Vending Machine Snacks & Kids Health Problems

Vended foods and beverages may be linked to obesity, diabetes and coronary artery disease, U-M study finds

School children who consume foods purchased in vending machines are more likely to develop poor diet quality – and that may be associated with being overweight, obese or at risk for chronic health problems such as diabetes and coronary artery disease, according to research from the University of Michigan Medical School.

The study also looked at foods sold in school stores, snack bars and other related sales that compete with USDA lunch program offerings and found that these pose the same health and diet risks in school-aged children.

"The foods that children are exposed to early on in life influence the pattern for their eating habits as adults," says lead study author Madhuri Kakarala, M.D., Ph.D., clinical lecturer of internal medicine at the U-M Medical School.

Previous studies assessing the nutritional value of school lunches and the impact they have on children's overall health have found similar results, but this study is the first to look specifically at competitive foods and beverages – those sold at snack bars or vending machines, rather than through the USDA lunch program.

Researchers analyzed data from 2,309 children in grades 1 through 12 from schools across the country. Interviewers administered questionnaires to obtain 24-hour food intake data on a given school day. Second-day food intake data was obtained from a group of students to account for day-to-day usual intakes.

Among those surveyed, 22 percent of school children consumed competitive or vended food items in a school day. Usage was highest in high school, where 88 percent of schools had vending machines, compared to 52 percent of middle schools and 16 percent of elementary schools. Competitive food and beverage consumers had significantly higher sugar intakes and lower dietary fiber, vitamin B levels and iron intakes than non-consumers.

Soft drinks accounted for more than two-thirds of beverages offered in school vending machines and stores. Desserts and fried snacks were the most commonly consumed vended items among elementary school children and beverages other than milk and fruit juice were the most commonly consumed items among middle and high school students. Other frequently consumed vended foods included candy, snack chips, crackers, cookies, cakes and ice cream.

The results did not show a significant difference in students' consumption of these items based on family income or race and ethnicity.

Findings of this study appear in the September issue of the Journal of School Health.

"Consumption of vended foods and beverages currently offered in U.S. schools is detrimental to children's diet quality," says Kakarala. "Childhood obesity, resulting from poor dietary choices, such as those found in this study, greatly increases the risk for many chronic diseases. A healthy school food environment can reduce these dietary risks."

Based on their findings, the study authors recommend school administrators design guidelines restricting vended and competitive foods and beverages to those that are rich with nutrients and not energy-dense. Additionally, school foodservice personnel can prepare point-of-service materials and displays to promote more healthful foods such as fresh fruit, yogurt, low-fat milk, juice and sandwiches.

"Targeted nutrition education to promote the importance of healthful snacks is further stressed by the Child Nutrition Act—the major federal legislation that determines school food policy and resources," Kakarala says. "These and other types of school-enforced policies can be very helpful for children in making smarter eating choices throughout the school day."

If more healthful snack options are not available in vending machines or school stores, children are at risk for poor nutrition by choosing these items over a USDA-choice lunch or a meal packed from home, Kakarala says.

Additional authors: Debra R. Keast, Ph.D., of the Food & Nutrition Database Research, Inc. and Sharon Hoerr, Ph.D., R.D., of the Michigan State University Department of Food Science and Human Nutrition. Reference: Journal of School Health, Vol. 80, No. 9, September 2010.

Teens' Low Grades Linked to Dopamine Genes

Nanotechnology Breakthrough in Cancer Research

Researchers clear hurdle on path toward gene-therapy treatment for disease.

Structure of an adenovirus

One of the most difficult aspects of working at the nanoscale is actually seeing the object being worked on. Biological structures like viruses are smaller than the wavelength of light, and invisible to standard optical microscopes, consequently difficult to capture in their native form.
 
A multidisciplinary research group at UCLA has now teamed up to not only visualize a virus but to use the results to adapt the virus so that it can deliver medication instead of disease.
 
In a paper published last week in the journal Science, Hongrong Liu, a UCLA postdoctoral researcher in microbiology, immunology and molecular genetics, and colleagues reveal an atomically accurate structure of the adenovirus that shows the interactions among its protein networks.

The work provides critical structural information for researchers around the world attempting to modify the adenovirus for use in vaccine and gene-therapy treatments for cancer.
 
