How Carbon Nanotubes Can Affect Lining Of The Lungs

ScienceDaily (Oct. 26, 2009) — Carbon nanotubes are being considered for use in everything from sports equipment to medical applications, but a great deal remains unknown about whether these materials cause respiratory or other health problems. Now a collaborative study from North Carolina State University, The Hamner Institutes for Health Sciences, and the National Institute of Environmental Health Sciences shows that inhaling these nanotubes can affect the outer lining of the lung, though the effects of long-term exposure remain unclear.

Using mice in an animal model study, the researchers set out to determine what happens when multi-walled carbon nanotubes are inhaled. Specifically, researchers wanted to determine whether the nanotubes would be able to reach the pleura, which is the tissue that lines the outside of the lungs and is affected by exposure to certain types of asbestos fibers which cause the cancer mesothelioma. The researchers used inhalation exposure and found that inhaled nanotubes do reach the pleura and cause health effects.

Short-term studies described in the paper do not allow conclusions about long-term responses such as cancer. However, the inhaled nanotubes "clearly reach the target tissue for mesothelioma and cause a unique pathologic reaction on the surface of the pleura, and caused fibrosis," says Dr. James Bonner, associate professor of environmental and molecular toxicology at NC State and senior author of the study. The "unique reaction" began within one day of inhalation of the nanotubes, when clusters of immune cells (lymphocytes and monocytes) began collecting on the surface of the pleura. Localized fibrosis, or scarring on parts of the pleural surface that is also found with asbestos exposure, began two weeks after inhalation.

The study showed the immune response and fibrosis disappeared within three months of exposure. However, this study used only a single exposure to the nanotubes. "It remains unclear whether the pleura could recover from chronic, or repeated, exposures," Bonner says. "More work needs to be done in that area and it is completely unknown at this point whether inhaled carbon nanotubes will prove to be carcinogenic in the lungs or in the pleural lining."

The mice received a single inhalation exposure of six hours as part of the study, and the effects on the pleura were only evident at the highest dose used by the researchers -- 30 milligrams per cubic meter (mg/m3). The researchers found no health effects in the mice exposed to the lower dose of one mg/m3.

The study, "Inhaled Carbon Nanotubes Reach the Sub-Pleural Tissue in Mice," was co-authored by Bonner, Dr. Jessica Ryman-Rasmussen, Dr. Arnold Brody, and Dr. Jeanette Shipley-Phillips of NC State, Dr. Jeffrey Everitt who is an adjunct faculty at NC State, Dr. Mark Cesta of the National Institute of Environmental Health Sciences (NIEHS), Earl Tewksbury, Dr. Owen Moss, Dr. Brian Wong, Dr. Darol Dodd and Dr. Melvin Andersen of The Hamner Institutes for Health Sciences. The study is published in the Oct. 25 issue of Nature Nanotechnology and was funded by The Hamner Institutes for Health Sciences, NIEHS and NC State's College of Agriculture and Life Sciences.

Asbestos Contamination: Health Impacts Of One Of The Nation's Largest Environmental Disasters

ScienceDaily (Nov. 2, 2009) — Over nearly a century, thousands of residents and workers in Libby, MT, have been exposed to asbestos-contaminated vermiculite ore, leading to markedly higher rates of lung disease and autoimmune disorders, and causing to Libby in 2002 to be added to the federal Environmental Protection Agency's "National Priorities List."

Researchers at Mount Sinai School of Medicine, leading a team of investigators from four institutions, are now launching three investigations into disease pathology in the town and to determine recommended cleanup efforts.

The Principal Investigator of the project is Stephen Levin, MD, Associate Professor of Preventive Medicine at Mount Sinai School of Medicine and a nationally known expert in occupational medicine and asbestos-related diseases who has also served as PI of the nationwide World Trade Center Medical Monitoring & Treatment Program, coordinated by Mount Sinai since 2002.

