Water vapour released into the air adds one degree Celsius to global warming for every one contributed by humanity through other greenhouse gas emissions.
The evidence for this phenomenon, long-debated among climate scientists, is now indisputable, according to a review of the evidence by Andrew Dessler of Texas A&M University and Steven Sherwood of the University of New South Wales (UNSW).
Known to science as water vapour feedback, it is responsible for a significant portion of the warming predicted to occur over the next century, according to Dessler and Sherwood. This is because water vapour itself is a greenhouse gas.
As a result of burning fossil fuels and other human activities, rising temperatures are increasing the volume of naturally occurring evaporation on our warm, watery planet, they point out. In turn, that evaporated water contributes additional global warming.
Dessler and Sherwood based their statement on studies of how atmospheric water vapour varies in line with the natural cycles that warm and cool the planet, such as the cyclical temperature change caused by the seasons and El Nino events.
'It's a vicious cycle: warmer temperatures mean higher humidity, which in turn leads to even more warming,' says Dessler, a professor.
Recent estimates suggest the earth will warm by between two to four degrees Celsius over the next century - a scenario that could have devastating long-term consequences, said an UNSW release.
The study was published in the latest issue of Science.
Friday, February 27, 2009
Scientists identify obesity gene
A group of researchers led by a scientist of Indian origin have determined that a specific gene plays a role in the weight-gain response to a high-fat diet.
The finding in an animal study suggests that blocking this gene could one day be a therapeutic strategy to reduce diet-related obesity and associated disorders, such as diabetes and liver damage, in humans.
Researchers found that a diet rich in fat induced production of this gene, called protein kinase C beta (PKC beta), in the fat cells of mice. These mice rapidly gained weight while eating a high-fat diet for 12 weeks.
On the other hand, mice genetically engineered to lack PKC beta gained relatively little weight and showed minimal health effects after eating the same high-fat diet.
'So we now know this gene is induced by a high-fat diet in fat cells, and a deficiency of this gene leads to resistance to fat-induced obesity and related insulin resistance and liver damage,' said Kamal Mehta, study co-author and professor of molecular and cellular biochemistry in Ohio State University College of Medicine.
'It could be that the high-fat diet is a signal to the body to store more fat. And when that gene is not there, then the fat storage cannot occur,' he said.
Research suggests that rather than storing fat, mice lacking the gene burn fat more rapidly than they would if the PKC beta were present, Mehta said, according to a Ohio release.
The research is available online in Hepatology and is scheduled for publication.
The finding in an animal study suggests that blocking this gene could one day be a therapeutic strategy to reduce diet-related obesity and associated disorders, such as diabetes and liver damage, in humans.
Researchers found that a diet rich in fat induced production of this gene, called protein kinase C beta (PKC beta), in the fat cells of mice. These mice rapidly gained weight while eating a high-fat diet for 12 weeks.
On the other hand, mice genetically engineered to lack PKC beta gained relatively little weight and showed minimal health effects after eating the same high-fat diet.
'So we now know this gene is induced by a high-fat diet in fat cells, and a deficiency of this gene leads to resistance to fat-induced obesity and related insulin resistance and liver damage,' said Kamal Mehta, study co-author and professor of molecular and cellular biochemistry in Ohio State University College of Medicine.
'It could be that the high-fat diet is a signal to the body to store more fat. And when that gene is not there, then the fat storage cannot occur,' he said.
Research suggests that rather than storing fat, mice lacking the gene burn fat more rapidly than they would if the PKC beta were present, Mehta said, according to a Ohio release.
The research is available online in Hepatology and is scheduled for publication.
Tuesday, December 30, 2008
Mesothelioma Legal Help
Getting legal help after your mesothelioma diagnosis is an important step toward protecting your legal rights. Most mesothelioma victims, however, have difficulty enough just dealing with the diagnosis—much less its legal implications. We can help. Contact us today to arrange a complimentary consultation to learn more about your legal options and get the legal help you need.
Recovering the Costs of Mesothelioma
The human costs of a chronic and life-threatening disease such as mesothelioma can be staggering. Years of mesothelioma treatment, medical costs, and hospice care can run into the tens of thousands of dollars, and few patients and their families are able to pay these costs on their own. Health insurance may not cover all the costs. In addition, the loss of a patient's income can be particularly burdensome, and the emotional costs of a potentially fatal disease are difficult to estimate.
Thousands of Americans have contracted mesothelioma after working with or being exposed to products that cause this pernicious disease, and if you are one such victim, you may be eligible for monetary damages from the product's maker or from your employer.
How an Attorney Can Help
Mesothelioma cases are complex matters. It is not necessarily obvious that there is a cause-and-effect link between a product or environment and someone's mesothelioma. An experienced mesothelioma attorney or law firm can help unravel the link between your mesothelioma and its cause.
Losses Due to Mesothelioma
An attorney's guidance is also very helpful when estimating a mesothelioma patient's losses. Such losses often involve:
* Medical costs including hospital care
* Loss of wages and/or earning capacity
* Loss of companionship or a spousal or parental relationship
* Loss of financial support
* Pain and suffering
* Funeral and burial costs
* Out-of-pocket expenses
Protecting Your Legal Rights
The maker of the asbestos product that caused your mesothelioma or the employer where you worked and contracted mesothelioma may not be agreeable to the idea that they should pay the damages you've incurred due to this disease. In such cases, representation by an attorney or law firm can make all the difference in the outcome of your case.
Just as in other types of personal injury cases, a mesothelioma attorney can:
* Investigate your case, including interviewing witnesses and getting documents
* Show the causation between the product or environment and your mesothelioma
* Help you estimate your total losses due to mesothelioma
* Negotiate with the defendant company on your behalf
* Represent you in court and other forums
* Help recover a settlement or verdict award
Get the Answers and Legal Help You Need
Whether you're experiencing the early symptoms of mesothelioma or are at a more advanced stage of the disease, or if you’ve lost a loved one to this devastating disease, consulting an experienced mesothelioma attorney will give you more insight into your options and your best course of action.
Contact a mesothelioma lawyer today to arrange a private consultation, and get the answers and legal help you need.
Recovering the Costs of Mesothelioma
The human costs of a chronic and life-threatening disease such as mesothelioma can be staggering. Years of mesothelioma treatment, medical costs, and hospice care can run into the tens of thousands of dollars, and few patients and their families are able to pay these costs on their own. Health insurance may not cover all the costs. In addition, the loss of a patient's income can be particularly burdensome, and the emotional costs of a potentially fatal disease are difficult to estimate.
Thousands of Americans have contracted mesothelioma after working with or being exposed to products that cause this pernicious disease, and if you are one such victim, you may be eligible for monetary damages from the product's maker or from your employer.
How an Attorney Can Help
Mesothelioma cases are complex matters. It is not necessarily obvious that there is a cause-and-effect link between a product or environment and someone's mesothelioma. An experienced mesothelioma attorney or law firm can help unravel the link between your mesothelioma and its cause.
Losses Due to Mesothelioma
An attorney's guidance is also very helpful when estimating a mesothelioma patient's losses. Such losses often involve:
* Medical costs including hospital care
* Loss of wages and/or earning capacity
* Loss of companionship or a spousal or parental relationship
* Loss of financial support
* Pain and suffering
* Funeral and burial costs
* Out-of-pocket expenses
Protecting Your Legal Rights
The maker of the asbestos product that caused your mesothelioma or the employer where you worked and contracted mesothelioma may not be agreeable to the idea that they should pay the damages you've incurred due to this disease. In such cases, representation by an attorney or law firm can make all the difference in the outcome of your case.
Just as in other types of personal injury cases, a mesothelioma attorney can:
* Investigate your case, including interviewing witnesses and getting documents
* Show the causation between the product or environment and your mesothelioma
* Help you estimate your total losses due to mesothelioma
* Negotiate with the defendant company on your behalf
* Represent you in court and other forums
* Help recover a settlement or verdict award
Get the Answers and Legal Help You Need
Whether you're experiencing the early symptoms of mesothelioma or are at a more advanced stage of the disease, or if you’ve lost a loved one to this devastating disease, consulting an experienced mesothelioma attorney will give you more insight into your options and your best course of action.
