Researchers in Singapore are reporting development of a new electronic sensor that shows promise as a faster, less expensive, and more practical alternative than tests now used to detect DNA. Such tests are done for criminal investigation, disease diagnosis, and other purposes. The new lab-on-a-chip test could lead to wider, more convenient use of DNA testing, the researchers say. Their study is scheduled for the Sept. 2 issue of the Journal of the American Chemical Society, a weekly publication.
In the new study, Zhiqiang Gao and colleagues note that current methods for detecting DNA involve the used of the polymerase chain reaction (PCR). This technique "amplifies" or makes multiple copies of trace amounts of DNA, much as a photocopier produces multiple copies of documents, in order to detect the genetic material more easily. The amplification step is one reason why tests involving PCR can be too expensive, cumbersome, and imprecise for wider use.
The researchers describe development of a so-called "nanogap sensor" that appears to overcome those obstacles. The process uses a pair of micro-sized metal electrodes separated by a nanogap, 1/50,000 the width of a human hair, in combination with special chemical probes to capture tiny segments of DNA. The newly formed "circuit" then translates the presence of DNA into an electrical signal so that it can be measured by a computer. In laboratory tests, the sensor showed "excellent" sensitivity at detecting trace amounts of human DNA and may eliminate the need for DNA amplification altogether, the researchers say.
Source
Journal of the American Chemical Society
понедельник, 30 мая 2011 г.
Is Hybridoma Production About To Take A Quantum Leap Forward?
Recently published research* has established the ability of Neowater® to enhance the various processes involved in the production of pure human monoclonal antibodies by refining the standard hybridoma production process.
Biopharmaceutical companies have started to evaluate the use of fully human monoclonal antibodies as a complementary or primary therapeutic agent against a variety of diseases. The most obvious advantage would be to bypass the interference from the patient's immune system that typically characterizes the use of chemerical or humanized antibodies. Due to the growing interest and the potential benefits, the efficient production of human monoclonal antibodies is a high priority. But any attempt to produce these by natural means encounters formidable obstacles, not only from an ethical standpoint but also from the difficulty inherent in generating human antibodies against human tissues.
The capacity to humanize monoclonal antibodies in 1988 through hybridoma cell production methods opened exciting new vistas in R&D and biomed products. If this method could be further refined to produce pure, natural human monoclonal antibodies, research would take a quantum leap forward in the development of new medical and pharmaceutical discoveries for serious and life-threatening conditions that cannot yet be successfully treated with synthesized hybrids.
One proven way to profoundly enhance the media solutions used for cell growth, and particularly membrane proteins, is Radio Frequency (RF) radiation. The RF is absorbed by the aqueous solution and stimulates new membrane formation - a vital stage in hybridoma cell growth. The problem is that the beneficial effect decays once the source of RF is removed, and the new membrane formation does not receive the full benefit. Without this extra "boost", the delicate process of producing viable, fully human monoclonal antibodies faces an insurmountable obstacle.
This obstacle has been effectively removed by Neowater®, a novel nanoparticle-doped (NPD) water created by a unique patented water-based nanotechnology.
Neowater® is a non-toxic form of water that mimics intracellular water, which is found uniquely in the human body and its cells. NPD water is characterized by a shifting in the physical properties of ordinary water, imparting new levels of compatibility with hydrophobic substances. Neowater® also maintains the beneficial effect of RF radiation on water for years after its production, thanks to its extraordinary structural stability.
The researchers performed numerous experiments to test the growth rate of hybridoma cells in NPD-based media. They specifically tested the effect of the NPD environment on the complete process of human monoclonal antibody production, and their results were published recently in the BMC Biotechnology Journal.
To evaluate the hybridoma formation process (utilizing the chemical fusion method), the researchers received samples of human peripheral blood mononuclear cells (PBMC) from several donors; each sample was tested either in a NPD or a DI (de-ionized) environment. In referring to the results, the researchers stated: "We witnessed a statistically significant difference in the yield of hybridoma cells between NPD and DI environments."
In another experiment, the isolation of subclones and autocrine activity of hybridoma cells was tested. The researchers reported: "We observed greater clonal outgrowth of antibody-secreting hybridoma cells in NPD-based media as compared to DI-based media." Moreover, they found that "the cloneability of cells from a semi-stable clone is also enhanced in NPD-based media."
The researchers noted that hybridoma clones grown on NPD-based media secreted more monoclonal antibodies into their environment. However, they also observed that "Some cells grow faster in NPD-based media…This result might not reflect greater secretion per cell, but rather greater proliferation of cells with a similar secretion." After normalization of this biased situation, the researchers calculated that "the secretion of monoclonal antibody in NPD-based media is roughly twice that obtained in DI-based media."
This interesting and unexpected result led the researchers to conduct further tests: To what extent are cell proliferation rates affected by NPD-based media" Growing CHO (Chinese Hamster Ovary) cells in NPD-based and DI-based media, the researchers observed an unmistakable increase in proliferation when cells were incubated in NPD-based media, in comparison to the DI-based media: "an increase by an average of nearly 30%" .
The researchers then tested the proliferation rate of primary human fibroblast cells incubated either in NPD-based or DI-based media. Unlike the CHO cells, these are sensitive to cell density and were grown at two different starting dilutions. Here the NPD-based media had the opposite effect: the CHO cells displayed a slower proliferation rate than that of DI-based media (in both dilutions). The researchers concluded: "As is evident from the curves, primary human fibroblasts proliferated poorly in NPD-based media, compared to DI-based media.... they appear to sense the lower effective cell density."
The above paper demonstrates the remarkable power of Neowater® for enhancing the stabilization, activity and proliferation of cells and antibodies - as well as inhibiting the proliferation of other cells. This is just one example of the wide research potential that Neowater® offers, which will eventually impact the healthcare industry. Imagine the novel and cutting-edge methodologies suddenly available to stem-cell therapeutics, site-specific antibody treatments, and targeted anti-cancer drugs using fully human mAbs.
Many promising biomed and therapeutic concepts that have been shelved, blocked by the basic difference between regular water and intracellular water, can now cross the "molecular water barrier", thanks to the nanoparticle restructuring capability of Neowater®. We can expect a new era in R&D as these concepts are facilitated by Neowater® technology and find realization in therapeutic applications.
