sábado, 25 de outubro de 2014

Paper-based synthetic gene networks could enable rapid detection of ebola and other viruses

 

October 23, 2014

Cell Press

Synthetic gene networks hold great potential for broad biotechnology and medical applications, but so far they have been limited to the lab. A study reveals a new method for using engineered gene circuits beyond the lab, allowing researchers to safely activate the cell-free, paper-based system by simply adding water. The low-cost, easy-to-use platform could enable the rapid detection of different strains of deadly viruses such as Ebola.


Synthetic gene networks hold great potential for broad biotechnology and medical applications, but so far they have been limited to the lab. A study published by Cell Press October 23rd in the journal Cell reveals a new method for using engineered gene circuits beyond the lab, allowing researchers to safely activate the cell-free, paper-based system by simply adding water. The low-cost, easy-to-use platform could enable the rapid detection of different strains of deadly viruses such as Ebola.

"Our paper-based system could not only make tools currently only available in laboratory readily fieldable, but also improve the development of new tools and the accessibility of these molecular tools to educational programs for the next generation of practitioners," says senior study author James Collins of the Wyss Institute for Biological Inspired Engineering at Harvard University.

The field of synthetic biology aims to re-engineer the molecular components of the cell to harness the power of biology. To accomplish this goal, researchers have designed synthetic gene networks that can control the activity of genes and recognize nucleic acids and small molecules. However, this technology has been restricted to the lab, in part because of biosafety concerns associated with cell-based systems and because the reactions involved have not been practical for field use.

Collins and his team overcame these hurdles by developing a cell-free, paper-based system suitable for use outside the lab. To test the clinical relevance of their method, the researchers developed sensors capable of detecting RNA molecules made from genes that allow bacteria to survive antibiotics, as well as RNA molecules encoding proteins from two different strains of the highly deadly Ebola virus. When freeze-dried onto paper, the sensors quickly detected the presence of these RNA molecules, demonstrating the usefulness of the approach for diagnostic purposes.

"Considering the projected cost, reaction time, ease of use, and no requirement for laboratory infrastructure, we envision paper-based synthetic gene networks significantly expanding the role of synthetic biology in the clinic, global health, industry, research, and education," Collins says.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Keith Pardee, Alexander A. Green, Tom Ferrante, D. Ewen Cameron, Ajay DaleyKeyser, Peng Yin, James J. Collins. Paper-Based Synthetic Gene Networks. Cell, October 2014 DOI: 10.1016/j.cell.2014.10.004

 

First protein microfiber engineered: New material advances tissue engineering and drug delivery

 

October 23, 2014

New York University Polytechnic School of Engineering

Researchers have broken new ground in the development of proteins that form specialized fibers used in medicine and nanotechnology. For as long as scientists have been able to create new proteins that are capable of self-assembling into fibers, their work has taken place on the nanoscale. For the first time, this achievement has been realized on the microscale -- a leap of magnitude in size that presents significant new opportunities for using engineered protein fibers.


Researchers at the New York University Polytechnic School of Engineering have broken new ground in the development of proteins that form specialized fibers used in medicine and nanotechnology. For as long as scientists have been able to create new proteins that are capable of self-assembling into fibers, their work has taken place on the nanoscale. For the first time, this achievement has been realized on the microscale -- a leap of magnitude in size that presents significant new opportunities for using engineered protein fibers.

Jin Kim Montclare, an associate professor of chemical and biomolecular engineering at the NYU School of Engineering, led a group of researchers who published the results of successful trials in the creation of engineered microfiber proteins in the journal Biomacromolecules.

Many materials used in medicine and nanotechnology rely on proteins engineered to form fibers with specific properties. For example, the scaffolds used in tissue engineering depend on engineered fibers, as do the nanowires used in biosensors. These fibers can also be bound with small molecules of therapeutic compounds and used in drug delivery.

Montclare and her collaborators began their experiments with the intention of designing nanoscale proteins bound with the cancer therapeutic curcumin. They successfully created a novel, self-assembling nanoscale protein, including a hydrophobic pore capable of binding small molecules. To their surprise, after incubating the fibers with curcumin, the protein not only continued to assemble, but did so to a degree that the fibers crossed the diameter barrier from the nanoscale to the microscale, akin to the diameter of collagen or spider silk.

