Antiaging therapy: an overview

Today's researchers are exploring caloric restriction, cell-based therapies, hormonal therapies, and genetic manipulations. So far, caloric restriction has the soundest basis, and estrogen replacement is among the interventions most widely used. As the human genome is studied, treatments with genetic mechanisms move all the closer to becoming reality.

Muscle metabolism in older subjects using 31P magnetic resonance spectroscopy

We used phosphorus magnetic resonance spectroscopy to study the calf muscles of elderly normal (mean +/- SD) (80.0 +/- 5.12 years), elderly impaired (80.7 +/- 0.58 years), old normal (66.8 +/- 1.92 years), and young normal people (24.6 +/- 4.72 years). Relative levels of inorganic phosphate (Pi), phosphocreatine (PCr), and adenosine triphosphate were measured with a 1.9-tesla, 30-cm bore magnet at rest and following plantra flexon exercise. No differences were found at rest or during recovery from exercise in the elderly normal subjects with respect to gender or the presence of stable medical problems treated with medication. At rest there was an age-related decrease in the ratio of PCr/Pi. After exercise, the time constant of PCr recovery increased with age. A mild 7-week exercise regimen consisting of plantar flexion had no effect on time constant of PCr recovery in the elderly subjects. Four elderly impaired subjects had lower PCr/Pi ratios at rest and slower time constant of PCr recovery after exercise than normal elderly subjects. We conclude that gender and the presence of stable medical problems had no effect on muscle metabolism in the elderly and that the elderly recovered slower than young controls. This slower recovery was not corrected with a mild exercise program.

Using DSM-III criteria to diagnose delirium in elderly general medical patients

Studies of delirium in general medical populations have used criteria for delirium different from current DSM-III or DSM-IIIR criteria of the American Psychiatric Association, or have used DSM-III or DSM-IIIR criteria without operationalizing the components of these criteria. Therefore this prospective study was conducted to establish an approach to operationalizing DSM-III criteria and to determine the incidence and prevalence of delirium. Two hundred thirty-five consecutive subjects age 70 and over admitted to general medicine underwent daily standardized screening. Patients with low scores on screening tests or clinical evidence suggestive of any psychiatric disorder and controls were seen by a psychiatrist, who determined whether delirium was present by applying explicit operational definitions to each component of the DSM-III criteria for delirium. We conclude that the syndrome of delirium as defined by the American Psychiatric Association is prevalent on admission among elderly on general medical services, but the number of cases developing in the hospital is much less than often stated in the literature.

Integrating residency training in geriatrics into existing outpatient curricula

In recent years, the need for increasing the geriatrics component of residency training has been repeatedly addressed; however, there are still many programs that have been unable to meet this need. While alternative sites, such as geriatric evaluation units and nursing homes, may be the ideal sites to teach some aspects of geriatrics, this article argues that the ambulatory care program, required in all residency programs, is the appropriate setting for teaching many of the core skills needed to care for most older adults. Teaching geriatrics in the ambulatory setting, which eliminates the strategic and financial obstacles of developing non-hospital-based sites, can be accomplished with relatively modest additional resources. This article describes the methods used to integrate geriatrics into the ambulatory care component of one internal medicine residency program and the necessary faculty resources as well as the documentation, via chart audit, of the interns' compliance with recommended practice patterns in five categories. With the exception of vaccination status, interns documented 18% or less of possible pieces of information for their patients. While this assessment showed statistically significant improvement in interns' care of older patients after the program intervention, the overall level of performance was still low, underscoring the need for the integration of geriatrics principles in the ambulatory curriculum.

Aging. Programmed change

Is aging due to random change or to a developmental program? This fundamental question motivates much research in gerontology and focuses clinical geriatrics research in different directions, as well. If aging changes are random, the prevalence and natural history of disease in the elderly might be unpredictable. Alternatively, if a developmental program continues to operate in late life, physiologic changes could predispose to certain disease or influence therapy in predictable ways. This article argues that the physiology of aging does result from a genetic program that continues to operate in late life.

Thyroid hormone-carbohydrate interaction in the rat: correlation between age-related reductions in the inducibility of hepatic malic enzyme by triiodo-L-thyronine and a high carbohydrate, fat-free diet

Previous studies from this laboratory have demonstrated an age-related decrease in hepatic malic enzyme (ME) levels and in the response of ME to triiodo-l-thyronine (T(3)). Moreover, we have recently shown a synergistic interaction of T(3) and a high carbohydrate diet in the induction of this enzyme. Studies were therefore undertaken to assess the response of aging rats to a high carbohydrate diet and to test the effect of such dietary manipulations on the responsiveness of ME to T(3). For this purpose, a new radio-immunoassay for ME was developed that, because of a 10-fold higher sensitivity, was particularly suited to the measurement of the low concentrations of hepatic enzyme in older animals. The level of ME per milligram of DNA fell approximately 70% between 1 and 6 mo with only minor further changes demonstrated between 6 and 18 mo. In contrast, the level of ME per milligram DNA in brain was slightly increased in the older animals. Although the absolute increment of hepatic ME resulting from seven daily injections of T(3) (15 mug/100 g body wt) fell with age, the ratio of the ME content per milligram DNA to that observed in control animals maintained on a regular chow diet remained relatively constant with an average value of 11.1. The responsivity of hepatic ME to a high carbohydrate, fat-free diet also decreased with age and could not be attributed exclusively to a reduction in food consumption. The age-related reduction in ME responsivity to dietary stimuli appeared to be due to a reduction in the formation of the specific messenger, (m)RNA for ME as determined in an in vitro translational assay. Our data are consistent with the following hypothesis. There is an age-related decreased hepatic responsivity to a high carbohydrate dietary stimulus. Thyroid hormone administration, as previously postulated by us, interacts with a product or an intermediate of carbohydrate metabolism in a multiplicative fashion. As a consequence, the absolute increment of ME induced by T(3) administration also declines with age.