* "ENHANCEMENT OF HYBRIDOMA FORMATION, CLONEABILITY AND CELL PROLIFERATION IN A NANOPARTICLE-DOPED AQUEOUS ENVIRONMENT", authored by Natalie Gavrilov-Yusim1, Ekaterina Hahiashvili1, Marina Tashker1, Victoria Yavelsky1, Ohad Karnieli2 and Leslie Lobel1
1Department of Virology and Developmental Genetics, Ben Gurion University of the Negev, Beer-sheva 84105, Israel
2Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel)
Source: Irit Gabbai
Do-Coop Technologies Ltd.
Biopharmaceutical companies have started to evaluate the use of fully human monoclonal antibodies as a complementary or primary therapeutic agent against a variety of diseases. The most obvious advantage would be to bypass the interference from the patient's immune system that typically characterizes the use of chemerical or humanized antibodies. Due to the growing interest and the potential benefits, the efficient production of human monoclonal antibodies is a high priority. But any attempt to produce these by natural means encounters formidable obstacles, not only from an ethical standpoint but also from the difficulty inherent in generating human antibodies against human tissues.
The capacity to humanize monoclonal antibodies in 1988 through hybridoma cell production methods opened exciting new vistas in R&D and biomed products. If this method could be further refined to produce pure, natural human monoclonal antibodies, research would take a quantum leap forward in the development of new medical and pharmaceutical discoveries for serious and life-threatening conditions that cannot yet be successfully treated with synthesized hybrids.
One proven way to profoundly enhance the media solutions used for cell growth, and particularly membrane proteins, is Radio Frequency (RF) radiation. The RF is absorbed by the aqueous solution and stimulates new membrane formation - a vital stage in hybridoma cell growth. The problem is that the beneficial effect decays once the source of RF is removed, and the new membrane formation does not receive the full benefit. Without this extra "boost", the delicate process of producing viable, fully human monoclonal antibodies faces an insurmountable obstacle.
This obstacle has been effectively removed by Neowater®, a novel nanoparticle-doped (NPD) water created by a unique patented water-based nanotechnology.
Neowater® is a non-toxic form of water that mimics intracellular water, which is found uniquely in the human body and its cells. NPD water is characterized by a shifting in the physical properties of ordinary water, imparting new levels of compatibility with hydrophobic substances. Neowater® also maintains the beneficial effect of RF radiation on water for years after its production, thanks to its extraordinary structural stability.
The researchers performed numerous experiments to test the growth rate of hybridoma cells in NPD-based media. They specifically tested the effect of the NPD environment on the complete process of human monoclonal antibody production, and their results were published recently in the BMC Biotechnology Journal.
To evaluate the hybridoma formation process (utilizing the chemical fusion method), the researchers received samples of human peripheral blood mononuclear cells (PBMC) from several donors; each sample was tested either in a NPD or a DI (de-ionized) environment. In referring to the results, the researchers stated: "We witnessed a statistically significant difference in the yield of hybridoma cells between NPD and DI environments."
In another experiment, the isolation of subclones and autocrine activity of hybridoma cells was tested. The researchers reported: "We observed greater clonal outgrowth of antibody-secreting hybridoma cells in NPD-based media as compared to DI-based media." Moreover, they found that "the cloneability of cells from a semi-stable clone is also enhanced in NPD-based media."
The researchers noted that hybridoma clones grown on NPD-based media secreted more monoclonal antibodies into their environment. However, they also observed that "Some cells grow faster in NPD-based media…This result might not reflect greater secretion per cell, but rather greater proliferation of cells with a similar secretion." After normalization of this biased situation, the researchers calculated that "the secretion of monoclonal antibody in NPD-based media is roughly twice that obtained in DI-based media."
This interesting and unexpected result led the researchers to conduct further tests: To what extent are cell proliferation rates affected by NPD-based media" Growing CHO (Chinese Hamster Ovary) cells in NPD-based and DI-based media, the researchers observed an unmistakable increase in proliferation when cells were incubated in NPD-based media, in comparison to the DI-based media: "an increase by an average of nearly 30%" .
The researchers then tested the proliferation rate of primary human fibroblast cells incubated either in NPD-based or DI-based media. Unlike the CHO cells, these are sensitive to cell density and were grown at two different starting dilutions. Here the NPD-based media had the opposite effect: the CHO cells displayed a slower proliferation rate than that of DI-based media (in both dilutions). The researchers concluded: "As is evident from the curves, primary human fibroblasts proliferated poorly in NPD-based media, compared to DI-based media.... they appear to sense the lower effective cell density."
The above paper demonstrates the remarkable power of Neowater® for enhancing the stabilization, activity and proliferation of cells and antibodies - as well as inhibiting the proliferation of other cells. This is just one example of the wide research potential that Neowater® offers, which will eventually impact the healthcare industry. Imagine the novel and cutting-edge methodologies suddenly available to stem-cell therapeutics, site-specific antibody treatments, and targeted anti-cancer drugs using fully human mAbs.
Many promising biomed and therapeutic concepts that have been shelved, blocked by the basic difference between regular water and intracellular water, can now cross the "molecular water barrier", thanks to the nanoparticle restructuring capability of Neowater®. We can expect a new era in R&D as these concepts are facilitated by Neowater® technology and find realization in therapeutic applications.
* "ENHANCEMENT OF HYBRIDOMA FORMATION, CLONEABILITY AND CELL PROLIFERATION IN A NANOPARTICLE-DOPED AQUEOUS ENVIRONMENT", authored by Natalie Gavrilov-Yusim1, Ekaterina Hahiashvili1, Marina Tashker1, Victoria Yavelsky1, Ohad Karnieli2 and Leslie Lobel1
1Department of Virology and Developmental Genetics, Ben Gurion University of the Negev, Beer-sheva 84105, Israel
2Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel)
Source: Irit Gabbai
Do-Coop Technologies Ltd.
