required”. (ANI)

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Natural plant hormone can help plants eliminate pesticide residues

September 10, 2009 By admin Leave a Comment

Washington, Sept 10 (ANI): Chinese researchers have discovered a natural plant hormone that can help plants eliminate residues of certain pesticides.

Researchers have been seeking new ways of minimizing pesticide residues that remain in food crops after harvest – with little success.

Previous research suggested that plant hormones called brassinosteroids (BRs) might be an answer to the problem.

During the study, lead researcher Jing Quan Yu and colleagues treated cucumber plants with one type of BR then treated the plants with various pesticides, including chloropyrifos (CPF), a broad-spectrum commercial insecticide.

The found that BR significantly reduced toxicity and residues in the plants.

BRs may be “promising, environmentally friendly, natural substances suitable for wide application to reduce the risks of human and environmental exposure to pesticides,” said the scientists.

The substances do not appear to be harmful to people or other animals, they added.

The study appears in ACS’ Journal of Agricultural and Food Chemistry. (ANI)

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Scientists use titanium dioxide nanoparticles to kill cancer cells, sparing healthy ones

August 20, 2009 By admin Leave a Comment

Washington, August 20 (ANI): Scientists in America have developed a way to target brain cancer cells using inorganic titanium dioxide nanoparticles bonded to soft biological material.

This achievement is a result of the joint efforts of scientists from the U.S. Department of Energy’s (DOE) and the University of Chicago’s Brain Tumor Center.

Thousands of people die from malignant brain tumours every year, and the tumors are resistant to conventional therapies.

The researchers say that their nano-bio technology may eventually provide an alternative form of therapy, which targets only cancer cells and does not affect normal living tissue.

“It is a real example of how nano and biological interfacing can be used for biomedical application. We chose brain cancer because of its difficulty in treatment and its unique receptors,” said scientist Elena Rozhkova with the DOE’s Argonne National Laboratory.

The novel approach relies upon a two-pronged approach.

The researchers describe titanium dioxide as a versatile photoreactive nanomaterial that can be bonded with biomolecules.

When linked to an antibody, they say, nanoparticles recognize and bind specifically to cancer cells.

When focused visible light is shined onto the affected region, the researchers add, the localized titanium dioxide reacts to the light by creating free oxygen radicals that interact with the mitochondria in the cancer cells.

Mitochondria act as cellular energy plants, and when free radicals interfere with their biochemical pathways, mitochondria receive a signal to start cell death.

“The significance of this work lies in our ability to effectively target nanoparticles to specific cell surface receptors expressed on brain cancer cells,” said Dr. Maciej S. Lesniak, Director of Neurosurgical Oncology at University of Chicago Brain Tumor Center.

“In so doing, we have overcome a major limitation involving the application of nanoparticles in medicine, namely the potential of these agents to distribute throughout the body. We are now in a position to develop this exciting technology in preclinical models of brain tumours, with the hope of one day employing this new technology in patients,” Lesniak added.

Using X-ray fluorescence microscopy at Argonne’s Advanced Photon Source, the researchers have also found that the tumours’ invadopodia, actin-rich micron scale protrusions that allow the cancer to invade surrounding healthy cells, can be also attacked by the titanium dioxide.

The researchers have thus far carried out tests on cells in a laboratory setting, but animal testing is planned for the next phase.

Results show an almost 100 percent cancer cell toxicity rate after six hours of illumination, and 80 percent after 48 hours.

Also, since the antibody only targets the cancer cells, surrounding healthy cells are not affected, unlike other cancer treatments such as chemotherapy and radiotherapy.

Rozhkova said that a proof of concept is demonstrated, and other cancers can be treated as well using different targeting molecules.

The expert, however, admits that the research is presently in the early stages. (ANI)

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How toxic various sizes of Alzheimer’s clusters can be to brain’s nerve cells

August 12, 2009 By admin Leave a Comment

Washington, August 12 (ANI): In a breakthrough that may pave the way for an effective treatment for Alzheimer’s disease, scientists at the University of California-Los Angeles (UCLA) have created various sizes of clusters in their lab, which exactly match the clusters of the amyloid ß-protein (Aß) protein that form in the brains of those affected with the disease.

The researchers say that their work has shown that the ability of these grape-like clusters to kill nerve cells in the brain, scientifically known as toxicity, increases dramatically as they increase in size.

They say that though the larger clusters are more toxic than smaller ones, the larger formations are relatively rare.

Given that smaller versions are numerous, the researchers say, they are an inviting target for the development of new therapeutic drugs.