Contact a mesothelioma lawyer today to arrange a private consultation, and get the answers and legal help you need.
What is Asbestosis?
Asbestosis is a debilitating and sometimes deadly respiratory disorder caused by inhaling high levels of asbestos fibers, which leads to scarring of the lung tissue and diminished breathing capacity.
Asbestosis Risks
Asbestos fibers were commonly used in insulation and other building materials prior to 1975 when it was discovered to cause serious and potentially fatal diseases such as asbestosis, lung cancer, and mesothelioma.
Individuals with prolonged exposure to asbestos fibers are among those most likely to develop asbestosis and/or other asbestos-related diseases. Also, those who work around asbestos fibers may carry the fibers home on their clothing, increasing the risk to their family members. Not all individuals with a history of asbestos exposure develop asbestosis. However, the key to diminishing the risk is to stop asbestos exposure altogether.
Asbestosis Symptoms
Common symptoms of asbestosis include:
* Coughing
* Chest pain
* Shortness of breath
* Tightness in chest
Other less common symptoms may include nail abnormalities and clubbing of fingers.
Asbestosis Diagnosis and Treatment
The first step a doctor usually takes in diagnosing asbestosis is to listen for a crackling sound in the patient's chest. The doctor may then use a chest x-ray, CT scan of the lungs, or pulmonary function tests to definitively establish a diagnosis of asbestosis.
While no cure for asbestosis is currently available, a number of mesothelioma treatments can help to alleviate symptoms. Some of these supportive treatments include postural drainage, chest percussion, and vibration - all of which serve to remove secretions from the lungs.
To further aid respiration, doctors may prescribe aerosol medications that thin lung secretions or employ the use of oxygen masks.
The prognosis for individuals diagnosed with asbestosis depends on the duration and extent of their asbestos exposure as well as the progression of the disease. Some patients with asbestosis develop complications such as malignant mesothelioma and pleural effusion. Developing mesothelioma significantly decreases an individual's chances of survival. Seventy-five percent of those also diagnosed with malignant mesothelioma die within one year.
Asbestosis Risks
Asbestos fibers were commonly used in insulation and other building materials prior to 1975 when it was discovered to cause serious and potentially fatal diseases such as asbestosis, lung cancer, and mesothelioma.
Individuals with prolonged exposure to asbestos fibers are among those most likely to develop asbestosis and/or other asbestos-related diseases. Also, those who work around asbestos fibers may carry the fibers home on their clothing, increasing the risk to their family members. Not all individuals with a history of asbestos exposure develop asbestosis. However, the key to diminishing the risk is to stop asbestos exposure altogether.
Asbestosis Symptoms
Common symptoms of asbestosis include:
* Coughing
* Chest pain
* Shortness of breath
* Tightness in chest
Other less common symptoms may include nail abnormalities and clubbing of fingers.
Asbestosis Diagnosis and Treatment
The first step a doctor usually takes in diagnosing asbestosis is to listen for a crackling sound in the patient's chest. The doctor may then use a chest x-ray, CT scan of the lungs, or pulmonary function tests to definitively establish a diagnosis of asbestosis.
While no cure for asbestosis is currently available, a number of mesothelioma treatments can help to alleviate symptoms. Some of these supportive treatments include postural drainage, chest percussion, and vibration - all of which serve to remove secretions from the lungs.
To further aid respiration, doctors may prescribe aerosol medications that thin lung secretions or employ the use of oxygen masks.
The prognosis for individuals diagnosed with asbestosis depends on the duration and extent of their asbestos exposure as well as the progression of the disease. Some patients with asbestosis develop complications such as malignant mesothelioma and pleural effusion. Developing mesothelioma significantly decreases an individual's chances of survival. Seventy-five percent of those also diagnosed with malignant mesothelioma die within one year.
Asbestos Lawsuits
Asbestos lawsuits are filed by plaintiffs who have suffered as the result of asbestos-related illness. Plaintiffs in asbestos lawsuits can include the victims of asbestos exposure, or their families or loved ones. Defendants against asbestos lawsuits are those parties considered responsible for the asbestos exposure. In the past, targets of asbestos lawsuits have included:
* Employers
* Asbestos manufacturers
* Asbestos installers
* Landlords
* Leasing agents
Financial Recovery
The purpose of asbestos lawsuits is to recover financial damages that result from asbestos related illness. Possible financial recoveries from asbestos lawsuits include:
* cost of medical bills
* lost wages
* other associated costs
In some asbestos lawsuits, punitive damages (designed to punish the defendant) are also awarded. A few states permit asbestos lawsuits to be filed by people who reasonably expect to develop asbestos-related illnesses. These asbestos lawsuits regulations allow individuals exposed to asbestos to attempt to prepare financially for likely diseases. Many asbestos lawsuits have served to help publicize the adverse health effects of asbestos exposure; increasing numbers of asbestos lawsuits are decided for the plaintiffs as information about asbestos exposure becomes common knowledge.
Although asbestos lawsuits can be complicated at first glance, a number of individuals have benefited from asbestos lawsuits, including families of victims, left with enormous medical and funeral costs. For more about asbestos lawsuits and whether your situation is appropriate for this proceeding, an attorney familiar with asbestos lawsuits may be the appropriate person to consult.
How Can a Mesothelioma Attorney Help?
Mesothelioma attorneys can help victims in recovering funds related to asbestos-caused mesothelioma. Many of the mesothelioma attorneys with experience in this field have successfully claimed costs from those responsible for asbestos exposure. Mesothelioma attorneys can regain medical costs, lost wages, and punitive fees for victims and their families.
A mesothelioma attorney can meet with victims to discuss liability in mesothelioma cases; using their prior experience, mesothelioma attorneys can often predict the likelihood of success of a particular case. A good mesothelioma attorney will have the legal knowledge and connections to pressure reluctant parties into accepting accountability; many mesothelioma attorneys end up enabling their client to collect without ever having to go to trial. Mesothelioma attorneys can also help put their clients in touch with the clients of other mesothelioma attorneys if both parties agree, so that the parties represented by both mesothelioma attorneys may exchange information and supportespecially important with such a rare disease.
Contact an Experienced Attorney
If you or a loved one has suffered from mesothelioma, please Contact a Mesothelioma Attorney to learn more information on mesothelioma and your legal rights!
* Employers
* Asbestos manufacturers
* Asbestos installers
* Landlords
* Leasing agents
Financial Recovery
The purpose of asbestos lawsuits is to recover financial damages that result from asbestos related illness. Possible financial recoveries from asbestos lawsuits include:
* cost of medical bills
* lost wages
* other associated costs
In some asbestos lawsuits, punitive damages (designed to punish the defendant) are also awarded. A few states permit asbestos lawsuits to be filed by people who reasonably expect to develop asbestos-related illnesses. These asbestos lawsuits regulations allow individuals exposed to asbestos to attempt to prepare financially for likely diseases. Many asbestos lawsuits have served to help publicize the adverse health effects of asbestos exposure; increasing numbers of asbestos lawsuits are decided for the plaintiffs as information about asbestos exposure becomes common knowledge.
Although asbestos lawsuits can be complicated at first glance, a number of individuals have benefited from asbestos lawsuits, including families of victims, left with enormous medical and funeral costs. For more about asbestos lawsuits and whether your situation is appropriate for this proceeding, an attorney familiar with asbestos lawsuits may be the appropriate person to consult.
How Can a Mesothelioma Attorney Help?
Mesothelioma attorneys can help victims in recovering funds related to asbestos-caused mesothelioma. Many of the mesothelioma attorneys with experience in this field have successfully claimed costs from those responsible for asbestos exposure. Mesothelioma attorneys can regain medical costs, lost wages, and punitive fees for victims and their families.