Organon And MRC Technology Sign Antibody Development Agreement
Organon, the human
healthcare business unit of Akzo Nobel, together with MRC Technology
(London, UK) announced that they have signed a collaborative
agreement to develop a humanized antibody for the treatment of certain
forms of cancer. The Therapeutic Antibody Group (TAG) at MRCT will use its
proprietary CDR grafting technology to generate a humanized clinical
candidate from a murine antibody discovered at Organon's Research Center
in Cambridge, MA (USA). Organon will pay MRCT research and development
milestones, and royalties based on net sales that may result from the
commercialization of any antibody products. Organon will retain all
development and commercialization rights. Additional financial terms were
not disclosed.
"Organon has been stepping up its efforts to discover and develop novel
biotherapeutics for oncology and auto-immune disorders. The collaboration with
MRCT on its well-validated antibody humanization technology is a further step
towards becoming effective biotherapeutic drug hunters," said David Nicholson,
EVP of R&D at Organon.
TAG has a proven track record of success in antibody humanization which
extends over 18 years and encompasses around 30 successfully humanized
antibodies," said Dr. Tarran Jones, Director of TAG. "Eight of these humanized
antibodies have progressed to the clinic and two, Elan/Biogen Idec's Tysabri® and
Chugai/Roche's Actemra®, have gone on to achieve market approval. We are
looking forward to applying our expertise in collaboration with Organon to
humanize their monoclonal antibody which addresses such an important disease
area."
Antibody humanization
Antibody humanization, also known as CDR-grafting (CDR is a synonym for
complementarity determining region) was first invented at the MRC Laboratory of
Molecular Biology in the UK by Dr. Sir Greg Winter and patented by the MRC in the late
1980's. CDR-grafting involves the genetic transfer of mouse CDRs (which are responsible
for antigen binding) into human frameworks of a variable region. A variable region is one
domain of an immunoglobulin chain, a whole antibody itself comprising of one light and
one heavy immunoglobulin chain. The key to success in antibody humanization is a careful
analysis of the mouse antibody to identify key framework residues important for the
preservation of antibody function in the humanized antibody.
About Organon
Organon creates, manufactures and markets innovative prescription medicines that
improve the health and quality of human life. Through a combination of innovation and
business partnerships, Organon seeks to leverage its position as a leading
biopharmaceutical company in each of its core therapeutic fields: fertility, gynecology and
selected areas of anesthesia. It has extensive expertise in neuroscience and a rich and
focused R&D program. Research areas also include immunology and specific areas of
oncology. Organon products are distributed in over 100 countries worldwide, of which more
than 50 have an Organon subsidiary. Organon is the human healthcare business unit of
Akzo Nobel.
About Medical Research Council Technology (MRCT)
MRCT is the exclusive commercialisation catalyst for the UK Medical Research Council
(MRC), working to translate cutting edge scientific discoveries into commercial products.
MRCT bridges the gap between innovative basic science and making medicine. By
providing both chemical tools and therapeutic antibody candidates, we give pharmaceutical
and biotechnology companies new starting points for drug discovery and development,
based on MRC advances in science.
MRCT's Therapeutic Antibody Group (TAG) scientists have a proven track record of
success in antibody humanisation which extends over 18 years and has produced 8
clinical candidates and two regulatory approved humanised antibodies. TAG collaborates
with MRC scientists to translate innovative antibody-based drug targets into potent and
selective therapeutic antibody candidates which can then be partnered with industry. In
addition, MRCT provides the pharmaceutical and biotechnology industry access to the
world-class antibody humanisation and expression expertise of TAG.
Safe Harbor Statement Organon*
This press release may contain statements which address such key issues as growth strategy, future
financial results, market positions, product development, pharmaceutical products in the pipeline, and
product approvals of Organon. Such statements should be carefully considered, and it should be
understood that many factors could cause forecasted and actual results to differ from these statements.
These factors include, but are not limited to, price fluctuations, currency fluctuations, progress of drug
development, clinical testing and regulatory approval, developments in raw material and personnel costs,
pensions, physical and environmental risks, legal issues, and legislative, fiscal, and other regulatory
measures. Stated competitive positions are based on management estimates supported by information
provided by specialized external agencies. For a more comprehensive discussion of the risk factors
affecting our business please see our Annual Report on Form 20-F filed with the United States Securities
and Exchange Commission, a copy of which can be found on the company's corporate website
akzonobel.
* Pursuant to the U.S. Private Securities Litigation Reform Act 1995.
View drug information on Actemra; Tysabri.
healthcare business unit of Akzo Nobel, together with MRC Technology
(London, UK) announced that they have signed a collaborative
agreement to develop a humanized antibody for the treatment of certain
forms of cancer. The Therapeutic Antibody Group (TAG) at MRCT will use its
proprietary CDR grafting technology to generate a humanized clinical
candidate from a murine antibody discovered at Organon's Research Center
in Cambridge, MA (USA). Organon will pay MRCT research and development
milestones, and royalties based on net sales that may result from the
commercialization of any antibody products. Organon will retain all
development and commercialization rights. Additional financial terms were
not disclosed.
"Organon has been stepping up its efforts to discover and develop novel
biotherapeutics for oncology and auto-immune disorders. The collaboration with
MRCT on its well-validated antibody humanization technology is a further step
towards becoming effective biotherapeutic drug hunters," said David Nicholson,
EVP of R&D at Organon.
TAG has a proven track record of success in antibody humanization which
extends over 18 years and encompasses around 30 successfully humanized
antibodies," said Dr. Tarran Jones, Director of TAG. "Eight of these humanized
antibodies have progressed to the clinic and two, Elan/Biogen Idec's Tysabri® and
Chugai/Roche's Actemra®, have gone on to achieve market approval. We are
looking forward to applying our expertise in collaboration with Organon to
humanize their monoclonal antibody which addresses such an important disease
area."
Antibody humanization
Antibody humanization, also known as CDR-grafting (CDR is a synonym for
complementarity determining region) was first invented at the MRC Laboratory of
Molecular Biology in the UK by Dr. Sir Greg Winter and patented by the MRC in the late
1980's. CDR-grafting involves the genetic transfer of mouse CDRs (which are responsible
for antigen binding) into human frameworks of a variable region. A variable region is one
domain of an immunoglobulin chain, a whole antibody itself comprising of one light and
one heavy immunoglobulin chain. The key to success in antibody humanization is a careful
analysis of the mouse antibody to identify key framework residues important for the
preservation of antibody function in the humanized antibody.
