Can radiation from cell phones affect the memory? Yes — at least it appears to do so in rat experiments conducted at the Division of Neurosurgery, Lund University, in Sweden. Henrietta Nittby studied rats that were exposed to mobile phone 1) ___ for 2 hours a week for more than a year. These rats had poorer results on a memory test than rats that had not been exposed to radiation. The memory test consisted of releasing the rats in a box with four objects mounted in it. These objects were different on the two occasions, and the placement of the objects was different from one time to the other. The actual test trial was the third occasion. This time the rats encountered two of the objects from the first and two of the objects from the second occasion. The control rats spent more time exploring the objects from the first occasion, which were more interesting since the rats had not seen them for some time. The experiment rats, on the other hand, showed less pronounced differences in 2) ___. The authors believe that the findings may be related to the team’s earlier findings, that is, that microwave radiation from cell phones can affect the so-called blood-brain 3) ___. This is a barrier that protects the brain by preventing substances circulating in the blood from penetrating into the brain tissue and damaging nerve cells. Studies have previously found that albumin, a protein that functions as a transport 4) ___ in the blood, leaks into brain tissue when laboratory animals are exposed to mobile phone microwave radiation. The research team also found certain 5) ___ damage in the form of damaged nerve cells in the cerebral cortex and in the hippocampus, the memory center of the brain. Albumin leakage occurs directly after radiation, while the nerve damage occurs only later, after four to eight weeks. Moreover, they have discovered alterations in the activity of a large number of genes, not in individual genes but in groups that are functionally related. We now see that things happen to the 6) ___ of lab animals after cell phone radiation. The next step is to try to understand why this happens. The author has a cell phone herself, but never holds it to her ear, using hands-free equipment instead, a behavior we all might want to follow.
ANSWERS: 1) radiation; 2) interest; 3) barrier; 4) molecule; 5) nerves; 6) brains
When the enemy of the people, is fast food, is it the 1) __ responsibility to ban or prevent it? A ban on fast food advertisements in the United States could reduce the number of 2) ___ children by as much as 18 percent, according to a new study being published this month in the Journal of Law and Economics. The study also reports that eliminating the tax deductibility associated with television advertising would result in a reduction of childhood 3) ___, though in smaller numbers. The study was conducted by researchers from the National Bureau of Economic Research (NBER) with funding from the National Institutes of Health. NBER economists Shin-Yi Chou of Lehigh University, Inas Rashad of Georgia State University, and Michael Grossman of City University of New York Graduate Center co-authored the paper, which measures the number of hours of fast food television advertising messages viewed by 4) ___ on a weekly basis. The authors found that a ban on fast food television advertisements during children’s programming would reduce the number of overweight children ages 3-11 by 18 percent, while also lowering the number of overweight 5) ___ ages 12-18 by 14 percent. The effect is more pronounced for males than females. Though a ban would be effective, the authors also question whether such a high degree of government involvement—and the costs of implementing such policies—is a practical option. Should the U.S. pursue that path, they would follow Sweden, Norway and Finland as the only countries to have banned commercial sponsorship of children’s programs. “We have known for some time that childhood obesity has gripped our culture, but little empirical research has been done that identifies television advertising as a possible cause,” says Chou, the Frank L. Magee Distinguished Professor at Lehigh’s College of Business and Economics. “Hopefully, this line of research can lead to a serious discussion about the type of policies that can curb America’s obesity 6) ___.” The study also found that the elimination of tax deductibility tied to advertising would similarly produce declines in childhood obesity, albeit at a smaller rate of 5-7 percent. Advertising is considered a business expense and, as such, it can be used to reduce a company’s taxable income. The authors deduce that, since the corporate income tax rate is 35 percent, the elimination of the tax deductibility of food advertising costs would be equivalent to increasing the price of advertising by 54 percent. Such an action would consequently result in the reduction of fast food advertising messages by 40 percent for children, and 33 percent for adolescents. The study—the 7) ___ of its kind to directly tie childhood obesity to fast food advertising on American television—is based on the viewing habits of nearly 13,000 children using data from the 1979 Child-Young Adult National Longitudinal Survey of Youth and the 1997 National Longitudinal Survey of Youth, both issued by the U.S. Department of Labor. A 2006 report issued by the Institute of Medicine indicated there is compelling evidence linking food advertising on television and increased childhood obesity. “Some members of the committee that wrote the report recommended congressional regulation of television food advertisements aimed at children, but the report also said that the final link that would definitively prove that children had become 8) ___ by watching food commercials aimed at them cannot be made,” says Grossman. Finally, two years later, here is that link of proof “Our study provides evidence of that link,” he says. The Centers for Disease Control estimate that, between 1970 and 1999, the percentage of overweight children ages 6-11 more than tripled to 13 percent. Adolescents between the ages of 12 and 19 also saw a significant increase, reaching 14 percent. Research indicates that there is an 80 percent chance an overweight adolescent will be an obese 9) ___ and that over 300,000 deaths can be attributed to obesity and weight in the United States every year.