"This was a surprising and thrilling achievement," said Montclare, explaining that this kind of diameter increase in the presence of small molecules is unprecedented. "A microscale fiber that is capable of delivering a small molecule, whether it be a therapeutic compound or other material, is a major step forward."

Montclare explained that biomaterials embedded with small molecules could be used to construct dual-purpose scaffolds for tissue engineering or to deliver certain drugs more efficiently, especially those that are less effective in an aqueous environment. Using microscopy, the team was able to observe the fibers in three dimensions and to confirm that the curcumin, which fluoresces when bound to structural protein, was distributed homogeneously throughout the fiber.

Despite the enormity of the jump from nano- to microscale, the research team believes they can devise even larger fibers. The next step, Montclare says, is developing proteins that can assemble on the milliscale, creating fibers large enough to see with the naked eye. "It's even possible to imagine generating hair out of cell assembly," she says.

Researchers from three institutions collaborated on this work. In addition to Montclare, NYU School of Engineering doctoral candidate Jasmin Hume, graduate student Rudy Jacquet, and undergraduate student Jennifer Sun co-authored the paper. Richard Bonneau, an associate professor in NYU's Department of Biology and a member of the computer science faculty at NYU's Courant Institute of Mathematical Sciences, and postdoctoral scholar P. Douglas Renfrew also contributed, along with M. Lane Gilchrist, associate professor of chemical engineering at City College of New York and master's degree student Jesse A. Martin, also from City College. Their work was supported by the Army Research Office and the National Science Foundation.


Story Source:

The above story is based on materials provided by New York University Polytechnic School of Engineering. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jasmin Hume, Jennifer Sun, Rudy Jacquet, P. Douglas Renfrew, Jesse A. Martin, Richard Bonneau, M. Lane Gilchrist, Jin Kim Montclare. Engineered Coiled-Coil Protein Microfibers. Biomacromolecules, 2014; 15 (10): 3503 DOI: 10.1021/bm5004948

 

Experimental breast cancer drug holds promise in combination therapy for Ewing sarcoma

 


Ewing sarcoma tumors disappeared and did not return in more than 70 percent of mice treated with combination therapy that included drugs from a family of experimental agents developed to fight breast cancer, reported St. Jude Children's Research Hospital scientists. The study will appear in the November 6 edition of the scientific journal Cell Reports.

The treatment paired two chemotherapy drugs currently used to treat Ewing sarcoma (EWS) with experimental drugs called poly-ADP ribose polymerase (PARP) inhibitors that interfere with DNA repair. PARP inhibitors are currently in clinical trials for the treatment of certain breast and ovarian cancers as well as other solid tumors. EWS is a cancer of the bone and soft tissue that strikes primarily adolescents and young adults.

A clinical trial using the three-drug combination therapy detailed in this research is expected to open later this year for adolescents and young adults with EWS whose tumors have not disappeared with standard therapy or have returned after treatment. The trial is a collaboration of researchers at St. Jude and the Dana-Farber/Harvard Cancer Center in Boston. The therapy will pair the PARP inhibitor olaparib with the chemotherapy drugs irinotecan (IRN) and temozolomide (TMZ).

The study is one of two clinical trials St. Jude plans to open soon combining IRN and TMZ with PARP inhibitors for the treatment for EWS. The tumor is diagnosed in about 250 U.S. residents each year, making it the second most common bone tumor in children and adolescents.

Long-term survival for EWS patients whose disease has not spread remains stalled at about 75 to 80 percent, and the outcome for patients with metastatic disease is dismal. "During the past 20 years there has been no significant improvement in the cure rate for Ewing sarcoma, and survival is just 15 to 20 percent for patients whose disease has spread or comes back after treatment," said co-corresponding author Michael Dyer, Ph.D., a Howard Hughes Medical Institute (HHMI) investigator and a member of the St. Jude Department of Developmental Neurobiology. The other corresponding author is Anang Shelat, Ph.D., an assistant member of the St. Jude Department of Chemical Biology and Therapeutics.

This study builds on earlier research from other investigators who reported that EWS cells growing in the laboratory were sensitive to the PARP inhibitor olaparib. A clinical trial of olaparib for treatment of adults with EWS that had spread or returned opened a short time later.

The latest report includes the St. Jude discovery that EWS cells have a defect in DNA damage repair. DNA is the molecule contained in nearly every cell that carries the instructions needed to assemble and sustain life.