About Organon
Organon creates, manufactures and markets innovative prescription medicines that
improve the health and quality of human life. Through a combination of innovation and
business partnerships, Organon seeks to leverage its position as a leading
biopharmaceutical company in each of its core therapeutic fields: fertility, gynecology and
selected areas of anesthesia. It has extensive expertise in neuroscience and a rich and
focused R&D program. Research areas also include immunology and specific areas of
oncology. Organon products are distributed in over 100 countries worldwide, of which more
than 50 have an Organon subsidiary. Organon is the human healthcare business unit of
Akzo Nobel.
About Medical Research Council Technology (MRCT)
MRCT is the exclusive commercialisation catalyst for the UK Medical Research Council
(MRC), working to translate cutting edge scientific discoveries into commercial products.
MRCT bridges the gap between innovative basic science and making medicine. By
providing both chemical tools and therapeutic antibody candidates, we give pharmaceutical
and biotechnology companies new starting points for drug discovery and development,
based on MRC advances in science.
MRCT's Therapeutic Antibody Group (TAG) scientists have a proven track record of
success in antibody humanisation which extends over 18 years and has produced 8
clinical candidates and two regulatory approved humanised antibodies. TAG collaborates
with MRC scientists to translate innovative antibody-based drug targets into potent and
selective therapeutic antibody candidates which can then be partnered with industry. In
addition, MRCT provides the pharmaceutical and biotechnology industry access to the
world-class antibody humanisation and expression expertise of TAG.
Safe Harbor Statement Organon*
This press release may contain statements which address such key issues as growth strategy, future
financial results, market positions, product development, pharmaceutical products in the pipeline, and
product approvals of Organon. Such statements should be carefully considered, and it should be
understood that many factors could cause forecasted and actual results to differ from these statements.
These factors include, but are not limited to, price fluctuations, currency fluctuations, progress of drug
development, clinical testing and regulatory approval, developments in raw material and personnel costs,
pensions, physical and environmental risks, legal issues, and legislative, fiscal, and other regulatory
measures. Stated competitive positions are based on management estimates supported by information
provided by specialized external agencies. For a more comprehensive discussion of the risk factors
affecting our business please see our Annual Report on Form 20-F filed with the United States Securities
and Exchange Commission, a copy of which can be found on the company's corporate website
akzonobel.
* Pursuant to the U.S. Private Securities Litigation Reform Act 1995.
View drug information on Actemra; Tysabri.
Sequencing Of Wasp Genome May Help Fight Human Diseases Spread By Insects
About 100 million years ago, the bacterium Wolbachia came up with a trick that has made it one of the most successful parasites in the animal kingdom: It evolved the ability to manipulate the sex lives of its hosts.
"When it developed this capability, Wolbachia spread rapidly among the world's populations of insects, mites, spiders and nematodes, producing the greatest pandemic in the history of life," says Seth Bordenstein, assistant professor of biological sciences at Vanderbilt, who is studying the relationship between this parasitic bacteria and Nasonia, a genus of small wasps that prey on various species of flies, including houseflies, blowflies and flesh flies.
Bordenstein is a member of the Nasonia Genome Working Group, a collaboration of scientists who published the complete genomes of three species of Nasonia in the January 15 issue of the journal Science. In the paper the group identifies several genes that the wasps appear to have picked up from the bacteria.
This new genetic information has allowed Bordenstein to identify one of the key tools in the bacteria's bag of tricks. It causes a gene in the wasp's immune system to produce less of the protein responsible for detecting bacterial intruders and issuing the chemical alarm signal that activates the wasp's various defense mechanisms. This hijacking of the immune system allows the bacteria to invade the bodies of its hosts with relative impunity, he proposes.
Exactly how the bacteria alters its hosts' reproductive systems to its advantage remains a matter for future study. But scientists have identified the bacteria's basic strategies. Depending on its host, the bacteria either:
Kills infected males;
Feminizes infected males so they develop as females or infertile pseudo-females;
Induces parthenogenesis: the reproduction of infected females without males;
Makes the sperm of infected males incompatible with the eggs of uninfected females or females infected with a different Wolbachia strain.
Wolbachia favors female over male offspring because they are present in mature eggs, but not in mature sperm. As a result, only infected females pass the infection on to their offspring.
"This makes them the ultimate feminist weapon," Bordenstein quips.
Although the bacteria's parasitism is limited to arthropods - animals with exoskeletons instead of backbones like insects, spiders and crustaceans - its prevalence means that it has a major impact on the biosphere. According to one study, more than 16 percent of the insect species in South and Central America, Mexico, the Caribbean Islands and southern Florida are infected and as many as 70 percent of all insect species are potential hosts.
Recognition of Wolbachia's capabilities has made it a promising candidate for genetic engineers looking for more effective ways to fight human diseases spread by insects. "Once we understand how Wolbachia works, we should be able to add some genes that allow us to control insects that vector human diseases like malaria and dengue fever," says Bordenstein. "There is already a number of research projects supported by the Gates Foundation and the National Institutes of Health pursuing this idea."
Although the ubiquitous bacteria cannot trick the human immune system, it does have an adverse impact on human health. For example, it infects many species of nematodes, including the filarial nematodes that infect more than 200 million people worldwide, causing debilitating inflammatory diseases, such as river blindness and elephantiasis.
In the last 10 years scientists have realized that it is actually the bacteria, not the nematode, that is responsible for most of the symptoms produced by these illnesses. Although Wolbachia can only survive about three days in the human body, the parasitic nematodes act as a continuing source of the bacteria that cause most of the damage. This surprising insight into the disease pathology has improved the treatment of these illnesses: They are now treated with an antibiotic that kills the bacteria and is less toxic than anti-nematode medications.
Bordenstein's research was supported by a grant from the National Institutes of Health and the genome sequencing was funded by the National Human Genome Research Institute. Additional details about the research conducted in the Bordenstein lab is available at bordensteinlab.vanderbilt.
