Oxado

mardi 8 janvier 2008

L'économie

Économie

Un article de Wikipédia, l'encyclopédie libre.

(Redirigé depuis Economie)
Pour les articles homonymes, voir économie (homonymie).

L’économie, ou l’activité économique, (grec ancien : οἰκονομία, « administration d'un foyer »« de οἶκος (maison, dans le sens de patrimoine) et νέμω (administrer) ») est l'activité humaine qui consiste à la production, la distribution, l'échange et la consommation de produits et services. L’économie est étudiée par les sciences économiques et prend appui sur des théories économiques.

On parle également de l'économie comme de la situation économique conjoncturelle d'un pays ou d’une zone, c'est-à-dire de sa position instantanée dans les cycles économiques. L’activité économique est régulée par la politique conjoncturelle des autorités monétaires et du gouvernement. Les administrations publiques mènent par ailleurs des politiques économiques dans le but de modifier le fonctionnement économique d'un pays.

Un des indicateurs économiques principaux est le produit intérieur brut (PIB), qui permet des comparaisons de puissance économique entre pays.

Sommaire

[masquer]

Histoire [modifier]

Article détaillé : Histoire de l'économie.

Pour découper l’histoire de l'économie, l’histoire économique recourt habituellement à une périodisation utilisant la notion de « révolution économique ». On recense essentiellement quatre périodes :

On ajoute parfois une cinquième période, bien qu'elle soit très récente (moins de 50 ans) : l’économie post-industrielle, liée à la « révolution informationnelle ».

Économie par pays, ensembles économiques, et zones [modifier]

Économie par pays [modifier]

Article détaillé : Catégorie:Économie nationale.

Par exemple, l’économie de la France.

par zones et ensembles économiques [modifier]

On étudie également l'économie des régions, de zones ou de continents (voir la catégorie économie régionale, et par exemple l’économie de l'Europe).

Il est de l'intérêt des pays de se regrouper au sein d’ensembles économiques ou monétaires, par exemple de libre-échange, pour favoriser leur développement économique. Parmi les ensembles les plus connus :

Secteurs économiques [modifier]

Article détaillé : Secteur économique.

La production économique peut être répartie entre plusieurs secteurs :

  • le secteur primaire concerne la collecte et l'exploitation directe de ressources naturelles (matériaux, énergie, et certains aliments),
  • le secteur secondaire concerne les industries de transformation (agissant sur une matière) ,
  • le secteur tertiaire regroupe les industries du service (essentiellement immatériel : assurances, intermédiation, formation, études et recherche, administration, services à la personne, sécurité, nettoyage, etc.).

Le crédit

Crédit

Un article de Wikipédia, l'encyclopédie libre.

(Redirigé depuis Credit)

Sommaire

[masquer]

En comptabilité générale [modifier]

Le mot crédit est un terme technique qui désigne une des deux colonnes de la comptabilité en partie double : cette colonne sert à enregistrer l'origine de fonds mis à disposition de l'entreprise soit en provenance de l'extérieur (ex : apports en capital, emprunts, crédits fournisseurs, ...) soit correspondant à une utilisation de richesses existantes dans l'entreprise (règlements faits par les clients, utilisation d'avoirs en banque ou en caisse, les ventes réalisées, ...). Par convention, la colonne "crédit" est toujours celle de droite.

En comptabilité bancaire [modifier]

L'extrait de compte fourni par le banquier fonctionne "à l'envers". Pour la banque, le déposant (nous) est un fournisseur d'argent. Chaque fois que le banquier reçoit notre argent, il le note à la fois au crédit du compte qu'il tient à notre nom et au débit du compte client qu'il tient dans sa propre comptabilité. Nous devenons créanciers de la banque, laquelle est débitrice envers nous.

En finance [modifier]

Le crédit englobe les diverses activités de prêt d'argent, que ce soit sous la forme de contrats de prêts bancaires ou de délais de paiement d'un fournisseur à un client.

Le crédit est généralement porteur d'un intérêt que doit payer le débiteur (le bénéficiaire du crédit, appelé aussi emprunteur) au créancier (celui qui accorde le crédit, appelé aussi prêteur).

