Snippets of Science

This is a blog covering insights from the latest in scientific research. The writing is done by me. The sources of information are linked at the bottom of each write-up. Tags Aging Animal Behavior Bacteriology Cancer Biology Cardiology Evolution Healthy Living Medical Mysteries Neuroscience Physiology Psychology Stem Cell Biology Surgery

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Neuroscience: The impact of violent video games

Researcher Dr Vincent Matthews and his team from Indiana University specialize in studying the effects of media violence. Their most recent investigation involved a group of 28 young, male students, assigned to either play violent or non-violent video games everyday for a period of 1 week.The students selected had no prior experience in video gaming. The participants were subjected to MRI scans before and after their gaming experience, while they carried out a series of tasks involving emotional or non-emotional content. 

The MRI scans revealed that the students who played the violent video game had much lower brain activity in regions governing emotions, attention and inhibition of impulses. Dr Matthews explains, "Behavioral studies have shown an increase in aggressive behavior after violent video games, and what we show is the physiological explanation for what the behavioral studies are showing."

A week after the investigation was completed, the participants were brought back in for another scan. The results of the post-investigation scan showed that a week of no exposure to the violent game resulted in a reversal of brain activity levels similar to the norm, although levels was not quite the same as before the experiment.

During the MRI scan, the male students were presented with violent and non-violent terms in different colors. They were asked to identify the color of the word instead of its meaning, a variation of the typical Stroop effect psychological test. Participants would have the tendency to process the meaning of the word before they are able to identify the color it is written in.

Participants who played non-violent games displayed increased brain activity in the regions involved in emotional responses, when they were shown words with violent indications. As expected, those who were exposed to violent gaming had significantly lower activity levels in comparison to their control scores taken at the start of the experiment.

Though none of these changes appear to be permanent, the study of the brain's response after regular exposure to violent video games could potentially be useful in determining the impact such activities have on young, developing minds.

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Healthy Living: Foods to chow down on if you want to lower your blood pressure

Patients with high blood pressure are typically encouraged to eat food that is low in saturated fat and cholesterol. Doctors often recommend diets that are fruit and vegetable-rich, often containing some of the following:

Celery

This particular vegetable is packed with a phytochemical known as phtalides, which help to relax the muscle tissue of the artery. As a result of the lowered constriction, there is increased blood flow and a resultant lowering of blood pressure.

Cold-Water Fish

Packed with anti-inflammatory omega-3 fatty acids, cold-water fish are known to be beneficial to our cardiovascular health by lowering blood pressure and reducing the risk of heart attacks and stroke. The omega-3 fat functions as a blood thinner, easing the flow of blood around the body, making the formation of clots less likely. Since omega-3 fatty acids cannot be synthesized by the body, dietary intake is our only source of this compound.

Berries

Berries are amongst the most nutritious foods available, since they are full of fiber as well as anti-inflammatory and anti-oxidant properties. Blueberries, strawberries and raspberries are the best within the family because they also help to lower blood pressure. Raspberries have the highest fiber content, while a cup of strawberries provides 136% of the daily vitamin C requirement. Blueberries function more directly, containing a compound known as pterostilbene, which prevents plaque accumulation in the arteries.  

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Aging: Kicking out old cells

Scientists from the Mayo Clinic College of Medicine have discovered that the removal of senescent or worn-out cells from aging mice can spare the animals from age-related conditions such as cataracts or muscle loss.

Using a specialized strain of mice with an accelerated aging process, the basis of the investigation involved a removal process as soon as these cells became senescent. Senescent cells are ones that have begun displaying signs of wear, and the body slowly phases them out of function. Once they have been classified as such, the cells will either start on a path to death or are kept around in a permanent senescent state.

The senescent cells that stick around begin producing proteins that normal, healthy cells do not. Scientists studying aging and age-related diseases speculate that these proteins are what leads to several aging-associated conditions. Researcher Darren Baker explains, "They start to turn on a variety of genes that are not good and are thought to be detrimental to the overall function of the tissue."

The accelerated aging mice used in the investigation are predisposed to developing cataracts, weakened muscles and typically die of heart disease when they reach 10 months of age. The research team treated these mice with a drug that would eliminate all senescent cells. This treatment was repeated every 3 days. Compared with control mice, the treated mice displayed stronger muscle tone, fewer occurrences of cataract development and less wrinkled skin.