Source: David F. Salisbury
Vanderbilt University
"When it developed this capability, Wolbachia spread rapidly among the world's populations of insects, mites, spiders and nematodes, producing the greatest pandemic in the history of life," says Seth Bordenstein, assistant professor of biological sciences at Vanderbilt, who is studying the relationship between this parasitic bacteria and Nasonia, a genus of small wasps that prey on various species of flies, including houseflies, blowflies and flesh flies.
Bordenstein is a member of the Nasonia Genome Working Group, a collaboration of scientists who published the complete genomes of three species of Nasonia in the January 15 issue of the journal Science. In the paper the group identifies several genes that the wasps appear to have picked up from the bacteria.
This new genetic information has allowed Bordenstein to identify one of the key tools in the bacteria's bag of tricks. It causes a gene in the wasp's immune system to produce less of the protein responsible for detecting bacterial intruders and issuing the chemical alarm signal that activates the wasp's various defense mechanisms. This hijacking of the immune system allows the bacteria to invade the bodies of its hosts with relative impunity, he proposes.
Exactly how the bacteria alters its hosts' reproductive systems to its advantage remains a matter for future study. But scientists have identified the bacteria's basic strategies. Depending on its host, the bacteria either:
Kills infected males;
Feminizes infected males so they develop as females or infertile pseudo-females;
Induces parthenogenesis: the reproduction of infected females without males;
Makes the sperm of infected males incompatible with the eggs of uninfected females or females infected with a different Wolbachia strain.
Wolbachia favors female over male offspring because they are present in mature eggs, but not in mature sperm. As a result, only infected females pass the infection on to their offspring.
"This makes them the ultimate feminist weapon," Bordenstein quips.
Although the bacteria's parasitism is limited to arthropods - animals with exoskeletons instead of backbones like insects, spiders and crustaceans - its prevalence means that it has a major impact on the biosphere. According to one study, more than 16 percent of the insect species in South and Central America, Mexico, the Caribbean Islands and southern Florida are infected and as many as 70 percent of all insect species are potential hosts.
Recognition of Wolbachia's capabilities has made it a promising candidate for genetic engineers looking for more effective ways to fight human diseases spread by insects. "Once we understand how Wolbachia works, we should be able to add some genes that allow us to control insects that vector human diseases like malaria and dengue fever," says Bordenstein. "There is already a number of research projects supported by the Gates Foundation and the National Institutes of Health pursuing this idea."
Although the ubiquitous bacteria cannot trick the human immune system, it does have an adverse impact on human health. For example, it infects many species of nematodes, including the filarial nematodes that infect more than 200 million people worldwide, causing debilitating inflammatory diseases, such as river blindness and elephantiasis.
In the last 10 years scientists have realized that it is actually the bacteria, not the nematode, that is responsible for most of the symptoms produced by these illnesses. Although Wolbachia can only survive about three days in the human body, the parasitic nematodes act as a continuing source of the bacteria that cause most of the damage. This surprising insight into the disease pathology has improved the treatment of these illnesses: They are now treated with an antibiotic that kills the bacteria and is less toxic than anti-nematode medications.
Bordenstein's research was supported by a grant from the National Institutes of Health and the genome sequencing was funded by the National Human Genome Research Institute. Additional details about the research conducted in the Bordenstein lab is available at bordensteinlab.vanderbilt.
Source: David F. Salisbury
Vanderbilt University
AGES Selects BrukerВґs MALDI Biotyper System For Mass Spectrometry-based Molecular Microbial Identification
At the 32rd OEGHMP annual meeting opening here today, Bruker announces that its MALDI Biotyper workflow for microbial identification in clinical microbiology has been selected by the Austrian Agency for Health and Food Safety (AGES) for MALDI-TOF based analyses of microorganisms.
AGES is responsible for several tasks in regard to public health and food safety for the Austrian government. The organization researches, analyzes and performs inspections according to the policy guidelines of Austrian Food Laws. The agency requires veterinary inspections and dedicates itself to the prevention and control of infectious diseases in the population. Just recently, scientists of the AGES discovered the source of a listeriosis outbreak in Austria and Germany that caused eight deaths due to contaminated cheese products. In order to provide always state of the art microbiological analyses AGES is the first organization in Austria using the IVD-CE marked IVD MALDI Biotyper system that is in accordance with the European Union In Vitro Diagnostic Directive 98/79/EC.
University Professor Dr. med. Franz Allerberger, Head of the Human Medicine Division, AGES commented: "Microbial analyses based on MALDI-TOF mass spectrometry as a molecular identification tool provide premium information in order to describe and differentiate microorganisms very reliably. With advantages in speed, accuracy and cost per sample over phenotypic standard tests, the MALDI Biotyper has the potential to become a new clinical standard for microbial identification. In particular, for fastidious microorganisms like anaerobic and non-fermenting bacteria the superior discrimination power of the MALDI Biotyper has been proven in several publications. In order to substantiate the MALDI Biotyper benefit especially for difficult species in the daily clinical routine AGES will be the leading organization for quality assurance and standardization for the analysis after Legionella infections. In this context we will also perform a respective round robin test comprising labs from all over the world."
Dr. Guido Mix, Bruker Daltonics Director for Microbiology Business Development, concluded: "The MALDI Biotyper is already a very suitable and reliable tool for daily microbiological routine analysis. Globally more than 100 clinical diagnostic labs, as well as further microbiology departments at industrial and academic sites operate this protein fingerprinting-based approach. We are very pleased to collaborate with an organization like the AGES in order to explore the MALDI Biotyper capabilities beyond current standardized operational species identification procedures, and towards strain typing or clone tracking."
About the Bruker MALDI Biotyper
Bruker's dedicated MALDI Biotyper solution enables identification, taxonomical classification or dereplication of microorganisms like bacteria, yeasts and fungi. Classification and identification of microorganisms is achieved reliably and fast using high-throughput MALDI-TOF mass spectrometry. Applications include clinical routine microbial identification (in EU only - for research use only elsewhere), environmental and pharmaceutical analysis, taxonomical research, food and consumer product processing and quality control, as well as in marine microbiology. Bruker's robust MALDI Biotyper method requires minimal sample preparation efforts and offers low cost per sample. For more information, please visit maldibiotyper.
