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From: donpat12/12/2011 4:38:53 PM
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New Finding Clears Malaria in Mice

ScienceDaily (Dec. 12, 2011) — University of Iowa researchers and colleagues have discovered how malaria manipulates the immune system to allow the parasite to persist in the bloodstream. By rescuing this immune system pathway, the research team was able to cure mice of bloodstream malaria infections.

The findings, which were published December 11 in the Advance Online Publication of the journal Nature Immunology, could point the way to a new approach for treating malaria that does not rely on vaccination and is not susceptible to the parasite's notorious ability to develop drug resistance.
[ nature.com  ]

"Malaria is chronic, prolonged infection and the host immune defense has a tough time clearing it and sometimes it never clears it," says Noah Butler, PhD, UI postdoctoral research scholar and lead study author. "We've determined that this prolonged infection actually drives dysfunction of the immune cells that are supposed to be fighting the infection, which in essence allows further persistence of the parasite infection."

More specifically, the study showed that the malaria parasite stimulate these key immune cells (known as CD4+ T cells) so that they continuously express molecules called inhibitory receptors. Under normal circumstances, these molecules help to "apply the brakes" to the immune response and prevent over-activation that can be harmful. However, by keeping the mechanism turned on, the malaria parasite damps down the immune response significantly, reducing the T cells' ability to fight the parasite and allowing it to persist.


Importantly, the team also showed that blocking the action of the inhibitory receptor molecules resulted in immediate and complete clearance of the malaria parasite.

"When we blocked the function of these molecules, we took the brakes off the host's immune response and everything got better -- the overall immune response was dramatically improved and there was immediate control and accelerated clearance of the parasite," says John Harty, PhD, professor of microbiology and pathology at the UI Carver College of Medicine and senior study author. "These findings suggest an alternative approach for the treatment of existing malaria infection."

200 Million Malaria Cases

More than half the world's population is at risk of malaria, a mosquito-borne parasite that causes anemia and high fever and which can persist for weeks or months. There are more than 200 million cases of malaria each year and an estimated 800,000 children die from malaria annually.

Harty notes that the current study was done in mice and it is not yet known if the same approach will work in humans. However, two factors suggest the strategy may have potential. First, drugs that block inhibitory receptor molecules are available and currently being tested as cancer therapies. And second, the UI team found that malaria infection in humans does lead to increased expression of inhibitory receptors on CD4+ T cells suggesting that these molecules could represent a viable target for human therapies.

The human findings were the product of an important collaboration between the UI team and malaria researchers working in the sub-Saharan country of Mali. The Mali team based at the University of Bamako works in a sophisticated lab set up by the National Institutes of Health. In Mali's dry season there are no mosquitoes, so there's no malaria; in the wet season, the mosquitoes come out and malaria appears.

"Workers in the NIH lab obtained blood samples from malaria-free children at the end of the dry season, and then when some of the children returned to the clinic with malaria at the beginning of the next wet season they were treated immediately and the workers also took a second blood sample," Harty explains. "This allowed us to analyze the blood for expression of this inhibitory molecule before and after infection and we found that the molecule went up after infection."

Malaria Further Compromises Immune System

A second collaboration, born closer to home, allowed Harty's team to prove that it is the CD4+ T cells that are disrupted by the malaria infection.

Using a new technique that was developed in the lab of UI microbiologist Steve Varga, PhD, the researchers were able to track the behavior of the responding T cells during malaria infection. They found that chronic malaria infection led to sustained expression of the inhibitory receptor molecules on the surfaces of this type of T cell and also showed that the T cells' ability to fight the parasite was significantly reduced.

The study also found that as the parasite persists the inhibitory receptor molecules remain upregulated and the immune system became more and more compromised.

"The T-cells are so over-stimulated that they eventually lose their function or even die -- this is known as T-cell exhaustion," Butler explains.

The concept that prolonged persistence of an "insult" to the immune system, such as cancer or chronic viral infections like HIV, disrupts and exhausts the immune response is well established. However, this study is the first time it has been shown for malaria. The study finding suggests that rescuing CD4+ T cells from exhaustion could be an effective strategy to control and clear bloodstream malaria infections.