"The asbestos-related disease in Libby is far more aggressive and rapidly progressive than what's seen in most asbestos-exposed workers, with high rates of cancers and severe effects on respiratory function," said Dr. Levin. "For that reason alone, the health problems in Libby are important to study and understand."

The first of the three programs will focus on particular risks of exposure to Libby asbestos during childhood, when lungs are still developing and maturing. This research may determine the level of environmental cleanup necessary in Libby to protect children, who are a particularly sensitive target population.

A second study will compare lung scarring among Libby residents who were exposed to asbestos only in their environment (and not at their place of employment) with lung scarring seen in workers with historically long-term, heavy exposure to common commercial forms of asbestos. Researchers hope to discover why Libby residents have advanced rates of lung scarring. They will also investigate the mechanism for asbestos-related scar formation and approaches to preventing scar formation after exposure has already occurred.

The third investigation will examine the relationships between autoimmune disorders, autoimmune antibody abnormalities, and CT-scan evidence of scarring lung disease in the context of exposure to Libby asbestos. Auto-immune disorders such as rheumatoid arthritis and lupus have been found to occur more frequently in Libby, and antibody levels to the body's own tissues are found in Libby residents more frequently and at higher concentrations.

Mount Sinai researchers will collaborate on the research effort, to be known as the Libby Epidemiology Research Program, with Libby's Center for Asbestos Related Disease (CARD), investigators from the University of Montana and Idaho State University, and a national scientific advisory group. The research will be supported by a grant of over $4.8 million from the Agency for Toxic Substances and Disease Registry (ATSDR) of the federal Center for Disease Control and Prevention.

The crisis in Libby, a mining town whose history has been shaped by vermiculite-producing corporations since the 1920s, is the result of community-wide occupational and environmental exposure to Libby's naturally occurring vermiculite, contaminated with asbestos and asbestos-like silicate fibers up to 26% by weight.

Health effects have been detected not just in mine and processing plant workers, area lumber mill workers and loggers (from asbestos dusting of forests) and their families, but also among other Libby residents and their children. Many were exposed through ambient air or to mine tailings and other contaminated materials provided to the town by mining companies for the construction of ball fields, school running tracks, playgrounds, public buildings and facilities, as well as for private gardens and house and business insulation.

There is evidence that even relatively low-level exposures to Libby asbestos can cause serious scarring lung diseases, which markedly impair respiratory function, as well as asbestos-related cancers like lung cancer and mesothelioma, which occur at higher rates among the Libby population than elsewhere in the United States.

The health crisis potentially extends far beyond the borders of Libby, since millions of homes and businesses in North America have used vermiculite from Libby as attic insulation, fireproofing and soil conditioner. The ore from Libby was shipped by rail to 49 plant locations throughout North America and the Caribbean for processing, exposing many more workers and communities to the hazardous dust.

CARD Director Brad Black, MD, said, "The pattern of asbestos disease caused by exposure to Libby amphibole asbestos has led to excessive morbidity and mortality for the Libby population, and has been exceedingly challenging for the medical community. The severity of nonmalignant pulmonary disease in non-occupational exposure has been very unusual, raising question as to the potency of the unique amphibole mixture. We look forward to working with Dr. Levin and Mount Sinai to find some of these answers."

Asbestos Disease Awareness Organization (ADAO) Holds Sixth Annual International Asbestos Awareness Conference

The Asbestos Disease Awareness Organization (ADAO) announced its sixth International Asbestos Awareness Conference to be held in Chicago April 9-11, 2010. Conferences each year bring together renowned doctors, scientists, researchers and most importantly, asbestos victims and their families - in a united forum for asbestos awareness, education and collaboration.