Source
Bruker Corporation
AGES is responsible for several tasks in regard to public health and food safety for the Austrian government. The organization researches, analyzes and performs inspections according to the policy guidelines of Austrian Food Laws. The agency requires veterinary inspections and dedicates itself to the prevention and control of infectious diseases in the population. Just recently, scientists of the AGES discovered the source of a listeriosis outbreak in Austria and Germany that caused eight deaths due to contaminated cheese products. In order to provide always state of the art microbiological analyses AGES is the first organization in Austria using the IVD-CE marked IVD MALDI Biotyper system that is in accordance with the European Union In Vitro Diagnostic Directive 98/79/EC.
University Professor Dr. med. Franz Allerberger, Head of the Human Medicine Division, AGES commented: "Microbial analyses based on MALDI-TOF mass spectrometry as a molecular identification tool provide premium information in order to describe and differentiate microorganisms very reliably. With advantages in speed, accuracy and cost per sample over phenotypic standard tests, the MALDI Biotyper has the potential to become a new clinical standard for microbial identification. In particular, for fastidious microorganisms like anaerobic and non-fermenting bacteria the superior discrimination power of the MALDI Biotyper has been proven in several publications. In order to substantiate the MALDI Biotyper benefit especially for difficult species in the daily clinical routine AGES will be the leading organization for quality assurance and standardization for the analysis after Legionella infections. In this context we will also perform a respective round robin test comprising labs from all over the world."
Dr. Guido Mix, Bruker Daltonics Director for Microbiology Business Development, concluded: "The MALDI Biotyper is already a very suitable and reliable tool for daily microbiological routine analysis. Globally more than 100 clinical diagnostic labs, as well as further microbiology departments at industrial and academic sites operate this protein fingerprinting-based approach. We are very pleased to collaborate with an organization like the AGES in order to explore the MALDI Biotyper capabilities beyond current standardized operational species identification procedures, and towards strain typing or clone tracking."
About the Bruker MALDI Biotyper
Bruker's dedicated MALDI Biotyper solution enables identification, taxonomical classification or dereplication of microorganisms like bacteria, yeasts and fungi. Classification and identification of microorganisms is achieved reliably and fast using high-throughput MALDI-TOF mass spectrometry. Applications include clinical routine microbial identification (in EU only - for research use only elsewhere), environmental and pharmaceutical analysis, taxonomical research, food and consumer product processing and quality control, as well as in marine microbiology. Bruker's robust MALDI Biotyper method requires minimal sample preparation efforts and offers low cost per sample. For more information, please visit maldibiotyper.
Source
Bruker Corporation
Improved Technique Determines Structure In Membrane Proteins
Understanding the form and function of certain proteins in the human body is becoming faster and easier, thanks to the work of researchers at the University of Illinois.
By combining custom-built spectrometers, novel probe designs and faster pulse sequences, a team led by Illinois chemistry professor Chad Rienstra has developed unique capabilities for probing protein chemistry and structure through the use of solid-state nuclear magnetic resonance spectroscopy.
The researchers' recent results represent significant progress toward atomic-scale resolution of protein structure by solid-state NMR spectroscopy. The technique can be applied to a large range of membrane proteins and fibrils, which, because they are not water-soluble, are often not amenable to more conventional solution NMR spectroscopy or X-ray crystallography.
"In our experiments, we explore couplings between atoms in proteins," Rienstra said. "Our goal is to translate genomic information into high-resolution structural information, and thereby be able to better understand the function of the proteins."
Solid-state NMR spectroscopy relaxes the need for solubility of the sample. In solution NMR spectroscopy, molecules are allowed to tumble randomly in the magnetic field. In solid-state NMR spectroscopy, molecules are immobilized within a small cylinder called a rotor. The rotor is then spun at high speed in the magnetic field.
"With increased speed and sensitivity, we can obtain very high resolution spectra," Rienstra said. "And, because we can resolve thousands of signals at a time - one for each atom in the sample - we can determine the structure of the entire protein."
To improve sensitivity and accelerate data collection, Rienstra's group is developing smaller rotors that can be spun at rates exceeding 25,000 rotations per second. The faster rotation rate and smaller sample size allows the researchers to obtain more data in less time, and solve structure with just a few milligrams of protein.
The determination of protein structure benefits not only from improvements in technology, but also from the researchers' novel approach to refining geometrical parameters.
Structure determination is normally based upon distances between atoms. Rienstra discovered a way of measuring both the distance between atoms and their relative orientations with very high precision.
"Using this technique, we can more precisely define the fragments of the molecule, and how they are oriented," Rienstra said. "That allows us to define protein features and determine structure at the atomic scale."
Rienstra will describe his group's latest findings and techniques at the national meeting of the American Chemical Society, to be held in Philadelphia, Aug. 17-21. Rienstra and his collaborators described their work - creating the highest resolution protein structure solved by solid-state NMR - in the March 25 issue of the Proceedings of the National Academy of Sciences.
The work was funded by the National Science Foundation and the National Institutes of Health.
Source: James E. Kloeppel
University of Illinois at Urbana-Champaign
By combining custom-built spectrometers, novel probe designs and faster pulse sequences, a team led by Illinois chemistry professor Chad Rienstra has developed unique capabilities for probing protein chemistry and structure through the use of solid-state nuclear magnetic resonance spectroscopy.
The researchers' recent results represent significant progress toward atomic-scale resolution of protein structure by solid-state NMR spectroscopy. The technique can be applied to a large range of membrane proteins and fibrils, which, because they are not water-soluble, are often not amenable to more conventional solution NMR spectroscopy or X-ray crystallography.
"In our experiments, we explore couplings between atoms in proteins," Rienstra said. "Our goal is to translate genomic information into high-resolution structural information, and thereby be able to better understand the function of the proteins."
Solid-state NMR spectroscopy relaxes the need for solubility of the sample. In solution NMR spectroscopy, molecules are allowed to tumble randomly in the magnetic field. In solid-state NMR spectroscopy, molecules are immobilized within a small cylinder called a rotor. The rotor is then spun at high speed in the magnetic field.
"With increased speed and sensitivity, we can obtain very high resolution spectra," Rienstra said. "And, because we can resolve thousands of signals at a time - one for each atom in the sample - we can determine the structure of the entire protein."