A mesothelioma attorney can meet with victims to discuss liability in mesothelioma cases; using their prior experience, mesothelioma attorneys can often predict the likelihood of success of a particular case. A good mesothelioma attorney will have the legal knowledge and connections to pressure reluctant parties into accepting accountability; many mesothelioma attorneys end up enabling their client to collect without ever having to go to trial. Mesothelioma attorneys can also help put their clients in touch with the clients of other mesothelioma attorneys if both parties agree, so that the parties represented by both mesothelioma attorneys may exchange information and supportespecially important with such a rare disease.
Contact an Experienced Attorney
If you or a loved one has suffered from mesothelioma, please Contact a Mesothelioma Attorney to learn more information on mesothelioma and your legal rights!
Mesothelioma Lawsuit
A mesothelioma lawsuit is filed by a victim of mesothelioma in order to recover damages associated with their development of this asbestos related cancer. A mesothelioma case can help a victim seek reparations for medical expenses, lost income and pain and suffering. Mesothelioma develops almost exclusively as a result of toxic exposure to asbestos. This disease can remain latent in a victim for up to forty years; therefore people who were exposed to asbestos in the environment in the 1950s may still be at risk for developing this disease.
Who Is At Risk?
Asbestos has been used to make more than 5000 products in the last few hundred years. Asbestos is a naturally occurring group of minerals that is used to make products such as vehicle brakes and building materials. Asbestos is added to these products because it aids in heat and corrosion resistance. The deadly effects of asbestos have been known for over sixty years, though it continues to be used in a variety of industries. People in the construction, automotive, factory, railroad, shipyard, and custodial industries may all be at risk for the serious health consequences resulting from toxic exposure to asbestos.
What Is Mesothelioma?
Mesothelioma is a rare but fatal cancer that is caused by this harmful exposure to asbestos. Mesothelioma affects the mesothelium that surrounds and protects the internal organs of the body and can affect any organ in the body including the brain, heart and reproductive organs. Pleural mesothelioma is the most common and affects the lining surrounding the lungs. This lining can become cancerous when asbestos is inhaled at toxic levels. Many times the disease is asymptomatic, though symptoms may include a persistent cough, pain in the chest area or shortness of breath.
Mesothelioma also affects the peritoneal lining of the organs in the abdominal cavity. This type of mesothelioma can also remain latent and asymptomatic for several years. If symptoms do develop they might include pain and swelling of the belly, nausea, bowel problems, weight loss, swollen feet, and anemia.
More Common in Men
Mesothelioma affects men three to five times more often than it affects women. It is diagnosed in patients at an average age of 50 to 70 years. Once diagnosed, mesothelioma is fatal. The average survival time after diagnosis is only one year, because the cancer is usually in its advanced stages by the time it is discovered. For people who are diagnosed earlier, about one half survive for two years and twenty percent make it to five years.
Why File a Mesothelioma Lawsuit?
A mesothelioma lawsuit can be filed in the legal system in order to seek reparations for medical expenses, loss of income and pain and suffering associated with the development of this disease. Employers and manufactures of asbestos containing products can be held liable for the injuries that develop as a result, especially when they were aware of the risks associated with the level of exposure they caused or permitted. Contacting a qualified lawyer is often the first step in discovering what your legal rights and options might be in a mesothelioma lawsuit. For more information on a mesothelioma lawsuit, please Contact a Mesothelioma Attorney who is familiar with other mesothelioma cases.
Who Is At Risk?
Asbestos has been used to make more than 5000 products in the last few hundred years. Asbestos is a naturally occurring group of minerals that is used to make products such as vehicle brakes and building materials. Asbestos is added to these products because it aids in heat and corrosion resistance. The deadly effects of asbestos have been known for over sixty years, though it continues to be used in a variety of industries. People in the construction, automotive, factory, railroad, shipyard, and custodial industries may all be at risk for the serious health consequences resulting from toxic exposure to asbestos.
What Is Mesothelioma?
Mesothelioma is a rare but fatal cancer that is caused by this harmful exposure to asbestos. Mesothelioma affects the mesothelium that surrounds and protects the internal organs of the body and can affect any organ in the body including the brain, heart and reproductive organs. Pleural mesothelioma is the most common and affects the lining surrounding the lungs. This lining can become cancerous when asbestos is inhaled at toxic levels. Many times the disease is asymptomatic, though symptoms may include a persistent cough, pain in the chest area or shortness of breath.
Mesothelioma also affects the peritoneal lining of the organs in the abdominal cavity. This type of mesothelioma can also remain latent and asymptomatic for several years. If symptoms do develop they might include pain and swelling of the belly, nausea, bowel problems, weight loss, swollen feet, and anemia.
More Common in Men
Mesothelioma affects men three to five times more often than it affects women. It is diagnosed in patients at an average age of 50 to 70 years. Once diagnosed, mesothelioma is fatal. The average survival time after diagnosis is only one year, because the cancer is usually in its advanced stages by the time it is discovered. For people who are diagnosed earlier, about one half survive for two years and twenty percent make it to five years.
Why File a Mesothelioma Lawsuit?
A mesothelioma lawsuit can be filed in the legal system in order to seek reparations for medical expenses, loss of income and pain and suffering associated with the development of this disease. Employers and manufactures of asbestos containing products can be held liable for the injuries that develop as a result, especially when they were aware of the risks associated with the level of exposure they caused or permitted. Contacting a qualified lawyer is often the first step in discovering what your legal rights and options might be in a mesothelioma lawsuit. For more information on a mesothelioma lawsuit, please Contact a Mesothelioma Attorney who is familiar with other mesothelioma cases.
Mesothelioma Attorney
The mission of a mesothelioma attorney is to help obtain compensation for individuals with this life-threatening cancer. The vast majority of cases of mesothelioma are due to exposure to the carcinogenic mineral asbestos, which was used in thousands of products dating from the 1880s through 1989. Every mesothelioma attorney knows of the devastation that this cancer wreaks on patients and their families.
Asbestos Exposure Is the Culprit
It’s estimated that since the early 1940s, at least three million Americans received high-level exposure to asbestos, often at their workplaces. Others have been exposed to asbestos at home, whether by washing asbestos dust-laden clothing or from the many building materials that contain asbestos. Still others grew up attending schools where asbestos was used in walls, ceilings, flooring, even bricks.
The asbestos industry was aware for over 60 years that their product caused mesothelioma, lung cancer, and asbestosis, but the management of the asbestos companies routinely kept that information from their employees, choosing to maximize company profits and savings at the expense of the employees.
Compensation from Defendant Companies
The medical bills alone for mesothelioma often run into the hundreds of thousands of dollars. Years of lost income or reduced earning capacity further add to the losses. When a loved one with mesothelioma passes away, the loss of support and companionship and the emotional pain and suffering can all be overwhelming. A mesothelioma attorney understands these losses, having helped other victims and their families obtain compensation for their damages.
In fact, mesothelioma attorneys have helped asbestos victims across the country receive millions of dollars worth of compensation for:
* Medical treatments including surgery and chemotherapy
* Hospice and/or palliative care
* Funeral/burial expenses
* Pain and suffering
* Loss of companionship
* More
If you are one of the thousands of patients who have not received fair compensation for your losses, a mesothelioma attorney can help you.
Contact an Experienced Mesothelioma Attorney
Attorneys who represent mesothelioma patients are prepared to discuss your circumstances with you and advise you of your legal rights. Whether you simply have questions or need full legal representation, the first step is to contact a mesothelioma attorney today for a complimentary consultation.
Asbestos Exposure Is the Culprit
It’s estimated that since the early 1940s, at least three million Americans received high-level exposure to asbestos, often at their workplaces. Others have been exposed to asbestos at home, whether by washing asbestos dust-laden clothing or from the many building materials that contain asbestos. Still others grew up attending schools where asbestos was used in walls, ceilings, flooring, even bricks.
The asbestos industry was aware for over 60 years that their product caused mesothelioma, lung cancer, and asbestosis, but the management of the asbestos companies routinely kept that information from their employees, choosing to maximize company profits and savings at the expense of the employees.