In addition to Harty and Butler, UI researchers Lecia Pewe, Lorraine Tygrett, and Thomas Waldschmidt, PhD, also were involved in the study. The team also included Jacqueline Moebius and Peter Crompton from the National Institute of Allergy and Infectious Diseases in Rockville, Maryland, and Boubacar Traore and Ogobara Doumbo from the Malaria Research and Training Center, University of Bamako in Mali.

The study was funded in part by grants from the NIH and the UI Department of Microbiology.

sciencedaily.com 

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To: donpat who wrote (2123)12/12/2011 5:43:57 PM
From: donpat   of 2502
 
Re--The concept that prolonged persistence of an "insult" to the immune system, such as cancer or chronic viral infections like HIV, disrupts and exhausts the immune response is well established.--

HIV upped risk for malaria, Plasmodium parasitemia in adults

PHILADELPHIA — Adults with HIV-1 infection were more likely to have Plasmodium parasitemia and combined parasitemia or history of clinical malaria, according to findings from the Kericho cohort study.

Douglas Shaffer, MD, MHS, of the US Military HIV Research Program and Walter Reed Army Institute of Research in Kericho, Kenya, and colleagues evaluated the association between HIV, Plasmodiumparasitemia and clinical malaria in adults participating in the 36-month prospective study in Kenya.

Shaffer and colleagues estimated the OR for prevalence of cases at baseline and the HR for follow-up incident cases between HIV and two malaria outcomes (Plasmodium parasitemia and combined parasitemia and/or history of clinical malaria).

Of 2,801 participants enrolled in the study, the researchers identified 14.3% with HIV at baseline and 33.2% with HIV plus parasitemia and/or clinical malaria prevalence.

Compared with non–HIV-infected participants, more HIV-infected participants had baseline parasitemia (6% vs. 3.5%, P=.02) and parasitemia/clinical malaria (40% vs. 31%, P,.01) with ORs of 1.73 (95% CI, 1.04-2.80) and 1.53 (95% CI, 1.22-1.91), respectively.

Overall, the researchers reported that adults with baseline HIV were at increased risk for both incident parasitemia (HR=1.69; 95% CI, 1.29-2.21) and parasitemia/clinical malaria (HR=1.41; 95% CI, 1.19-1.69).

For more information:

  • Shaffer D. #22. Presented at: the American Society of Tropical Medicine and Hygiene 60th Annual Meeting; Dec. 4-8, 2011; Philadelphia.
  • Disclosure: The researchers report no relevant financial disclosures.

    infectiousdiseasenews.com 

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    From: donpat12/13/2011 11:56:00 AM
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    New discovery on how the body fights dengue fever

    December 12, 2011

    Worldwide, dengue fever strikes roughly 50 million people every year and takes the lives of thousands, but specific therapies or a vaccine for this mosquito-borne illness remain unavailable. A report coming out in the online journal mBio® on December 13 describes a new discovery about how the body fights the dengue virus, a finding that could explain differences in the ability to fight off the virus and help in developing a drug to boost this response.

    Dengue is relatively unknown here in the U.S., but according to the World Health Organization the global incidence of dengue infection has been rising alarmingly in the past decades. Today, 2.5 billion people are at risk from dengue fever and from dengue hemorrhagic fever, a lethal complication of infection. Despite the high infection rates, there are currently no specific treatments for dengue fever and no vaccine to prevent infection with the dengue virus. Many scientists who study the disease have been searching for ways to boost the human immune response to dengue so that it can't gain a foothold in the body.

    Researchers from Washington University, Walter Reed Army Institute of Research and the University of Copenhagen, Denmark, report a new finding that a part of the immune system called mannose-binding lectin (MBL) is involved in targeting dengue viruses for destruction. MBL recognizes sugar molecules present on the outsides of many different kinds of viruses and bacteria. When it finds these sugars, MBL activates the complement system, which targets foreign materials in the body for destruction in any of a number of cruel ways. Scientists have known that the complement system takes a hit during dengue infection, but until now no one knew that it was also involved in getting rid of dengue viruses.