To modify a virus for gene therapy, researchers remove its disease-causing DNA, replace it with medications and use the virus shell, which has been optimized by millions of years of evolution, as a delivery vehicle.
 
Lily Wu, a UCLA professor of molecular and medical pharmacology and co-lead author of the study, and her group have been attempting to manipulate the adenovirus for use in gene therapy, but the lack of information about receptors on the virus's surface hampered their work.
 
"We are engineering viruses to deliver gene therapy for prostate and breast cancers, but previous microscopy techniques were unable to visualize the adapted viruses," Wu said. "This was like trying to a piece together the components of a car in the dark, where the only way to see if you did it correctly was to try and turn the car on." 
 
To better visualize the virus, Wu sought assistance from Hong Zhou, a UCLA professor of microbiology, immunology and molecular genetics and the study's other lead author. Zhou uses cryo-electron microscopy (cryoEM) to produce atomically accurate three-dimensional models of biological samples such as viruses. The researchers used cryoEM to create a 3-D reconstruction of the human adenovirus from 31,815 individual particle images.
 
"Because the reconstruction reveals details up to a resolution of 3.6 angstroms, we are able to build an atomic model of the entire virus, showing precisely how the viral proteins all fit together and interact," Zhou said. An angstrom is the distance between the two hydrogen atoms in a water molecule, and the entire adenovirus is about 920 angstroms in diameter.
 
Armed with this new understanding, Wu and her group are now moving forward with their engineered versions of adenovirus to use for gene therapy treatment of cancer.
 
"This breakthrough is a great leap forward," Wu said. "If our work is successful, this therapy could be used to treat most forms of cancer, but our initial efforts have focused on prostate and breast cancers because those are the two most common forms of cancer in men and women, respectively."
 
The group is working with the adenovirus because previous research has established it as a good candidate for gene therapy as it efficiently delivers genetic materials. The virus shell is also a safe as tests have shown that the shell does not cause cancer, a problem encountered with some other virus shells. The adenovirus is relatively non-pathogenic naturally, causing only temporary respiratory illness in 5 to 10 percent of people.
 
CryoEM enables such a high-resolution reconstruction of biological structures.

In contrast, with X-ray crystallography (the conventional technique for atomic resolution models of biological structures), researchers must grow crystal structures replicating the sample - and then use diffraction to solve the crystal structure.

This technique is limited due to the difficulty of growing crystals for all proteins, samples for x-ray crystallography need to be very pure and uniform, and crystals of large complexes may not diffract to high resolution.
 
The study was funded by the National Cancer Institute and the U.S. Department of Defense.
 
The California NanoSystems Institute at UCLA is an integrated research center operating jointly at UCLA and UC Santa Barbara whose mission is to foster interdisciplinary collaborations for discoveries in nanosystems and nanotechnology; train the next generation of scientists, educators and technology leaders; and facilitate partnerships with industry, fueling economic development and the social well-being of California, the United States and the world.

Infant's Gaze May be Early Mark of Autism

Insecurity Linked to Early Puberty In Girls

Girls are hitting puberty earlier and earlier. One recent study found that more than 10 percent of American girls have some breast development by age 7.

This news has upset many people, but it may make evolutionary sense in some cases for girls to develop faster, according to the authors of a new paper published in Psychological Science, a journal of the Association for Psychological Science.

Girls who physically mature earlier tend to start dating, have sexual intercourse at a younger age, and have more sexual partners than girls who develop later. That puts them at risk of sexually transmitted diseases and makes them more likely to have a child while they’re still teenagers. These are generally seen as bad things, says Jay Belsky, of Birkbeck University in London, given that many psychologists and doctors think there are right and wrong ways to develop.

But, he says, it makes more sense to look at development the way nature does—from an evolutionary perspective. This leads to the expectation that growing up in a risky, unstable environment—the kind that fosters an insecure rather than secure attachment of infant to mother—should accelerate pubertal maturation thus increasing the chances that one could reproduce before they die.

To test the relationship between a risky, unstable environment, as reflected in an insecure infant-mother attachment bond, and early puberty, Belsky and his colleagues used data on 373 white females from a large study of early child development sponsored by the National Institute of Child Health and Human Development.