Compensation from Defendant Companies
The medical bills alone for mesothelioma often run into the hundreds of thousands of dollars. Years of lost income or reduced earning capacity further add to the losses. When a loved one with mesothelioma passes away, the loss of support and companionship and the emotional pain and suffering can all be overwhelming. A mesothelioma attorney understands these losses, having helped other victims and their families obtain compensation for their damages.
In fact, mesothelioma attorneys have helped asbestos victims across the country receive millions of dollars worth of compensation for:
* Medical treatments including surgery and chemotherapy
* Hospice and/or palliative care
* Funeral/burial expenses
* Pain and suffering
* Loss of companionship
* More
If you are one of the thousands of patients who have not received fair compensation for your losses, a mesothelioma attorney can help you.
Contact an Experienced Mesothelioma Attorney
Attorneys who represent mesothelioma patients are prepared to discuss your circumstances with you and advise you of your legal rights. Whether you simply have questions or need full legal representation, the first step is to contact a mesothelioma attorney today for a complimentary consultation.
Friday, November 7, 2008
Mesothelioma
Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos. In this disease, malignant cells develop in the mesothelium, a protective lining that covers most of the body's internal organs. Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the heart, the pericardium (a sac that surrounds the heart) or tunica vaginalis.
Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in other ways. Washing the clothes of a family member who worked with asbestos can also put a person at risk for developing mesothelioma.Unlike lung cancer, there is no association between mesothelioma and smoking. Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).
The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.
Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in other ways. Washing the clothes of a family member who worked with asbestos can also put a person at risk for developing mesothelioma.Unlike lung cancer, there is no association between mesothelioma and smoking. Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).
The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.
- Pathophysiology
- Staging
- Screening
- Diagnosing mesothelioma
- Signs and symptoms of mesothelioma
- Epidemiology
- Treatment for Mesothelioma
- Notable people who died from mesothelioma
- Legal History
Pathophysiology
The mesothelium consists of a single layer of flattened to cuboidal cells forming the epithelial lining of the serous cavities of the body including the peritoneal, pericardial and pleural cavities. Deposition of asbestos fibres in the parenchyma of the lung may result in the penetration of the visceral pleura from where the fibre can then be carried to the pleural surface, thus leading to the development of malignant mesothelial plaques. The processes leading to the development of peritoneal mesothelioma remain unresolved, although it has been proposed that asbestos fibres from the lung are transported to the abdomen and associated organs via the lymphatic system. Additionally, asbestos fibres may be deposited in the gut after ingestion of sputum contaminated with asbestos fibres.
Pleural contamination with asbestos or other mineral fibres has been shown to cause cancer. Long thin asbestos fibers (blue asbestos, amphibole fibers) are more potent carcinogens than "feathery fibers" (chrysotile or white asbestos fibers). However, there is now evidence that smaller particles may be more dangerous than the larger fibers. They remain suspended in the air where they can be inhaled, and may penetrate more easily and deeper into the lungs. "We probably will find out a lot more about the health aspects of asbestos from [the World Trade Center attack], unfortunately," said Dr. Alan Fein, chief of pulmonary and critical-care medicine at North Shore-Long Island Jewish Health System. Dr. Fein has treated several patients for "World Trade Center syndrome" or respiratory ailments from brief exposures of only a day or two near the collapsed buildings.
Mesothelioma development in rats has been demonstrated following intra-pleural inoculation of phosphorylated chrysotile fibres. It has been suggested that in humans, transport of fibres to the pleura is critical to the pathogenesis of mesothelioma. This is supported by the observed recruitment of significant numbers of macrophages and other cells of the immune system to localised lesions of accumulated asbestos fibres in the pleural and peritoneal cavities of rats. These lesions continued to attract and accumulate macrophages as the disease progressed, and cellular changes within the lesion culminated in a morphologically malignant tumour.
Experimental evidence suggests that asbestos acts as a complete carcinogen with the development of mesothelioma occurring in sequential stages of initiation and promotion. The molecular mechanisms underlying the malignant transformation of normal mesothelial cells by asbestos fibres remain unclear despite the demonstration of its oncogenic capabilities. However, complete in vitro transformation of normal human mesothelial cells to malignant phenotype following exposure to asbestos fibres has not yet been achieved. In general, asbestos fibres are thought to act through direct physical interactions with the cells of the mesothelium in conjunction with indirect effects following interaction with inflammatory cells such as macrophages.
Analysis of the interactions between asbestos fibres and DNA has shown that phagocytosed fibres are able to make contact with chromosomes, often adhering to the chromatin fibres or becoming entangled within the chromosome. This contact between the asbestos fibre and the chromosomes or structural proteins of the spindle apparatus can induce complex abnormalities. The most common abnormality is monosomy of chromosome 22. Other frequent abnormalities include structural rearrangement of 1p, 3p, 9p and 6q chromosome arms.
Common gene abnormalities in mesothelioma cell lines include deletion of the tumor suppressor genes:
* Neurofibromatosis type 2 at 22q12
* P16INK4A
* P14ARF
Asbestos has also been shown to mediate the entry of foreign DNA into target cells. Incorporation of this foreign DNA may lead to mutations and oncogenesis by several possible mechanisms:
* Inactivation of tumor suppressor genes
* Activation of oncogenes
* Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
* Activation of DNA repair enzymes, which may be prone to error
* Activation of telomerase
* Prevention of apoptosis
Asbestos fibers have been shown to alter the function and secretory properties of macrophages, ultimately creating conditions which favour the development of mesothelioma. Following asbestos phagocytosis, macrophages generate increased amounts of hydroxyl radicals, which are normal by-products of cellular anaerobic metabolism. However, these free radicals are also known clastogenic and membrane-active agents thought to promote asbestos carcinogenicity. These oxidants can participate in the oncogenic process by directly and indirectly interacting with DNA, modifying membrane-associated cellular events, including oncogene activation and perturbation of cellular antioxidant defences.
Asbestos also may possess immunosuppressive properties. For example, chrysotile fibres have been shown to depress the in vitro proliferation of phytohemagglutinin-stimulated peripheral blood lymphocytes, suppress natural killer cell lysis and significantly reduce lymphokine-activated killer cell viability and recovery. Furthermore, genetic alterations in asbestos-activated macrophages may result in the release of potent mesothelial cell mitogens such as platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) which in turn, may induce the chronic stimulation and proliferation of mesothelial cells after injury by asbestos fibres.
Pleural contamination with asbestos or other mineral fibres has been shown to cause cancer. Long thin asbestos fibers (blue asbestos, amphibole fibers) are more potent carcinogens than "feathery fibers" (chrysotile or white asbestos fibers). However, there is now evidence that smaller particles may be more dangerous than the larger fibers. They remain suspended in the air where they can be inhaled, and may penetrate more easily and deeper into the lungs. "We probably will find out a lot more about the health aspects of asbestos from [the World Trade Center attack], unfortunately," said Dr. Alan Fein, chief of pulmonary and critical-care medicine at North Shore-Long Island Jewish Health System. Dr. Fein has treated several patients for "World Trade Center syndrome" or respiratory ailments from brief exposures of only a day or two near the collapsed buildings.
Mesothelioma development in rats has been demonstrated following intra-pleural inoculation of phosphorylated chrysotile fibres. It has been suggested that in humans, transport of fibres to the pleura is critical to the pathogenesis of mesothelioma. This is supported by the observed recruitment of significant numbers of macrophages and other cells of the immune system to localised lesions of accumulated asbestos fibres in the pleural and peritoneal cavities of rats. These lesions continued to attract and accumulate macrophages as the disease progressed, and cellular changes within the lesion culminated in a morphologically malignant tumour.
Experimental evidence suggests that asbestos acts as a complete carcinogen with the development of mesothelioma occurring in sequential stages of initiation and promotion. The molecular mechanisms underlying the malignant transformation of normal mesothelial cells by asbestos fibres remain unclear despite the demonstration of its oncogenic capabilities. However, complete in vitro transformation of normal human mesothelial cells to malignant phenotype following exposure to asbestos fibres has not yet been achieved. In general, asbestos fibres are thought to act through direct physical interactions with the cells of the mesothelium in conjunction with indirect effects following interaction with inflammatory cells such as macrophages.