    "Before, people thought the complement system was involved primarily in pathogenesis," says Sujan Shresta, an Associate Professor at the La Jolla Institute for Allergy and Immunology, who reviewed the paper and was not involved in the work. "This paper is the first to look at the role of the complement system in the context of protection" from the dengue virus, says Shresta.

    This is an important discovery in terms of human health, continues Shresta, because different people naturally make different amounts of MBL. Some people have high levels of MBL, some people have low levels, a fact that may help explain why some individuals are able to fight off the virus while others are not.

    The authors showed that blood samples with high levels of MBL neutralized dengue more efficiently than samples with lower levels of MBL. This finding suggests that people with high MBL levels in their blood could well be better at fighting dengue infection.

    This is a clue that could help scientists create therapies for the disease. "You could develop antivirals that work through a similar mechanism," to deactivate dengue viruses, says Shresta. Vaccines could also be designed to activate this pathway, she says, helping boost the normal functions of the immune system to fight off infection.

    Provided by American Society for Microbiology

    medicalxpress.com 

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    From: donpat12/13/2011 9:46:15 PM
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    "Pep Talk" Can Revive Immune Cells Exhausted by Chronic Viral Infection

    Dec. 13, 2011

    Contacts: Holly Korschun: 404-727-3990

    Adoptive transfer of "trained" immune cells has been applied to cancer and is being examined for chronic viral infections.

    Chronic infections by viruses such as HIV or hepatitis C eventually take hold because they wear the immune system out, a phenomenon immunologists describe as exhaustion.

    Yet exhausted immune cells can be revived after the introduction of fresh cells that act like coaches giving a pep talk, researchers at Emory Vaccine Center have found. Their findings provide support for an emerging strategy for treating chronic infections: infusing immune cells back into patients after a period of conditioning.


    The results are published this week in Proceedings of the National Academy of Sciences Early Edition.
    pnas.org 

    The first author of the paper is Rachael Aubert, a student in Emory’s Immunology and Molecular Pathogenesis program who completed her doctorate in 2009. Senior author Rafi Ahmed, PhD, is director of the Emory Vaccine Center and a Georgia Research Alliance Eminent Scholar.

    Ahmed’s laboratory has extensive experience studying mice infected with lymphocytic choriomeningitis virus (LCMV). Immune responses against LCMV are driven by CD8 or “killer” T cells, which destroy virus-infected cells in the body. But a few weeks after exposure to LCMV, the mice develop a chronic infection that their immune systems cannot shake off, similar to when humans are infected by viruses like HIV and hepatitis C.

    Aubert and her co-workers examined what happened to mice chronically infected with LCMV when they infused CD4 or “helper” T cells from uninfected mice. After the infusion, the CD8 cells in the infected mice revived and the levels of virus in their bodies decreased by a factor of four after a month. Like coaches encouraging a tired athlete, the helper cells drove the killer cells that were already in the infected mice to emerge from exhaustion and re-engage.

    The cell-based treatment was especially effective when combined with an antibody that blocks the molecule PD-1, which appears on exhausted T cells and inhibits their functioning. The antibody against PD-1 helps the exhausted T cells to revive, and enhances the function of the helper cells as well: the combination reduced viral levels by roughly ten-fold, and made the virus undetectable in some mice.

    “We have not seen this sharp of a reduction in viral levels in this system before,” says co-author Alice Kamphorst, a postdoctoral fellow.

    The helper cells were all genetically engineered to recognize LCMV, a difference between mouse experiments and potential clinical application. However, it may be possible to remove helper T cells from a human patient and stimulate them so that all the cells that recognize a given virus grow, Kamphorst says.

    “This is an active area of research and several laboratories are looking at how best to stimulate T cells and re-introduce them,” she says.

    In addition, she and her co-workers are examining what types of hormones or signaling molecules the helper cells provide the killer cells. That way, that molecule could be provided directly, instead of cell therapy, she says
    .
    The molecule PD-1 was previously identified by Ahmed and colleagues as a target for therapy designed to re-activate exhausted immune cells. Antibodies against PD-1 have been undergoing tests in clinical studies against hepatitis C and several forms of cancer.

    Collaborators from Harvard Medical School/Dana Farber Cancer Institute contributed to the paper. The research was supported by the National Institutes of Health and the Cancer Research Institute.

