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Scientists have developed a slimming drug that successfully suppresses appetite and results in a dramatic loss of weight without any apparent ill effects. The drug interferes with appetite control and prevents the build-up of fatty tissue. More importantly, the drug appears to prevent a serious decline in metabolic rate-causing tiredness and lethargy—which is typically associated with living on a starvation diet. As a result, mice taking the drug lost 45 percent more weight than mice fed the same amount of food, which compensate for the lack of food by becoming more sluggish. The scientists, from the Johns Hopkins University in Baltimore, said that C 75 is likely to produce a similar effect on humans because appetite control in the brain is thought to be based largely on the same chemical pathways as those in mice. " We are not claiming to have found the fabled weight-loss drug. What we have found, using C 75, is a major path way in the brain that the body uses naturally in regulating appetite at least in mice," said Francis Kuhajda, a pathologist and senior team member. "We badly need effective drugs for weight loss. Obesity is a huge problem. We"re hoping to explore the possibilities of this new pathway," he said. Discovering a biochemical pathway in the brain that controls appetite raises new prospects for developing slimming aids. Research on leptin, a hormone produced in fatty tissue for controlling fat deposits, has so far failed to produce the expected slimming drug break-through. The latest study, published in the journal Science, showed that even moderate doses of C 75 produced a significant loss of appetite, which returned to normal after a few months. The scientists believe that C 75, which they produced synthetically in the laboratory, binds to an enzyme called fatty acid sythase, which is involved in storing excess food intake as fat. Inhibiting the enzyme causes a build-up of a chemical in the liver which acts as a precursor to fat deposition. This precursor is thought to have an indirect effect on the brain, causing appetite suppression. Normally, when animals fast, a hormone called neuropeptide Y increases sharply in the appetite control centers of the brain, stimulating the desire for food. However, when animals are given C 75, levels of this hormone fall, leading to a loss of interest in food. Dr Kuhajda said discovering that C 75 has no effect on metabolic rate is one of the most significant findings of the study. "If you try to lose weight by starving, your metabolism slows down after a few days," he said. " It" s a survival mechanism that sabotages many diets. We see this in fasting mice. Yet metabolic rate in the C 75-treated mice doesn"t slow at all. " Further animals studies will be needed before C 75 could be tested on humans. Living on a starvation diet may result in______ .
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Researchers have recently found a connection between disease and stressful situations. To test this theory, psychologists are trying to find a link between the brain and the immune system. The immune system in our bodies fights the bacteria and viruses which cause disease. Therefore , whether or not we are likely to get various diseases depends on how well our immune system works. Biologists used to think that the immune system was a separate, independent part of our bodies. Recently, however, they have found that our brain can affect our immune system. This discovery indicates that there may be a connection between emotional factors, such as stress or depression, and illness. Although many doctors in the past suspected a connection between emotional factor and disease, they had no proof. Scientists have only recently discovered how the brain and the immune system function. Before this, no one could see a link between them. As a result, medical science never seriously considered the idea that psychological factors could cause disease. Several recent studies showed a connection between stress and illness, for example, researchers went to an American military school to study the students. They found that the sick students there had a lot of academic pressure and wanted to achieve, but they were not very good students. In a similar study, researchers studied a group of student nurses and found that the nurses who developed cold sores were the ones who described themselves as generally unhappy people. In addition to these results, which support their theory, researchers are also looking for proof that stress can damage the immune system. Researchers studied recently bereaved people, i. e. , people whose loved ones have just died, because they are more likely to become ill or die. By examining the immune system of recently bereaved people, the researchers made an important discovery. They examined some white blood cells which are an important part of the immune system. They were not functioning properly. The fact that they were not working correctly indicates that severe psychological stress, such as a loved one" s death, may damage an important part of our immune system. There is still no positive proof of a connection between the immune system and psychological factors. Researchers also say that the results of the studies on bereaved people could have a different explanation. For example, bereaved people often sleep and eat less than normal, or may drink alcohol or take medication. These factors can also affect the immune system. More research is needed to clearly establish the connection between the immune system and psychological factors. The immune system______.