L'accord de crédit [modifier]

Le mot "crédit" à la même étymologie que le mot "croire" (en latin, "credo" = je crois, j'ai confiance), c'est donc une activité qui repose sur la confiance, celle que le prêteur accorde à l'emprunteur de qui il attend le remboursement du prêt. De manière générale, plus le prêteur aura confiance dans l'emprunteur, plus il lui prêtera une somme importante avec un faible taux d'intérêt. Inversement, moins l'emprunteur aura de crédit aux yeux du prêteur, plus celui-ci sera frileux, exigera des garanties importantes et prêtera l'argent à un taux d'intérêt élevé.

Des méthodes automatisées de "scoring de crédit" ou credit scoring, consistant à attribuer une note chiffrée à la capacité de remboursement d'un emprunteur à partir de diverses informations (revenus, endettement...) sont utilisées pour faciliter l'analyse pour les opérations de crédit les plus simples (crédit à la consommation, carte de crédit...)

Crédit et intérêts [modifier]

Les intérêts représentent la rémunération du risque du prêteur. En France, la notion d'intérêt s'accompagne d'un taux référent, en l'occurrence ici "limite", qui est le taux d'USURE. Un taux d'usure est attribué à chaque catégorie de prêts, et ce taux correspond, par catégorie, à la moyenne des trois derniers mois des taux pratiqués par l'ensemble des acteurs financiers prêteurs en France, Banques et établissements financiers assimilés.

TEG : le taux effectif global [modifier]

C'est le taux qui est censé représenter le coût réel pour le client usager ; il intêgre les coûts associés OBLIGATOIRES CONTRACTUELLEMENT, à savoir frais de dossiers, commissions diverses, coût de garanties particulières. Dans la pratique, beaucoup d'éléments sont présentés de manière facultative (exemple des assurances) et ne sont donc pas intègrés dans le TEG. Il faut par ailleurs distinguer encore coûts accessoires liés à des services (maintenance par exemple pour un crédit automobile) aux côuts accessoires d'assurance. La pratique actuelle est de développer des produits et solutions de financement s'apparentant à des locations et ne relevant pas de l'obligation de produire le TEG contractuellement. Il y a en ce domaine un cheminement à faire pour que les professionnels produisent un niveau d'information suffisant et clair.

Catégories [modifier]

Les banques, qui sont les principaux fournisseurs de crédit, tant aux particuliers qu'aux entreprises, distinguent généralement les crédits :

  • à court terme (de 1 jour à 2 ans),
  • à moyen terme (de 2 à 7 ans),
  • et à long terme (au-delà).

(détail : voir types de crédits bancaires). Ce découpage n'est pas très rigoureux et varie d'une banque à l'autre.

Par ailleurs on distingue généralement :

Mesothelioma Attorneys

http://www.claimshelp.com/mesotheliomaclaims.htm

Mesothelioma Cancer Support : Providing the most up to date mesothelioma (asbestos cancer) medical information, types, stages, symptoms, treatment and legal advice for malignant mesothelioma patients and their families

Mesothelioma Attorneys:

Making a Selection:

WWW.CLAIMSHELP.COM Advocates for the Insured ä would like to provide the consumer with information on how to consider the selection of an attorney for their mesothelioma claims. We hope the following is informative.

Be selective and ask questions before making a decision to hire a mesothelioma claim Attorney.

What is mesothelioma? Over simplified, mesothelioma has resulted due to human exposure to asbestos during the manufacturing of products that contained asbestos. Companies that manufacture products that contain asbestos have known for over 60 years that asbestos can cause serious diseases such as mesothelioma. Because many manufacturers of products that contained asbestos wanted to increase their profits, the hazards of asbestos were kept out of the public eye. As a consequence this situation endangered their workers.

Laws have been put into effect that help protect the workers who have been harmed by their exposure to asbestos-related products and great sums of money have been set aside to compensate those who have contracted mesothelioma.

Past publications indicate that a typical mesothelioma claim settlement is $1 million. Attorneys may charge fees representing 40% of this amount. Past cases that actually went to trial, have resulted in awards near $6 million and have been increasing over the years.
mesothelioma lawyer is extremely important.

Due to such large settlements and litigation awards, mesothelioma attorneys are very eager to find individuals that suffer from mesothelioma. It is vital that consumers select the right attorney that is best suited for their situation.