Girls in the study were followed from birth until the age of 15. At 15 months, security of attachment to mother was evaluated using a standard procedure involving separating and reuniting the baby with her mother in a university laboratory. Babies who smiled, vocalized, reached, or otherwise demonstrated appreciation that their mother was back were considered to be secure; those who avoided their mother following the separation or could not be comforted by her return were considered insecure.

Pubertal development was evaluated by means of annual physical exams administered by nurses or physicians starting when girls were 9.5 years of age. Results revealed, as predicted, that girls who were insecure as babies started their pubertal development sooner—by about two to four months—than girls who were secure as babies. They also completed pubertal development sooner and had their first period earlier than girls who were secure as infants.

A risky, unstable early environment, as reflected in an insecure attachment, is not the only reason girls mature early; it’s also partly due to genetics. Environmental chemicals may also have some effect. Also, there’s been a trend over the last 150 years of girls maturing earlier, possibly because of improved nutrition.

But the early rearing environment and the infant-mother attachment relationship are important influences and should not be ignored, says Belsky. He cowrote the study with Renate Houts of Duke University and Pasco Fearon of the University of Reading.

“An evolutionary biology perspective says, ‘look, the thing that nature most cares about—with respect to all living things, humans included—is dispersing genes in future generations,’” says Belsky. “Thus, under those conditions in which the future appears precarious, where I might not even survive long enough to breed tomorrow, then I should mature earlier so I can mate earlier before that precarious future might get me.”

This is the evolutionary logic, according to Belsky, which led to the prediction—and now evidence—that early insecurity should be related to earlier pubertal development.

Mothers Matter!

Protein Tools for Editing Genes

An Iowa State University team of researchers has developed a type of hybrid protein that can make double-strand DNA breaks at specific sites in living cells, possibly leading to better gene replacement and gene editing therapies.

Bing Yang, assistant professor of genetics, development and cell biology, and his colleagues developed the hybrid protein by joining parts of two different bacterial proteins. One called TAL effector, functions to find the specific site on the gene that needs to be cut, and the other, an enzyme called a nuclease, cuts the DNA strands.

Yang hopes the research will lead to the ability to modify genomes by cutting out defective or undesirable parts of DNA, or by replacing defective or undesirable gene segments with a functioning piece of replacement DNA - a process called homologous recombination.

Yang says that his hybrid proteins can be constructed to locate specific segments of the DNA in any type of organism.

"This breakthrough could eventually make it possible to efficiently modify plant, animal and even human genomes," said Yang. "It should be effective in a range of organisms."

The proteins work by binding onto the specific segment of DNA the researcher wants to change. Yang's proteins do this by reading the DNA sequence and finding the specific area to be cut.

Once the protein binds onto the DNA at the correct spot, the other half of Yang's protein then cuts the double-stranded DNA.

Bad or undesirable DNA can be removed and good or more desirable DNA can be introduced. When the DNA heals, the good DNA is included in the gene.

Yang started his research about a year ago after seeing the results of research by Adam Bogdanove, ISU associate professor of plant pathology, showing that TAL effectors use a very straightforward code to bind to a specific DNA sequence.

This discovery allowed Yang to predict exactly where the TAL effector nuclease will bind on the DNA to make the cut.

Another study had similar results.

The concept has also been proven by Bogdanove and Dan Voytas, collaborator in genetics, development and cell biology at Iowa State, and director of the Center for Genome Engineering at the University of Minnesota, Twin Cities.

The TAL effector-nuclease approach improves on tools currently in use. And, it should be faster and less expensive to make TAL effector nucleases, and easier to design them to recognize specific DNA sequences, according to Yang.

Yang's findings recently appeared in the online version of the journal Nucleic Acids Research. Voytas' and Bogdanove's study also appeared recently in the journal Genetics.

Voytas and Bogdanove were also able to show that the TAL effector part of the hybrid protein can be customized to target new DNA sequences.

Yang's team includes Ting Li, graduate assistant; Sheng Huang, post doctoral researcher; David Wright, associate scientist; and Martin Spalding, professor and chair; all of the genetics, development and cell biology department at Iowa State; Wen Zhi Jiang, research associate; and Donald Weeks, professor; both from the University of Nebraska, Lincoln.