Analysis of the interactions between asbestos fibres and DNA has shown that phagocytosed fibres are able to make contact with chromosomes, often adhering to the chromatin fibres or becoming entangled within the chromosome. This contact between the asbestos fibre and the chromosomes or structural proteins of the spindle apparatus can induce complex abnormalities. The most common abnormality is monosomy of chromosome 22. Other frequent abnormalities include structural rearrangement of 1p, 3p, 9p and 6q chromosome arms.
Common gene abnormalities in mesothelioma cell lines include deletion of the tumor suppressor genes:
* Neurofibromatosis type 2 at 22q12
* P16INK4A
* P14ARF
Asbestos has also been shown to mediate the entry of foreign DNA into target cells. Incorporation of this foreign DNA may lead to mutations and oncogenesis by several possible mechanisms:
* Inactivation of tumor suppressor genes
* Activation of oncogenes
* Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
* Activation of DNA repair enzymes, which may be prone to error
* Activation of telomerase
* Prevention of apoptosis
Asbestos fibers have been shown to alter the function and secretory properties of macrophages, ultimately creating conditions which favour the development of mesothelioma. Following asbestos phagocytosis, macrophages generate increased amounts of hydroxyl radicals, which are normal by-products of cellular anaerobic metabolism. However, these free radicals are also known clastogenic and membrane-active agents thought to promote asbestos carcinogenicity. These oxidants can participate in the oncogenic process by directly and indirectly interacting with DNA, modifying membrane-associated cellular events, including oncogene activation and perturbation of cellular antioxidant defences.
Asbestos also may possess immunosuppressive properties. For example, chrysotile fibres have been shown to depress the in vitro proliferation of phytohemagglutinin-stimulated peripheral blood lymphocytes, suppress natural killer cell lysis and significantly reduce lymphokine-activated killer cell viability and recovery. Furthermore, genetic alterations in asbestos-activated macrophages may result in the release of potent mesothelial cell mitogens such as platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) which in turn, may induce the chronic stimulation and proliferation of mesothelial cells after injury by asbestos fibres.
Staging
Mesothelioma is described as localized if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs.
Screening
There is no universally agreed protocol for screening people who have been exposed to asbestos. Screening tests might diagnose mesothelioma earlier than conventional methods thus improving the survival prospects for patients. The serum osteopontin level might be useful in screening asbestos-exposed people for mesothelioma. The level of soluble mesothelin-related protein is elevated in the serum of about 75% of patients at diagnosis and it has been suggested that it may be useful for screening. Doctors have begun testing the Mesomark assay which measures levels of soluble mesothelin-related proteins (SMRPs) released by diseased mesothelioma cells.
Diagnosing mesothelioma
Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient's medical history. A history of exposure to asbestos may increase clinical suspicion for mesothelioma. A physical examination is performed, followed by chest X-ray and often lung function tests. The X-ray may reveal pleural thickening commonly seen after asbestos exposure and increases suspicion of mesothelioma. A CT (or CAT) scan or an MRI is usually performed. If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe. For pleural fluid this is done by a pleural tap or chest drain, in ascites with an paracentesis or ascitic drain and in a pericardial effusion with pericardiocentesis. While absence of malignant cells on cytology does not completely exclude mesothelioma, it makes it much more unlikely, especially if an alternative diagnosis can be made (e.g. tuberculosis, heart failure).
If cytology is positive or a plaque is regarded as suspicious, a biopsy is needed to confirm a diagnosis of mesothelioma. A doctor removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.
If the cancer is in the abdomen, the doctor may perform a laparoscopy. To obtain tissue for examination, the doctor makes a small incision in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
If cytology is positive or a plaque is regarded as suspicious, a biopsy is needed to confirm a diagnosis of mesothelioma. A doctor removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.
If the cancer is in the abdomen, the doctor may perform a laparoscopy. To obtain tissue for examination, the doctor makes a small incision in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
| Positive | Negative |
| EMA (epithelial membrane antigen) in a membranous distribution | CEA (carcinoembryonic antigen) |
| WT1 (Wilms' tumour 1) | B72.3 |
| Calretinin | MOC-3 1 |
| Mesothelin-1 | CD15 |
| Cytokeratin 5/6 | Ber-EP4 |
| HBME-1 (human mesothelial cell 1) | TTF-1 (thyroid transcription factor-1) |
Signs and symptoms of mesothelioma
Symptoms of mesothelioma may not appear until 20 to 50 years after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space are often symptoms of pleural mesothelioma.
Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions.
Mesothelioma that affects the pleura can cause these signs and symptoms:
* chest wall pain
* pleural effusion, or fluid surrounding the lung
* shortness of breath
* fatigue or anemia
* wheezing, hoarseness, or cough
* blood in the sputum (fluid) coughed up (hemoptysis)
In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.
Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:
* abdominal pain
* ascites, or an abnormal buildup of fluid in the abdomen
* a mass in the abdomen
* problems with bowel function
* weight loss
In severe cases of the disease, the following signs and symptoms may be present:
* blood clots in the veins, which may cause thrombophlebitis
* disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
* jaundice, or yellowing of the eyes and skin
* low blood sugar level
* pleural effusion
* pulmonary emboli, or blood clots in the arteries of the lungs
* severe ascites
A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.
Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions.
Mesothelioma that affects the pleura can cause these signs and symptoms:
* chest wall pain
* pleural effusion, or fluid surrounding the lung
* shortness of breath
* fatigue or anemia
* wheezing, hoarseness, or cough
* blood in the sputum (fluid) coughed up (hemoptysis)
In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.
Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:
* abdominal pain
* ascites, or an abnormal buildup of fluid in the abdomen
* a mass in the abdomen
* problems with bowel function
* weight loss
In severe cases of the disease, the following signs and symptoms may be present:
* blood clots in the veins, which may cause thrombophlebitis
* disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
* jaundice, or yellowing of the eyes and skin
* low blood sugar level
* pleural effusion
* pulmonary emboli, or blood clots in the arteries of the lungs
* severe ascites
A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.
Epidemiology
Incidence
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence rate is approximately one per 1,000,000. The highest incidence is found in Britain, Australia and Belgium: 30 per 1,000,000 per year.[7] For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades.It has been estimated that incidence may have peaked at 15 per 1,000,000 in the United States in 2004. Incidence is expected to continue increasing in other parts of the world. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. Approximately one fifth to one third of all mesotheliomas are peritoneal.
Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States . Between 1973 and 1984, there has been a threefold increase in the diagnosis of pleural mesothelioma in Caucasian males. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases of mesothelioma are misdiagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.
Risk factors
Working with asbestos is the major risk factor for mesothelioma.Mesothelioma is now known to occur in those who are genetically pre-disposed to it. A history of asbestos exposure exists in almost all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite.
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
The combination of smoking and asbestos exposure significantly increases a person's risk of developing cancer of the airways (lung cancer, bronchial carcinoma). The Kent brand of cigarettes used asbestos in its filters for the first few years of production in the 1950s and some cases of mesothelioma have resulted. Smoking modern cigarettes does not appear to increase the risk of mesothelioma.
Some studies suggest that simian virus 40 (SV40) may act as a cofactor in the development of mesothelioma.
Exposure
Asbestos was known in antiquity, but it wasn't mined and widely used commercially until the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not publicly known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace, and created guidelines for engineering controls and respirators, protective clothing, exposure monitoring, hygiene facilities and practices, warning signs, labeling, recordkeeping, and medical exams. By contrast, the British Government's Health and Safety Executive (HSE) states formally that any threshold for mesothelioma must be at a very low level and it is widely agreed that if any such threshold does exist at all, then it cannot currently be quantified. For practical purposes, therefore, HSE does not assume that any such threshold exists. People who work with asbestos wear personal protective equipment to lower their risk of exposure. Recent findings have shown that a mineral called erionite has been known to cause genetically pre-dispositioned individuals to have malignant mesothelioma rates much higher than those not pre-dispositioned genetically. A study in Cappadocia, Turkey has shown that 3 villiages in Turkey have death rates of 51% attributed to erionite related mesothelioma.