Working with EWS cells grown in the laboratory and mice, investigators showed the EWS defect could be exploited to help patients by combining DNA-damaging chemotherapy with a PARP inhibitor. PARP inhibitors work by interfering with activity of an important DNA-repair enzyme.

St. Jude researchers conducted a series of mouse experiments designed to mirror the human phase I, II and III studies that gauge the safety and effectiveness of experimental treatment in humans. The research showed that PARP inhibitors work synergistically with IRN and TMZ to kill EWS. The Phase III study included 274 mice with EWS treated in a double-blind, placebo controlled, randomized study. The study included 15 different treatment groups using different combinations and doses of IRN, TMZ and three PARP inhibitors currently in development for pediatric cancer treatment.

EWS disappeared and had not returned in more than four months in 71 percent of mice treated with IRN, TMZ and the PARP inhibitor olaparib. The results were even better when IRN and TMZ were combined with the PARP inhibitor talazoparib. The combination led to a durable, complete remission in 88 percent of the 16 mice treated.

"Our preclinical results suggest Ewing sarcoma is particularly sensitive to this combination therapy, a possible indication that the tumor's DNA repair defect provides us with a much needed advantage to knock out tumor cells," Shelat said. "There is some evidence that this type of defect is present in other pediatric tumors, and we are actively investigating drug sensitivity in those cancers."

Researchers used the low-dose, protracted IRN treatment schedule pioneered at St. Jude to reduce IRN toxicity. Adult cancer patients receive fewer, but higher doses of IRN. The adult treatment regimen led to higher toxicity in mice. "The only way to move forward was using the irinotecan approach proven in earlier St. Jude solid tumor clinical research," Dyer said.

One of the planned St. Jude-led clinical trials will combine talazoparib and IRN for the treatment of patients age 1 and older. The other will involve triple drug therapy for treatment of patients age 16 and older.


Story Source:

The above story is based on materials provided by St. Jude Children's Research Hospital. Note: Materials may be edited for content and length.


Journal Reference:

  1. Elizabeth Stewart et al. Targeting the DNA Repair Pathway in Ewing Sarcoma. Cell Reports, October 2014 DOI: 10.1016/j.celrep.2014.09.028

 

California's tobacco control efforts losing steam, finds report

 

October 23, 2014

University of California, San Francisco (UCSF)

California’s position as a leader in tobacco control is under threat, according to a new report. Once a highly successful program and international model, the state's anti-tobacco efforts now appear to be waning due to the decreased spending power of the California Tobacco Control Program, a resurgence of the tobacco industry in state politics, and the emergence of new unregulated tobacco products.


California's position as a leader in tobacco control is under threat, according to a new report from the UC San Francisco Center for Tobacco Control Research and Education. Once a highly successful program and international model, the state's anti-tobacco efforts now appear to be waning due to the decreased spending power of the California Tobacco Control Program, a resurgence of the tobacco industry in state politics, and the emergence of new unregulated tobacco products.

"The combination of weak leadership at the state level, willingness of political leaders to accept tobacco industry money, and inflation eroding the spending power of the California Tobacco Control Program are compromising its effectiveness, which will lead, even in the short term, to more smoking," said Stanton Glantz, PhD, UCSF professor of medicine and director of the UCSF Center for Tobacco Control Research and Education.

The report will be published on Oct. 23 in eScholarship, which provides open-access scholarly publishing services to the University of California.

The report covers tobacco policymaking and tobacco industry political influence in California from 2007 to 2014 and is the latest in a series of reports on the state dating to 1976. It is part of a longstanding research project that tracks the effect of tobacco programs in protecting public health. To date, 29 states have been studied.

The California report draws from a comprehensive collection of sources including legislative records, campaign contribution data, lobbying reports, media reports, interviews, and peer reviewed journals.

In 1989, the California Tobacco Control Program was established after voters enacted Proposition 99 -- the Tobacco Tax and Health Protection Act. It has since achieved great success in reducing tobacco use by Californians. From 1989 to 2012, the percentage of adult smokers in California dropped from 22.7 percent to 12.6 percent, and while nearly 2.5 billion packs of cigarettes were sold in California in 1988, only 951 million packs were sold by 2012. Between 1989 and 2008, the California Tobacco Control Program cost $2.4 billion to run but led to a cumulative healthcare savings of $134 billion.

Despite these triumphs, the program is now much smaller and less aggressive than in its early years. By 2014, inflation had reduced the program's spending power to 53 percent of what it was when it began.