    Reference: R.D. Aubert et al. Antigen-specific CD4 T-cell help rescues exhausted CD8 T cells during chronic viral infection. PNAS Early Edition (2011).

    Writer: Quinn Eastman

    http://shared.web.emory.edu/whsc/news/releases/2011/12/pep-talk-can-revive-immune-cells-exhausted-by-chronic-viral-infection-.html

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    From: donpat12/14/2011 12:24:01 PM
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    U.S. Lead in Nanotechnology Depends on Growth of FDA and Gov’t Initiatives

    Dec 14, 2011

    Alex Philippidis

    European revenue from nanotech-enabled products is projected to surpass that of the U.S. by 2015, according to Lux Research.

    The National Center for Toxicological Research (NCTR), which identifies issues related to new products like nanomaterials, was given $60 million for fiscal 2012. [© James Steidl - Fotolia.com]

    The recently enacted spending bill, which covered FDA, contained some good news for proponents of nanotechnology as well as the promise of more to come in years ahead. The latter will be harder to deliver considering the overall budget constraints of the U.S. Making good on the promise, however, is likely key to the country’s ability to at least retain its number one position in nanotechnology if not expand this lead.

    FDA’s National Center for Toxicological Research (NCTR) was approved $60 million for fiscal 2012, which was proposed by President Barack Obama and favored over the $51.5 million sought by the Republican-controlled House of Representatives. While NCTR’s latest approved budget did not increase compared to fiscal year 2011, at least it did not go down. NCTR’s duties include conducting peer-reviewed research to identify health and safety issues related to new medical products like nanomaterials.

    More importantly, perhaps, than this year’s money is language inserted into the spending bill’s House-Senate conference report by Sen. Mark Pryor (D-AR) endorsing future plans by the agency to fund that even further: “The conferees support FDA in its mission to expand upon current research in nanotechnology and support the eventual development of a Nanotechnology Core Center to meet its mission.”

    “Nanotechnology activities at FDA are focused on three main activities: (1) laboratory and product testing capacity; (2) scientific staff development and professional training; and (3) collaborative and interdisciplinary research to address product characterization and safety,” FDA spokeswoman Rita Chappelle told GEN. “These enterprise-wide programs are in addition to focused regulatory science research activities conducted at each of the FDA centers.”

    Lynn L. Bergeson, a founding member of the law firm Bergeson & Campbell, pointed out to GEN, however, that “while the FDA speaks to its well-established experience and expertise in assessing nano-enabled products, the transparent record of this expertise is less apparent. A center expressly devoted to FDA nano research would help strengthen the reality and the perception that FDA is expert in the regulation of nanoscale materials pertinent to FDA-regulated products.”

    This Year in NanotechDuring FY 2011, a Nanotechnology Core Facility overseen by NCTR and the agency’s Office of Regulatory Affairs (ORA) became operational at FDA’s Jefferson Laboratory campus in Arkansas. A similar facility at FDA’s White Oak headquarters campus, to be overseen by NCTR and several FDA centers, “is scheduled to be operational in FY 2012,” according to Chappelle.

    Sally Tinkle, Ph.D., deputy director of the National Nanotechnology Coordination Office of the National Science and Technology Council, told GEN that in October NCI’s Alliance for Nanotechnology in Cancer initiated Translation of Nanotechnology In Cancer (TONIC), a public-private consortium designed to promote translational R&D opportunities for nanotechnology-based cancer solutions. Consortium members will include government agencies and biopharma companies. Last year, NCI approved a second phase of an alliance program, awarding $30 million a year over five years in multi-institution research grants.

    On October 6, Pryor introduced the Nanotechnology Regulatory Science Act of 2011 (S.1662). It would direct FDA to develop safety regulations for companies using nanotech. FDA would be authorized to spend $48 million over three years: $15 million in the FY 2013, followed by $16 million and $17 million in FY 2014 and FY 2015, respectively.

    Also this year, the Obama administration has issued two nanotech-related reports through the National Nanotechnology Initiative (NNI). These positioned nanotech as a top science initiative, identified goals, and called for better coordination of research, training programs, and resources. Currently, NNI coordinates the individual and cooperative nanotechnology-related activities of FDA and 24 other federal agencies.