Occupational
Exposure to asbestos fibres has been recognised as an occupational health hazard since the early 1900s. Several epidemiological studies have associated exposure to asbestos with the development of lesions such as asbestos bodies in the sputum, pleural plaques, diffuse pleural thickening, asbestosis, carcinoma of the lung and larynx, gastrointestinal tumours, and diffuse mesothelioma of the pleura and peritoneum.
The documented presence of asbestos fibres in water supplies and food products has fostered concerns about the possible impact of long-term and, as yet, unknown exposure of the general population to these fibres. Although many authorities consider brief or transient exposure to asbestos fibres as inconsequential and an unlikely risk factor, some epidemiologists claim that there is no risk threshold. Cases of mesothelioma have been found in people whose only exposure was breathing the air through ventilation systems. Other cases had very minimal (3 months or less) direct exposure.
Commercial asbestos mining at Wittenoom, Western Australia, occurred between 1945 and 1966. A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure, 85 deaths attributable to mesothelioma had occurred by 1985. By 1994, 539 reported deaths due to mesothelioma had been reported in Western Australia.
Paraoccupational secondary exposure
Family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibres, asbestos workers are usually required to shower and change their clothing before leaving the workplace.
Asbestos in buildings
Many building materials used in both public and domestic premises prior to the banning of asbestos may contain asbestos. Those performing renovation works or DIY activities may expose themselves to asbestos dust. In the UK use of Chrysotile asbestos was banned at the end of 1999. Brown and blue asbestos was banned in the UK around 1985. Buildings built or renovated prior to these dates may contain asbestos materials.
Environmental exposures
Incidence of mesothelioma had been found to be higher in populations living near naturally occurring asbestos. For example, in Cappadocia, Turkey, an unprecedented mesothelioma epidemic caused 50% of all deaths in three small villages. Initially, this was attributed to erionite, however, recently, it has been shown that erionite causes mesothelioma mostly in families with a genetic predisposition.
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence rate is approximately one per 1,000,000. The highest incidence is found in Britain, Australia and Belgium: 30 per 1,000,000 per year.[7] For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades.It has been estimated that incidence may have peaked at 15 per 1,000,000 in the United States in 2004. Incidence is expected to continue increasing in other parts of the world. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. Approximately one fifth to one third of all mesotheliomas are peritoneal.
Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States . Between 1973 and 1984, there has been a threefold increase in the diagnosis of pleural mesothelioma in Caucasian males. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases of mesothelioma are misdiagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.
Risk factors
Working with asbestos is the major risk factor for mesothelioma.Mesothelioma is now known to occur in those who are genetically pre-disposed to it. A history of asbestos exposure exists in almost all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite.
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
The combination of smoking and asbestos exposure significantly increases a person's risk of developing cancer of the airways (lung cancer, bronchial carcinoma). The Kent brand of cigarettes used asbestos in its filters for the first few years of production in the 1950s and some cases of mesothelioma have resulted. Smoking modern cigarettes does not appear to increase the risk of mesothelioma.
Some studies suggest that simian virus 40 (SV40) may act as a cofactor in the development of mesothelioma.
Exposure
Asbestos was known in antiquity, but it wasn't mined and widely used commercially until the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not publicly known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace, and created guidelines for engineering controls and respirators, protective clothing, exposure monitoring, hygiene facilities and practices, warning signs, labeling, recordkeeping, and medical exams. By contrast, the British Government's Health and Safety Executive (HSE) states formally that any threshold for mesothelioma must be at a very low level and it is widely agreed that if any such threshold does exist at all, then it cannot currently be quantified. For practical purposes, therefore, HSE does not assume that any such threshold exists. People who work with asbestos wear personal protective equipment to lower their risk of exposure. Recent findings have shown that a mineral called erionite has been known to cause genetically pre-dispositioned individuals to have malignant mesothelioma rates much higher than those not pre-dispositioned genetically. A study in Cappadocia, Turkey has shown that 3 villiages in Turkey have death rates of 51% attributed to erionite related mesothelioma.
Occupational
Exposure to asbestos fibres has been recognised as an occupational health hazard since the early 1900s. Several epidemiological studies have associated exposure to asbestos with the development of lesions such as asbestos bodies in the sputum, pleural plaques, diffuse pleural thickening, asbestosis, carcinoma of the lung and larynx, gastrointestinal tumours, and diffuse mesothelioma of the pleura and peritoneum.
The documented presence of asbestos fibres in water supplies and food products has fostered concerns about the possible impact of long-term and, as yet, unknown exposure of the general population to these fibres. Although many authorities consider brief or transient exposure to asbestos fibres as inconsequential and an unlikely risk factor, some epidemiologists claim that there is no risk threshold. Cases of mesothelioma have been found in people whose only exposure was breathing the air through ventilation systems. Other cases had very minimal (3 months or less) direct exposure.
Commercial asbestos mining at Wittenoom, Western Australia, occurred between 1945 and 1966. A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure, 85 deaths attributable to mesothelioma had occurred by 1985. By 1994, 539 reported deaths due to mesothelioma had been reported in Western Australia.
Paraoccupational secondary exposure
Family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibres, asbestos workers are usually required to shower and change their clothing before leaving the workplace.
Asbestos in buildings
Many building materials used in both public and domestic premises prior to the banning of asbestos may contain asbestos. Those performing renovation works or DIY activities may expose themselves to asbestos dust. In the UK use of Chrysotile asbestos was banned at the end of 1999. Brown and blue asbestos was banned in the UK around 1985. Buildings built or renovated prior to these dates may contain asbestos materials.
Environmental exposures
Incidence of mesothelioma had been found to be higher in populations living near naturally occurring asbestos. For example, in Cappadocia, Turkey, an unprecedented mesothelioma epidemic caused 50% of all deaths in three small villages. Initially, this was attributed to erionite, however, recently, it has been shown that erionite causes mesothelioma mostly in families with a genetic predisposition.
Treatment for Mesothelioma
Treatment of malignant mesothelioma using conventional therapies has not proved successful and patients have a median survival time of 6 - 12 months after presentation[citation needed]. The clinical behaviour of the malignancy is affected by several factors including the continuous mesothelial surface of the pleural cavity which favours local metastasis via exfoliated cells, invasion to underlying tissue and other organs within the pleural cavity, and the extremely long latency period between asbestos exposure and development of the disease.
Surgery
Surgery, either by itself or used in combination with pre- and post-operative adjuvant therapies, has proved disappointing. A pleurectomy/decortication is the most common surgery, in which the lining of the chest is removed. Less common is an extrapleural pneumonectomy (EPP), in which the lung, lining of the inside of the chest, the hemi-diaphragm and the pericardium are removed.
Radiation
For patients with localized disease, and who can tolerate a radical surgery, radiation is often given post-operatively as a consolidative treatment. The entire hemi-thorax is treated with radiation therapy, often given simultaneously with chemotherapy. This approach of using surgery followed by radiation with chemotherapy has been pioneered by the thoracic oncology team at Brigham & Women's Hospital in Boston.[12] Delivering radiation and chemotherapy after a radical surgery has led to extended life expectancy in selected patient populations with some patients surviving more than 5 years. As part of a curative approach to mesothelioma, radiotherapy is also commonly applied to the sites of chest drain insertion, in order to prevent growth of the tumor along the track in the chest wall.
Although mesothelioma is generally resistant to curative treatment with radiotherapy alone, palliative treatment regimens are sometimes used to relieve symptoms arising from tumor growth, such as obstruction of a major blood vessel. Radiation therapy when given alone with curative intent has never been shown to improve survival from mesothelioma. The necessary radiation dose to treat mesothelioma that has not been surgically removed would be very toxic.
Chemotherapy
In February 2004, the United States Food and Drug Administration approved pemetrexed (brand name Alimta) for treatment of malignant pleural mesothelioma. Pemetrexed is given in combination with cisplatin. Folic acid is also used to reduce the side-effects of pemetrexed.