Interested in finding out the difference between an early initiated removal and a later phase removal of senescent cells, the researchers treated a second group of accelerated aging mice, but the treatment on these mice only started after 5 months of age. Though the late phase treatment was not able to reverse the aging symptoms in the 5-month old mice, repeated doses lead to a stop in the deterioration of muscles and fat cells.

It should be noted that the removal of senescent cells does not extend lifetime, it simply holds off the development of age-related diseases and conditions. The researchers speculate that death is linked to other pathways independent of these types of cells. Information from further mice studies will be used to hopefully develop gene therapies or vaccines against senescent cells.

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Psychology: Avoiding PTSD - To counsel or not to counsel?

Surviving severe natural disasters such as an earthquake and a tsunami is expected to impact a person both mentally and emotionally. However, medical personnel directly involved in the recent traumatic event in Japan were advised not to provide immediate counseling to survivors, after latest research suggests the lack of counseling support might be more beneficial in countering post-traumatic stress disorder (PTSD) development.

Dr David Forbes of the Australian Center for Posttraumatic Mental Health indicates that PTSD is caused by "an increased engraving of the horrifying memories in the brain, reducing their potential to fade.". From as far back as the 1980s, some psychologists and counselors begun to consider the possibility that people could be spared from developing PTSD if they were not required to discuss the experience immediately after going through it.

The decision not to counsel the Japan earthquake survivors was sanctioned by Japanese mental health authority officials, after an international review revealed that only 5-10% of natural disaster survivors develop PTSD. A separate investigation published recently also concluded that there was no evidence to indicate that immediate intervention would prevent PTSD.

Researcher Justin Kennard from the University of Queensland believes that middle ground in this debate lies in a specialized version of cognitive behavioral therapy (CBT). This therapy technique involves 4-12 therapy sessions that are administered at least a month after the traumatic event. He postulates that such a time period is sufficient for the survivors to internalize and deal with the emotional impact in their own ways, leaving only those that at most risk to PTSD easily identifiable.

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Neuroscience: Immunity functions of microglia affects memory and learning

Microglia are specialized immune cells located in our brain. These cells function by scavenging pathogens, protecting neurons from infection. In addition, they clean up debris created from damaged neurons. Recent research carried out Duke neuroscientist Staci Bilbo and her team indicates that microglia behavior has a vital impact on memory and learning.

Previous research by Assistant Professor Bilbo had demonstrated that lab rats subjected to infections at an early age, responded by producing a strong immune reaction against any subsequent infections. During this induction of immunity, microglia release a signaling molecule called Interleukin-1, or IL-1 for short. However, high levels of IL-1 has been known to affect learning abilities and memory development in laboratory animals.

These observations were obtained during a series of experiments that spanned close to a decade, in which very young rats were exposed to infection and challenged again with a similar yet harmless infection later in life. The second challenge is often followed by a highly effective immune response.

The extra IL-1 production by microglia takes place even if the second infection occurs outside the brain. In order to determine how this immune response affects memory, the team placed lab rats in a novel environment, before exposing them to a sound followed closely by a mild electric shock. Control rats that were not subjected to infection at an early age, remembers the novel environment and the subsequent shock treatment after one exposure. Placing normal rats into the novel environment a second time results in them almost immediately freezing in place out of fear. The converse was observed in previously infected rats, which were observed to run around curiously through the new environment almost as if they had never seen the area before.

The rats that were exposed to infection were aged proportionately to a third trimester human fetus, though Dr Bilbo believes more research is required before an accurate prediction of effects can be made for the human brain.

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Healthy Living: Energy Drinks - The components behind the boost

A slew of different energy drinks have been flooding the market these past few years. This is not a surprising observation when you note that Americans have spent $9 billion dollars buying these drinks in 2011 alone. Manufacturers that do not have a finger in the pie are eager to jump on board, with the tantalizing promise of boosting your mental capacity and health via the usage of natural substances only. Let's see if some of these popular ingredients really work.

Caffeine

Being a chemical compound that can stimulate our central nervous system, the effects of caffeine on our bodies have been heavily investigated. Scientific research has indicated that caffeine does work, hence it is found in almost every energy drink in the market. An Austrian study carried out on 100 men given a 100mg of caffeine, displayed a significant increase in brain activity. A similar observation occurred in an investigation by a group from the University of Chicago, in which fatigued people who were give a 200mg jolt, appeared to become twice as alert compared to their non-caffeinated counterparts.