Adapted from materials provided by Lehigh University.
1) government’s; 2) overweight; 3) obesity; 4) children; 5) adolescents; 6) epidemic; 7) largest; 8) fatter; 9) adult
Dr. Gero Htter, a German hematologist replaced a patient’s bone marrow cells with those from a donor who has a naturally occurring genetic mutation that renders his cells immune to almost all strains of HIV. The patient, a 42-year-old American living in Berlin, is still recovering from his leukemia therapy, but he appears to have won his battle with AIDS. Doctors have not been able to detect the 1) ___ in his blood for more than 600 days, despite his having ceased all conventional AIDS medication. This development suggests a potential new therapeutic approach as the search for a 2) ___ has adopted new urgency. Known as 3) ___, current AIDs medications prevent the virus from replicating. Last year, AIDS killed two million people; 2.7 million more contracted the virus. Back in 1996, when “cocktails” of antiretroviral drugs were proved effective, some researchers proposed that all 4) ___ harboring HIV might eventually die off, leading to eradication of HIV from the body. Those hopes foundered on the discovery that HIV, which integrates itself into a patient’s own 5) ___, hides in so-called “sanctuary cells,” where it lies dormant. But that same year, researchers discovered that some gay men astonishingly remained uninfected despite engaging in risky encounters with multiple partners. These men had inherited a mutation from both their parents that made them virtually 6) ___ to HIV. The mutation prevents a molecule called CCR5 from appearing on the surface of cells. CCR5 acts as a kind of door for the virus. Since most HIV strains must bind to CCR5 to enter cells, the 7) ___ bars the virus from entering. A new AIDS drug, Selzentry, made by Pfizer Inc., doesn’t attack HIV itself but works by 8) ___ CCR5. About 1% of Europeans, and even more in northern Europe, inherit the CCR5 mutation from both parents. People of African, Asian and South American descent almost never carry it. Dr. Htter remembered this research when his American leukemia patient failed first-line 9) ___. He was treating the patient at Berlin’s Charit Medical University, the same institution where German physician Robert Koch performed some of his groundbreaking research on infectious diseases in the 19th century. Finally, he recommended standard second-line treatment: a bone marrow 10) ___ — but from a donor who had inherited the CCR5 mutation from both parents. Bone marrow is where immune-system cells are 11) ___, so transplanting mutant bone-marrow cells could render the patient immune to HIV into perpetuity. There were a total of 80 compatible blood donors living in Germany. Luckily, the mutation appeared from both parents on the 61st sample tested. To prepare for the transplant, Dr. Htter first administered a standard regimen of powerful drugs and radiation to kill the patient’s own bone marrow cells and many immune-system cells. This procedure, lethal to many cells that harbor HIV, may have helped the treatment succeed. The transplant specialists ordered the patient to stop taking his AIDS drugs when they transfused the donor cells, because they feared the powerful drugs might undermine the cells’ ability to survive in their new host. They planned to resume the drugs once HIV re-emerged in the blood. But it never did. Nearly two years later, standard tests haven’t detected virus in his 12) ___.
