Daily ReCAP May 8, 2017

Chronic: Sleep Deprivation Increases Pain Sensitivity

Patients with chronic pain may experience relief through improved sleeping habits, according to a study published inNature Medicine. Investigators measured the effects of acute or chronic sleep loss on sleepiness and sensitivity to painful and nonpainful stimuli. They also tested standard medications, such as ibuprofen and morphine, as well as wakefulness agents, such as caffeine and modafinil. The mice were kept awake for 12 hours in 1 session or 6 hours for 5 consecutive days by providing them with toys and activities when they were supposed to go to sleep. The results of the study showed that 5 consecutive days of moderate sleep deprivation can significantly exacerbate pain sensitivity over time in otherwise healthy mice. “The response was specific to pain, and was not due to a state of general hyperexcitability to any stimuli,” said investigator Chloe Alexandre, PhD. In addition, common drugs such as ibuprofen did not block sleep-loss—induced pain hypersensitivity, and even morphine lost most of its efficacy in sleep-deprived mice. The findings suggest that patients who use these medications for pain relief may need to increase their dosage to compensate for the lost efficacy as a result of sleep loss, increasing the risk for adverse events. Contrastingly, both caffeine and modafinil successfully blocked the pain hypersensitivity caused by acute and chronic sleep loss. The authors concluded that patients with chronic pain may benefit more from better sleep habits, plus daytime wakefulness agents.

Acute: Fluorescent Light Indicates Presence of Influenza with Naked Eye

Scientists have engineered dye molecules to make influenza visible to the naked eye, according to a study published in theJournal of the American Chemical Society. By targeting a specific enzyme of the virus, the investigators created a test that emitted fluorescent light when illuminated with a hand-held lamp or blue laser pointer. The investigators used test samples that mimicked those of infected patients and added the enzyme neuraminidase. The samples emit red fluorescent light to indicate the presence of the influenza virus and blue light to indicate a negative result. Upon positive enzyme recognition, the investigators tested the dye with influenza antiviral drugs Zanamivir (Relenza) and Oseltamivir (Tamiflu). The samples that contained the dye and neuraminidase were combined with each of the antivirals and illuminated, according to the study. Red light indicated that the enzyme was active and that the antiviral failed, whereas blue light indicated that the enzyme had been blocked and that the treatment was effective. “Viral cultures are the gold standard for diagnosis of influenza but take several days to develop,” said co-author Bradley Smith. “By targeting an enzyme inherent to the virus and identifying its presence in a sample, we can make a rapid determination of the influenza in a patient for an efficient and immediate diagnostic that would improve patient treatment and reduce overuse of antivirals.”

Preventive: Newly Identified Antibody Neutralizes the Zika Virus

Scientists have identified an antibody that can neutralize the Zika virus, and could lead to the development of a new vaccine. In a study published inCell, investigators used blood samples obtained from more than 400 individuals in Brazil and Mexico. They found that there were several antibodies that blocked the virus from initiating an infection, particularly the antibody Z004. When the antibody was given to mice vulnerable to Zika, they found that the antibody protected the animals from developing serious infections. Upon further examination of the interaction between the antibody and a fragment of the virus’ envelope protein, the investigators determined that the molecular structure formed as the 2 units interacted. They revealed that the antibody pinches a ridge on the virus when it binds to it. Although efforts to develop a Zika vaccine use all or most of the virus to stimulate an immune response, the investigators believed using only a tiny fragment that contains the ridge may be safer.