An average caffeine energy drink contains caffeine levels equivalent to two cups of coffee. Such an amount should not pose any problems to most people, provided they stay away from other caffeinated beverages throughout the day. Downing coffee, cola and the occasional energy drink daily could lead to headaches, sleeplessness and nausea.

Glucose

The body utilizes glucose to churn out the energy we require, hence increasing glucose levels via energy drinks seems an understandable enough concept. Men who drank a 6% glucose drink before cycling, demonstrated a 22 minute longer endurance period on the bicycle when compared to those who did not. Despite the increased energy, it should be noted that glucose does not fight fatigue nor keep someone awake.

Given the precarious nature of the body's blood glucose nature, we should think twice before guzzling glucose-based energy drinks. The sudden influx of glucose would cause the body's insulin levels to skyrocket, and signal to the body to stop burning fat.

Guarana

The newest arrival to the energy drink market, Guarana is a small South American shrub.The Guarana seed has a caffeine content of 4-5%, as compared to a coffee bean which only contains 1-2%. However, analysts have discovered the dosage of Guarana in most energy drinks are very low. Associate Professor Kevin A. Clauson sums it up, "It probably doesn't have much of a safety risk, but it also won't do you any good."

The various studies that have been carried out on Guarana indicate that an impact can be felt only when you drink enough of it. People who were given a 222mg dosage reported feeling slightly less fatigued and also demonstrated a 30 second faster reaction time. Some scientists are convinced that these effects are due to Guarana's caffeine content, but others believe the existence of some other component that either produces it's own stimulative effects or bolsters that of caffeine. 

Ginseng

The ginseng content in most energy drinks is derived from the extract of the ginseng plant root. While studies have shown that it does not improve physical performance, ginseng can improve our brain power. A 200mg extract was given to participants in a study, before they took a cognitive test. Those who were not given the extract performed significantly poorer in the test compared to those who did. Researchers believe this beneficial property stems from ginseng's ability to increase blood glucose uptake by brain cells. However, most energy drinks in the market do not contain the optimal amount required for the improved cognitive effects to be observed. 

While harmful effects are unlikely to occur from the intake of ginseng energy drinks, some reported negative side effects include diarrhea and its interaction with blood thinning drugs.

Taurine

One of the most abundant amino acids in the human brain, taurine has neurotransmitter properties. However, most scientists are not convinced that taurine can boost mental alertness. This is especially since the amino acid is not able to pass from the blood stream through the membranes that surround the brain. 

Like most others, taurine-based energy drinks are harmless in small amounts, although one should be reminded of the recent case of seizures suffered by 3 people in Phoenix, Arizona, when they drank two heavy-dosage drinks within a short period of time. At this point, studies on the effects of taurine consumption are still lacking, making it difficult to conclude anything regarding its safety or its supposed energy boosting role.

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Stem Cell Biology: Neural stem cells turned into insulin-manufacturing pancreatic cells

The insulin-producing cells in our body are known as beta cells, and they reside within our pancreas. Diabetics suffer from the disease because of either having their beta cells destroyed by immune cells, or because their beta cells never produced sufficient insulin to begin with. Now, a group from Japan's National Institute of Advanced Industrial Science and Technology believe they have discovered the key to beating diabetes; neural stem cells.

The researchers extracted these stem cells from the olfactory bulb via the nose. The olfactory bulb is a region of the brain that processes smell signals. They also obtained some stem cells from the memory-governing hippocampus. The two groups of neural stem cells are easily obtained since they are both accessible via the nose.

The neural stem cells were then exposed to Wnt3a, a human protein that induces insulin production, and also to an antibody against a protein that inhibits insulin production. The stem cells were allowed to replicate, before they were placed on thin sheets of collage that acted as a removable scaffold. The thin sheets can be placed on top of the rat pancreas without causing harm to the organ.

Both type I and type II diabetic mice that received the stem cell transplantation were observed to have insulin levels matching their non-diabetic counterparts. Accordingly, elevated blood glucose levels that existed previously no longer occurred. These effects remained for 19 weeks, the time point at which the scientists removed the scaffold. The diabetic condition returned soon after the stem cells were removed. 

Several labs around the world have attempted to convert stem cells from various body regions into beta cells, usually succeeding only with genetic manipulation. This study brings about the possibility of skipping the genetic manipulation step, preventing any necessary safety concerns. In addition, there is no cause for concern with regards to rejection or the usage of immunosuppressive drugs since the neural stems cells can be obtained easily from the host.

