Age and sex associations of 40 autoimmune diseases.

Self-injury by the host's immune system is believed to be a factor in the etiology of many diseases. Much attention has been given to the part played by sex hormones in such processes. Current literature frequently maintains that females are more susceptible than males to autoimmune diseases. In order to gain information about this factor, a tabulation has been made of the sex incidence of 40 autoimmune diseases which occur at different periods of life: childhood, early adult life, mature adult life, and old age. To some extent the tabulations substantiate female preponderance, but in some there is no gender difference, and in others, particularly the autoimmune nephropathies, male preponderance is the rule. Findings in experiments with animal analogues of human autoimmune disease, showing that administration of estrogen augments the manifestations, whereas androgen treatment suppresses them, do not correlate closely with clinical experience.

One hundred years of American internal medicine. A view from the inside.

The term internal medicine began to be used by German writers in the late 19th century to designate a branch of practice incorporating the growing understanding of morbid anatomy, microbiology, physiology, and biochemistry. American practitioners of internal medicine began to take a respected place in world medicine toward the close of the 19th century. Noteworthy changes followed World War II, owing to allocation of large sums of money for biomedical research by governments, philanthropic organizations, and the pharmaceutical industry. Clinical problems in this period shifted in preponderance from acute infections to the chronic diseases that accompany aging. Complex diagnostic procedures, together with a diversity of therapeutic choices, created need for full-time teachers and clinical investigators in medical schools, as well as for subspecialists in practice. The pendulum may have swung too far toward specialization, and in the future a substantial proportion of practitioners of internal medicine will still continue to serve as generalist physicians.

Alleged susceptibility of the elderly to infection.

The widely held notion, common in clinical medicine, that the elderly are more susceptible to infection is discussed critically. Implied but unstated in this sentiment is a premise that host defense mechanisms are less effective in the elderly, or that immune surveillance becomes defective with aging. No clear evidence exists to support these concepts; indeed, available information points to a normally functioning immune system in the elderly. An increased incidence of morbidity and mortality resulting from infection in the elderly does exist, however, and it is suggested that this stems from many of the functional and anatomical deficits which accompany the aging process and therefore predispose the elderly to infection. Examples of these degenerative problems are pulmonary hypoventilation, bronchopulmonary aspiration, immobility, and urinary retention. These conditions can predispose the elderly to infection by common extracellular microorganisms that are the normal flora of the mucosal and skin surfaces of the body. More precise information on the nature of injuries caused by these organisms in the elderly and on the causes of the resulting higher mortality rates in the elderly is required before an increased incidence of infection in the elderly can be attributed to an increase in their susceptibility to infection because of defective immune or host defense mechanisms.