ANSWERS: 1) virus; 2) cure; 3) antiretrovirals; 4) cells; 5) DNA; 6) immune; 7) mutation; 8) blocking; 9) chemotherapy; 10) transplant; 11) generated; 12) blood
A new study has analyzed the effect of urinary frequency on the risk of bladder cancer. The research, which is published in the latest number of the International Journal of Cancer, shows a direct association between the number of times people get up at night to urinate and protection against bladder cancer. Night-time is usually the period during which there is the longest time interval between 1) ___. For this reason the length of time 2) ___ agents, such as those from tobacco for example, are present in the urine, constitutes an important factor towards the likelihood of developing bladder cancer, explains Juan Alguacil, a researcher from the University of Huelva and one of the authors of the study. The research group, made up of Spanish and North American scientists, analyzed the urinary frequency in 884 recently diagnosed bladder cancer cases and in 996 non-cancer control patients, from five regions in Spain. The patients, aged between 21 and 80 years, came from 18 hospitals in Valls, Barcelona, Asturias, Alicante and Tenerife. Although the best advice is to avoid exposure to carcinogenic agents (e.g. to stop smoking and to avoid direct contact with chemical products or pollution particles), the risk of bladder cancer could be 3) ___ by increasing urinary frequency and drinking water. The results of the analysis indicate that those people who usually get up at night at least twice to pass urine reduced their risk of suffering from bladder cancer by 40-59%. This protective effect was found in both men and women and did not relate to the consumption of tobacco or the quantity of water they drank. This was an exhaustive 4) ___ study undertaken to date about the effect of urinary frequency in bladder cancer. Throughout the world there are 357,000 new cases of bladder cancer every year with 145,000 deaths. The incidence of this 5) ___, one of the highest in the world, is rising mainly due to a greater life expectancy for the population and to the increasing incidence among women. According to the authors, to an extraordinary degree, the consumption of tobacco is leading to an increase of the incidence of this disease among 6) ___, which until now has been infrequent. In fact, it is estimated that in the near future the incidence of bladder cancer will be equal in both genders, owing to the increase in the number of women who smoke. It is estimated that between 50 and 70% of smokers will end up developing a bladder cancer, the main warning sign of which is the appearance of blood in the urine.
ANSWERS: 1) urination; 2) carcinogenic; 3) reduced; 4) international; 5) tumor; 6) women
Age-related Macular Degeneration (AMD) is a disease associated with aging that gradually destroys sharp, central 1) ___. Central vision is needed for seeing objects clearly and for common daily tasks such as reading and driving. AMD affects the 2) ___, the part of the eye that allows you to see fine detail. AMD causes no 3) ___. In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. An estimated 8 million older-age Americans are at high 4) ___ to develop advanced AMD. Of these 8 million, 1.3 million would develop advanced AMD within five years. Research results from the Case Western Reserve University School of Medicine show that the progression of age-related macular degeneration (AMD) is markedly slowed in new laboratory-engineered mice when they received treatments of retinylamine, a trial drug that has been tested in a medical school laboratory. AMD is a leading cause of vision loss in Americans 5) ___ years of age and older. The findings from the National Eye Institute-funded research are reported in the Journal of Biological Chemistry. Led by postdoctoral researcher Akiko Maeda, the findings provide evidence for biochemical change in the retina that resemble AMD. AMD currently isn’t usually treated until toward the end of the disease. However, with the discovery by Maeda and her research team, retinylamine can potentially prevent the rapid degeneration of the eye, slowing the rate of progression of AMD. As humans go through the aging process, it eventually affects our vision. A fraction of us will progress further and potentially develop AMD. Through their work on mouse models, Maeda and her team of researchers have learned to modify the 6) ___ that establish the rate of changes related to AMD. But the biochemical trigger of these changes had not been understood until now as a result of the retinylamine treatments. The research team has proven this observation, genetically, biochemically and pharmacologically. Dr. Maeda, who studies retinal degenerative diseases and works to develop models that will facilitate the evaluation of the safety and effectiveness of 7) ___ candidates, designed to combat retinal disease in humans, has done superb work in this area.
ANSWERS: 1) vision; 2) macula; 3) pain; 4) risk; 5) 60; 6) genes; 7) drug
