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Biomedical subjects

F E Kaiser

Publications and source records attributed to F E Kaiser.

At least 19 recordsLinked to original sources
PubMed1995

Age-related decrease of plasma testosterone in SAMP8 mice: replacement improves age-related impairment of learning and memory.

Corticosterone increases with aging but pregnenolone, dehydroepiandrosterone, and testosterone decrease. The marked decrease in hormones that occurs with aging may contribute to the age-related deficit in learning and memory. Administration of these hormones after training was found to improve long-term memory processing in normal young mice. SAMP8 (P8) mice show an age-related loss of learning and memory for a variety of tasks whereas age-matched control mice of the closely related SAMR1 (R1) strain do not. In this study, we found an age-related decrease in serum testosterone levels of 71% between P8 mice 4 and 12 months of age, but only a 26% decrease between R1 mice of the same ages. The difference between the P8 mice was significant (p < 0.01) and the difference between the R1 mice was not. The decrease in testosterone in 12-month-old P8 mice was not accompanied by gross morphological change in the testes. A SC testosterone implant, sufficient to increase plasma testosterone levels to 414 +/- 25 ng/dl, alleviated impaired learning and memory of a foot shock avoidance task in P8 mice. Castration of 4-month-old P8 mice did not produce a deterioration in learning and memory, indicating that low levels of testosterone per se are not responsible for the impairment seen in 12-month-old P8 mice. This suggests that impaired cognitive functioning of the older P8 mice was due to an interaction of aging and reduced testosterone levels.

Aging↗
PubMed1995

Effect of ovarian steroids on footshock avoidance learning and retention in female mice.

Mice were trained to avoid footshock in a T-maze, with retention tested one week later. Adult male CD-1 mice made their first avoidance during acquisition after fewer trials than random cycling females and with less variability. Female mice in diestrus, when plasma levels of progesterone are low, learned to avoid footshock faster than females in estrus. Ovariectomized (OVX) mice learned in fewer trials than intact random cycling mice. Similar differences, though of a smaller magnitude, were found on the retention tests (i.e. males had better retention than females, mice in diestrus showed better retention 8 days later when in the same part of the estrous cycle than those in estrus, and OVX mice had better retention than cycling females). OVX mice with estrogen implants learned faster than those with progesterone implants or progesterone plus estrogen implants. Hormonal status did not affect sensitivity to acoustic or footshock stimuli as measured by a startle reflex, nor did it affect activity. Pretraining administration of amphetamine, picrotoxin and strychnine attenuated the impairing effect of progesterone on acquisition. The possibility that progesterone may impair learning and to some extent, retention by facilitating the GABAergic activity and thereby reducing arousal level is discussed.

Animals↗
PubMed1995

Age-related impairment in learning but not memory in SAMP8 female mice.

Four-month and 12-month-old SAM (Senescence Accelerated Mouse)-P8 and -R1 female mice, either intact or ovariectomized, were trained to avoid foot shock in a T-maze. Mice were trained until they made their first avoidance. Memory retention of this task was then tested 1 week later. The results indicated that P8, but not R1, female mice whether intact or ovariectomized, showed an age-related learning impairment. This impairment was more apparent in ovariectomized mice, as ovariectomy was associated with a significant reduction in the mean trials to make an avoidance in all groups except 12-month P8 females. Of greatest interest was the absence of any age-related impairment of retention in P8 females. In several previous studies, SAM-P8, but not R1, males showed an age-related impairment of learning and memory. These results indicate that age-related impairment of memory in P8 mice may be inherited in a sex-related manner, and suggests that the mechanisms involved in the development of impaired learning and memory are different.

Aging↗
PubMed1994

Idiopathic CD4+ T lymphopenia in older persons.

OBJECTIVE: Survey of the association of idiopathic CD4+ T cell lymphocytopenia in older persons with protein energy undernutrition and unusual infections/colonizations. METHOD: Retrospective chart analysis. RESULTS: Five subjects aged 61 to 87 years, with unusual organisms and/or either marasmus or kwashiorkor, were noted to have absolute CD4+ and CD8+ T cell lymphocytopenia. All were HIV negative. CONCLUSION: T cell lymphocytopenia may not be a uncommon finding in malnourished older persons, but additional studies to determine its prevalence need to be undertaken. Its role in disease and impact on therapeutic response needs to be further explored.

Age Factors↗
PubMed1993

Cholesterol and the older adult.

The National Cholesterol Education Program and physician/patient awareness of the risks of hypercholesterolemia have resulted in aggressive screening and treatment of elevated cholesterol levels. The "one size fits all" concept has been used as the criterion for intervention. However, this has been promulgated without convincing evidence that levels of cholesterol are as important in older individuals as in those of middle age. Clearly, cholesterol is not the only contributor to cardiovascular risk, and other risk factors such as smoking, hypertension, diabetes, and obesity should not be ignored. To prevent unnecessary intervention, overzealous interpretation of cholesterol values should be avoided.

Aged↗
PubMed1993

Effects of testosterone replacement therapy in old hypogonadal males: a preliminary study.

