Women diagnosed with metastatic breast cancer who have also endured previous traumatic or stressful events see their cancer recur nearly twice as fast as other women, according to a report by a University of Rochester Medical Center scientist.
The small, retrospective study showed that women who faced physical or sexual abuse or life-threatening situations see metastatic tumors return after about 2.5 years, compared with women who have more peaceful lives, who see recurrence at about five years, Biologynews.net reported.
While some of the reported events are less common than others, they all took a toll on the women and, scientists believe, may have contributed to the recurrence of disease.
“There is such a dramatic difference between women who had experienced traumatic things and those who didn’t,“ said Oxana Palesh, Ph.D., first author of the study and research assistant professor of Radiation Oncology and Psychiatry at the James P. Wilmot Cancer Center at the University of Rochester Medical Center. “Clearly this study demonstrates that it’s important to recover from trauma or stressful event for your mental and physical health.“
The relationship between stress and breast cancer has been heavily studied, however the results are murky. Studies have shown that stress can alter the immune system’s function, and that the activity of natural killer cells is related to breast cancer progression. But scientists have had more difficulty showing a link between stress and the development of breast cancer. Some large-scale studies have shown connections between recent stressful life events, such as the death of a spouse, and breast cancer risk, while others have not. Scientists are intrigued by the conflicting evidence, and research continues.
In this most recent effort, the bi-coastal team interviewed 94 women from the San Francisco Bay area and categorized their life experiences as either traumatic or stressful, and compared them with a control group of women who had not faced similar situations. The participants reported traumatic experiences such as childhood sexual abuse, rape, suicide of a family member or life-threatening injury. Stressful events included adoption, parent’s death, living with their mother-in-law, earthquake, divorce or having a family member imprisoned.
In the three study groups, 39 women reported traumatic events in their history, and median disease-free interval was 2.5 years; for 27 women who had experienced stressful situations, it was 37 months--just over three years. And in the final group of 28 women who reported no stress or trauma in their history, the median disease-free interval was 62 months--just over five years.

Very high doses of caffeine and acetaminophen (such as Tylenol), taken together, could lead to liver damage, researchers warn.
This combo produces a byproduct enzyme that’s toxic to the organ, researchers from the University of Washington report, according to HealthDay.
This toxic twosome can occur not only by drinking caffeine while taking acetaminophen, the experts added, but also from large doses of painkillers that combine caffeine and acetaminophen. These painkillers are often used to treat migraines, menstrual discomfort and other conditions.
“Caffeine can interact with an enzyme that can form a toxic metabolite of acetaminophen in such a way that it increases the formation of that toxic metabolite,“ said lead researcher Sid Nelson, a professor of medicinal chemistry. “This can result in liver damage,“ he said.
In the study, Nelson’s team tested the effects of acetaminophen and caffeine on E. coli bacteria. These bacteria had been genetically engineered to mimic a human enzyme in the liver that detoxifies many prescription and nonprescription drugs, explained the authors in a report in the Oct. 15 issue of the journal Chemical Research in Toxicology.
Nelson noted that it takes large qualities of caffeine to produce this reaction.
“Normally people wouldn’t be ingesting that amount of caffeine,“ he said. “It would take 10 times the amount of caffeine found in a couple of cups of coffee,“ Nelson said.
His team found that caffeine triples the amount of a toxin called N-acetyl-p-benzoquinone imine (NAPQI) produced by the enzyme as it breaks down acetaminophen.
In prior studies, Nelson’s team had found that high doses of caffeine boosted liver damage in rats that had already suffered acetaminophen-linked liver damage.
The bacteria used in the study were exposed to doses of acetaminophen and caffeine far higher than most people would be exposed to, Nelson noted. It’s not clear at what point such a mixture becomes toxic, he said.

During evolution, many of a species’ properties are shaped by ecological interactions. This is readily evident in mammalian teeth, whose many features closely reflect what each species eats.
However, for a long time scientists have suspected that genetic and developmental interactions may also influence species-specific properties. Now, researchers at the University of Helsinki’s Institute of Biotechnology show how development affects the evolution of teeth, and have devised a simple developmental model to predict aspects of teeth across many species, Eurekalert reported.
In the study in the field of evolutionary developmental biology, the researchers Kathryn Kavanagh, Jukka Jernvall and Alistair Evans in the Institute of Biotechnology of the University of Helsinki first studied cheek tooth, or molar, development in mice. Similarly to human teeth, mouse molars develop from front-to-back so that the first molar appears first and the posterior molars bud sequentially along the jaw.
Normally the last molar to develop is the third, or wisdom tooth. Experiments on cultured mouse molars revealed that the size and number of posterior molars depend on previously initiated molars. The mechanism, called an “inhibitory cascade“, acts much like a ratchet that cumulatively increases size differences of teeth along the jaw. By quantifying their experiments, the researchers constructed a simple mathematical model which they then used to predict relative size and number of molars across many other mouse and rat species.
They show that the model accurately predicts tooth proportions and numbers, one curious effect being that the second molar makes up one-third of total molar area, irrespective of species-specific molar proportions.
This new research demonstrates that with advances in the study of the molecular regulation of development, it is now possible to identify how development influences evolution. And this may help explain the troublesome wisdom teeth of modern humans--the blame may lie within a weak inhibitory cascade that allows the development of the last molar in a jaw that is too small.

Clover plants can warn each other via a network of runners.

