Bacterial Interactions With Mucosal Surfaces

Whether it be in the lungs, the urinary bladder, or the intestine, the flourishing of bacteria depends upon their attachment to, and successful interac tions with, mucosal surfaces. The interactive processes in which various types of bacteria engage include attachment and effacement, translocation across epithelial or endothelial barriers either between cells (pericellular route) or through cells (transcellular route), and invasion of host cells. Only in the last decade have these various...

Relatively Common Bacterial Infections Of Aging Humans

Some important infectious diseases and their relative mortality in elderly subjects are shown in Table 2-1 (1). As expected, that list reflects the fact that there are three principal routes of infection respiratory, urinary, and gastrointestinal (GI). The most compelling explanations of the prevalence of those diseases in the elderly are 1) age-associated changes in the structure and function of the respiratory, urinary, and gastrointestinal organs 2) underlying pathological changes resulting...

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The increase that occurred in Japan during that 25 years was profound and Japan now leads the world in life expectancy at birth (2). A similar demographic shift has been occurring in the less-developed regions around the world. In those regions, the life expectancy rose from around age 40 in the early 1950s to an average of about 62 in 1990 (3). The worldwide aging of the population is the consequence of two contributing phenomena a) the increase in life expectancy at birth, and b)...

Theories Of Senescence

Numerous theories to explain senescence have been promulgated. Each of them offers some promise, at least, for understanding the heightened susceptibility of the older population to infections. Here, we briefly review the more substantive theories and later, consider more fully the theories most relevant to infections in the elderly. The theories in their various forms are presented below under four major subheadings. To date, the only known practical method of extending longevity of mammals is...

Agerelated Changes In Macrophages

When the field of immunogerontology was still quite young, it was generally concluded that MPs display no effects of senescence. Now that the field is older, more wisdom has accrued. MPs do, in fact, show signs of aging. The changes in MPs for which the evidence seems most compelling are (a) diminished ability to generate ROI upon stimulation (b) enhanced potential for producing NO upon stimulation (c) altered arachidonic acid metabolism associated, in particular, with elevated intracellular...

Limits On Life Expectancy And Future Prospects

Because we do not understand the mechanisms of biological aging or the reasons for aging, estimating the limits of human life expectancy is highly empirical. There is a strong evolutionary and genetic influence on life expectancy (7-9). The forces of natural selection decrease with advancing age because, in natural populations, few individuals survive past the reproductive ages. Therefore, among the survivors, random mutations (alleles) will accumulate and their detrimental effects will be...

Contents

1 Human Aging Present and Infectious Diseases of the Limits on Life Expectancy and Future Theories of Chapter 2 Aging and Altered Resistance to Relatively Common Bacterial Infections of Aging Humans 20 Selected Examples of Age-Associated Susceptibility to Bacterial Bacterial Interactions with Mucosal Antibiotic Resistance and Bacterial Viral Infections in Aging Protozoan Parasites in Aging Fungal Infections in Aging Chapter 3 Senescence of Natural Innate Resistance to Infection 61 Pattern...

Antibiotic Resistance And Bacterial Variation

Resistance to antibiotics is increasing rapidly among human pathogens as pointed out by many authors (e.g., refs. 65 and 66). The reasons center around one problem the failure to control the human use of antibiotics. Numerous studies have shown that in medicine antibiotics are frequently prescribed unnecessarily or inappropriately. For example, it was estimated that in 1992, 12 million adults who presented bronchitis or upper respiratory infections received prescriptions for antibiotics that...