Bone is made up of a matrix organic and inorganic materials, that harden to trap cells. The inorganic part (bone mineral) is called hydroxyapatite.

The organic part contains collagens that are exported to form Fibrils and include other materials such as:- glycosaminoglycans, osteocalcin, osteonectin, bone sialo protein, osteopontin with a cell attachment factor.

Calcium is used to help strengthen bones and the reformation of broken bones.

Mesothelioma is a type of cancer that invades the body tissues. Primarily, the tissues of the pleural cavities in the chest are lined with mesothelial cells. Also, the heart, abdomen and lungs are lined with these special tissues that create secretions for the function of other organs. Those affected with the cancer mesothelioma have typically been exposed to the inhalation of asbestos. It can take years for the inhalation of asbestos to have a negative effect on the mesothelial cells; however, mesothelioma is typically deadly.

In the 1970s and 1980s, commercial asbestos was used in the building of homes, and was a popular construction material. By the 1990s, the use of asbestos was halted once those affected became ill with cancer and other lung-related problems. Asbestos is still used occasionally, as well as being present in older buildings, and it is important to minimize risks, mainly through prevention.

Those who have a job in construction, coal mining, the railroad or shipbuilding, and factories should be especially concerned, and should encourage their superiors to conduct asbestos testing to ensure safety. Loved ones who live with those in these occupations should also test their homes, as asbestos fibers can make their way into the home on an affected person's clothing. The breathing in of these fibers is still incredibly dangerous.

Also, if one lives in a house that pre-dates 1990s, the house should be checked for asbestos contamination, especially in the insulation. Professional asbestos home testers can be contacted to conduct a test. Home test kits are available as well, but may be dangerous to perform.

Symptoms of mesothelioma may include difficulty breathing, coughing, weight loss, swelling, and muscle fatigue, if the cancer is located in the chest. If the cancer is located in the abdomen, pain, weight loss, and vomiting may be symptoms.

If illness from asbestos is suspected, an MRI or PET scan should be performed. Those with mesothelioma have a better chance of combating the disease through early detection. Blood tests can also be performed, checking for an elevated presence of osteopontin and soluble mesothelin-peptides, which may indicate mesothelioma. Mesothelioma manifests itself as a tumor, so a biopsy may need to be performed; however, not all tumors of the mesothelial cells are malignant or harmful.

There are a number of methods to measure hypoxia in tissues; all have advantages and disadvantages. Three key methods that are relevant to the discussions in this paper are below (for reviews see Refs 142,143,144,145,146,147).

Hypoxia marker drugs

These drugs are 2-nitroimidazoles; after entering cells they undergo 1-2 electron reduction in cells and the reduced drug is a highly reactive free radical that binds to macromolecules, including proteins148. However, when oxygen is present, the drug is oxidized and reverts back to its original state, allowing it to diffuse out of the cell and eventually into the circulation. The rate of protein binding of the reduced drug increases exponentially with a decrease in partial pressure of O2, particularly below 10 mmHg144, 149. The presence of drug-protein adducts can be detected immunohistochemically using antibodies specific for the drug protein adduct. 18F-labelled versions of these drugs are also being developed for positron-emission tomography imaging150, 151.

Hypoxia marker proteins

As HIF1 upregulates the synthesis of many proteins, it has been proposed that identification of such proteins in tissues could be markers of hypoxia. Literally dozens of such proteins have been studied at the preclinical level and in clinical trials152. Some of the more promising endogenous markers include carbonic anhydrase IX (CA9), plasminogen activator inhibitor 1 (PAI1, also known as SERPINE), osteopontin and lysyl oxidase. Combinations of markers might prove to be better predictors of clinical outcome than any single marker153.

Oxygen electrodes and optical probes

Oxygen can be measured in any aqueous media using polarography. In principle, two electrodes are placed into the medium and a polarizing voltage of - 0.7 volts is applied across them. This voltage corresponds to the binding energy of outer shell electrons of oxygen. The electrons are captured by the cathode and the current generated is linearly proportional to oxygen concentration. In practice, the cathode is embedded into a needle that can be introduced into tissues and the anode is placed on the body surface. This technique has been used extensively in preclinical and clinical studies; the presence of hypoxia is an independent predictive factor for poor prognosis in many different tumour types154. Optical probes have also been developed: these are implanted into tissues and contain a fluorochrome that emits fluorescent light with a certain decay rate when illuminated. The rate of fluorescent light decay is proportional to the oxygen concentration in the region of measurement. These probes yield data similar to that of the oxygen electrode6.