Furthermore, the rate of decline in tobacco consumption in California has slowed compared to the national rate. From 2004 to 2013, consumption per capita in California dropped 28.2 percent, while national consumption decreased 34.8 percent. In the previous ten-year period, however, the reverse was true, with California consumption dropping 40.8 percent, compared to a national decline of 20.5 percent.

The decrease in youth smoking in California was lower than that nationally between 2000 and 2011, especially among middle school students, who saw a 28.4 percent decline in California compared to a 60.9 percent decline nationally.

"It's unquestionably concerning to see that where we once were a leader we are now starting to fall behind," said lead author Elizabeth Cox, an assistant research specialist at the UCSF Center for Tobacco Control Research and Education. "The resources just aren't there anymore, and state leaders are no longer prioritizing tobacco control."

The report details how the tobacco industry has utilized its massive spending power in recent years to influence tobacco policymaking in California through campaign contributions and powerful lobbyists. Between 2007 and 2013, the industry spent nearly $64.5 million on California political activity. This period also saw an increase in the Democratic leadership's willingness to accept tobacco industry money, including the first California governor to take tobacco money in years, Governor Edmund G. Brown Jr.

Despite the need for new tobacco control funding sources, California leaders have fallen short in making this a priority, explains the report. California has the 33rd lowest cigarette tax in the nation, and yet none of the seven bills introduced to increase the cigarette excise tax from 2007 to 2014 moved past the legislature.

"Public health advocates need to increase pressure on politicians to again refuse tobacco industry money and to prioritize public health," Glantz said. "Only concerned action by health organizations to hold the politicians accountable will change this situation."

The new report also documents the influence of the rising electronic cigarette industry. According to the authors, as e-cigarettes become increasingly popular, they pose an unregulated threat to undermine tobacco control efforts. Despite the strong connection between cigarette smoking and e-cigarette use, the California Department of Public Health has not integrated e-cigarettes into its media campaign or other aspects of the California Tobacco Control Program. Furthermore, only one state bill has been passed to prohibit the sale of e-cigarettes to minors, but it lacks any enforcement measures.

With state leaders failing to take action, local policymaking has remained the most effective form of tobacco control. California led the nation on efforts to protect residents of multiunit housing from secondhand smoke. By 2014, 37 localities had passed ordinances restricting smoking in multiunit housing. In addition, 14 strong local tobacco retail licensing ordinances passed, and 40 percent of California residents were protected from e-cigarette smoke in public places by local ordinances from Eureka to Los Angeles.

"The bright spot in California is clearly at the local level, where political leaders have been putting the public interest above the tobacco companies by enacting strong legislation," Glantz said. "It is my sincere hope that state policymakers will take note of these successes and begin to follow suit, beginning by announcing that they are refusing and returning campaign cash from tobacco companies."

The full report will be available online at http://www.escholarship.org/uc/item/4jj1v7tv. Reports on other states are available at http://tobacco.ucsf.edu/states and for other countries at http://escholarship.org/uc/search?entity=ctcre_tcpmi.


Story Source:

The above story is based on materials provided by University of California, San Francisco (UCSF). The original article was written by Elizabeth Fernandez. Note: Materials may be edited for content and length.


 

Cancer exosome 'micro factories' aid in cancer progression

 


Exosomes, tiny, virus-sized particles released by cancer cells, can bioengineer micro-RNA (miRNA) molecules resulting in tumor growth. They do so with the help of proteins, such as one named Dicer. New research from The University of Texas MD Anderson Cancer Center suggests Dicer may also serve as a biomarker for breast cancer and possibly open up new avenues for diagnosis and treatment. Results from the investigation were published in Cancer Cell.

"Exosomes derived from cells and blood serum of patients with breast cancer, have been shown to initiate tumor growth in non-tumor-forming cells when Dicer and other proteins associated with the development of miRNAs are present," said Raghu Kalluri, M.D., Ph.D., chair of the department of cancer biology at MD Anderson. "These findings offer opportunities for the development of exosomes-based biomarkers and shed insight into the mechanisms of how cancer spreads."

Exosomes are small vesicles consisting of DNA, RNA and proteins enclosed in a membranes made up of two lipid layers. They perform specialized functions such as coagulation, intercellular signaling and cell "waste management." They are shed into bodily fluids forming a source of disease-specific nucleic acids and proteins. Increasingly, exosomes are studied for their potential as both indicators of disease, and as a prospective new treatment approach.