Often attorneys have a simple goal of advertising to retain a mesothelioma claimant and simply refer these cases to other law firms. These attorneys may receive part of the fee for their efforts.

Ask your attorney if this is being done in your case. Do not necessarily rule this attorney out.

A good attorney who has the ability to set you in the right direction should not be disregarder. Allowing an attorney who has the knowledge and contacts to direct your mesothelioma claim to the best legal offices may put you in a better position than settling for an attorney who dose not have the experience you need.

Although Attorneys do not provide medical information regarding the aspects of this serious disease (This aspect of your mesothelioma claim is in the hands of the medical professionals who have diagnosed your condition.) the attorney handling your mesothelioma claim should have experience in dealing with claims and litigation involving serious medical issues.

An attorneys personal level of experience in representing mesothelioma patients is important. Find out how many cases the attorney has actually handled. Inquire as to how many mesothelioma claims were settled out of court and how many mesothelioma claims were litigated.

Mesothelioma claims can be complicated. The law firm for which your attorney works should have the staff and the resources to represent you should your individual mesothelioma claim linger in the court system.

It is important to know if the individual attorney that you will be dealing with face to face will be the actual attorney handling your mesothelioma claim from start to finish. This may or may not be the case. Attorneys have different skill levels and different attorneys in a law firm may handle different aspects of your mesothelioma claim or litigation. Ask to meet with them.

Find out what is involved in this kind of claim/lawsuit. You want to get an overview of the process, and what your role will be in it. You also want to get a sense of how good a communicator the attorney who will negotiating your mesothelioma claim is or how experienced the trial attorney is should your mesothelioma claims proceed to a trial.

Fees:

Mesothelioma claims and verdicts bring in big dollars for mesothelioma claimants and also the attorneys handling the mesothelioma claims.

Attorney fees in these cases are generally based on contingency fee contracts, meaning that the attorneys receive a percentage of the settlement or award the mesothelioma claimant recovers if the claim or suit is successful. If the suit is not successful, then the attorneys earn no fee.

It can be very expensive to handle a mesothelioma claim due to the cost of the claim presentation and legal case preparations. Thousands of dollars may be spent on initial costs associated with preparing for the trial, such as travel, hiring expert witnesses, depositions, etc.

Mesothelioma claim expenses are ordinarily paid for by the attorney who represents you and are sometimes treated as advances against the final settlement of your Mesothelioma claim.

A lot is at stake financially in these lawsuits. Therefore, it is ordinarily a good idea to interview a number of attorneys before you make a final decision about who will represent you. Consider trying to get at least two or three recommendations so you can make the best decision for yourself. If you are comfortable with the first attorney that your meet stay with him. For some, your first personal judgment can be your best.

Written by: Douglas L. LaFaive.

Mesothelioma Claims

http://www.scambusters.org/mesothelioma-attorney.html

Selecting a Mesothelioma Attorney: Consumer Tips

Questions to ask when selecting a mesothelioma attorney.

These pages provide consumer tips for how to deal with the financial aspects of selecting a mesothelioma attorney. They do not provide any information regarding the medical aspects of this serious disease.

Since so much is at stake, selecting the right mesothelioma lawyer is very important. According the Wall Street Journal, lawyers say a typical mesothelioma award in a mesothelioma settlement is $1 million, and attorneys get 40% of this amount. If the case actually goes to trial, the average award was $6 million in 2001, which was triple the amount awarded just two years earlier.

So, mesothelioma attorneys are very eager to find mesothelioma patients. And it's vital that patients select the mesothelioma attorneys that are best for them.

A Brief Background on Your Legal Rights Regarding Mesothelioma

Companies that manufacture products that contain asbestos have known for over 60 years that asbestos can cause serious diseases.

Unfortunately, because many of these companies wanted to increase their profits, they kept this information quiet, thereby seriously endangering their workers.

There are now laws that help protect the workers who have been harmed by their exposure to these asbestos-related products.

However, since representing mesothelioma can be so profitable to attorneys, it is important that people who have mesothelioma be especially careful selecting attorneys who are really qualified to represent them. Therefore, we have created a list of...

Important Questions to Ask When Selecting a Mesothelioma Attorney

Question #1 to Ask When Selecting a Mesothelioma Attorney:

What is your personal experience in representing mesothelioma patients? Your goal is to find out how many cases the attorney has actually handled.