The researchers are confident of applying the principles of this set-up to humans, since other research groups have demonstrated the extraction of adult neural stem cells from the olfactory bulb by using an endoscope.

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Physiology: Power generated from human respiration

Graduate student Jian Shi and Professor Wang

Materials Science and Engineering professor Xudong Wang and his team from the University of Wisconsin-Madison have created a plastic microbelt that vibrates when in contact with low-speed airflow, such as that from respiration in the human nose. 

The microbelt was engineered using a material known as polyvinylidene fluoride (PVDF). The material accumulates an electrical charge upon mechanical stimulation. The researchers tweaked the properties of the PVDF such that the microbelt could generate enough energy to power small devices.

Professor Wang comments about the implications of this finding, "Basically, we are harvesting mechanical energy from biological systems...We calculated that if we made this material thin enough, small vibrations could produce a microwatt of electrical energy that could be useful for sensors or other devices implanted in the face."

With advances in nanotechnology and miniaturized electronics, researchers hope to develop biomedical devices that can be placed within the body to monitor blood glucose or heart rate. The power supply required to run these devices could eventually come from waste energy in blood flow, motion, heat or respiration. 

The team will now move on to further scale down the thickness of the microbelt, aiming to reduce it to the submicron level. Professor Wang also hopes to take advantage of the bio-compatibility of PVDF, by creating a micro-scale device to harvest energy from the respiratory process.

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Physiology: What do you know about your ears?

We don't see them and we hardly feel their presence on our heads. For most of us, they have never caused us health problems of any sort. It is easy to see how our ears could be taken for granted, leading us to forget to pay attention to this particular organ's bill of health. Let's go through some interesting ear health pointers that just might make you sit up and listen.

Cleaning out earwax

Doctors remain in the dark with regards to the exact purpose of earwax, although the general belief is that it participates in the ear's self-cleaning process. Earwax also serves practical functions such as being toxic to small bugs, preventing from getting very far into the ears. It does the same to dirt and debris, trapping them at the front of the organ.

For most of us, the earwax removal tool of choice is the cotton swab. Dr J. Randolph Schnitman, a board-certified otolaryngologist (more commonly known as an ENT or a ear, nose and throat specialist), wants us to be more careful during the process, "You can use cotton swabs to clean around the (outside folds) of your ears, but you should be careful not to...push the wax further in or you can damage the ear drums." In fact, for normal people who do not produce excessive amounts of ear wax, cleaning your inner ear while in the shower would be most convenient. You can do so by allowing warm water to go into your ear, before tilting your head sideways to dump the water out. Make sure the water is warm, as using hot or cold water could cause you to suffer from vertigo. Excessive earwax build-up can usually be removed by over-the-counter earwax remover, although visiting an ENT is encouraged if the issue is chronic. 

The bones that allow us to hear

The three smallest bones in our bodies can be found in the middle ear, namely the malleus, incus and stapes. These bones act as amplifiers of sort, transmitting the energy of sound waves in the air around your eardrum to your inner ear. These transmissions trigger nerve stimulation in the brain, initiating the interpretation of sound. Like any other bone, the bones in our middle ear can be broken, resulting in conductive hearing loss. Thankfully, surgical processes exist to replace them with artificial prostheses. 

The dangers of flying with stuffed ears

With the experience of flying on an airplane no longer being much of a novelty for most of us, we are perhaps used to the feeling of stuffed ears during altitude changes. However, be advised that the combination of stuffed ears and a cold can be dangerous.

The Eustachian tubes, a structure that runs from the middle of each ear cavity to the back of our throats, functions to release pressure when we encounter altitude changes. During a cold, the tubes become filled with liquid and makes it difficult for them to carry out the releasing of pressure. This difficulty could cause eardrums to implode and pinch inwards, leading to damage. Dr Schnitman recommends flyers who frequently suffer from colds to take a decongestant before the flight. 

Your ears and your taste buds

Our ears contribute to taste processing in the brain because of the transmission purpose it plays. A group of nerves called the chorda tympani, connects the taste buds on the front of the tongue to the brain via the middle ear. As such, it is not unheard of for complications or infections arising from ear surgery to negatively impact a patient's sense of taste.

