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 fibers in the parenchyma of the lung may result in the penetration of the visceral pleura from where the fiber 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 fibers from the lung are transported to the abdomen and associated organs via the lymphatic system. Additionally, asbestos fibers may be deposited in the gut after ingestion of sputum contaminated with asbestos fibers.Pleural contamination with asbestos or other mineral fibers 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).[6] 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 fibers. It has been suggested that in humans, transport of fibers 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 localized lesions of accumulated asbestos fibers 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 tumor.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 fibers 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 fibers has not yet been achieved. In general, asbestos fibers 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 fibers and DNA has shown that phagocytosed fibers are able to make contact with chromosomes, often adhering to the chromatin fibers or becoming entangled within the chromosome. This contact between the asbestos fiber 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 22q12Asbestos 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 apoptosisAsbestos 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

Signs and symptoms of mesothelioma

Most people are familiar with the pink cancer awareness ribbons that symbolize breast cancer, it seems that these pink beauties are everywhere. But, did you know that there are many other kinds them out there that represent different kinds of cancer that affect women all around the world? You might have seen one or two different colored pins and not even known what they meant. Here are some of the other colors of cancer awareness ribbons so you will know what they mean the next time that you see them:
Teal This color of cancer awareness ribbons are for ovarian cancer. While this cancer isn't as prevalent as breast cancer, its numbers are, unfortunately, on the rise. So, when you see a teal cancer awareness ribbon or pin, you will know what they stand for.
Peach This color of cancer awareness ribbons are for uterine cancer. This type of cancer is also not one that is mentioned much, but is a killer if not detected early enough and fought correctly.
Lavender This color of are for gynecological cancer. This encompasses several different kinds of cancers, from ovarian to cervical, basically anything that has to do with the female reproductive organs falls under this category.Teal and White This color are for cervical cancer. This cancer is hard to detect as well, unless it is screened for, but, when caught early, can be removed and treated.
All of these cancer awareness ribbons and pins are different colors to distinguish between the different types of cancer. It helps for survivors and loved ones to spread their message of hope and survival to those who may not have heard of this particular type of cancer and make sure that other women have their screenings to ensure that they catch these potentially fatal diseases early enough for treatments to be effective. So, the next time that you see different colored cancer awareness ribbon pins, be sure to ask the wearer about it and share their story with you. It might just be the motivation that you need to see your doctor and get screened or to push a friend or family member to get their screening. After all, women are more likely to push their friends and family to get in to see their doctors sooner than later. And, like the breast cancer pins and other types of cancer awareness merchandise, most of the proceeds go toward research and the search for a cure.

mesothelioma

Mesothelioma, more precisely malignant mesothelioma, is a rare form of cancer that develops from the protective lining that covers many of the body's internal organs, the mesothelium . It is usually caused by exposure to asbestosis .Its most common site is the pelura  (outer lining of the lungs  and internal chest wall), but it may also occur in the peritonium  (the lining of the abdominal cavity), the heart,the percardium (a sac that surrounds the heart .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. It has also been suggested that washing the clothes of a family member who worked with asbestos can put a person at risk for developing mesothelioma. Unlike lung cancer, there is no association between mesothelioma and smoking, but smoking greatly increases the risk of other asbestos-induced cancers.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 SACAN, and is confirmed with a biopsy  (tissue sample) and microscopic examination like (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 chemothera py , radiation therapy  or sometimes surgery , the disease carries a poor prognosis. Research about screen test  for the early detection of mesothelioma is ongoing

Peritoneal mesothelioma

Peritoneal mesothelioma is the name given to the cancer  that attacks the lining of the abdomen. This type of cancer affects the lining that protects the contents of the abdomen and which also provides a lubricating fluid to enable the organs to move and work properly.The peritoneum is made of two parts, the visceral and parietal peritoneum. The visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract. Covering the abdominal cavity is the parietal peritoneum Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. 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.Peritoneal mesothelioma has two clinical types which can be differentiated with the help of CT findings, the "dry" type and the "wet". It is classified as "dry" when there are multiple tiny masses or one dominant localized mass and generally little or no ascites. The "wet" type has widespread small nodules, no dominant mass and a presence of ascites. If fluid is found, the process of eliminating it is through paracentesis; however the analysis of this fluid has limited diagnostic significance. Normally, a definitive diagnosis may be obtained through tissue biopsy. Causes Asbestos is a known cause of peritoneal mesothelioma in humans Mesothelioma, more precisely malignant mesothelioma, is a rare form of cancer that develops from the protective lining that covers many of the body's internal organs, the mesothelium. It is usually caused by exposure to asbestos.[1]

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,[2] 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. It has also been suggested that washing the clothes of a family member who worked with asbestos can put a person at risk for developing mesothelioma. Unlike lung cancer, there is no association between mesothelioma and smoking, but smoking greatly increases the risk of other asbestos-induced cancers.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.