To improve sensitivity and accelerate data collection, Rienstra's group is developing smaller rotors that can be spun at rates exceeding 25,000 rotations per second. The faster rotation rate and smaller sample size allows the researchers to obtain more data in less time, and solve structure with just a few milligrams of protein.
The determination of protein structure benefits not only from improvements in technology, but also from the researchers' novel approach to refining geometrical parameters.
Structure determination is normally based upon distances between atoms. Rienstra discovered a way of measuring both the distance between atoms and their relative orientations with very high precision.
"Using this technique, we can more precisely define the fragments of the molecule, and how they are oriented," Rienstra said. "That allows us to define protein features and determine structure at the atomic scale."
Rienstra will describe his group's latest findings and techniques at the national meeting of the American Chemical Society, to be held in Philadelphia, Aug. 17-21. Rienstra and his collaborators described their work - creating the highest resolution protein structure solved by solid-state NMR - in the March 25 issue of the Proceedings of the National Academy of Sciences.
The work was funded by the National Science Foundation and the National Institutes of Health.
Source: James E. Kloeppel
University of Illinois at Urbana-Champaign
Super-Thin Membrane Design Opens Possibility For Better Dialysis, Fuel Cells, Neuro-Stem Cell Cultivation
A newly designed porous membrane, so thin it's invisible edge-on, may revolutionize the way doctors and scientists manipulate objects as small as a molecule.
The 50-atom thick filter can withstand surprisingly high pressures and may be a key to better separation of blood proteins for dialysis patients, speeding ion exchange in fuel cells, creating a new environment for growing neurological stem cells, and purifying air and water in hospitals and clean-rooms at the nanoscopic level.
At more than 4,000 times thinner than a human hair, the new barely-there membrane is thousands of times thinner than similar filters in use today.
Details on the membrane, developed at the University of Rochester, appear in today's issue of the journal Nature. "It's amazing, we have a material as thin as some of the molecules it's sorting, and even riddled with holes, but can withstand enough pressure to make real-world nano-filtering a practical reality," says research associate Christopher Striemer, co-creator of the membrane. "That ultra-thinness means much higher efficiency and lower sample loss, so we can do things that can't normally be done with current materials."
The membrane is a 15-nanometer-thick slice of the same silicon that's used every day in computer-chip manufacturing. In the lab of Philippe Fauchet, professor of electrical and computer engineering at the University, Striemer discovered the membrane as he was looking for a way to better understand how silicon crystallizes when heated.
He used such a thin piece of silicon - only about 50 atoms thick - because it would allow him to use an electron microscope to see the crystal structure in his samples, formed with different heat treatments.
Striemer found that as parts of the silicon contracted into crystals, holes opened up in their wakes. Imagine a party of people spread out evenly throughout a room, but as the evening progresses and people huddle into cliques, scattered areas of empty floor open up.
In talks with Striemer and Fauchet, James L. McGrath, assistant professor of biomedical engineering, and his graduate student, Tom Gaborski, realized that since the membrane's holes were only nanometers in size, it might be possible to separate objects as small as proteins much more effectively than is being done now.
Current molecular-level filters use a polymer-based design that is a jumble of varying holes and tunnels. The sizes of holes in the polymer model vary greatly, and since its "holes" are really convoluted tunnels through the material, they require much more time for proteins to pass through, and they are prone to clogging.
Recently, researchers had tried to design an ideal filter by drilling holes into a thin slice of another silicon-based material with an ion beam. While the effort did result in a filter with regular holes, the process was too laborious to be cost effective, and its membrane was so brittle that it required an elaborate support structure to prevent it from shattering.
While McGrath knew he might have the exact filter researchers have been searching for, he needed to test if the predictions held up. "When you build something at this scale, you're closing in on the quantum world and you never know what the properties are going to be," he says.
When Striemer tested his design, he found that the same 50-atom thickness could hold back an astonishing 15 pounds per square inch of pressure.
To test the membrane, Gaborski placed a solution of two blood proteins, albumin and IgG, behind the membrane and forced it gently through the nanoscopic holes. In just over six minutes, the albumin had passed through, but the larger IgG protein was stopped.
And as if filtering by nanoscale size weren't enough, the Rochester team has found a way for the nano-filter to carry a fixed charge, effectively making the hole "smaller" for molecules of a certain charge than for others. In a single filter it's now possible to quickly and easily separate molecules by their size and their chargeвЂ"a serious boon for fuel cell researchers, who wish to move only certain ions from one part of a fuel cell to another.
Separating molecules by size and charge efficiently is also the goal of kidney dialysis researchers. Johnson & Johnson recently gave the Rochester team a $100,000 grant to pursue developing the membrane's use in separating blood proteins with the hope of creating a more efficient method of dialysis.
"Kidneys do a much better job than dialysis machines of filtering blood proteins and keeping the ones you need, like albumin, and getting rid of toxins, which in some cases are smaller proteins," says McGrath. "They use a type of cellulose or plastic membrane with relatively poor discrimination. We think we can engineer these membranes to provide superior discrimination of proteins, which may make the process of dialysis faster and more effective than it is today."
The Rochester group sees many more applications for the membrane in the future. One of the most intriguing ideas is that it may play a role in growing neurons from stem cells.
Steve Goldman, Glenn-Zutes Chair in Biology of the Aging Brain and professor of neurology at the University of Rochester, discussed the technology with McGrath and colleagues and was impressed. "It's a spectacularly interesting technology, that opens a realm of new possibilities in fields as diverse as organ reconstitution, proteomics and microfluidics," says Goldman. "Its potential applications to neuroscience, cell biology and medical research may be profound."
Recent evidence suggests that neurological stem cells may grow better when in the immediate vicinity of certain "helper" cells. A problem arises after the new neurons are grown, when scientists need to separate the neurons from these helper cells. McGrath suggests that the neurological stem cells can be adhered to one side of the membrane, and the helper cells on the other.
The silicon membrane is about the thickness of the cell's own membranes, meaning the two groups of cells can actually touch each other through the membrane's pores without passing through themselves. The chemical communication between the helper and stem cells can continue as if the two sets of cells were in direct contact, but after the neurons are fully formed, they can easily be separated from the helper cells.