Recent research from Vidi researcher Josef Stuefer at the Radboud University Nijmegen reveals that plants have their own chat systems that they can use to warn each other.
Therefore plants cannot be considered boring and passive organisms that just stand there waiting to be cut off or eaten up. Many plants form internal communications networks and are able to exchange information efficiently, Science Daily reported.
Many herbal plants such as strawberry, clover, reed and ground elder naturally form networks. Individual plants remain connected with each other for a certain period of time by means of runners. These connections enable the plants to share information with each other via internal channels. They are therefore very similar to computer networks. But what do plants want to chat to each other about?
Recently Stuefer and his colleagues were the first to demonstrate that clover plants warn each other via the network links if enemies are nearby. If one of the plants is attacked by caterpillars, the other members of the network are warned via an internal signal. Once warned, the intact plants strengthen their chemical and mechanical resistance so that they are less attractive for advancing caterpillars.
Thanks to this early warning system, the plants can stay one step ahead of their attackers. Experimental research has revealed that this significantly limits the damage to the plants.
However there are two sides to the coin. That is not just the case for the Internet but also for plants. It appears that plant viruses can use the infrastructure present to rapidly spread through the connected plants. The infection of one plant therefore leads to the infection of all plants within the network.
This research clearly reveals that the general image of plants is a poor reflection of reality. Who had now suspected that the majority of plants around us are constantly networking?

CockroachÕs memory is so strongly modulated by its circadian clock.

In its ability to learn, the cockroach is a moron in the morning and a genius in the evening. Dramatic daily variations in the cockroach’s learning ability were discovered by a new study performed by Vanderbilt University biologists and published online this week in the Proceedings of the National Academy of Sciences.
“This is the first example of an insect whose ability to learn is controlled by its biological clock,“ says Terry L. Page, the professor of biological sciences who directed the project. Undergraduate students Susan Decker and Shannon McConnaughey also participated in the study, Physorg.com reported.
The few studies that have been done with mammals suggest their ability to learn also varies with the time of day. For example, a recent experiment with humans found that people’s ability to acquire new information is reduced when their biological clocks are disrupted, particularly at certain times of day. Similarly, several learning and memory studies with rodents have found that these processes are modulated by their circadian clocks. One study in rats associated jet lag with retrograde amnesia.
In the current study, the researchers taught individual cockroaches to associate peppermint--a scent that they normally find slightly distasteful--with sugar water, causing them to favor it over vanilla, a scent they find universally appealing.
The researchers trained individual cockroaches at different times in the 24-hour day/night cycle and then tested them to see how long they remembered the association. They found that the individuals trained during the evening retained the memory for several days. Those trained at night also had good retention. During the morning, however, when the cockroaches are least active, they were totally incapable of forming a new memory, although they could recall memories learned at other times.
Most previous studies of circadian rhythm have focused on the visual system. “The advantage of eyes becoming more sensitive at night is so obvious that people haven’t looked much at other sensory systems,“ says Page. “The fact that our study involves the olfactory system suggests that the circadian cycle could be influencing a number of senses beyond vision.“
In the study, the researchers used cockroaches of the species Leucophaea maderae. It doesn’t have a common name but it is commonly used in scientific experiments because it was used extensively in early physiological and endocrinological studies.
The discovery that the cockroach’s memory is so strongly modulated by its circadian clock opens up new opportunities to learn more about the molecular basis of the interaction between biological clocks and memory and learning in general.

Are there times when it is better to simply give up? Psychologists have been exploring this question, and more specifically a possible link between tenacity and both physical and mental health.
According to Science Daily, it would seem that persistence would be tonic over the long haul; hanging tough should increase the odds that you’ll succeed, and personal success is closely linked to well-being. But what if the goal is extremely unlikely? When does an admirable trait like perseverance start to look more like beating your head against the wall?
To test this in the laboratory, psychologists Gregory Miller and Carsten Wrosch developed a psychological instrument that can reliably distinguish between people who when faced with a difficult goal either persist or let go of it. In a series of experiments, the psychologists exhaustively studied these two personality types to see how healthy and well adjusted they are.
In their most recent study, published in the September issue of Psychological Science, a journal of the Association for Psychological Science, the psychologists followed teenagers for a full year. Over that time, individuals who did not persist obtaining hard to reach goals had much lower levels of a protein called CRP, an indicator of bodily inflammation. Inflammation has recently been linked to several serious diseases, including diabetes and heart disease, suggesting that healthy but overly tenacious teens may already be on the road toward chronic illness later in life.
Accordingly, Miller and Wrosch suggest it may be more prudent to cut one’s losses in the face of an insurmountable obstacle. “When people are faced with situations in which they cannot realize a key life goal, the most adaptive response for physical and mental health may be to disengage from this goal,“ write the authors.
But all is not lost for go-getters. The psychologists also sorted both groups by their willingness to re-engage and set new goals after they gave up on something important. While they did not find a direct link between re-engagement and physical health, they did find that people who readily jumped back into life had a greater sense of purpose and mastery and were less likely to ruminate about the past.
Setting these new goals appears to buffer the emotional consequences of failure, especially for those who have the hardest time letting go.

Dragonflies have two pairs of wings, which sometimes move up and down in harmony. At other times the front set of wings flap out of sync with the back set.

Dragonflies adjust their wing motion while hovering to conserve energy, according to a Cornell University study of the insect’s flight mechanics. The revelation contradicts previous speculation that the change in wing motion served to enhance vertical lift.
The Cornell physicists came to their conclusions after analyzing high speed images of dragonflies in action. The insects have two pairs of wings, which sometimes move up and down in harmony. At other times the front set of wings flap out of sync with the back set, according to Science Daily.
The physicists found that dragonflies maximized their lift, when accelerating or taking off from a perch, by flapping both sets of wings together. When they hover, however, the rear wings flap at the same rate as the front, but with a different phase (imagine two people clapping at the same speed, but with one person’s clap delayed relative to the other).
The physicists’ analysis of the out-of-sync motion showed that while it didn’t help with lift, it minimized the amount of power they had to expend to stay airborne, allowing them to conserve energy while hovering in place.