New “MiniPromoter Tools” for Neuro Therapies

"Notch" Signals Where Sensory Cells Will Form

Although these signals disappear early in fetal development, it is hoped they could be recharged to restore hearing loss in adults.

Researchers have tracked in embryonic mice the cell-to-cell signaling pathways that designate the future location of an ear's sensory organs. They then succeeded in activating the signal more widely across the embryonic tissue that becomes the inner ear with the result that patches of sensory structures began growing in spots not normally associated with hearing.

A normal sensory patch from the balance organs in a mouse inner ear. Alongside, a patch of sensory tissue where the Notch pathway has been stimulated, and sensory nerve cells stand out - hair cells in red, and supporting cells in green.	An enlargement of a sensory patch with Notch signaling activated. The patch contains the sensory hair cells (red) and their associated supporting cells (green).

These new structures contained tufted cells, called hair cells, which respond to sound waves and other sensations, and additional nerve cells that amplify or code sounds for the brain to interpret.

The results suggest an avenue for further investigation in restoring hearing loss from nerve damage.

The findings are reported this week in the early online edition of Proceedings of the National Academy of Sciences by researchers Byron H. Hartman, Thomas Reh, and Olivia Bermingham-McDonogh of the Department of Biological Structure at the University of Washington (UW) in Seattle. All three are members of the UW Institute for Stem Cells and Regenerative Medicine. The senior author, Bermingham-McDonogh, is also an affiliate of the UW Virginia Merrill Bloedel Hearing Research Center.

"As the population ages," said Bermingham-McDonogh, "there's a great interest in discovering how to regenerate the inner ear sensory cells that we need for our hearing and balance. Both of these falter as we get older -- we get hard of hearing and unsteady on our feet -- due to accumulated destruction of the sensory cells in the inner ear."

The goal of their research is to develop ways to restore inner ear sensory hair cells in people who have lost them due to age, excessive noise or other toxic damage. The hair cells do not spontaneously recover after they are lost, and adult stem cells have not been found in the mammalian inner ear. In order to devise a way to restart hair cell formation in the adult ear, Bermingham-McDonogh's group is studying how hair cells are made in the first place during ear development.

The first stage in the normal development of hair cells is called prosensory specification. In the growing embryo, regions of the ear-forming tissue are selected to become the inner ear organs that detect sound and allow for our sense of balance. This action is similar to digging the foundation of a building. All the subsequent, complex steps in the construction of the building require a solid foundation.

Byron Hartman, a postdoctoral fellow in the Bermingham-McDonogh lab, found that a signaling system called the Notch pathway is important in laying the foundation for the inner ear sensory hair cells and their associated supporting cells. The researchers were able to activate the Notch pathway in regions of the inner ear that would normally never make hair cells and convert these regions to patches of new sensory tissue.

In other words, they could encourage the formation of new building foundations throughout the inner ear. Once these new sensory patches were made, new hair cells and support cells were properly produced within them. So by starting the ball rolling with the Notch signal, the researchers observed that the rest of the developmental processes followed along correctly.

Notch proteins straddle the inside and outside of the cell membrane. They collect information at the cell surface and report to the cell's operations center, the nucleus. Embryologists and cancer researchers have been studying the Notch pathway for many years. More recently scientists in the regenerative medicine field have begun taking advantage of this key regulatory signal to restart developmental processes in adults.

"The Notch signaling for prosensory specification does not appear to be active in the mature inner ear," the UW researchers noted, "and this could explain their lack of ability to regenerate new hair cells." They are now studying ways of manipulating the Notch pathway in the adult inner ear to see if this will stimulate hair cell regeneration in the hearing and balance organs.

If ways could be found to safely re-start particular Notch signals in adults, therapies might be designed to regenerate specific tissues, like nerves, and thereby repair damage and restore lost function, like hearing. Perhaps this knowledge, they noted, may lead to ideas on how to re-create this earlier state in the mature adult ear to stimulate re-growth of the cells critical to hearing.

The research for "Notch signaling specifies processor domains via lateral induction of the developing mammal inner ear" was supported by a National Research Service Award and grants from the National Institute on Deafness and Other Communication and National Eye Institute, both part of the National Institutes of Health, and assistance from the Lynn and Mike Garvey Cell Imaging Laboratory at the UW Institute for Stem Cell and Regenerative Medicine Research.

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