    Maintaining a Competitive EdgeDr. Tinkle acknowledged the tight budget climate as a continuing challenge for nanotech. The Obama administration has proposed raising NNI’s budget to $2.1 billion from $1.76 billion in FY 2011. But, in the current tight budget climate and with an election looming next year for Obama, all of the House, and one-third of the Senate, any extra funds for increased nanotech R&D are uncertain at best. Unless Congress hammers out a long-term deficit plan, FDA will lose money for nanotech and everything else through the forced 7.8% sequestration required by the Budget Control Act enacted in August.

    As Bergeson correctly notes, expanding NNI will be much easier said than done. “The challenges are, of course, of epic proportion,” Bergeson pointed out, such as the 17.3% drop in federal nanotech spending during FY 2010, a result of the weak economy.

    Washington’s difficulty in stepping up funding for nanotech has created an opening for other nations eager to grow their own nanotech industries. According to data from Lux Research presented at a November 15 Congressional Nanotechnology Caucus briefing, European revenue from nanotech-enabled products is projected to surpass that of the U.S. by 2015, with both expected to rack up more than $1 trillion. Among individual nations, the U.S. remains at the top of corporate nanotech spending at nearly $3.5 billion as of 2010 followed by Japan (almost $3 billion) and then Germany (about $1 billion).

    “The rest of the world now understands the importance of this field, and many countries are building efforts that rival what has been established by the NNI,” Chad A. Mirkin, Ph.D., director of the Northwestern University International Institute for Nanotechnology, said in a testimony July 14 to the Senate Subcommittee on Science and Space. He identified China, Great Britain, Russia, Saudi Arabia, Singapore, and Taiwan as nations where research institutes have advanced nanotech.

    “If the United States does not act now and aggressively pursue the development of nanoscience and nanotechnology,” Dr. Mirkin cautioned, “we will lose our position as the global leader in this transformative field. Moreover, we will lose the opportunities it can afford us to build our economy and new manufacturing base.”

    Dr. Mirkin called for expanding NNI by requiring its member agencies to assign senior executives to participate in coordination activities; by positioning the National Nanotechnology Coordination Office (NNCO) as NNI’s coordination entity; and by mandating that NNCO develop metrics for nanotechnology-specific programs using dedicated funding. He noted that 0.3% of NNI’s budget was recommended for NNCO by the President’s Council of Advisors on Science and Technology, on which he serves.

    Bergeson pointed out, “The identification of research priorities and their correlation with commercialization goals is more challenging as nanotechnology matures, and the most obvious of basic research needs are filled. Coupled with the usual turf battles and the sheer complexity of managing a national nanotechnology initiative, the task Dr. Tinkle faces is indeed daunting.

    “It is not the case that nano has not delivered on its enormous promise,” Bergeson continued. “The flattening of the global economy and the pressures domestically to reprioritize fiscal expenditures due to election-year pressures and the lack of a coherent Congressional commitment to nano has undermined U.S. dominance in this area,” she said.

    It’s hard to have coherence when nanotech activity is spread across 25 agencies. While NNI is praised among nano professionals, its funding is far smaller than its mission. Aligning NNI’s financial backing and goals is a longer-term project, but level funding for NNI in FY 2012 is a welcome first step.

    genengnews.com 

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    From: donpat12/14/2011 2:28:11 PM
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    Viral pink eye spreading throughout Valley says Phoenix doctor


    Credit: Dr. P. Marazzi / Photo Researchers, Inc. via WebMd.com


    by Catherine Holland

    azfamily.com

    Posted on December 14, 2011 at 8:44 AM

    Updated today at 9:38 AM

    PHOENIX -- A Valley doctor says a severe strain of pink eye is making its way around the Valley.

    According to Dr. Timothy Sinek, most of the cases they're seeing at Southwestern Eye Center are viral and highly contagious.

    Also known as conjunctivitis, pink eye is redness and inflammation of both the clear membranes that cover the whites of the eyes and the membranes on the inner part of the eyelids -- the conjunctiva.

    Most cases of conjunctivitis are caused by a virus or bacteria, but allergies, chemicals or an underlying disease can also spark pink eye.