The Rochester team is working to realize the potential of the membrane by refining its fabrication. Striemer found he could "tune" the size of the filter holes depending on the temperature to which the silicon is heated, but the process is not yet accurate enough for engineers to simply select any pore size and fabricate it.
The researchers have just founded a company, SiMPore, to commercialize the numerous applications of the nanomembrane. Many of the University's laboratories will be involved in testing and developing the membrane, and the founders have already been approached by semiconductor giants such as Intel to see if the filter could remove nanoparticles from solutions used in microchip-manufacturing.
The team is currently testing the membranes to see how they stand up to regular wear and tear, and how resistant they are to clogging, which is a chief problem with conventional filters.
Contact: Jonathan Sherwood
University of Rochester
The 50-atom thick filter can withstand surprisingly high pressures and may be a key to better separation of blood proteins for dialysis patients, speeding ion exchange in fuel cells, creating a new environment for growing neurological stem cells, and purifying air and water in hospitals and clean-rooms at the nanoscopic level.
At more than 4,000 times thinner than a human hair, the new barely-there membrane is thousands of times thinner than similar filters in use today.
Details on the membrane, developed at the University of Rochester, appear in today's issue of the journal Nature. "It's amazing, we have a material as thin as some of the molecules it's sorting, and even riddled with holes, but can withstand enough pressure to make real-world nano-filtering a practical reality," says research associate Christopher Striemer, co-creator of the membrane. "That ultra-thinness means much higher efficiency and lower sample loss, so we can do things that can't normally be done with current materials."
The membrane is a 15-nanometer-thick slice of the same silicon that's used every day in computer-chip manufacturing. In the lab of Philippe Fauchet, professor of electrical and computer engineering at the University, Striemer discovered the membrane as he was looking for a way to better understand how silicon crystallizes when heated.
He used such a thin piece of silicon - only about 50 atoms thick - because it would allow him to use an electron microscope to see the crystal structure in his samples, formed with different heat treatments.
Striemer found that as parts of the silicon contracted into crystals, holes opened up in their wakes. Imagine a party of people spread out evenly throughout a room, but as the evening progresses and people huddle into cliques, scattered areas of empty floor open up.
In talks with Striemer and Fauchet, James L. McGrath, assistant professor of biomedical engineering, and his graduate student, Tom Gaborski, realized that since the membrane's holes were only nanometers in size, it might be possible to separate objects as small as proteins much more effectively than is being done now.
Current molecular-level filters use a polymer-based design that is a jumble of varying holes and tunnels. The sizes of holes in the polymer model vary greatly, and since its "holes" are really convoluted tunnels through the material, they require much more time for proteins to pass through, and they are prone to clogging.
Recently, researchers had tried to design an ideal filter by drilling holes into a thin slice of another silicon-based material with an ion beam. While the effort did result in a filter with regular holes, the process was too laborious to be cost effective, and its membrane was so brittle that it required an elaborate support structure to prevent it from shattering.
While McGrath knew he might have the exact filter researchers have been searching for, he needed to test if the predictions held up. "When you build something at this scale, you're closing in on the quantum world and you never know what the properties are going to be," he says.
When Striemer tested his design, he found that the same 50-atom thickness could hold back an astonishing 15 pounds per square inch of pressure.
To test the membrane, Gaborski placed a solution of two blood proteins, albumin and IgG, behind the membrane and forced it gently through the nanoscopic holes. In just over six minutes, the albumin had passed through, but the larger IgG protein was stopped.
And as if filtering by nanoscale size weren't enough, the Rochester team has found a way for the nano-filter to carry a fixed charge, effectively making the hole "smaller" for molecules of a certain charge than for others. In a single filter it's now possible to quickly and easily separate molecules by their size and their chargeвЂ"a serious boon for fuel cell researchers, who wish to move only certain ions from one part of a fuel cell to another.
Separating molecules by size and charge efficiently is also the goal of kidney dialysis researchers. Johnson & Johnson recently gave the Rochester team a $100,000 grant to pursue developing the membrane's use in separating blood proteins with the hope of creating a more efficient method of dialysis.
"Kidneys do a much better job than dialysis machines of filtering blood proteins and keeping the ones you need, like albumin, and getting rid of toxins, which in some cases are smaller proteins," says McGrath. "They use a type of cellulose or plastic membrane with relatively poor discrimination. We think we can engineer these membranes to provide superior discrimination of proteins, which may make the process of dialysis faster and more effective than it is today."
The Rochester group sees many more applications for the membrane in the future. One of the most intriguing ideas is that it may play a role in growing neurons from stem cells.
Steve Goldman, Glenn-Zutes Chair in Biology of the Aging Brain and professor of neurology at the University of Rochester, discussed the technology with McGrath and colleagues and was impressed. "It's a spectacularly interesting technology, that opens a realm of new possibilities in fields as diverse as organ reconstitution, proteomics and microfluidics," says Goldman. "Its potential applications to neuroscience, cell biology and medical research may be profound."
Recent evidence suggests that neurological stem cells may grow better when in the immediate vicinity of certain "helper" cells. A problem arises after the new neurons are grown, when scientists need to separate the neurons from these helper cells. McGrath suggests that the neurological stem cells can be adhered to one side of the membrane, and the helper cells on the other.
The silicon membrane is about the thickness of the cell's own membranes, meaning the two groups of cells can actually touch each other through the membrane's pores without passing through themselves. The chemical communication between the helper and stem cells can continue as if the two sets of cells were in direct contact, but after the neurons are fully formed, they can easily be separated from the helper cells.
The Rochester team is working to realize the potential of the membrane by refining its fabrication. Striemer found he could "tune" the size of the filter holes depending on the temperature to which the silicon is heated, but the process is not yet accurate enough for engineers to simply select any pore size and fabricate it.
The researchers have just founded a company, SiMPore, to commercialize the numerous applications of the nanomembrane. Many of the University's laboratories will be involved in testing and developing the membrane, and the founders have already been approached by semiconductor giants such as Intel to see if the filter could remove nanoparticles from solutions used in microchip-manufacturing.
The team is currently testing the membranes to see how they stand up to regular wear and tear, and how resistant they are to clogging, which is a chief problem with conventional filters.
Contact: Jonathan Sherwood
University of Rochester
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