Recent quotes:

Opioids produce analgesia via immune cells: Researchers from the Charité find new signaling pathway -- ScienceDaily

"We were able to show that opioid agonists activate opioid receptors on immune cells, which triggered the release of endogenous painkillers (opioid peptides) and produced analgesia in a mouse model of neuropathic pain," explains Prof. Machelska. She adds, "This led us to conclude that opioids can exert enhanced analgesia when they act directly in painful tissue -- providing that this tissue is inflamed and contain immune cells."

Exercising to avoid the flu? It’s all about the sweet spot - The Globe and Mail

a 2011 study of 1,002 adults by Dr. David Nieman at Appalachian State University found that those who exercised five or more days a week were 43 per cent less likely to develop upper respiratory tract infections during the fall and winter than those who exercised once a week or less.

Birth year dictates which flu strains make you sick

They discovered that people born before the Hong Kong flu pandemic of 1968 – in which H7N9’s ancestor, H3N2, first emerged – were largely protected from the older-type H5N1, but were vulnerable to severe illness from H7N9. Those born after 1968 showed the opposite responses. This explains a pattern that has puzzled scientists since 2013, when H7N9 itself was first detected: flu viruses from the H5N1 “family” disproportionately affect children and young adults, while those more closely related to H7N9 are more likely to infect older adults.

Tickling the brain can boost immunity: study

"Feeding and sex expose one to bacteria," explained Rolls said. "It would give one an evolutionary advantage if -- when the reward system is activated -- immunity is also boosted."

Why your muscles get less sore as you stick with your gym routine: Unexpected immune system cells may help repair muscles -- ScienceDaily

"T-cells, up until recently, were not thought to enter healthy skeletal muscle," said lead author and grad student Michael Deyhle. "We hadn't planned on measuring them because there's no evidence that T-cells play a role in infiltrating damaged muscle tissue. It's very exciting." The presence of the T-cells suggests that muscles become more effective at recruiting immune cells following a second bout of exercise and that these cells may facilitate accelerated repair. In other words, the muscle seems to remember the damaging insult and reacts similarly to when the immune system responds to antigens--toxins, bacteria or viruses. The group was also surprised to find inflammation actually increased after the second round of exercise. Hyldahl, his students and many physiologists have long thought inflammation goes down after the second bout of exercise, contributing to that "less sore" effect. Instead, the slightly enhanced inflammatory response suggests inflammation itself probably does not worsen exercise-induced muscle damage. "Many people think inflammation is a bad thing," Deyhle said. "But our data suggest when inflammation is properly regulated it is a normal and healthy process the body uses to heal itself." Adds Hyldahl: "Some people take anti-inflammatory drugs such as Ibuprofen and Aspirin after a workout, but our study shows it may not actually be effective. The inflammation may not be directly causing the pain, since we see that muscle soreness is reduced concurrent with increases in inflammation."

Researchers reveal mechanisms of how body remembers, fights infections: Scientists find new evidence of immune system plasticity -- ScienceDaily

"It was once believed that effector and memory cells arose as two distinct populations, with some cells initially fated to be effector type and some to be memory," McDonald said. "We've now seen that there is much more fluidity between the cell types than originally thought." The presence of certain proteins can influence the cell's fate. Interleukin-2, for instance, is a highly inflammatory protein produced at the start of an infection.