All exosomes contain a cellular stew of smaller components including proteins, messenger RNA (mRNA) and miRNAs. Kalluri's team reported that breast cancer associated exosomes contain specific miRNAs associated with a multi-protein complex known as RNA-induced silencing complex (RISC).

In addition to RISC, the breast cancer exosomes also house Dicer and two other proteins, AGO2 and TRBP, all of which together provoke tumor growth.

"The role of miRNAs associated with exosomes in cancer progression is largely unknown. Many studies have suggested the presence of miRNAs in exosomes and speculated on their function," said Kalluri. "We demonstrated that inhibiting the action of Dicer in cancer exosomes significantly impairs tumor growth, raising the possibility that miRNAs in exosomes contributes to cancer progression."

Kalluri's study indicated that the interplay between Dicer and its "host" exosome may allow cancer cells to develop an "oncogenic field effect" by manipulating surrounding cells via exosomes. Think of a child blowing a dying dandelion's spores into the wind where they float over a newly mowed lawn and one can envision how this molecular mixer easily spreads the disease to surrounding tissue.

"These studies reflect the need to evaluate the functional contribution of miRNA machinery in exosomes and their role in tumor progression and metastasis," said Kalluri.


Story Source:

The above story is based on materials provided by University of Texas M. D. Anderson Cancer Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Raghu Kalluri, M.D., Ph.D. et al. Cancer Exosomes Perform Cell-Independent MicroRNA Biogenesis and Promote Tumorigenesis. Cancer Cell, October 2014 DOI: 10.1016/j.ccell.2014.09.005

Sweat-analyzing skin patch could replace blood sampling

 

Prof. Jason Heikenfeld with the prototype patch (left) and the upcoming Bluetooth version ...

Prof. Jason Heikenfeld with the prototype patch (left) and the upcoming Bluetooth version (Photo: University of Cincinnati)

Nobody likes having blood samples drawn. What's more, such samples typically have to be analyzed in a lab before they're able to tell us anything. But now scientists at the University of Cincinnati and the US Air Force Research Laboratory are developing a system in which a Band-Aid-like skin patch is able to gather and transmit medical data in almost real time, by analyzing the patient's sweat ... and you just need a smartphone to read it, no poking or prodding required.

Developed by a team led by U Cincinnati's Prof. Jason Heikenfeld, the flexible adhesive patch contains an electronic circuit, communications antenna, controller chip, and a microfluidic paper-based sweat-sampling system. That paper wicks minute amounts of sweat from the skin in a tree root-shaped pattern, in order to maximize the sampling area.

In order to keep the sweat flowing through the paper for a sustained period of time (instead of just initially saturating it), a superabsorbent hydrogel is also incorporated into the patch, to draw in and store the sampled perspiration – even after several hours of collecting sweat, that gel reportedly only swells by 2 to 3 millimeters.

The flexible adhesive patch contains an electronic circuit, communications antenna, contro...

The patch has no power source of its own, but instead draws power from an adjacent smartphone's signal – just like a passive RFID tag. Once a phone is close enough to it, the patch sets to work measuring ion concentrations of given biomarkers present in the sweat. The current prototype patch has been designed to measure sodium and chloride concentrations, although future versions could also measure things like electrolytes, metabolites, proteins, small molecules, and amino acids.

That data is wirelessly transmitted to an app on the phone. By analyzing the biomarker ion concentrations, it's possible to ascertain the patient's physical state. This means that the technology could one day be used for applications such as keeping athletes from cramping up by monitoring their electrolyte levels, non-invasively keeping tabs on premature infants' vital signs, allowing diabetics to watch their glucose levels, or for fine-tuning medication dosages by measuring drug metabolites in the patient's sweat.

Human trials of the system are expected to begin later this year. Additionally, a second-generation patch is almost complete, which communicates with the phone via Bluetooth.

Heikenfeld recently described his project in an article he wrote for IEEE Spectrum magazine. Similar research is being conducted at the University of California, San Diego. There, a team led by Prof. Joseph Wang has been using sweat-analyzing temporary tattoos to measure athletes' lactate levels, and to detect metabolic problems.