Our fragile eardrums

We know our eardrums are fragile and that we should avoid sticking anything potentially hazardous into our ears, but how thin are our eardrums exactly? Try picturing a piece of paper or even a sliver of fingernail. Our eardrums comprise of 3 layers, a fibrous middle layer sandwiched between two linings. Any damage to the middle layer often heals insufficiently. Taking out the middle layer severely compromises the integrity of the eardrum, making it highly susceptible to rupture. 

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Healthy Living: Seven-and-a-half to eight-and-a-half hours of sleep keeps insulin and blood sugar optimum in teenagers.

62 obese, American teenagers took part in a study that attempted to determine if there was a co-relation between the amount of sleep and the body's insulin and blood sugar levels. The study carried out by the Children's Hospital of Philadelphia, revealed that teenagers who slept between seven-and-a-half to eight-and-a-half hours had optimum blood sugar and insulin levels. Conversely, sleeping more or less increases blood glucose levels while a lower amount of deep sleep would lead to a drop in insulin levels.

Such findings indicate a possibility that such a specific sleeping pattern could help to ward off the onset of diabetes, and also backs up previous research that indicated a higher chance of type 2 diabetes occurrence in sleep-deprived adults.

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Healthy Living: Potential stroke triggers in our diet

A stroke occurs when blood vessels in or connected to the brain bursts or are blocked by blood clots. This situation impedes the movement of nutrients into the brain, effectively starving the organ. One of the most terrifying things about suffering a stroke is how sudden the condition afflicts the patient, doing so almost without warning. Given that we can hardly predict stroke occurrences without the help of professional medical personnel and equipment, perhaps we should do what we can diet-wise to reduce our chances of going through this condition.

Chips, store-bought pastries and baked goods

What do muffins, donuts, chips and other baked goods have in common besides their savory and delicious flavor? They are loaded with a specific type of fat compound known as trans-fat. Trans-fat are hydrogenated oils that are highly used in commercial bakeries because of their ability to remain in a solid state at room temperature, negating the need to refrigerate the products. Other food products that are rich in trans-fat include snack foods, frozen foods and fried fast food.

High trans-fat content is potentially fatal to us not only because it increases bad cholesterol in the blood, but also because it leads to artery blockages. A study carried out by the University of North Carolina revealed that women who had a 7 gram intake of trans-fat daily, equivalent to two donuts or half a serving of french fries, had a 30% higher stroke incidence rate. Trans-fat has also been found to increase inflammation and C-reactive protein, both of which are factors for diabetes, heart disease and stroke.

Smoked and processed meats

Processed meat products such as pastrami, hot dogs, sausages and bacon have become common protein components in our diet. This is probably because such products are not only yummy but also easily accessible. However, smoked and processed meats are packed with sodium, as well as numerous types of preservatives that help to keep the meat from going bad. Researchers have demonstrated the ability of sodium nitrate in damaging blood vessels, leading to hardening and narrowing of arteries. Having overly-narrowed blood vessels increases stroke risk greatly. Beyond that, meta-analysis carried out on subjects that ate a portion of processed meat a day, revealed a 42% increase in coronary heart disease occurrence.

It is advisable to vary your sandwiches, perhaps choosing to have a tuna or peanut butter sandwich instead of a smoked ham one every afternoon. If you find yourself craving a meat sandwich, try to cook the turkey or chicken yourself, making sure to slice the meat thinly so as to reduce the sodium ingested.

Red meat

A study on 35,000 Swedish women, all of whom consumed a large amount of red meat each day, was concluded recently. After studying this group for ten years, researchers discovered that they had a 42% higher stroke incidence rate.

The saturated fat in red meat has a tendency to clog up arteries and lead to the formation of protein plaques. Hemoglobin, a molecule that gives red meat its high iron content, is under heavy investigation with regards to increasing stroke risk. Researchers speculate that the consumption of heme iron increases the thickness and viscosity of blood, upping the occurrences of blood clots and blockages.

Attempts should be made to replace some parts of our red meat diet with poultry or fish, both of which are low in heme iron. Other heart-healthy sources of protein include beans, nuts and tofu.

Canned soup and prepared foods

Canned foods, frozen dinners and prepared food mixes rely heavily on sodium to increase flavor and extend their shelf lives. The American Heart and Stroke Association recommends a daily intake of less than 1,500 mg of sodium. When you compare that to the fact that a can of chicken noodle soup contains 1,100 mg sodium, you can easily see the problem.

