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Proceedings of the National Academy of Sciences

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Testosterone increases social vigilance

Socially naïve people may become shrewder and less trusting after ingesting testosterone, according to a study. In a double-blind experiment, Jack van Honk and colleagues administered testosterone or a placebo to 24 young women with an average age of 20 years, and then asked the subjects to rate the trustworthiness of strangers' faces depicted in a series of photographs on a scale from -100 (very untrustworthy) to +100 (very trustworthy). The researchers report that high-trusting women, or the half of subjects who rated faces as most trustworthy after the placebo, scored the photographs an average 10 points lower after ingesting testosterone. However, women who exhibited little trustworthiness in faces when given the placebo showed no change in their ratings after testosterone administration. Tests to reveal the subjects' pre-experiment mood and baseline testosterone levels demonstrated no correlation between these factors and the experimental results. The authors suggest that testosterone, a hormone associated with social dominance and success in competition, may adaptively increase social vigilance in trusting individuals to prepare them for competition over status and resources.

Article #09-11700: "Testosterone decreases trust in trusting humans," by Peter Bos, David Terburg, and Jack van Honk

MEDIA CONTACT: Jack van Honk, Department of Psychiatry, University of Cape Town, Cape Town, SOUTH AFRICA;  tel +27-21-782-0158; e-mail: j.vanhonk@uu.nl

Peter Bos, Department of  Experimental Psychology, Utrecht University, Utrecht, NETHERLANDS; tel +31-30-253-2640; e-mail: p.a.bos@uu.nl

Inhaled chemotherapy may help fight lung cancer

An inhaled chemotherapy cocktail may help increase lung cancer patient survival beyond the current rate while limiting harmful side effects. Tamara Minko and colleagues designed an inhalable chemotherapy treatment that included anticancer drugs and compounds designed to inhibit genes associated with chemotherapy resistance, and administered the treatment to mice with multiple human lung cancer tumors. The authors report that the inhalation treatment killed cancerous cells and decreased tumor size more successfully than the drugs alone or in treatments administered through IVs. Tests revealed that, compared to injections, the inhalation method enhanced the drugs' exposure to the mice's lungs and limited toxic accumulation in other healthy organs. Lung cancer is the leading cause of cancer-related death worldwide, and disease mortality rates have varied little from an approximately 20 percent survival rate over the last half century. The treatment could help patients overcome some of the obstacles to chemotherapy, such as cancer cell resistance, low drug accumulation in the lungs, and adverse side effects, according to the authors.

Article #10-04604: "Inhibition of lung tumor growth by complex pulmonary delivery of drugs with oligonucleotides as suppressors of cellular resistance," by Olga Garbuzenko, Maha Saad, Vitaly Pozharov, Kenneth Reuhl, Gediminas Mainelis, and Tamara Minko

MEDIA CONTACT: Tamara Minko, Department of Pharmaceutics, Rutgers University, Piscataway, NJ; tel: 732-445-3831; e-mail: minko@rci.rutgers.edu

Protecting the environment may boost local economies

Contrary to the belief that conservation laws burden local economies, protected ecosystems may promote tourism, create jobs, and improve the infrastructure in remote areas, according to a study. By analyzing national census and geospatial data, Paul Ferraro and colleagues found that protected ecosystems may have alleviated poverty in Costa Rica and Thailand, where substantial investments aimed at maintaining biodiversity have produced a successful eco-tourism industry. To isolate the economic effects of conservation laws, the researchers compared poverty statistics for communities that neighbored protected areas, to "matched" control communities that had similar economic characteristics but were not restricted by environmental protections that might limit agriculture or access to natural resources. The authors report that communities near areas that have been protected for 15 years or more had lower poverty rates than the control communities. The analysis suggests that policies designed to maintain biodiversity can potentially be tailored to protect the environment and alleviate poverty, according to the authors. The researchers propose that the study's use of matched controls can be extended to a variety of environmental protection policies to gain a better understanding of how protected areas impact human welfare.

Article #09-14177: "Ecosystem protection and poverty alleviation," by Kwaw Andam, Paul Ferraro, Katharine Sims, Margaret Holland, and Andrew Healy

MEDIA CONTACT: Paul J. Ferraro, Department Of Economics, Georgia State University, Atlanta, GA; tel: 404-413-0201 (day), 404-377-1808 (evening); e-mail: pferraro@gsu.edu

A "golden" flu treatment

Gold nanorods may provide a method for delivering an effective treatment for seasonal and pandemic flu, according to a study. During an influenza infection, an RNA sensor, called RIG-I, activates a person's innate immune system, which then works to fend off the virus. A ligand called 5'PPP-ssRNA activates RIG-I; however, researchers have had difficulty getting the ligand into cells. Paras N. Prasad and colleagues attached 5'PPP-ssRNA to gold nanorods, which earlier work found capable of safely delivering molecules into cells. When the researchers delivered the gold nanocomplex containing 5'PPP-ssRNA to cultured human epithelial cells infected either with a seasonal influenza virus or the pandemic 2009 H1N1 influenza virus, the cells successfully internalized them. In addition, the nanocomplex activated an antiviral response and reduced replication of both seasonal and 2009 H1N1 influenza viruses. These findings suggest that biocompatible nanocomplexes hold potential for treating seasonal and 2009 H1N1 influenza outbreaks, according to the authors.

Article # 09-14561: "Gold nanorod delivery of an ssRNA immune activator inhibits pandemic H1N1 influenza viral replication," by Krishnan V. Chakravarthy, Adela C. Bonoiu, William G. Davis, Priya Ranjan, Hong Ding, Rui Hu, Bradford J. Bowzard, Earl J. Bergey, Jacqueline M. Katz, Paul R. Knight, Suryaprakash Sambhara and Paras N. Prasad

MEDIA CONTACT: Paras N Prasad, Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo, Buffalo, NY; tel: 716-645-4148; email: pnprasad@buffalo.edu


Ancient animals' body temperatures stored in bone apatite

The in-life body temperature of ancient animals can be inferred from the isotopic composition of apatite, a biological mineral that is preserved in fossilized bones and teeth.

Article #09-11115: "Body temperatures of modern and extinct vertebrates from 13C-18O bond abundances in bioapatite," by Robert Eagle, Edwin Schauble, Aradhna Tripati, Thomas Tütken, Richard Hulbert, and John Eiler

MEDIA CONTACT: Robert A. Eagle, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA; tel: 626-395-3872; e-mail: robeagle@caltech.edu

Using metals to track seabird populations

Researchers suggest that feces and carcasses from two different bird species caused unique metal concentrations in sediment readings from their respective nearby Canadian ponds.

Article #10-01333: "Trophic position influences the efficacy of seabirds as metal biovectors," by Neal Michelutti, Jules Blais, Mark Mallory, Jaclyn Brash, Joshua Thienpont, Lynda Kimpe, Marianne Douglas, and John Smol

MEDIA CONTACT: Neal Michelutti, Paleoecological Environmental Assessment and Research Laboratory, Queen's University, Kingston, Ontario, CANADA; tel: 613-533-6159; e-mail: nm37@queensu.ca



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