Immunotherapy
Treatment regimens involving immunotherapy have yielded variable results. For example, intrapleural inoculation of Bacillus Calmette-Guérin (BCG) in an attempt to boost the immune response, was found to be of no benefit to the patient (while it may benefit patients with bladder cancer). Mesothelioma cells proved susceptible to in vitro lysis by LAK cells following activation by interleukin-2 (IL-2), but patients undergoing this particular therapy experienced major side effects. Indeed, this trial was suspended in view of the unacceptably high levels of IL-2 toxicity and the severity of side effects such as fever and cachexia. Nonetheless, other trials involving interferon alpha have proved more encouraging with 20% of patients experiencing a greater than 50% reduction in tumor mass combined with minimal side effects.
Heated Intraoperative Intraperitoneal Chemotherapy
A procedure known as heated intraoperative intraperitoneal chemotherapy was developed by Paul Sugarbaker at the Washington Cancer Institute.[13] The surgeon removes as much of the tumor as possible followed by the direct administration of a chemotherapy agent, heated to between 40 and 48°C, in the abdomen. The fluid is perfused for 60 to 120 minutes and then drained.
This technique permits the administration of high concentrations of selected drugs into the abdominal and pelvic surfaces. Heating the chemotherapy treatment increases the penetration of the drugs into tissues. Also, heating itself damages the malignant cells more than the normal cells.
Surgery
Surgery, either by itself or used in combination with pre- and post-operative adjuvant therapies, has proved disappointing. A pleurectomy/decortication is the most common surgery, in which the lining of the chest is removed. Less common is an extrapleural pneumonectomy (EPP), in which the lung, lining of the inside of the chest, the hemi-diaphragm and the pericardium are removed.
Radiation
For patients with localized disease, and who can tolerate a radical surgery, radiation is often given post-operatively as a consolidative treatment. The entire hemi-thorax is treated with radiation therapy, often given simultaneously with chemotherapy. This approach of using surgery followed by radiation with chemotherapy has been pioneered by the thoracic oncology team at Brigham & Women's Hospital in Boston.[12] Delivering radiation and chemotherapy after a radical surgery has led to extended life expectancy in selected patient populations with some patients surviving more than 5 years. As part of a curative approach to mesothelioma, radiotherapy is also commonly applied to the sites of chest drain insertion, in order to prevent growth of the tumor along the track in the chest wall.
Although mesothelioma is generally resistant to curative treatment with radiotherapy alone, palliative treatment regimens are sometimes used to relieve symptoms arising from tumor growth, such as obstruction of a major blood vessel. Radiation therapy when given alone with curative intent has never been shown to improve survival from mesothelioma. The necessary radiation dose to treat mesothelioma that has not been surgically removed would be very toxic.
Chemotherapy
In February 2004, the United States Food and Drug Administration approved pemetrexed (brand name Alimta) for treatment of malignant pleural mesothelioma. Pemetrexed is given in combination with cisplatin. Folic acid is also used to reduce the side-effects of pemetrexed.
Immunotherapy
Treatment regimens involving immunotherapy have yielded variable results. For example, intrapleural inoculation of Bacillus Calmette-Guérin (BCG) in an attempt to boost the immune response, was found to be of no benefit to the patient (while it may benefit patients with bladder cancer). Mesothelioma cells proved susceptible to in vitro lysis by LAK cells following activation by interleukin-2 (IL-2), but patients undergoing this particular therapy experienced major side effects. Indeed, this trial was suspended in view of the unacceptably high levels of IL-2 toxicity and the severity of side effects such as fever and cachexia. Nonetheless, other trials involving interferon alpha have proved more encouraging with 20% of patients experiencing a greater than 50% reduction in tumor mass combined with minimal side effects.
Heated Intraoperative Intraperitoneal Chemotherapy
A procedure known as heated intraoperative intraperitoneal chemotherapy was developed by Paul Sugarbaker at the Washington Cancer Institute.[13] The surgeon removes as much of the tumor as possible followed by the direct administration of a chemotherapy agent, heated to between 40 and 48°C, in the abdomen. The fluid is perfused for 60 to 120 minutes and then drained.
This technique permits the administration of high concentrations of selected drugs into the abdominal and pelvic surfaces. Heating the chemotherapy treatment increases the penetration of the drugs into tissues. Also, heating itself damages the malignant cells more than the normal cells.
Notable people who died from mesothelioma
Mesothelioma, though rare, has had a number of notable patients. Hamilton Jordan, Chief of Staff for President Jimmy Carter and life long cancer activist, died in 2008. Australian anti-racism activist Bob Bellear died in 2005. British science fiction writer Michael G. Coney, responsible for nearly 100 works also died in 2005. American film and television actor Paul Gleason, perhaps best known for his portrayal of Principal Richard Vernon in the 1985 film The Breakfast Club, died in 2006. Mickie Most, an English record producer, died of mesothelioma in 2003. Paul Rudolph, an American architect known for his cubist building designs, died in 1997.
Bernie Banton was an Australian workers' rights activist, who fought a long battle for compensation from James Hardie after he contracted mesothelioma after working for that company. He claimed James Hardie knew of the dangers of asbestos before he began work with the substance making insulation for power stations. Mesothelioma eventually took his life along with his brothers and hundreds of James Hardie workers. James Hardie made an undisclosed settlement with Banton only when his mesothelioma had reached its final stages and he was expected to have no more than 48hrs to live. Australian Prime Minister-elect Kevin Rudd mentioned Banton's extended struggle in his acceptance speech after winning the 2007 Australian Federal Election.
Steve McQueen was diagnosed with peritoneal mesothelioma on December 22, 1979. He was not offered surgery or chemotherapy because doctors felt the cancer was too advanced. McQueen sought alternative treatments from clinics in Mexico. He died of a heart attack on November 7, 1980, in Juárez, Mexico, following cancer surgery. He may have been exposed to asbestos while serving with the U.S. Marines as a young adult—asbestos was then commonly used to insulate ships' piping—or from its use as an insulating material in car racing suits. (It is also reported that he worked in a shipyard during World War II, where he might have been exposed to asbestos.[citation needed]
United States Congressman Bruce Vento died of mesothelioma in 2000. The Bruce Vento Hopebuilder is awarded yearly by his wife at the MARF Symposium to persons or organizations who have done the most to support mesothelioma research and advocacy.
After a long period of untreated illness and pain, rock and roll musician and songwriter Warren Zevon was diagnosed with inoperable mesothelioma in the fall of 2002. Refusing treatments he believed might incapacitate him, Zevon focused his energies on recording his final album The Wind including the song "Keep Me in Your Heart," which speaks of his failing breath. Zevon died at his home in Los Angeles, California, on September 7, 2003.
Christie Hennessy, the influential Irish singer-songwriter, died of mesothelioma in 2007, and had stridently refused to accept the prognosis in the weeks before his death.His mesothelioma has been attributed to his younger years spent working on building sites in London.
Bob Miner, one of the founders of Software Development Labs, the forerunner of Oracle Corporation died of mesothelioma in 1994.
Scottish Labour MP John William MacDougall died of mesothelioma on August 13th, 2008, after fighting the disease of two years..
Canberra journalist and news presenter, Peter Leonard also succumbed to the condition on 23 September 2008.
Terrence McCann Olympic gold medalist and longtime Executive Director of Toastmasters, died of mesothelioma on June 7, 2006 at his home in Dana Point, California.
Bernie Banton was an Australian workers' rights activist, who fought a long battle for compensation from James Hardie after he contracted mesothelioma after working for that company. He claimed James Hardie knew of the dangers of asbestos before he began work with the substance making insulation for power stations. Mesothelioma eventually took his life along with his brothers and hundreds of James Hardie workers. James Hardie made an undisclosed settlement with Banton only when his mesothelioma had reached its final stages and he was expected to have no more than 48hrs to live. Australian Prime Minister-elect Kevin Rudd mentioned Banton's extended struggle in his acceptance speech after winning the 2007 Australian Federal Election.