    Both viral and bacterial pink eye are quite contagious. The best defense is to wash your hands often and avoid rubbing your eyes. Also, do not share towels, change towels and linens, particulalry pillowcases, every day and throw away any eye makeup that might have become contaminated.

    While pink eye is relatively common, especially in children, and rarely serious enough to cause long-term vision damage if treated promptly, it can be extremely uncomfortable.

    Symptoms include red eyes, swollen eyelids, eye pain, blurred vision, excessive tearing, itchy eyes, a burning sensation in the eyes, drainage that can be either clear with viral pink eye or greenish-yellow with bacterial pink eye, crusty eyelids, sensitivity to light and a feeling that you have something in your eye.

    The symptoms generally show up in one eye first and then spread to the other eye within a few days.

    If any of these symptoms because severe, it could be a sign that the infection has spread beyond the conjunctiva, which means you should contact your doctor immediately.

    While bacterial pink eye can be treated with antibiotic eye drops, ointments and pills, viral pink eye usually needs to run its course although the symptoms themselves can be treated.

    Doctors usually suggest cold or warm compresses on the eyes to relieve pain and remove discharge. Be sure to use a clean washcloth each time to avoid spreading the infection.

    Sinek says most infectious cases of pink eye will clear up in about 10 days.

    With viral conjunctivitis, you are contagious as long as you exhibit symptoms. In cases of bacterial conjunctivitis, you are usually good to go within 24 hours of starting antibiotics as long as the symptoms are better.

    azfamily.com 

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    From: donpat12/18/2011 8:40:21 AM
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    Plasma knocks out deadly viruses

    Submitted by admin4 on 18 December 2011 - 4:37pm

    International Science/Health
    By IANS,

    Sydney: Adenoviruses that can cause respiratory, eye, and intestinal tract infections, must adopt the cellular machinery of infected organisms to produce more of their own, scientists suggest.

    Scientists from Chinese and Australian universities have found a way to disrupt the hijacking process by using plasma to damage the viruses before they come into contact with host cells.

    The research led by Z. Xiong and X. Lu (HuaZhong University of Science and Technology, China) and K. Ostrikov (University of Sydney, Australia), prepared solutions containing adenoviruses.

    They then subjected the samples with a low-temperature plasma, a highly energized state of matter which is created by applying a voltage to a gaseous mixture in a syringe, the journal Applied Physics Letters reported.

    The plasma damaged the viral DNA. When the virus solutions were later added to colonies of embryonic kidney cells, plasma-treated samples showed much less viral activity, a university statement said.

    If the virus solution was covered during treatment to maximize plasma-virus interactions, more than 99 percent of the viruses could be deactivated in eight minutes.

    twocircles.net 

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    To: donpat who wrote (2096)12/18/2011 11:00:34 AM
    From: donpat   of 2502
     
    UW scientists under scrutiny over bird flu research

    By Shelley Walcott

    CREATED 8:03 AM

    MADISON - Starting with the virus that causes bird flu, two scientists have created a highly contagious version in the laboratory that one calls "probably one of the most dangerous viruses you can make."

    A government committee is now deciding on how much detail scientific journals should reveal when they publish the studies, and the controversial decision is due soon.

    But some top scientists think the entire project is wrong.

    "It's just a bad idea for scientists to turn a lethal virus into a lethal and highly contagious virus," said Dr. Dr. Thomas Inglesby with the University of Pittsburgh Center for bioterrorism "And it's a second bad idea for them to publish how they did it so others can copy it."

    Bird flu--called H5N1 --first jumped from chickens to humans in Hong Kong in 1998 and was deadly; killing about 60 percent of the people it infected.

    The city stopped the '98 outbreak by killing all chickens, and since then periodic outbreaks have occurred in southeast Asia, but the virus has never been very contagious...infecting only a few people at a time.

    The two scientists--one in Europe, the other--Yoshihiro Kawaoka at the University of Wisconsin--genetically altered wild bird flu so it could easily be transmitted from person to person.

    They proved this using ferretts, which transmit flu like humans.

    They submitted their results to two top journals Science and Nature.