You also want to know: how many of these were settled, and how many of these went to trial? What were the results of each case?

You should ask the same questions about his or her law firm. You're goal is to find out about the firm -- is this an area the firm specializes in?

Question #2 to Ask When Selecting a Mesothelioma Attorney:


Next, you want to ask if the lawyer intends to actually handle your case him or herself. Many attorneys simply refer these cases to another law firm and receive part of the fee in exchange. This may not be in your best interest.

Click here for more questions to ask when selecting a mesothelioma lawyer



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Mesothelioma on Wikipedia

Mesothelioma

From Wikipedia, the free encyclopedia

Jump to: navigation, search
Mesothelioma
Classification & external resources
ICD-10 C45.
ICD-9 163
ICD-O: 9050-9055
OMIM 156240
DiseasesDB 8074
MedlinePlus 000115
eMedicine med/1457
MeSH D008654

Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos.[1] 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 chest cavity), but it may also occur in the peritoneum (the lining of the abdominal cavity) or the pericardium (a sac that surrounds the heart).

Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or have been exposed to asbestos dust and fibre in other ways, such as by washing the clothes of a family member who worked with asbestos, or by home renovation using asbestos cement products. Unlike lung cancer, there is no association between mesothelioma and smoking [2].

Contents

[hide]

[edit] Signs and symptoms

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

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:

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.

[edit] Diagnosis

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 opening 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.

Typical immunohistochemistry results
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)

[edit] Screening

There is no universally agreed protocol for screening people who have been exposed to asbestos. However some research indicates that 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.[3]

[edit] 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.

[edit] 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).[4] However, there is now evidence that smaller particles may be more dangerous than the larger fibers.[1][2] 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.[3]

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:

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 fibres 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.

[edit] Epidemiology

[edit] Incidence

Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence is approximately one per 1,000,000. 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.[5] 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 [4]. 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.

[edit] Risk factors

Working with asbestos is the major risk factor for mesothelioma. 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.[6]

[edit] 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.

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 Exposure

Incidence of mesothelioma had been found to be higher in populations living near Naturally Occurring Asbestos (NOA).

[edit] Treatment

Treatment of MM using conventional therapies has not proved successful and patients have a median survival time of 6 - 12 months after presentation. 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.

[edit] 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. It is not possible to remove the entire mesothelium without killing the patient.

[edit] Radiation

Wikibooks

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. [7] 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.

[edit] 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.

[edit] 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.

[edit] Heated Intraoperative Intraperitoneal Chemotherapy

A procedure known as heated intraoperative intraperitoneal chemotherapy was developed by Paul Sugarbaker at the Washington Cancer Institute.[7] 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.

[edit] Prevention & Expectations

What can be done to prevent the disease? Since the 1970s, the Environmental Protection Agency and the Occupational Safety and Health Administration have regulated the asbestos industry in the U.S. In the past, asbestos was used as a fire retardant and an insulator. Other products are now used in its place. The controversy involving exposure to different forms of asbestos continues.

There are two major types of asbestos: chrysotile and amphibole. It is thought that exposure to the amphibole form is more likely to cause mesothelioma. However, chrysotile has been used more frequently, hence many mesotheliomas are caused by chrysotile.

Removal is taking place in schools and other public buildings throughout the U.S. The hope is that these measures will greatly reduce the occurrence of this cancer.

What are the long-term effects of the disease? A mesothelioma is a highly aggressive tumor that is generally deadly. Current treatment of malignant mesothelioma is designed to make the person with cancer comfortable. Although long-term survival cannot usually be expected, the case of famed paleontologist Stephen Jay Gould is a noted exception.

What are the risks to others? Mesothelioma is not contagious and cannot be passed from one person to another. The exposure to the asbestos that caused the cancer occurred many years to several decades before the disease appeared. People who live with asbestos workers have a higher risk of getting this cancer.

What happens once treatment is over? Although mesothelioma is very unpleasant it's still important for person after treatment is over to keep up all follow-up appointments and that's vital because further testing is always needed to check whether cancer is coming back or to examine possible side effects that could be rather unpleasant and what's even worse permanent.