Numerous honorees will be recognized at the 2010 event for their outstanding work and dedication to asbestos awareness related activities including:

- The Honorable Richard Durbin, United States Senator, Tribute of Hope Award
- Dr. Hedy Kindler, Selikoff Lifetime Achievement Award
- Center for Asbestos Related Disease (CARD), Libby, MT, Tribute of Unity Award
- Fernanda Giannasi, Tribute of Inspiration Award
- Honoree To be Announced, Warren Zevon "Keep me in Your Heart" Memorial Tribute
- June Breit, honored posthumously, The Alan Reinstein Memorial Award

"As we get even closer to a full asbestos ban, we are encouraged yet simultaneously reminded that the reverberations of asbestos exposure can last decades," stated Linda Reinstein, Co-Founder & Executive Director of the Asbestos Disease Awareness Organization. "Our annual conferences drive home the importance of the need for increased awareness, education and research. We are again honored to have the opportunity to bring together some of the world's most renowned experts while recognizing some of the most influential leaders in the battle against asbestos exposure. They are true asbestos awareness heroes and prove that together, change is possible."

"I've received countless requests for my father's song, 'Keep Me In Your Heart,' to be used at memorials for asbestos victims," stated Jordan Zevon, ADAO Spokesperson. "You can imagine how proud it makes me to know that my father's Grammy winning song has touched so many families, but it is bittersweet because of the nature of those requests and the origin of the song's conception. The ADAO "Warren Zevon Keep Me In Your Heart Tribute", the success of his album, and my recent fatherhood would have made my Dad burst with pride. In his honor, I will continue to work with ADAO to ban asbestos to spare future generations from the same fate."

ADAO's mission is to provide the most advanced medical, occupational and environmental information available about asbestos related diseases to individuals throughout the world. Presentations will include preventing exposure, advances in diagnosing and treating asbestos-related diseases, providing patient resources, and a global advocacy session.

The conference is made possible with the support and collaborative efforts of the Barbara Ann Karmanos Cancer Institute and the International Ban Asbestos Secretariat (IBAS).

Online registration is available at http://adao.eventbrite.com/ and additional conference details can be found at here.

Source:
Asbestos Disease Awareness Organization , www.medicalnewstoday.com

Pleural Fluid Mesothelin May Help Diagnose Mesothelioma

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - Increased levels of the glycoprotein mesothelin in pleural fluid samples are associated with mesothelioma and may be useful in diagnosing the malignancy, according to a report in the September 1st issue of the American Journal of Respiratory and Critical Care Medicine.

Pleural effusion "can be maddeningly difficult to diagnose as a wide variety of malignant and benign causes exist," lead author Dr. Helen Davies, from Oxford University, said in a statement. "One of the causes, malignant pleural mesothelioma, is a relatively rare cancer, but its incidence is rapidly increasing on a global scale."

Serum mesothelin is a known biomarker for mesothelioma, but levels of the protein are much higher in pleural fluid and measuring such levels may improve the diagnosis of the malignancy.

In the current study, mesothelin levels were analyzed in pleural fluid samples from 166 patients with pleural effusions, including 24 with mesothelioma, 67 with other malignancies, and 75 with benign pleural effusion.

The median pleural fluid level of mesothelin in mesothelioma patients -- 40.3 nM -- was much higher than the levels seen in patients with other cancers benign effusions, 6.1 and 3.7 nM, respectively (p <>

For distinguishing mesothelioma from other causes of pleural effusion, mesothelin measurement had a sensitivity of 71%, specificity of 89%, and negative predictive value of 95%. The corresponding values with cytologic examination were 35%, 100%, and 82%.

With a "suspicious" cytologic reading, pleural fluid mesothelin was 100% specific for mesothelioma, the authors note. The negative predictive value with cytology-negative effusions was 94%.

The results also showed that when measured serially, there was little variation in pleural fluid mesothelin levels in patients with mesothelioma, just 0.15 nM with a 7-day test interval. Moreover, pleurodesis and the presence of bacteria did not influence the mesothelin results.

"Pleural fluid mesothelin provides a valuable adjunct in the diagnostic assessment of patients presenting with pleural effusions, especially when cytological examination is not definitive, and can improve clinical practice," Dr. Davies concluded.

Source:

Am J Respir Crit Care Med 2009;180:437-444. & www.cancerpage.com