Steve McQueen was diagnosed with peritoneal mesothelioma on December 22, 1979. He was not offered surgery or chemotherapy because doctors felt the cancer was too advanced. McQueen sought alternative treatments from clinics in Mexico. He died of a heart attack on November 7, 1980, in Juárez, Mexico, following cancer surgery. He may have been exposed to asbestos while serving with the U.S. Marines as a young adult—asbestos was then commonly used to insulate ships' piping—or from its use as an insulating material in car racing suits. (It is also reported that he worked in a shipyard during World War II, where he might have been exposed to asbestos.[citation needed]
United States Congressman Bruce Vento died of mesothelioma in 2000. The Bruce Vento Hopebuilder is awarded yearly by his wife at the MARF Symposium to persons or organizations who have done the most to support mesothelioma research and advocacy.
After a long period of untreated illness and pain, rock and roll musician and songwriter Warren Zevon was diagnosed with inoperable mesothelioma in the fall of 2002. Refusing treatments he believed might incapacitate him, Zevon focused his energies on recording his final album The Wind including the song "Keep Me in Your Heart," which speaks of his failing breath. Zevon died at his home in Los Angeles, California, on September 7, 2003.
Christie Hennessy, the influential Irish singer-songwriter, died of mesothelioma in 2007, and had stridently refused to accept the prognosis in the weeks before his death.His mesothelioma has been attributed to his younger years spent working on building sites in London.
Bob Miner, one of the founders of Software Development Labs, the forerunner of Oracle Corporation died of mesothelioma in 1994.
Scottish Labour MP John William MacDougall died of mesothelioma on August 13th, 2008, after fighting the disease of two years..
Canberra journalist and news presenter, Peter Leonard also succumbed to the condition on 23 September 2008.
Terrence McCann Olympic gold medalist and longtime Executive Director of Toastmasters, died of mesothelioma on June 7, 2006 at his home in Dana Point, California.
Legal History
The first lawsuit against asbestos manufacturers was brought in 1929. The parties settled that lawsuit, and as part of the agreement, the attorneys agreed not to pursue further cases. It was not until 1960 that an article published by Wagner et al first officially established mesothelioma as a disease arising from exposure to crocidolite asbestos.[22] The article referred to over 30 case studies of people who had suffered from mesothelioma in South Africa. Some exposures were transient and some were mine workers. In 1962 McNulty reported the first diagnosed case of malignant mesothelioma in an Australian asbestos worker.[23] The worker had worked in the mill at the asbestos mine in Wittenoom from 1948 to 1950.
In the town of Wittenoom, asbestos-containing mine waste was used to cover schoolyards and playgrounds. In 1965 an article in the British Journal of Industrial Medicine established that people who lived in the neighbourhoods of asbestos factories and mines, but did not work in them, had contracted mesothelioma.
Despite proof that the dust associated with asbestos mining and milling causes asbestos related disease, mining began at Wittenoom in 1943 and continued until 1966. In 1974 the first public warnings of the dangers of blue asbestos were published in a cover story called "Is this Killer in Your Home?" in Australia's Bulletin magazine. In 1978 the Western Australian Government decided to phase out the town of Wittenoom, following the publication of a Health Dept. booklet, "The Health Hazard at Wittenoom", containing the results of air sampling and an appraisal of worldwide medical information.
By 1979 the first writs for negligence related to Wittenoom were issued against CSR and its subsidiary ABA, and the Asbestos Diseases Society was formed to represent the Wittenoom victims.
In the town of Wittenoom, asbestos-containing mine waste was used to cover schoolyards and playgrounds. In 1965 an article in the British Journal of Industrial Medicine established that people who lived in the neighbourhoods of asbestos factories and mines, but did not work in them, had contracted mesothelioma.
Despite proof that the dust associated with asbestos mining and milling causes asbestos related disease, mining began at Wittenoom in 1943 and continued until 1966. In 1974 the first public warnings of the dangers of blue asbestos were published in a cover story called "Is this Killer in Your Home?" in Australia's Bulletin magazine. In 1978 the Western Australian Government decided to phase out the town of Wittenoom, following the publication of a Health Dept. booklet, "The Health Hazard at Wittenoom", containing the results of air sampling and an appraisal of worldwide medical information.
By 1979 the first writs for negligence related to Wittenoom were issued against CSR and its subsidiary ABA, and the Asbestos Diseases Society was formed to represent the Wittenoom victims.
Wednesday, October 1, 2008
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Thursday, September 25, 2008
Dhoni gets Khel Ratna Award
THE RAJIV Gandhi Khel Ratna award instituted in the year 1991-1992, recognises sporting talent. The award along with the Dronacharya award is given on the National Sports Day every year, which is incidentally the birthday of former Indian hockey legend Dhyan Chand. It is definitely the highest honour that can be given to a sportsperson in India and for Mahendra Singh Dhoni to get this at such a young age is definitely a huge achievement.
Dhoni has had a dream journey since he made his cricketing debut. After announcing his arrival in cricket with his flamboyant stroke play, this young man went on to capture the hearts of millions of cricket fans in India. The small town boy from Ranchi went on to lead India to its first 20-20 World Cup triumph since the Prudential Cup in 1983.
Dhoni represents the Indian youth of today- flamboyant, aggressive and confidant. He loves bikes and cars, still wakes up to drink milk in the morning and as a Pepsi commercial says was never good in studies. But the transition took place once he was entrusted with a job of responsibility. Since Dhoni has become the captain of the ODI and the 20-20 side of India, he has gone from strength to strength and achieved greater heights. From being a young keeper batsman in world cricket he has gone on to become one of the most shrewd and dependable captains of today. His relaxed approach behind the stumps, instilling confidence in all his players and his positive attitude has won him the respect of all his teammates and former cricketers.
The noticeable difference in Dhoni since his debut has been the change in his batting approach. From being a dasher in the early part of his career to the finisher of the innings, he has succeeded in both. The highlight of his career would definitely be the 20-20 World Cup win in Johannesburg beating Pakistan. It was the perfect gift for a billion plus cricket crazy nation and made up for the World Cup debacle in the Caribbean islands.
Dhoni has become the poster boy of cricket in India and it is only fitting that he got the Rajiv Gandhi Khel Ratna award- an award that has gone to sportsmen who have had tremendous achievements in the international sector. Sachin Tendulkar is the only cricketer to have been awarded with this recognition. The other men who have been given this honour include Vishwanathan Anand, Geet Sethi, Cdr. Homi D. Motivala and Lt. Cdr. P.K.Garg(Yachting), Karnam Malleshwari, Leander Paes and Nameirakpam Kunjarani (Joint), Jyotirmoyee Sikdar, Dhanraj Pillay, Pullela Gopichand, Abhinav Bindra, Anjali Ved Pathak Bhagwat and K M Beenamol, Anju Bobby George, Rajyavardhan Singh Rathore, Pankaj Advani and Manavjit Singh Sandhu.
Dhoni also represents the dreams and the aspirations of the small town people. Players from the major cities and towns had a strong hold over cricket, but this generation is producing players, who are coming from small places like Ranchi, Baroda, Rae Bareli. Dhoni has realised the dreams of many such youngsters who thought that it would not be possible.
Dhoni epitomises the aspirations of millions of young cricketers in India today. He has shown that apart from having the talent he also has the cricketing acumen to make him a successful cricketer. As long as we have a cricketer like Dhoni as captain of the side, you can be rest assured that Indian cricket is in safe hands. He has emerged as one of the greatest sportspersons of this country.
Saturday, August 9, 2008
PHOTOS: Olympics Opening Ceremony Bursts With Color #7
Beijing, China, August 8, 2008—Illuminated Olympic rings take center stage amid a sea of spectators during the three-hour plus opening ceremony of the 2008 Summer Olympic Games.
Held in the iconic National Stadium—also known as the ''Bird's Nest''—,the much-anticipated opening ceremony drew over cheering crowd of over 91,000.
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photograph #1
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