Sources: University of Cincinnati, IEEE Spectrum

 

YEATS protein potential therapeutic target for cancer

 

October 23, 2014

University of Texas M. D. Anderson Cancer Center

Federal Express and UPS are no match for the human body when it comes to distribution. There exists in cancer biology an impressive packaging and delivery system that influences whether your body will develop cancer or not, scientists say. Researchers have announced findings indicating a possible new way of manipulating chromatin and its histones through a protein reader known as the YEATS domain protein, providing new hope for cancer treatment.


Federal Express® and UPS® are no match for the human body when it comes to distribution. There exists in cancer biology an impressive packaging and delivery system that influences whether your body will develop cancer or not.

One area of interest focuses on histones, the chief component of chromatin, a cluster of large molecules. Aberrations in chromatin are thought to lead to DNA damage such as with cancer. Researchers at The University of Texas MD Anderson Cancer Center announced findings indicating a possible new way of manipulating chromatin and its histones through a protein reader known as the YEATS domain protein. Protein readers attach to histone "tails" and play an important role in gene activation.

"Our findings indicate the importance of the YEATS domains as potential therapeutic targets for the treatment of cancer," said Xiaobing Shi, Ph.D., assistant professor of epigenetics and molecular carcinogenesis at MD Anderson. "We have identified YEATS as a novel 'reader' for histone acetylation.

Shi's findings are published in this month's issue of Cell.

When DNA wraps around histones much like baling twine on a spool, they form a larger collection of DNA-wrapped histones called nucleosomes. Nucleosomes are further packaged into chromatin containing DNA, protein and RNA. Chromatin's role is to shrink DNA to fit into a cell thus preventing DNA damage and allowing healthy cell division through controlled gene expression. Certain histone modifications such as acetylation and methylation are critical to chromatin's performance.

"These histone modifications serve as docking sites for reader proteins which recognize specific modifications and influence downstream biological outcomes," said Shi. "Compared with a great variety of readers that have previously been identified for histone methylation, few reader proteins that recognize histone acetylation are known."

In other words, if the scanner doesn't recognize the barcode on your package, things can go terribly wrong. In the case of something as crucial as DNA packaging and delivery, it could mean cancer. A family of histone acetylation readers called bromodomain was discovered about a decade ago and was thought to be the sole "reader" for histone acetylation, until now.

"Earlier identification of potent inhibitors target bromodomain proteins has proved histone acetylation readers to be attractive therapeutic targets," said Shi. "Our findings add to this understanding by identifying the YEATS domains as yet another histone acetylation reader that we believe is connected to both healthy and potentially cancer-causing processes."


Story Source:

The above story is based on materials provided by University of Texas M. D. Anderson Cancer Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Yuanyuan Li, Hong Wen, Yuanxin Xi, Kaori Tanaka, Haibo Wang, Danni Peng, Yongfeng Ren, Qihuang Jin, Sharon Y.R. Dent, Wei Li, Haitao Li, Xiaobing Shi. AF9 YEATS Domain Links Histone Acetylation to DOT1L-Mediated H3K79 Methylation. Cell, 2014; 159 (3): 558 DOI: 10.1016/j.cell.2014.09.049

 

Sleep difficulties common among toddlers with psychiatric disorders

 


John Boekamp, Ph.D., clinical director of the Pediatric Partial Hospital Program (PPHP) at Bradley Hospital recently led a study that found sleep difficulties -- particularly problems with falling asleep -- were very common among toddlers and preschool-aged children who were receiving clinical treatment for a wide range of psychiatric disorders. The study, titled "Sleep Onset and Night Waking Insomnias in Preschoolers with Psychiatric Disorders," is now published online in the journal Child Psychiatry & Human Development.

"The most common sleep difficulties reported nationally for toddlers and preschoolers are problems of going to bed, falling asleep and frequent night awakenings -- collectively, these problems are referred to as behavioral insomnias of childhood," said Boekamp. "Sleep problems in young children frequently co-occur with other behavioral problems, with evidence that inadequate sleep is associated with daytime sleepiness, less optimal preschool adjustment, and problems of irritability, hyperactivity and attention."

Boekamp's team was interested in learning more about sleep and sleep problems in young children with behavior problems, as early sleep problems may be both a cause and consequence of children's difficulties with behavioral and emotional self-regulation. "Essentially, these young children might be caught in a cycle, with sleep disruption affecting their psychiatric symptoms and psychiatric symptoms affecting their sleep-wake organization," said Boekamp.