The Centers for Disease Control estimates that Americans take in approximately 3,500mg of sodium each day. High amounts of sodium raises blood pressure considerably, a physiological state that is the primary cause of stroke. Be advised that sodium in canned food labels are easily disguised under less common names such as MSG (monosodium glutamate), Disodium phosphate and sodium alginate.

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Healthy Living: Regular exercise increases mitochondria numbers in the muscle AND the brain

The positive physical effects of regular exercise such as the gaining of strength or endurance, has formerly been attributed to the increase in muscle mitochondrial levels. In addition, regular exercise also appears to contribute to our mental function by relieving depression and improving memory. A recent study by a team from the University of South Carolina has revealed that regular exercise can lead to an increase in the brain's mitochondrial levels. This has lead to speculation that the improved mental function observed after regular exercise stems from this occurrence.

The researchers studied two groups of mice; one group was subjected to an hour of running on an inclined treadmill everyday, while the others lived in exactly the same conditions with the exception of a sedentary period replacing the running activity. After eight weeks of study, brain and muscle tissue from both groups were closely examined. Mice from each group were also subjected to a "run-till-fatigued" test to determine any changes in endurance levels. 

As expected, mice from the group that participated in regular exercise had increased muscle mitochondrial levels compared to the sedentary group mice. What surprised the researchers was the discovery that mitochondrial markers increased in the brains of the active mice. Some of the markers include peroxisome proliferator-activated receptor-g coactivator 1-alpha and citrate synthase, both of which are indicators of mitochondrial biogenesis. The mice in the exercise group were also able to prolong their "run-till-fatigued" times by an average of 56 minutes, while the sedentary group did not display any change in endurance timing.

The investigators believe that this increase in brain mitochondrial levels could be involved in strengthening the brain against fatigue, preventing a reduction in physical performance and boosting exercise endurance. Beyond the usage of this discovery for the improvement of athletic performance, the team hopes the findings can be used as a basis for anti-aging research or in the treatment of neurological diseases. 

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Neuroscience: Craving for high-calorie food increases when the brain goes hungry

Brain imaging scans taken by researchers from Yale and the University of Southern California have demonstrated that a drop in the brain's blood glucose level, is followed by a reduction in brain activity from a region that functions to reduce our craving for high calorie foods.

The research team monitored and manipulated glucose levels intravenously while study subjects were shown 3 different types of pictures; high-calorie foods, low-calorie foods and non-foods. An fMRI scan was conducted during the picture-viewing process. When blood glucose levels were reduced, a brain region known as the hypothalamus senses this change. The insula and the striatum, two other regions, get activated and generates in us a desire to eat. The region that reacted the most strongly to lowered blood glucose levels was the prefrontal cortex. When subjected to this scenario, the prefrontal cortex seemed to lose its ability to inhibit signals generated by the striatum and was soon overpowered. This loss of ability was particularly evident in obese subjects who were shown pictures of high-calorie foods.

Assistant professor Kathleen Page, one of the lead investigators, believes the results could be an indication that obese individuals find it more difficult to ignore the desire to eat, especially when their blood glucose levels are reduced. Professor Rajita Sinha, another researcher from the study, feels that the take-away message is clear, "The key seems to be eating healthy foods that maintain glucose levels. The brain needs its food."

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Bacteriology: Blocking superantigens

Superantigens are a group of potentially fatal bacterial toxins produced by Staphylococcal and Streptococcal bacteria. These superantigens induce an extreme immune reaction, one with a magnitude much higher than a regular response. This is known as an "immune storm". Fatality occurs when the immune storm causes toxic or septic shock to the patient.

Researchers from the Hebrew University Faculty of Medicine discovered that superantigens must first bind to a human immune cell surface protein receptor called CD28 before it can initiate the immune storm. CD28 is a vital receptor that is involved in almost every immune response, however the ability of the receptor to bind the superantigen was virtually unheard of before this investigation.

Mapping out the exact binding region between CD28 and the superantigen, the research team designed decoys, small protein fragments that are highly similar to the binding area of CD28. These decoys were able to block the superantigens from binding to the actual CD28 molecule, protecting the test animals from the extreme immune response and sparing them from suffering the usual fatal outcome.

The decoy proteins are a possible therapy for Staphylococcal or Streptococcal bacteria-induced toxic shock. Since this therapy is host-orientated, meaning that it is directed toward the human immune system instead of against a pathogen, bacterial resistance is unlikely to become an issue.

