Research Briefs

FIC: Mexican Flu Pandemic Study Supports Social Distancing

Would closing schools, movie theaters, and restaurants help improve health? Yes, at least in terms of mitigating unusual infectious disease outbreaks. According to NIH researchers, these social distancing interventions proved effective during the 2009 influenza pandemic in Mexico. Mexican health authorities implemented a nationwide mandatory school closure policy, effectively reducing disease transmission by more than one-third. The research team provided the first comprehensive epidemiological description of the age, geographical, and severity patterns of the 2009 pandemic in Mexico. Eighteen-day periods of mandatory school closures and other social distancing measures were associated with a 29 to 37 percent reduction in influenza transmission rates in Mexico during the 2009 pandemic. The authors applied mathematical modeling to influenza surveillance data compiled by a large private health system, the Mexican Institute for Social Security, which covers 40 percent of the population. (NIH authors: G. Chowell, C. Viboud, L. Simonsen, J. Tamerius, M.A. Miller; PLoS Med 8:e1000436, 2011)

NCI: Study Rules Out XMRV as Cause for Human Disease

The road to finding the cause for disease is sometimes paved with disappointment. Retrovirologists were excited to explore the role of a retrovirus known as xenotropic murine leukemia virus-related virus (XMRV), which was thought to contribute to prostate cancer and chronic fatigue syndrome (CFS). However, recent studies have shown a lack of association between the XMRV and human disease. NCI researchers, in collaboration with others, have provided an understanding of when and how XMRV arose and explained the original, incorrect assumption. They examined human prostate cancer cells, which contained XMRV, as well as the tumors from which these prostate cell specimens arose after they were grafted into mice. Based on this genetic analysis, the scientists concluded that XMRV was not present in the original prostate tumor samples but arose only after they had been put into mice. Another study in the same issue of the journal found a lack of association between XMRV and CFS. (NIH authors: T. Paprotka, K.A. Delviks-Frankenberry, W. Hu, M.J. Fivash Jr., V.K. Pathak; Science DOI: 10.1126/1205292)

NINDS, NCI: Probing the Activity of a New Multiple Sclerosis Drug

Daclizumab is one of the newest therapies for treating multiple sclerosis (MS), a chronic disease marked by inflammation in the central nervous system and development of lesions in the brain. Scientists knew that the therapy works by targeting a single molecule on immune cells, but they didn’t understand how. Now NIH investigators have gained insights into the drug’s effects and the basic biology of the immune system. Their data reveal a previously unknown mechanism and suggest that the expression of cytokine signaling chains on various cells of the immune system can regulate T cell functions through a single cytokine. This information may provide a basis for the development of more effective therapies. (NIH authors: S. Wuest, J. Edwan, J. Martin, S. Han, J. Perry, C. Cartagena, E. Matsuura, D. Maric, T. Waldmann, B. Bielekova; Nat Med: 17:604–610, 2011)

NCCAM, NLM, NIAID: Acupuncture for Patients With Job’s Syndrome

Hyper-immunoglobulin E (IgE) syndrome (HIES)—a rare immunological disorder—received its more common name, Job’s syndrome, from a biblical passage in which Job was smote “with sore boils from the sole of his foot unto his crown.” Job’s syndrome patients suffer from a variety of symptoms, which often include abscesses similar to boils. NIH conducted a retrospective case series and demonstrated that acupuncture is a clinically useful and safe therapy for symptom management in patients with HIES. Acupuncture treatments were given to eight adult patients with HIES, ages 23–56, who had varying symptoms. Treatment efficacy was measured and evaluated using a 0–10 assessment instrument pre- and post-treatment. Acupuncture treatments uniformly decreased the self-reported severity of symptoms. (NIH authors: A. Ge, M. Ryan, S. Holland, A. Freeman, V. Anderson, J. Fleshman; J Altern Complent Med 17:71–76, 2011)

NICHD: Key Step Identified in Legionnaires’ Disease

NIH researchers have uncovered a key step in the biochemical sequence the bacterium that causes Legionnaires’ disease uses to reproduce inside cells. The disease, a form of pneumonia, is named after its discovery in people attending an American Legion convention in 1976. The bacterium activates a cell protein to help it hide from the cell’s defenses while it reproduces. The researchers discovered how the bacterium switches off the protein so that its offspring can leave the cell and begin the infection process anew. The finding may one day lead to new ways to treat Legionnaires’ disease and diseases caused by related bacteria. Previous studies conducted by the NIH researchers have shown that the Legionella bacteria hide out inside the phagosomes, subverting the cell’s defense machinery for its own purposes. The bacterium forces the cell to camouflage the phagosome. The bacterium does this by hijacking Rab1, a protein that the cell makes. In the current study, the researchers searched the bacterium’s genes and found the information needed to produce a protein called SidD. They found that the SidD protein sliced the AMP molecule from Rab1, which stopped summoning vesicles to the surface of the phagosome. (NIH authors: M. Machner, M. Neunuebel, Y. Chen, A. Gaspar, P. Backlund Jr., and A. Yergey; Science Express DOI: 10.1126/science.1207193)

Compiled by Stephanie Bonhomme, NIH management intern on rotation with OIR