The partial program that Boekamp leads at Bradley Hospital is a family-centered, intensive day treatment program for very young children aged from newborn to six who have serious emotional, behavioral or relationship disturbances. This study examined the nature and prevalence of diagnostically defined sleep disorders, including Sleep Onset Insomnia (SOI) and Night Waking Insomnia (NWI), in a group of 183 young children admitted to the program. Diagnosable sleep disorders, particularly SOI, were quite common in the group, exceeding previous estimates obtained in community settings. Overall, 41 percent of children in the study also met diagnostic criteria for a sleep disorder. Sleep problems were especially common in children with disruptive behavior, attention, anxiety and mood problems.

"It is important for families to be aware of how important sleep is to the behavioral adjustment and wellbeing of young children," said Boekamp. "Sleep disorders may be unrecognized and under-diagnosed in young children, particularly when other behavioral or emotional problems are present."

Difficulties with sleep may be particularly important to address when children are also struggling with challenging daytime behaviors, such as problems with compliance, aggression, attention and mood. Sleepiness and fatigue may exacerbate these problem behaviors.

"This study is a great reminder that it's critical for mental health providers working with young children and their families to ask about children's sleep," said Boekamp. "Simple questions about children's sleep patterns, including how long it takes a child to fall asleep at night and how frequently a child awakens after falling asleep, may yield important information that is relevant to clinical care, even when sleep problems are not the primary focus of treatment."


Story Source:

The above story is based on materials provided by Lifespan. Note: Materials may be edited for content and length.


Journal Reference:

  1. John R. Boekamp, Lauren R. Williamson, Sarah E. Martin, Heather L. Hunter, Thomas F. Anders. Sleep Onset and Night Waking Insomnias in Preschoolers with Psychiatric Disorders. Child Psychiatry & Human Development, 2014; DOI: 10.1007/s10578-014-0505-z

 

Designer 'barrel' proteins created

 


The orthogonal views of 5-, 6- and 7-helix barrel proteins created by Drew Thomson, Dek Woolfson and colleagues at the University of Bristol, UK, and described this week in Science. The images show the central channels in these structures to which the team aim to add functions in future.

Proteins are long linear molecules that fold up to form well-defined 3D shapes. These 3D molecular architectures are essential for biological functions such as the elasticity of skin, the digestion of food, and the transport of oxygen in blood.

Despite the wide variety of tasks that natural proteins perform, they appear to use only a limited number of structural types, perhaps just a few thousand or so. These are used over and over again, being altered and embellished through evolution to generate many different functions. This raises the question: are more protein structures possible than those used and presented to us by nature?

A team from Bristol's School of Chemistry and School of Biochemistry, headed by Professor Dek Woolfson, have addressed this by designing humanmade protein molecules from scratch.

Although the design principles used are learned from natural proteins, from which the team develops rules for assembling their proteins, some of the designed protein shapes are completely new and have not been observed in nature yet.

Specifically, the scientists have made proteins with central cavities, or channels, running through them. The team believes that these will be useful in designing new protein functions, such as catalysts for breaking down fats, or molecules that span cell membranes to allow new communications between cells.

Professor Woolfson said: "This is a really exciting time to be exploring what can be done with biological principles and building blocks to make new and useful molecules, but completely outside the context of biology itself. It is one aspect of the emerging field of synthetic biology, in which Bristol is taking a lead both nationally and internationally."

This work has been highly collaborative combining computational modelling, peptide chemistry, biophysics and protein X-ray crystallography across the Schools of Chemistry (Drew Thomson, Antony Burton, Gail Bartlett and Dek Woolfson) and Biochemistry (Richard Sessions and Leo Brady), and an South West Doctoral Training Partnership student (Chris Wood) working between the two Schools.


Story Source:

The above story is based on materials provided by University of Bristol. Note: Materials may be edited for content and length.


Journal Reference:

  1. Andrew R. Thomson, Christopher W. Wood, Antony J. Burton, Gail J. Bartlett, Richard B. Sessions, R. Leo Brady, and Derek N. Woolfson. Computational design of water-soluble α-helical barrels. Science, October 2014 DOI: 10.1126/science.1257452

 

Anaplastic lymphoma kinase immunohistochemistry testing comparable to fluorescence [in situ] hybridization testing

 

October 23, 2014

International Association for the Study of Lung Cancer

Sixteen institutions across Europe collaborated together to show for the first time that a semi-quantitative anaplastic lymphoma kinase protein expression test, immunohistochemistry, is reliable amongst several laboratories and reviewers when test methodology and result interpretation are strictly standardized and the scoring pathologists are appropriately trained on the test.