[edit] Notable people that died from mesothelioma

Mesothelioma, though rare, has had a number of notable patients. 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 Mr 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 Mr 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 US Marines as a young adult—asbestos was then commonly used to insulate ships' piping—or because of its use as an insulating material in car racing suits.[8] (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 [9]. His mesothelioma has been attributed to his younger years spent working on building sites in London.[10][11]

Bob Miner, one of the founders of Software Development Labs, the forerunner of Oracle Corporation died of mesothelioma in 1994.

[edit] Notable people that have lived for some time with mesothelioma

Although life expectancy with this disease is typically limited, there are notable survivors. In July 1982, Stephen Jay Gould was diagnosed with peritoneal mesothelioma. After his diagnosis, Gould wrote the "The Median Isn't the Message"[12] for Discover magazine, in which he argued that statistics such as median survival are just useful abstractions, not destiny. Gould lived for another twenty years eventually succumbing to metastatic adenocarcinoma of the lung, not mesothelioma.

Author Paul Kraus was diagnosed with mesothelioma in June 1997 following an umbilical hernia operation. His prognosis was "a few months." He continues to survive using a variety of integrative and complimentary modalities and has written a book about his experience.

[edit] Legal issues

Main article: asbestos and the law

The first lawsuits against asbestos manufacturers were in 1929. Since then, many lawsuits have been filed against asbestos manufacturers and employers, for neglecting to implement safety measures after the links between asbestos, asbestosis, and mesothelioma became known (some reports seem to place this as early as 1898). The liability resulting from the sheer number of lawsuits and people affected has reached billions of dollars.[citation needed] The amounts and method of allocating compensation have been the source of many court cases, and government attempts at resolution of existing and future cases.

[edit] 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.[13] 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.[14] 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.

[edit] References

  1. ^ United States Department of Health and Human Services.
  2. ^ "Cigarette smoking, asbestos exposure, and malignant mesothelioma" by Muscat JE, Wynder EL in Cancer Research (1991) volume 51 pages 2263-7 Entrez PubMed 2015590
  3. ^ "Soluble mesothelin-related protein--a blood test for mesothelioma" by B. W. Robinson, J. Creaney, R. Lake, A. Nowak, A. W. Musk, N. de Klerk, P. Winzell, K. E. Hellstrom and I. Hellstrom in Lung Cancer (2005) volume 49, pages S109-S111 Entrez PubMed 15950789.
  4. ^ "Malignant mesothelioma and occupational exposure to asbestos: a clinicopathological correlation of 1445 cases" by V. L. Roggli, A. Sharma, K. J. Butnor, T. Sporn and R. T. Vollmer in Ultrastruct Pathol (2002) volume 26 pages 55-65 Entrez PubMed 12036093.
  5. ^ "Advances in Malignant Mesothelioma" by Bruce W. S. Robinson and Richard A. Lake in The New England Journal of Medicine (2005) volume 353 pages 1591-1603 Entrez PubMed 16221782.
  6. ^ "SV40 in human tumors: new documents shed light on the apparent controversy" by D. S. MacLachlan in Anticancer Res (2002) volume 22, pages 3495-3499 Entrez PubMed 12552945.
  7. ^ a b "Resection margins, extrapleural nodal status, and cell type determine postoperative long-term survival in trimodality therapy of malignant pleural mesothelioma: results in 183 patients." by D. Sugarbaker in J Thorac Cardiovasc Surg (1999) volume 117, pages 54-63 Entrez PubMed 9869758.
  8. ^ McQueen's Legacy of Laetrile. New York Times (2005-11-15).
  9. ^ RTE radio 1, Playback, 8 December
  10. ^ u.tv
  11. ^ Irish singer Hennessy dies at 62 - BBC News - 11 December 2007
  12. ^ Gould, Stephen Jay. The Median Isn't the Message.
  13. ^ "Diffuse pleural mesothelioma and asbestos exposure in the North Western Cape Province" by J. C. Wagner, C. A. Sleggs and P. Marchand in Br J Ind Med. (1960) volume 17, pages 260-271 Entrez PubMed 13782506.
  14. ^ "Malignant pleural mesothelioma in an asbestos worker" by J. C. McNulty in Med J Aust (1962) volume 49, pages 953-954 Entrez PubMed 13932248.