    UW spokesman terry devitt told the Milwaukee Journal Sentinel: "We have comprehensive and stringent biosafety and biosecurity measures in place."

    todaystmj4.com 

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    From: donpat12/18/2011 1:46:46 PM
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    New insights into nanoparticles and dividing cells


    Posted: Dec 18th, 2011

    (Nanowerk News) What happens when living cells take up nanoparticles, those tiny entities that could offer new ways of delivering drugs into the body? A new study from researchers at University College Dublin (UCD) has tracked the progress of nanoparticles as cells divide, and their findings - which were published recently in Nature Nanotechnology ( "Role of cell cycle on the cellular uptake and dilution of nanoparticles in a cell population") - will help us better understand how different tissues in the body process a dose of nanoparticles.


    Dr. Anna Salvati

    "Nanoparticles are engineered materials that we are producing, and what is very interesting about them is that they have a size that is in the nanometre range, so they are a bit bigger than proteins," says Dr Anna Salvati, a post-doctoral researcher at UCD School of Chemistry & Chemical Biology. "Their size allows them to interact with the cell in new ways."

    These nano-interactions open up potential opportunities to deliver drugs in new ways into cells, so they offer one of the most promising ways to treat currently untreatable diseases, from cancers to neurodegeneration, according to Dr Salvati: "If we learn why nanoparticles can enter so easily and what decides where they go in the cell, then we could potentially design new delivery systems and learn how to deliver medicines," she says.

    We also need to understand bio-nano-interactions more generally from a safety perspective, she adds. "We could be exposed to nanomaterials in some cases because they are used for many applications from energy harvesting, electronics to paints. Ensuring they are safe is important."

    Dr Salvati works on a team with Prof Kenneth A. Dawson at the Centre for BioNano Interactions, the UCD-based national platform for nanosafety, nanobiology and nanomedicine, and UCD Conway Institute for Biomolecular and Biomedical Research.

    Together with Jong Ah Kim and Dr Christoffer Aberg, one strand of their research has been looking at the fate of nanoparticles during the life cycle of individual cells as they grow and divide. The UCD researchers introduced nanoscale polystyrene particles to human lung carcinoma cells growing in the lab, and used fluorescent markers to track the nanoparticles over space and time.

    What they identified was that nanoparticles could enter the cell easily and were not expelled during the cell cycle of growth, but rather got passed on to daughter cells as individual cells split into two."When a cell divides, the internalised nanoparticle dose is split between the daughter cells," explains Dr Salvati. "This means that cells in the same population can have different amounts of internalised nanoparticles, depending on the phase of their cell cycle."

    The important observation is that a dose of nanoparticles in a cell population can be affected as cells divide, and that individual cells can end up with differing amounts of nanoparticles.

    "When you give a dose of nanoparticles and a certain exposure time, you don't have just one simple answer where every cell behaves in the same way - we have seen that individual cells behave differently and that can affect the cell's dose of nanoparticles," explains Dr Salvati.

    "The implications can be extended also for humans - inside the body the most specialised cells tend to have very slow cell division, while other cells divide very frequently. A cell that divides more frequently will dilute the amount of nanoparticles because every time it divides it dilutes the load, and a cell that divides less often potentially might accumulate more nanoparticles." These findings will also help assure safety of nanoparticles, according to Dr Salvati, and the UCD researchers are continuing to develop their understanding of the interactions.

    "We are looking to describe the nanoparticle accumulation and kinetics with theoretical models so they could be used to predict how nanoparticles are going to behave in cell populations," she says.

    "It would also be interesting for us to be able to design a nanoparticle able to target cells that divide rapidly, such as cancer cells, or where we could control in which stage it enters the cell, so it might enter more easily in certain phases as the cell grows. It will open up a whole new range of options in medicine."
    Source: University College Dublin

    nanowerk.com 

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    From: donpat12/18/2011 1:59:11 PM
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    Challenge to develop Low-cost devices to diagnose diseases in developing countries unveiled



    A child wails while being tested for malaria. Imagine a hand-held, battery-powered device that can take a drop of blood and, within minutes, tell a healthcare worker in a remote village whether a feverish child has malaria, dengue or a bacterial infection-that will soon be a reality. Photo/FILE

    Grand Challenges Canada and the Bill & Melinda Gates Foundation have teamed up on an unprecedented global effort to discover and develop affordable, easy-to-use tools to help developing country health workers rapidly diagnose diseases in rural communities.

