Friday May 25, 2012
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Influenza Virus Particle
Image: CDC/Frederick Murphy |
Viruses cannot replicate or express their genes without the help of a living cell. A single virus particle (virion) is in and of itself essentially inert. It lacks needed components that cells have to reproduce. When a virus infects a cell, it marshals much of the cellular machinery to replicate. Unlike what we have seen in cellular replication processes such as mitosis and meiosis, viral replication produces many progeny, that when complete, leave the host cell to infect other cells in the organism.
A virus particle, also known as a virion, is essentially nucleic acid (DNA or RNA) enclosed in a protein shell or coat. Viruses may have double-stranded DNA, double-stranded RNA, single-stranded DNA or single-stranded RNA. Viruses can infect animals, plants and even bacteria. Do you know what viruses that infect bacteria are called? Test your knowledge of viruses, take the Virus Quiz!
More Information About Viruses:
Thursday May 24, 2012
A National Cancer Institute (NCI) research study indicates that drinking coffee reduces the risk of death among older adults. These individuals are less likely to die from complications such as heart disease, stroke, diabetes and infections. The researchers are not ready to say that drinking coffee increases a person's life span, but state that there is definitely an association between the two. The results of the study indicate that those who drink three or more cups of coffee a day have approximately a 10 percent reduced risk of death.
According to researcher Neal Freedman, "Coffee is one of the most widely consumed beverages in America, but the association between coffee consumption and risk of death has been unclear. We found coffee consumption to be associated with lower risk of death overall, and of death from a number of different causes. Although we cannot infer a causal relationship between coffee drinking and lower risk of death, we believe these results do provide some reassurance that coffee drinking does not adversely affect health." It is still unclear as to the reasons for the protective effects of coffee. The coffee drinkers in the study consumed both caffeinated and/or decaffeinated coffee.
Learn more about this study, see:
Friday May 18, 2012
When you are getting an injection, do you look at the needle or look away? Research suggests that looking away when receiving an injection reduces the strength of the expected pain. In the study, it was discovered that when participants viewed a video of a needle pricking a hand, they experienced a pain that was more intense than viewing a hand only or a hand that was being touched by a Q-tip. The intense pain sensation was also accompanied by increased activity of the participants' autonomic nervous system.
According to the lead author of the study, Marion Höfle, "Throughout our lives, we repeatedly experience that needles cause pain when pricking our skin, but situational expectations, like information given by the clinician prior to an injection, may also influence how viewing needle pricks affects pain." The study indicates that expectations about receiving an injection influence the intensity of the pain. The pain may be reduced if the clinician provides information that lessens the expectation of pain and recommends that the patient not look at the needle when receiving an injection.
Learn more about this study, see:
Thursday May 17, 2012
Be careful when you eat. A study published in the journal Cell Metabolism indicates that eating at random times throughout the day can lead to weight gain. The researchers believe this to be so because our organs, including those of the digestive system, have times when they work most efficiently and times when they rest. Our metabolic cycles are set to "turn on" when we eat and slow down when we are not eating. Eating at various times of the day can upset these metabolic cycles.
According to lead author of the study, Satchidananda Panda, "When we eat randomly, those genes aren't on completely or off completely." As a result, we gain weight due to inefficient breakdown of food for energy. The study suggests that restricting meal times may help to prevent weight gain. The researchers believe that when studying obesity, just as much attention should be given to when a person eats as it is to what a person eats.
Learn more about this study, see:
