Dilated cardiomyopathy refers to overall enlargement (dilatation) of the heart chambers, especially the ventricles. Although this enlargement is a key part of dilated cardiomyopathy, it is not the initial problem but rather the heart’s own response to a weakness of heart muscle and poor pumping ability. The weakness of the heart muscle in this condition is generalized (“global”); all parts of the myocardium are affected about equally. Enlargement of the heart is the heart’s way of trying to compensate for the weakness of its muscle. This is called a compensatory mechanism.If the heart muscle is weak, it is unable to pump out the same portion of blood that it could at normal strength. But our bodies have an impressive capability of adjusting to changes. Rather than simply “accepting” the limitations of decreased pumping ability, the heart and other organs of the body undergo compensatory changes to try to maximize their efforts.Think of the heart chambers expanding and contracting like a soft plastic bottle being squeezed while being held underwater. It your grip has become weakened you cannot squeeze very much of the water out. Let’s say that at normal strength you could squeeze out60 percent of the water that flowed into the bottle when you let it exp under water. Similarly, a heart may pump out 60 percent of the blood it contained at the end of diastole.*87\252\8*
Clearly, age and race appear to have a significant influence on ‘ whether or not a person gets cancer and what the eventual prognosis may be. As already noted, many possible explanations exist for racial and cultural disparities in incidence and survival of cancer, not the least of which are access to health care and socioeconomic status. Consider the following statistics:
Among Women• The incidence rate for female breast cancer is highest among white women (113 per 100,000) and lowest among American Indian women (33.9 per 100,000). • Black women have the highest incidence rates of colon and rectal cancer (44.9 per 100,000) and lung and bronchus cancer (46.2 per 100,000), followed by whites, Asian/Pacific Islanders, Hispanic Americans, and American Indians. • Black women are more likely to die of breast cancer (31.4 per 100,000) and colon/rectum cancer (20 per 100,000) than are women of any other racial and ethnic group. White and black women have the highest mortality rates of lung and bronchus cancer, followed by American Indian, Asian/Pacific Islander, and Hispanic women.
Among Men• Black men have the highest incidence rates of prostate cancer (223 per 100,000), colon and rectum cancer (58 per 100,000), and lung and bronchus cancer (112 per 100,000).• Black men are at least 50 percent MORE LIKELY to develop prostate cancer than are men of any other racial or ethnic group. Like American Indian women, American Indian men have consistently lower rates of cancer incidence than men of other racial and ethnic groups.• Black men have the highest mortality rates from colon and rectum cancer (28 per 100,000), lung and bronchus cancer (101 per 100,000), and prostate cancer (55 per 100,000). Black men are twice as likely to die of prostate cancer than men of other racial and ethnic groups.*4/277/5*
Perhaps our single most critical early defense system is the skin. Layered to provide an intricate web of barriers, the skin allows few pathogens to enter. Enzymes, complex proteins manufactured by the body that appear in body secretions such as sweat, provide additional protection, destroying microorganisms on skin surfaces by producing inhospitable pH levels. Normal body pH is 7.0, but enzymatic or biochemical changes may cause the body chemistry to become more acidic (pH of less than 7.0), or more alkaline (pH of more than 7.0). In either case, microorganisms that flourish at a selected pH will be weakened or destroyed as these changes occur. A third protection is our frequent slight elevations in body temperature, which create an inhospitable environment for many pathogens. Only when cracks or breaks occur in the skin can pathogens gain easy access to the body.The linings of the body provide yet another protection against pathogens. Mucous membranes in the respiratory tract and other linings of the body trap and engulf invading organisms. Cilia, hair-like projections in the lungs and respiratory tract, sweep unwanted invaders toward body openings, where they are expelled. Tears, nasal secretions, ear wax, and other secretions found at body entrances contain enzymes designed to destroy or neutralize invading pathogens. Finally, any invading organism that manages to breach these initial lines of defense faces a formidable specialized network of defenses thrown up by the immune system.*18/277/5*