“We now have the best understanding yet of what types of toxic A-beta structures we should target with new classes of therapeutic drugs,” said senior author David Teplow, a professor of Neurology at UCLA.

The researchers have found that the larger the cluster, the greater the toxicity, but they also found that the increase in toxicity with these clusters is not linear.

“Clusters that contain two Aß molecules are more toxic than a single Aß molecule, and those with three molecules are more toxic that those with two,” said Teplow.

He pointed out that clusters composed of two Aß molecules are three-fold more toxic than the simple monomer compound, but those made of three molecules and four four molecules are more than 10-fold more toxic than are monomers.

This suggests that the larger, more toxic clusters should be the target for scientists trying to stop Alzheimer’s.

But Teplow notes that the relative amounts of the smaller clusters are far greater than that of the bigger clusters, and are, in total, more toxic.

So in an Alzheimer’s brain, the larger clusters are relatively rare, he said.

“Think of the molecules being wrapped in very weak Velcro. So a number of molecules can bind together to form large clusters, but they break apart very easily,” he said.

Having developed a process in the lab to be able to make pure forms of these Aß clusters of specific size will enable detailed study of their structures to show where every atom is.

“This will make development of drugs much easier and likely more successful,” he said. (ANI)

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Toxic substance helps birds ‘see’ Earth’s magnetic field

July 10, 2009 By admin Leave a Comment

Washington, July 10 (ANI): In a new research, scientists at the University of Illinois, US, have determined that a toxic molecule, ‘superoxide’, known to damage cells and cause disease may also play a pivotal role in bird migration, as it allows them to ‘see’ Earth’s magnetic field.

According to principal investigator Klaus Schulten, who holds the Swanlund Chair in Physics at Illinois, the discovery occurred as a result of a ‘mistake’ made by a collaborator.

His postdoctoral collaborator, Ilia Solov’yov, of the Frankfurt Institute for Advanced Studies, did not know that superoxide was toxic, seeing it instead as an ideal reaction partner in a biochemical process involving the protein cryptochrome in a bird’s eye.

Cryptochrome is a blue-light photoreceptor found in plants and in the eyes of birds and other animals. Schulten was the first to propose (in 2000) that this protein was a key component of birds’ geomagnetic sense, a proposal that was later corroborated by experimental evidence.

He made this prediction after he and his colleagues discovered that magnetic fields can influence chemical reactions if the reactions occur quickly enough to be governed by pure quantum mechanics.

“Prior to our work, it was thought that this was impossible because magnetic fields interact so weakly with molecules,” he said.

Such chemical reactions involve electron transfers, “which result in freely tumbling spins of electrons. These spins behave like an axial compass,” Schulten said.

Changes in the electromagnetic field, such as those experienced by a bird changing direction in flight, appear to alter this biochemical compass in the eye, allowing the bird to see how its direction corresponds to north or south.

“Other researchers had found that cryptochrome, acting through its own molecular spins, recruits a reaction partner that operates at so-called zero spin. They suggested that molecular oxygen is that partner,” Schulten said.

“We propose that the reaction partner is not the benign oxygen molecule that we all breathe, but its close cousin, superoxide, a negatively charged oxygen molecule,” he added.

When Solov’yov showed that superoxide would work well as a reaction partner, Schulten was at first dismissive.

“But then I realized that the toxicity of superoxide was actually crucial to its role,” he said.

According to Schulten, the body has many mechanisms for reducing concentrations of superoxide to prevent its damaging effects.

But this gives an advantage, since the molecule must be present at low concentrations – but not too low – “to make the biochemical compass work effectively,” he said. (ANI)

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Scientists unveil prostate cancer ‘homing device’ for drug delivery

July 8, 2009 By admin Leave a Comment

Washington, July 7 (ANI): Purdue University researchers have come up with a new prostate cancer “homing device” that can improve detection, and allow for the first targeted treatment of the disease.

The researchers have revealed that they have synthesized a molecule that finds and penetrates prostate cancer cells, and created imaging agents and therapeutic drugs that can link to the molecule and be carried with it as cargo.

Philip Low, the Ralph C. Corley Distinguished Professor of Biochemistry who led the team, said that a targeted treatment could be much more effective in treating cancer and would greatly reduce the harmful side effects associated with current treatments.

“Currently none of the drugs available to treat prostate cancer are targeted, which means they go everywhere in the body as opposed to only the tumour, and so are quite toxic for the patient,” said Low, who is a member of the Purdue Cancer Center.

