Old Age Diseases and Aging

In February 1997, the Scottish scientist Ian Wilmut and colleagues at the Roslin Institute announced the birth of a cloned sheep called Dolly in July 1996. They had removed the nucleus from the egg cell of a sheep and replaced it with the nucleus from an adult sheep. Dolly was born from a surrogate mother sheep and is an exact clone of the adult sheep, unlike offspring from the reproductive process, in which the offspring inherits the genes from both parents. 

Dolly suffered from premature arthritis in 2002 and had to be put down in February 2003 at the age of 6V2, because of progressive lung disease common in older sheep. It is not known whether Dolly s premature death is related to cloning her life was about half the normal sheep lifespan of 12 years. 

In November 2003, the members of the Europe Parliament voted to approve embryonic stem cell research, using techniques similar to that adopted for cloning Dolly the sheep, although severe restrictions were put in place. For US scientists, however, the US legislation meant that they were only allowed to performed research using 12 existing sources of the embryonic stem cells and were not allowed to create any new sources. 

We are living in an aging society. The United Nations estimates that the world will have two billion people over the age of 60 by 2050. With the aging population, there are old age diseases that we have to face and treat with more effective therapies. Hypertension, stroke, Alzheimer s disease, heart disease, type II diabetes, Parkinson s disease, and osteoporosis are some examples (Exhibit 11.8). 

For some of these diseases, such as hypertension and heart disease, drugs such as ACE inhibitors and beta-blockers are available for treatment. For some other diseases, such as Alzheimer s disease, more effective drugs have yet to be discovered. For stroke, two late stage (Phase III) trials of NXY-059 and desmoteplase failed to meet the trial criteria. Other clinical trials in progress for ischemic stroke are presented in Table 11.1. 

In April 2003, the members of the Europe Parliament voted to impose severe restrictions on the use of stem cells taken from human embryos. They also called for an outright ban on human reproductive cloning. The decision has to be approved by the 15 Member States before it becomes law. If adopted, it will have a serious effect on embryonic stem cell research. 

A stroke occurs when there is an interruption of blood supply to the brain. An ischemic stroke occurs when a clot prevents blood flow in the brain. A hemorrhagic stroke is when there is a rupture of a blood vessel in the brain. In either case, the brain cells in the affected area die. This area is called an infarct. Medical treatment is required to arrest the damage. More effective treatment can be administered within six hours of the onset of stroke. A stroke may result in weakness, paralysis, impairment of speech and memory, or even death. Medical treatment includes the use of anticoagulants to treat stroke victims. 

This disease is due to the accumulation of jff-amyloid protein in the brain. The protein is believed to trigger brain degeneration through cell deaths of the neurons. Alzheimer s disease is characterized by loss of memory and intellectual performance, and slowness in thought. In the US, a class of drugs called cholinesterase inhibitors is approved to treat Alzheimer s disease. In Europe, a drug called memantine is approved for treatment of Alzheimer s disease, and it is under review by the FDA. 

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In recent years increasing attention has been paid to the possibility of delaying or even reversing the memory loss that accompanies old age or the more tragic loss of human capabilities associated with premature senility - Alzheimer s disease. Progress is hampered by the difficulty of identifying suitable animal tests, and there is presently no reliable therapy. 

Older adults are at increased risk for fluid overload because of the increased incidence of cardiac disease and decreased renal function that may accompany old age. Careful monitoring for signs and symptomsof fluid overload (see Table 58-2) isextremely important when administering fluids to older adults... 

Another special dietary area is the production of gluten-free bread for those who suffer from coeliac disease. As this is a problem of old age and the population is ageing, demand for this sort of product is increasing. 

The so-called normal range of blood and serum vitamin levels is always derived from observations on healthy young subjects. How about a comparison with healthy old subjects, whose percentage in the population is steadily increasing Much may be learned about the cause of the decrease of physiological function and of the increased susceptibility to organic disease in old age, if the role of vitamins as parameter of these alterations were investigated with a view to preventive theory. 

It is important to bear in mind that constipation is common in old age and often has negative effects on both health and quality of life. Constipation is often caused by chronic diseases and by many different drugs. It is best treated by life style changes and drugs that can cause constipation should be avoided or discontinued if possible. 

Both females and males experience age-related problems from the urinary tracts, for example prostate hypertrophy in men and urinary incontinence in women. Kidney problems become more frequent in old age not only because of the normal functional decline but as a result of diseases associated with aging, and their treatment. 

The prevalence rates of schizophrenia are lower in old age than in younger age groups (Copeland et al. 1998). The incidence of Alzheimer s disease with psychosis is much more frequent than the incidence of schizophrenia in old age (Jeste and Finkel 2000). For the frail Alzheimer s patients, medications may induce or aggravate the symptoms. 

It is obviously important not to terminate the study too early for fatal conditions, which are normally strongly age-related. Less obviously, going on for too long in a study can be a mistake, partly because the last few weeks or months may produce relatively few extra data at a disporportionate cost, and partly because diseases of extreme old age may obscure the detection of tumors and other conditions of more interest. For nonfatal conditions, the ideal is to sacrifice the animals when the average prevalence is around 50%. 

Rheumatoid arthritis (RA) is the most common type of rheumatological disorder, with a prevalence of about 1 % worldwide. The onset of the disease may be any time between puberty and old age, with peak times of onset be-... 

There are numerous metabolic diseases, infantile and other tetanies, steatorrhea, osteomalacia, arthritis of old age, epilepsy, etc., in which calcium either is or may be implicated. Each of these diseases needs to be studied against a background of wide variability in calcium needs, probably genetically determined, and involving "normal" individuals as well as those having overt disease. 

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