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Evolution: The biological response to fatherhood

A recent study carried out by a group from Northwestern University has revealed that testosterone levels in men decrease greatly upon fatherhood, with the largest difference observed in fathers who are especially hands-on with raising their children. Scientists speculate that this drop in testosterone level might biologically emphasize a man's commitment to his family, strengthen his focus on caring for his children, as well as increase his sensitivity to their needs.

The researchers collected saliva samples from 465 21-year old, single, men. This process was repeated in the same group when they turned 26 years old. Each man gave two samples, one in the morning where testosterone levels are typically the highest, and another in the evening where the levels are known to decline.

As expected, within the five year period, some men remained single, others got married but did not have children, while the rest found themselves married and settled down with kids. The single men had twice the amount of testosterone compared to the fathers in the group, while the men who were married without children had testosterone levels that fell in the middle of the two.

Going one step further, the fathers were questioned regarding their involvement in the raising of their children - whether they played with them, took them on walks, fed or bathed them. The fathers who spent more than three hours a day carrying out these activities displayed the lowest testosterone levels in the group.

Looking at this research from an evolutionary point-of-view, it indicates a possible biological response to fatherhood. The results provide a contradiction to the long held belief that the male species are hunter-gatherers while the women stayed home with the children. This decline in testosterone has also been observed in males of certain bird species that help out in taking care of the offspring.

Principle researcher Lee Gettler, a biological anthropologist, believes that this decrease could be due to the fact that women needed more help taking care of their children over the years, "Humans wouldn't have been as successful if fathers weren't helping. It is an ongoing debate in anthropology. But this is suggestive that caring for children is a role fathers were playing in human evolution to the extent that it has become embedded in human male physiology."

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Addiction: Enzyme targeted for treatment against smoking and alcoholism

An enzyme known as Protein Kinase C (PKC) epsilon has displayed an involvement in the brain's reaction to nicotine and alcohol, making it a potential drug target in nicotine addiction or alcohol abuse treatment. 

Researchers from the Gallo Clinic and Research Center genetically engineered a group of mice lacking the PKC epsilon gene. Over a period of four weeks, these mice were observed to consume less nicotine-containing water and seemed less interested in returning to the chamber where they are fed nicotine. Normal mice however, had a steadily increasing nicotine solution intake.

In both humans and mice, nicotine binds to a specific group of nicotinic receptors located on dopamine neurons. Upon binding, these neurons release dopamine in the brain, leading to a generation and interpretation of a sense of enjoyment and reward. The researchers discovered that mice that lacked the PKC epsilon gene were deficient in these nicotinic receptors.

The leading investigator of this study, Dr Robert O. Messing, had carried out previous research revealing that mice lacking PKC epsilon also drank less alcohol and were less likely to return to the alcohol feeding chamber. As such he speculates that PKC epsilon regulates a part of the reward system of the brain, controlling the nicotinic receptors and affecting the craving for nicotine, alcohol or other addictive substances.

Messing wishes to further his research by developing drug compounds that lower the activity of PKC epsilon. Such medication would hopefully help addicts get over the reward craving that prevents them from sobering up.

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Neuroscience: Babies start feeling pain a few weeks before birth

Exactly when does a baby gain the ability to differentiate between a basic touch and one that causes pain? A study by Lorenzo Fabrizi and his group from University College London, indicates that most babies start sensing pain at 35-37 weeks, a time period just before they are born. The determination of this time point could potentially improve clinical care for premature newborns.

The scientists monitored the brain activity of 21 premature babies, ranging from 28 weeks to 37 weeks of age. The process of a routine heel lance, the pricking a baby's foot to collect blood for clinical analysis, was monitored via electroencephalography (EEG). The EEG would enable the group to monitor if there was a change from general brain activity to a localized brain reaction, indicating the neural interpretation of pain. However, Fabrizi does state that such measurements cannot rule out the possibility that babies do feel pain before the development of localized brain reactions.

During the development of the brain in babies, general neuronal activity declines while specific neuronal activity in response to certain sensory inputs tend to increase. Fabrizi explains, "In very young brains, all stimulations are followed by bursts of activity, but at a critical time in development, babies start to respond with activity specific to the type of stimulation."

The EEGs recorded by Fabrizi and his team, determined that at the 35-37 week time point, the general bursts of activity in the brain were altered to specific areas displaying localized activity. The team hypothesizes that this is the point where babies are able to discern the difference between touch and a painful stimulation.