    The ultimate innovation would lead to a timely and appropriate treatment of illnesses in poor countries, potentially saving countless lives.

    “Imagine a hand-held, battery-powered device that can take a drop of blood and, within minutes, tell a healthcare worker in a remote village whether a feverish child has malaria, dengue or a bacterial infection,” says Peter A. Singer, MD, Chief Executive Officer of Grand Challenges Canada. “More rapid diagnosis of malaria alone could prevent 100,000 deaths a year. We believe this and other life-saving opportunities are within our reach.”

    The five research areas of this Grand Challenge break the diagnostic problem down into its component parts: Draw blood (or other biological sample) and prep it for analysis, analyze the sample to identify disease, develop the technologies to obtain and transmit data and receive back results, and ensure the device will work in the field where there is often no electricity or refrigeration.

    "The project is analogous to software developers creating new apps for smart phones and tablet computers,” says Rebecca Lackman, Grand Challenges Canada Program Officer for Diagnostics.

    “Researchers have accepted the challenge to create novel sampling and testing systems that can be plugged into a standardized analyzer that can test for malaria, tuberculosis, HIV and a variety of tropical diseases. The ‘Integrated Innovation’ approach means they will also investigate the social and business innovations needed for successful product delivery and use.”

    “This initiative is unique in many respects: it will allow health workers to identify multiple diseases and pathogens from one patient specimen; plug-and-play platforms will allow best-in-class components to be developed and integrated in a diagnostic device; and we are creating a common application platform; thereby, reducing both commercialization costs and regulatory issues, making it more attractive for industry to invest in diagnostics for global health.”

    One grantee, Bigtec Labs in Bangalore, India, has already developed a handheld analyser called a mini-PCR (Polymerase Chain Reaction) machine capable of identifying malaria from its DNA fingerprint.

    “A colleague here one day was ill with what he thought was food poisoning," said B. Chandrasekhar Nair, Director of Bigtec Labs. "We ran a blood sample through our mini-PCR and it turned out to be malaria.” Immediately treated, the colleague returned to health within a week.

    With its CAD $1.3 million grant, Bigtec will use nano-materials to develop a sophisticated filter to concentrate pathogen DNA from samples of blood, sputum, urine, or nasal and throat swabs. Once concentrated, the DNA can be processed and illnesses identified in the mini-PCR.

    Other innovative point-of-care diagnostic tools such as a piece of woven fabric which can test blood or urine for disease and a simple, easy to use test for diagnosing diarrheal disease -- the biggest killer of developing world children under the age of 5 -- are also among the projects receiving funding.

    “Safe, effective methods of diagnosing illness at the point-of-care are vital to improving health in developing countries,” said Chris Wilson, Director of Global Health Discovery at the Bill & Melinda Gates Foundation. “We hope these innovative ideas lead to technologies that allow patients to get the right treatment quickly—speeding recovery, limiting the spread of disease and helping them to lead healthy, productive lives.”

    The innovative projects receiving funding include:

    •Dr. Dhananjaya Dendukuri from Achira Labs in Bangalore India, and Dr. Nandini Dendukuri from McGill University in Montreal are developing a piece of silk that can be used as a cost-effective and simple diagnostic for blood and urine samples. Called Fabchips (Fabric Chips) the woven diagnostic has the added benefit of providing jobs to local artisans and being environmentally friendly.

    •Dr. David Goldfarb, a Canadian working in Botswana, is testing a simple, rapid, easy-to-use cotton swab for the detection of diarrheal disease in the developing world.

    •Dr. Wendy Stevens from the University of Witwatersrand in South Africa is testing new point-of-care technologies for the integrated management of HIV and TB treatment to encourage equity, affordability and accessibility to treatment.

    •Dr. Patricia Garcia at the Universidad Peruana Cayetano Heredia in Peru will look at ways to overcome social and commercial barriers to delivering point-of-care diagnostic tests aimed at improving maternal and child health – two of the UN’s Millennium Development goals for 2015.

    businessdailyafrica.com 

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