All cancer cells were once thought to be equal, but recent research suggests otherwise. A growing body of evidence indicates that only certain cancer cells are capable of generating and maintaining a 1) ___. Dubbed cancer stem cells, they can divide indefinitely to perpetuate the cancer over time. They may also be the reason why some therapies fail to wipe out a cancer entirely: cancer stem cells seem to be particularly 2) ___ to standard cancer treatments and can remain behind like the roots of a weed. If this hypothesis holds true, cancer stem cells could be the most promising 3) ___ for new therapies. A team of researchers at Harvard Medical School has now developed a new way to find drugs that selectively kill cancer stem cells or prevent them from dividing. The team is currently using the method to identify drug candidates for leukemia, a disease for which cancer stem cells have been well characterized. Typical high throughput drug screens, which use cell 4) ___ grown in petri dishes, don’t always yield good results because the cells are too removed from their natural context. With stem cells in particular, the 5) ___ seems to be an important contributor for how the cells function. When grown in the lab, the cells can lose their “stemness,” or ability to generate new cells. Instead, the Harvard drug-screening method uses cells taken directly from diseased 6) ___. To better mimic the natural environment of cancer stem cells, the team incorporated other cells that support them. Cancer cells don’t exist in 7) ___. In tissues, these cells may hijack the support systemcalled, the stromal cells. Stromal cells form connective tissue surrounding an 8) ___. Stromal cells help provide an environment where stem cells flourish. To find treatments for leukemia, the team first isolated leukemic stem cells from the bone 9) ___ of diseased mice, then added them to stromal cells from the bone marrow. These two cell types were placed in plates with tiny wells that can be treated with drugs and analyzed using robotic methods. By transplanting the leukemic stem cells into a healthy mouse, the scientists have confirmed that the cells retain their ability to form new cancerous cells for up to four weeks. To determine how different drugs affect the cells, scientists use an imaging analysis method that searches for drugs that decrease the number of leukemic stem cells, which are labeled with a fluorescent red marker. The software also analyzes the 10) ___ of the cells. Leukemic stem cells tend to group together to form structures called cobblestones, described as “a biological readout of stemness.” By evaluating the number of cobblestone formations, the team can find 11) ___ that interfere with the activity of cancer stem cells. The team has already identified compounds that can kill off cancer stem cells without affecting stromal cells. Parallel tests are being performed on normal bone-marrow stem cells, in order to identify 12) ___ that specifically target cancer stem cells without killing their normal counterparts. The overall idea of targeting cancer stem cells is an attractive one because it suggests a path to therapies that are truly curative. The approach faces some difficulties. It’s already clear that cancer stem cells are more 13) ___ to most therapies than the bulk of the cancer cells in the tumor. Furthermore, if it is possible to wipe out cancer stem cells selectively, it still remains unproven whether doing so will truly eradicate the tumor. Cancer stem cells were first identified in leukemia in 1994, but in the past several years, the cancer stem-cell hypothesis has gained ground as stem cells have been identified in other types of cancer, including those of the breast, prostate, brain, and pancreas. Source: MIT Technology Review, October 2008
ANSWERS: 1) tumor; 2) resistant; 3) target; 4) lines; 5) microenvironment; 6) animals; 7) isolation; 8) organ; 9) marrow; 10) structure; 11) drugs; 12) compounds; 13) resistant
Researchers at St. Jude Children’s Hospital have found that brain tumors appear to arise from cancer 1) ___ cells that live inside tiny protective ‘niches’ formed by blood vessels in the brain. Breaking down these niches is a promising strategy for eliminating the tumors and preventing them from 2) ___. Scientists previously believed that 3) ___ are lumps of cancerous tissue that must be completely removed or destroyed to cure a patient. But over the last five years, cancer researchers have learned that not all cancer cells are created equal. In the same way that normal tissue in the body is generated from stem cells, so are cancer stem cells (CSCs). CSCs are the ultimate 4) ___ of the tumor, consistently supplying it with new cells. Researchers have identified the CSCs for acute myeloma 5) ___, four types of brain cancer, and breast cancer. So it is possible that we need not kill all cancer cells to rid a patient of the disease. Targeting the CSCs specifically might be much more efficient. To find a weakness for CSCs, neurobiologists at St. Jude compared them to 6) ___ neural stem cells. These neural tissue generators are concentrated in regions rich in blood vessels. The vessels are lined with 7) ___ cells, which secrete chemical signals that help stem cells survive. In over 70 human brain tumors, the CSCs were frequently located close to tiny vessels called capillaries. When the researchers injected mice with a mix of stem and endothelial cells from human brain tumors, those animals sprouted larger tumors than the mice that received stem cells alone. The new findings from St. Jude indicates that it is possible to kill the cancer by disrupting the shielded compartments in the small 8) ___ of the brain where CSCs reside. 9) ___ drugs, such as Avastin, block the formation of new blood vessels. In tests with mice, those same drugs cause a significant drop in cancer stem cells and slow tumor growth. 10) ___ clinical trials are currently in progress at St. Jude to determine the effectiveness of Avastin and another anti-angiogenic drug in eliminating tumors and preventing their recurrence in children with brain cancers. Other cancers, like those of the blood, breast and colon, also contain cancer stem cells and may be treated in a similar way in the future.