Whether the cause is maternal anti-bodies, heavy metals or something else, there is no question that the brains of young children with autism have unusual features. To begin with, they tend to be too big. In studies based on magnetic resonance imaging(MRI)and basic tape-measure readings , neuroscientist Eric Courchesne at Children" s Hospital of San Diego showed that while children with autism are born with ordinary-size brains, they experience a rapid expansion by age 2—particularly in the frontal lobes. By age 4, says Courchesne, autistic children tend to have brains the size of a normal 13-year-old. More recent studies by Admiral and others have found that the amygdale, an area associated with social behavior, is also oversize, a finding Admiral believes is related to the high levels of anxiety seen in as many as 80% of people with autism. Harvard pediatric neurologist Dr. Martha Herbert reported last year that the excess white matter in autistic brains has a specific distribution; local areas tend to be over connected, while links between more distant regions of the brain are weak. The brain" s right and left hemispheres are also poorly connected. It" s as if there are too many competing local services but no long distance. This observationjibesneady with imagining studies that look at live brain activity in autistic people. Studies using functional MRI show a lack of coordination among brain regions, says Marcel Just, director of Carnegie Mellon" s Center for Cognitive Brain Imaging in Pittsburgh, Pa. Just has scanned dozens of 15-to-35-year-old autistic people with IQs in the normal range, giving them thinking tasks as he monitors their brain activity. " One thing you see," says Just, " is that activity in different areas is not going up and down at the same time. There" s a lack of synchronization, sort of like a difference between a jam session and a string quartet. In autism, each area does its own thing. " What remains unclear is whether the interconnectivity problem is the result of autism or its cause. "It" s impossible to tell the chicken from the egg at this point," Just says. Autistic people have been shown to use their brains in unusual ways; they memorize alphabet characters in apart of the brain that ordinarily processes shapes. They tend to use the visual centers in the back of the brain for tasks usually handled by the prefrontal cortex. They often look at the mouth instead of the eyes of someone who is speaking. Their focus, says psychologist Ami Klin of Yale" s Child Study Center, is " not on the social allegiances—for example, the longing gaze of a mother—but physical allegiances—a mouth that moves. " The best title for the passage is______.
For eight months he has floated in his private ocean. This morning he awakens, opens his eyes, yawns and kicks vigorously several times. His umbilical cord drifts by his questing fingers. He plays with it briefly, brings his hands up to his mouth and sucks his thumb. Over his mother" s heartbeat and the gurgles of her digestive tract, he can hear her talking with his father. Interested, he stops sucking to listen. Until recent years, we could only speculate on what life was like for an unborn baby. Then, major advances inultrasound scanningbegan opening a window to the womb; doctors could view every movement of the baby on a television—like screen. The pictures show unborn babies yawning, sucking, grasping, stretching, blinking and making faces—in short, all the things they will do after birth. Normally an unborn baby never experiences hunger or thirst. But if a mother does not consume sufficient nutrients, the baby" s diet will not be adequate either. When an unborn baby is severely malnourished—for instance, because his mother" s heavy smoking restricts blood flow to the placenta—Dr, Jason Birnholz, an ultrasound expert, believes he has seen the baby" s chest and throat making crying motions. A radio startles him awake. He blinks and grimaces at the new sensation, but then becomes interested in the music. He turns his head to bring his ear closer to the outside world. He notices the pressure of the book his mother is resting on her belly. He kicks at it, her laugh comes to him as a dull, echoing rumble. She pats the spot he kicked and, entering into the spirit of the game, he kicks back. They play several rounds before he loses interest and falls asleep. Can a mother" s stress, anger, shock or grief harm her baby No. The normal stresses and strains of life won" t hurt him. As the expert Maurers put it, such periods are the womb equivalent of having a spell of " bad weather". Some are startled when exposed to a series of loud buzzes, but some then turn an ear to listen. Severe continuous stress may be another story. It remains unclear whether problems arise from the stress itself or from the poor nutrition, smoking, drinking or drug taking that likely accompany it. In any case the baby is affected. People generally believe that______.
Charles Paul and his wife, Hazel, stopped using the motor home they bought several years ago; it sits idle behind their house in Richardson, Texas. Travel is just one sacrifice they made to pay for the cost of their prescriptions, more than a dozen medications for the two of them. They found relief by switching drugstores, to one in nearby McKinney. A prescription for Paul" s diabetes had cost $ 89. 88 when he got it from a national chain but dropped down to $ 58 from McKinney" s Smith Drug. Smith, which claims to be the oldest drugstore in Texas, has been getting a lot of attention since a Dallas newspaper touted its astoundingly low prices. The overwhelming response from the public has been " a little scary," says co-owner Kaylei Mosier. She says the store simply marks each prescription up enough to cover its costs, but for many prescriptions that" s a lot lower than at other stores. The Smith Drug story has highlighted a little-known fact: prescription prices vary from city to city and block to block, and a little research can save consumers hundreds or thousands of dollars. Insurance copays can make these differences invisible, but they" re a huge deal to the 45 million uninsured Americans. Why the price swings Howard Schiff, executive director of the Maryland Pharmacists Association , explains that pharmacies generally buy their drugs from a wholesaler, who doesn" t sell to every drugstore at the same price. Once the drug is in the pharmacy, each owner chooses how much to mark it up. Because fewer than 10 percent of consumers comparison-shop for prescriptions the way they might for a quart of milk—and drug prices generally are not advertised—pharmacies don" t worry that higher prices will drive people away, says Stanford economist Alan Scorensen. There is a downside to hopping from drugstore to drugstore. If people price-shop, they" re going to lose some protection that comes from having one pharmacy track all your medications. Going to many pharmacies keeps one pharmacist from noticing potentially harmful interactions between prescriptions. Comparison-shopping is further complicated because pharmacies that have the best price on one drug don" t usually have the lowest prices across the board, so finding a good price on one drug at a pharmacy does not guarantee a cheaper total bill. Some drugstores can sell drugs at a higher price than others because______.
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