“By being able to target only the cancer cells, we could eliminate toxic side effects of treatments. In addition, the ability to target only the cancer cells can greatly improve imaging of the cancer to diagnose the disease, determine if it has spread or is responding to treatment,” Low added.

The Purdue team say that the molecule they have created attaches to prostate-specific membrane antigen (PSMA), a protein that is found on the membrane of more than 90 percent of all prostate cancers.

Low points out that it is also found on the blood vessels of most solid tumours, and may provide a way to cut off the tumour blood supply.

“A lot of new drugs are being designed to destroy the vasculature of solid tumours, and, if they could be linked to this new targeting molecule, we could have a two-pronged attack for prostate cancer. We could not only kill the prostate cancer cells directly, we could also destroy the vasculature that feeds the tumours,” he said.

The researcher says that there also is potential for the targeting molecule to be used to attack the vasculature of solid tumours of other types of cancers.

Animal studies carried out by the researchers have shown an ability to eliminate human prostate cancer cells in mice, without any collateral toxicity in normal tissue.

“The molecule acts like a homing device for prostate cancer. PSMA, which is found only on prostate cancer cells and tumor blood vessels, acts as the homing signal that the molecule targets. The molecule and its cargo go only to cancerous tissue, leaving healthy tissue unharmed,” says Sumith Kularatne, a graduate student in Purdue’s chemistry department and first author of both papers who compared the targeting molecule to a homing device.

He has revealed that the molecule is designed with a specific shape that fits with the protein like a key to a lock. The molecule and its cargo are then carried inside the cell with the protein as it goes through its normal cycle.

A radioimaging application used for body scans is expected to enter clinical trials this fall, and an optical imaging application used to measure prostate cancer cells in blood samples is already in clinical trials.

The findings of the researchers have been described in two research articles published in the journal Molecular Pharmaceutics. (ANI)

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Novel targeted therapy shows promise to eliminate leukaemia stem cells

July 3, 2009 By admin Leave a Comment

Washington, July 3 (ANI): A piece of research has shown that it is possible to eliminate stem cells related to human acute myeloid leukemia (AML), a notoriously treatment-resistant blood cancer, using a new targeted therapy.

Associate Professor Richard Lock, from the Children’s Cancer Institute Australia and the University of New South Wales, has revealed that the new therapeutic approach has been found to selectively attack human cancer cells grown in the lab as well as in animal models of leukaemia.

AML is a cancer of the white blood cells that has an extremely poor prognosis and does not respond well to conventional chemotherapy.

“The cellular and molecular basis for this dismal picture is unclear. However, previous research has suggested that leukaemia stem cells (LSCs) may lie at the heart of post-treatment relapse and chemoresistance,” says Lock.

LSCs are cells that can initiate AML and are critical for its long-term growth.

Lock and his colleagues exploited the fact that the molecule CD123 is expressed at very high levels on LSCs but not on normal blood cells.

The researchers created a therapeutic antibody that recognized and bound to CD123, hoping that the antibody would selectively interfere with AML-LSC survival.

When AML-LSCs from human patients were transplanted into mice treated with the antibody, called 7G3, cytokine signalling in the tumour cells was blocked.

The research team also observed that 7G3 impaired migration of the AML-LSCs to bone marrow, and activated the innate immune system of the host mouse to destroy the AML-LSCs.

They say that, overall, treatment with 7G3 substantially improved mouse survival when compared with control groups.

Lock and his colleagues are currently using a CD123-targeting antibody in phase 1 clinical trials of advanced AML. They say that there are no signs of treatment-related toxicity.

These results hold substantial promise for future cancer therapeutics.

“The recent characterization of defined populations of cancer stem cells in a range of human malignancies, as well as their relative resistance to conventional chemotherapy and radiotherapy, supports the broad applicability of our approach and provides rationale for the progression of AML-LSC-targeted therapeutics from preclinical evaluation to clinical trials,” concludes Associate Professor Lock.

A research article on the study has been published in the journal Cell Stem Cell. (ANI)

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‘Superoxide’ may help birds “see” Earth’s magnetic field

June 23, 2009 By admin Leave a Comment

Washington, June 23 (ANI): In a new research, scientists at the University of Illinois, US, have determined that a toxic molecule, ‘superoxide’, known to damage cells and cause disease may also play a pivotal role in bird migration, as it allows them to “see” Earth’s magnetic field.

According to principal investigator Klaus Schulten, who holds the Swanlund Chair in Physics at Illinois, the discovery occurred as a result of a “mistake” made by a collaborator.