ANSWERS: 1) stem; 2) regrowing; 3) tumors; 4) source; 5) leukemia; 6) noncancerous; 7) endothelial; 8) capillaries; 9) Anti-angiogenic; 10) Human
In addition to pruning cells out of the way during embryonic development, the much-studied process of programmed cell death, or 1) ___, has been newly found to exert significant mechanical force on surrounding cells. This mechanical force may be harnessed throughout biology by tissues to aid wound formation, organ development and other processes that require cell movement, according to a Duke University team that melds biology with physics to investigate force at the 2) ___ level. Cells are known to move in coordinated fashion during the closure of an eye-shaped opening on the back of a developing fruit fly embryo, a model system Duke biophysicists have been working on for nearly a decade. The newly discovered 3) ___ created by apoptotic cells imploding and withdrawing is making a force sort of like a friend helping you tuck the edge of the sleeping bag in. Dying cells appear to occur at random times across the plane of cells comprising the shrinking opening, in a pattern that totals about 10% of the population of cells. It was first hypothesized that the apoptotic 4) ___ might be particularly significant for force production. The next step was to carefully measure the motion of cells immediately surrounding a dying cell. What was observed by laser-induced fluorescence, was that as a dying cell collapsed and sunk beneath the surface, it contributed to the 5) ___ pulling the edges of the opening closer together. It was concluded that apoptosis is not a single cell event but is amplified by the five-to-seven surrounding cells. On balance, these dying cells exert perhaps a third to a half of the force that is moving the edges of the opening together, so it’s a very significant part of the 6) ___. The forces at work here are measured in perhaps billionths of a Newton, but that’s because you’re moving cells, [one pound = 4.45 newtons]. At the cellular scale, these forces are quite substantial. The group’s findings appear in the Sept. 19 edition of Science. Though this finding is so far limited to dorsal closure in the fruit fly embryo, next steps are to begin looking for the mechanical force of apoptosis elsewhere. Earlier findings on the fruit fly model so far have appeared applicable to wound closure and organ development in vertebrates like humans. It’s entirely possible, that evolution has harnessed the 7) ___ force created by dying cells in many other ways.
ANSWERS: 1) apoptosis; 2) cellular; 3) force; 4) cells; 5) forces; 6) process; 7) mechanical
Marauding 1) ___ cause the tissue damage that underlies heart attacks, sunburn, Alzheimer’s and hangovers. But scientists at the Stanford University School of Medicine say they may have found ways to combat the carnage after discovering an important cog in the body’s molecular detoxification machinery. The culprit molecules are 2) ___ by-products called free radicals. These highly unstable molecules start chain reactions of cellular damage – an escalating storm that ravages healthy tissue. A totally new pathway for reducing the damage caused by free 3) ___, such as the damage that happens during a heart attack, has been found. Before the study, scientists knew that heart muscle could be preconditioned by alcohol to resist heart attack damage; for instance, it is known that moderate drinkers tend to have smaller, less severe heart attacks than teetotalers. But scientists didn’t understand how pre-conditioning worked. To figure out how alcohol protects heart 4) ___ from free-radical damage, the Stanford team tested alcohol pretreatment in a rat heart-attack model. They compared the enzymes activated during the attacks to those switched on with no alcohol. Surprisingly, the treatment activated aldehyde dehydrogenase 2 (ALDH2), an obscure alcohol-processing 5) ___. Alcohol pretreatment increased the enzyme’s activity during heart attack by 20%, leading to a 27% drop in the associated damage. Although this enzyme was discovered a long time ago, this research group knew nothing about the enzyme except that it helps remove 6) ___ when people drink. The enzyme 7) ___ an aldehyde molecule, a toxic byproduct of the ethanol in alcoholic beverages. But aldehydes are also formed in the body when free radicals react with fat molecules. It’s very easy for free radicals to find 8) ___ and oxidize it to aldehydes. Inside cells, the accumulating aldehydes permanently bind and damage cellular machinery and DNA. Such damage occurs in many diseases, from heart attack and Parkinson’s to sun-induced aging of the skin. After learning of ALDH2’s novel role in reducing the damage, the team searched for a molecule that could make the enzyme function even better. They enlisted the Stanford High Throughput Bioscience Center, to find a molecule that heightened the enzyme’s activity. The winner of this contest was a tiny molecule that reduced heart attack 9) ___ by 60% in the rat model. The molecule, Alda-1, has a surprising mode of action: it protects ALDH2 itself from aldehyde attack. The enzyme, it turns out, was being hobbled by the very 10) ___ it removes. Because Alda-1 is small, it should be easy to adapt for pharmacological use. So far, Alda-1 has been tested only in the rat model, but the Stanford lab is investigating other possible applications, such as fighting neurodegenerative disease and sun damage on the skin. In addition to its lofty medical applications, Alda-1 could also have a much lowlier use: fighting hangovers. Many nasty hangover symptoms are due to aldehyde buildup. The tiny molecule may also improve alcohol tolerance and reduce susceptibility to free-radical diseases in people with a common ALDH2 mutation. The mutation affects 40% of people of Asian descent and causes an 11) ___ for alcohol.
ANSWERS: 1) molecules; 2) oxygen; 3) radicals; 4) muscle; 5) enzyme; 6) alcohol; 7) neutralizes; 8) fat; 9) damage; 10) chemical; 11) intolerance