Sixteen institutions across Europe collaborated together to show for the first time that a semi-quantitative anaplastic lymphoma kinase (ALK) protein expression test, immunohistochemistry (IHC), is reliable amongst several laboratories and reviewers when test methodology and result interpretation are strictly standardized and the scoring pathologists are appropriately trained on the test.

ALK tyrosine kinase inhibitors (TKIs) shrink tumors and increase progression-free survival in late-stage non-small cell lung cancer (NSCLC) patients positive for ALK as determined by the fluorescence in situ hybridization (FISH) test, a test for DNA rearrangement within the gene. Testing positive for ALK is required in order to be prescribed the therapeutic inhibitors. However, the FISH test is expensive, time-consuming, and requires specialized equipment and expertise. Many other studies have shown comparable results between IHC and FISH but none have compared a highly standardized test and scoring methodology performed at multiple institutions in numerous countries.

Fifteen well-characterized NSCLC specimens were tested and scored for IHC at 16 institutes of pathology in Belgium, Denmark, France, Germany, Scotland, Spain, Sweden and Switzerland. The specimens were pre-tested 3 times by FISH at 2 separate institutions in Germany. Prior to the IHC testing all the equipment was standardized between all the institutions and the scoring pathologists all attended an internet-based training session with teaching cases.

The results published in the November issue of the Journal of Thoracic Oncology, the official journal for the International Association for the Study of Lung Cancer (IASLC), show that all 16 institutions agreed with 100% concordance on the 7 FISH/IHC negative and on 4 FISH/IHC positive specimens. There was also 100% concordance from all institutions on 2 obvious IHC positive cases that were uncertain by FISH ("borderline"). These 2 cases were confirmed ALK positive by a third test, reverse transcription-polymerase chain reaction (RT-PCR). The last 2 cases were ALK-FISH positive and were scored IHC positive by 15/16 and 12/16 institutions, respectively. However, those not scoring these 2 cases as unequivocal ALK IHC positive, called them IHC equivocal and would have demanded an additional ALK test (FISH, PCR) under diagnostic conditions.

The authors conclude "after harmonization of the staining instruments and training of the observers, the ALK IHC assay can be regarded as a reliable multicenter technique for the detection of ALK protein expression." For the future the authors note "there is need to compare validated ALK IHC assays and ALK-FISH in clinical trials as therapy response data of patients with differing ALK IHC and FISH results will help to implement ALK-IHC not only as a prescreening tool, but also as a potential stand-alone test (at least in cases displaying a clear staining pattern). Until then ALK diagnosis should be based on the rational application of both methods adapted to the given case as FISH has some disadvantages and even validated IHC may produce equivocal staining patterns."

Lead author Dr. Maximilian von Laffert, senior author Dr. Manfred Dietel, and co-authors Drs. Arne Warth, Keith M. Kerr, Fernando Lopez-Rios, Patrick Pauwels, Lukas Bubendorf, and Alex Soltermann are members of IASLC.


Story Source:

The above story is based on materials provided by International Association for the Study of Lung Cancer. The original article was written by Murry W. Wynes. Note: Materials may be edited for content and length.


Journal Reference:

  1. Maximilian von Laffert, Arne Warth, Roland Penzel, Peter Schirmacher, Keith M. Kerr, Göran Elmberger, Hans-Ulrich Schildhaus, Reinhard Büttner, Fernando Lopez-Rios, Simone Reu, Thomas Kirchner, Patrick Pauwels, Katja Specht, Enken Drecoll, Heinz Höfler, Daniela Aust, Gustavo Baretton, Lukas Bubendorf, Sonja Stallmann, Annette Fisseler-Eckhoff, Alex Soltermann, Verena Tischler, Holger Moch, Frederique Penault-Llorca, Hendrik Hager, Frank Schäper, Dido Lenze, Michael Hummel, Manfred Dietel. Multicenter Immunohistochemical ALK-Testing of Non–Small-Cell Lung Cancer Shows High Concordance after Harmonization of Techniques and Interpretation Criteria. Journal of Thoracic Oncology, 2014; 9 (11): 1685 DOI: 10.1097/JTO.0000000000000332