OBJECTIVE: To examine the effects of testosterone administration to older hypogonadal males (bioavailable testosterone less than 70 ng/dL). DESIGN: Alternate-case controlled trial. SETTING: St. Louis University. PATIENTS: Eight males (mean age 77.6 +/- 2.3 years) who received testosterone and six males (mean age 76 +/- 2.3 years) who served as controls. Selected from alumni of the SHEP trial and attendees at the St. Louis University Impotence Clinic. INTERVENTIONS: Testosterone enanthate (200 mg/mL) was administered intramuscularly to the treatment group every 2 weeks for 3 months. MEASUREMENTS: Serum testosterone, bioavailable testosterone and estradiol, weight, % body fat, right hand muscle strength, balance, cholesterol, HDL-cholesterol, hematocrit, BUN, creatinine, albumin, calcium, PTH, 25(OH) vitamin D, 1,25(OH)2 vitamin D, osteocalcin, prostate-specific antigen, and fructosamine. RESULTS: Males who received testosterone had a significant increase in testosterone and bioavailable testosterone concentration, hematocrit, right hand muscle strength and osteocalcin concentration. They had a decrease in cholesterol (without a change in HDL-cholesterol) levels and decreased BUN/Creatinine ratios. CONCLUSION: These preliminary findings support the need for long term studies of testosterone therapy in older hypogonadal males.

Aged↗
PubMed1993

The effects of thiazide diuretics on calcium metabolism in the aged.

OBJECTIVE: To determine the effects of long-term use of the thiazide diuretic chlorthalidone on serum bone-related biochemical variables in older persons. DESIGN: Cross-sectional comparison. SETTING: Community-dwelling subjects who had participated in the Systolic Hypertension in the Elderly (SHEP) program. PARTICIPANTS: Sixty-six Caucasians (36 male and 30 female), age range 70 to 89 years, of whom 23 were taking a thiazide diuretic. MEASUREMENTS: 25-hydroxyvitamin D (25OHD), parathyroid hormone, osteocalcin, calcitonin, and serum bioavailable testosterone. RESULTS: In both groups, there was a high prevalence of low 25 (OHD) levels (30%). Log 25OHD showed a significant inverse relationship to parathyroid hormone (r = .33, P < 0.05). Thiazide users had lower levels of osteocalcin (P < 0.05) and parathyroid hormone levels (P < 0.05) compared with non-thiazide users. Male thiazide users had decreased bioavailable testosterone levels compared with non-thiazide users (P < 0.05). Serum osteocalcin was significantly related to bioavailable testosterone in men not on thiazide (r = .43, P < 0.05). CONCLUSIONS: Hypovitaminosis D is a common finding in older individuals with associated elevations in parathyroid hormone. Parathyroid hormone and testosterone concentration (in men) are correlated with serum osteocalcin, a measure of osteoblastic activity. Long-term thiazide use alters these relationships and produces a biochemical profile suggestive of decreased bone formation. Reduced bioavailable testosterone may also play a role in these biochemical changes.

Age Factors↗
PubMed1993

A preliminary report of vitamin D and calcium metabolism in older African Americans.

OBJECTIVE: To determine normal serum bone-related biochemical variables in older African-Americans. DESIGN: A convenience sample of older African-Americans who had a health screening and blood testing for calciotropic hormones was compared with white Americans who were recruited at the end of the Systolic Hypertension in the Elderly Program (SHEP) study and were not on a thiazide diuretic. SETTING: Community-dwelling African-Americans who participated in SHEP or who attended one of two mass health screenings. PARTICIPANTS: Thirty-two African-Americans aged 68-93 years and 43 white Americans aged 70-89 years. MEASUREMENTS: Twenty-five hydroxyvitamin D (25OHD), parathyroid hormone, osteocalcin, and calcitonin. RESULTS: Serum 25OHD levels in 38% of the African-American men and 38% of African-American women were less than 8 ng/mL compared with 22% of Caucasian men and 40% of Caucasian women. Serum parathyroid hormone (PTH) was above the normal range in 25% of men and 33% of women of African-American descent and 14% of Caucasian men and 30% of Caucasian women. Serum 25OHD was lower (P < 0.05) in individuals with a previous history of fracture. Serum albumin (P < 0.05), calcitonin (P < 0.05), and osteocalcin (P < 0.05), but not 25OHD, were lower in African-Americans (men and women) when compared with Caucasians (P < 0.05). Serum calcium corrected for albumin was higher in the African-Americans than in the Caucasians (P < 0.05). As previously reported in Caucasians, PTH was inversely related to log 25OHD in African-Americans. Serum osteocalcin was positively correlated to PTH in African-Americans, as previously reported in Caucasians. Log 25OHD correlated inversely with osteocalcin in African-Americans, but this was not seen in Caucasians. CONCLUSIONS: In this limited sample, hypovitaminosis D (as assessed by 25OHD level) with secondary hyperparathyroidism occurred frequently in elderly African-Americans. Osteocalcin, a measure of osteoblast activity, correlated with 25OHD and parathyroid hormone. Osteocalcin serum levels were lower in African-Americans than Caucasians, but serum calcium corrected for albumin was higher in the former compared to the latter.

Aged↗
PubMed1993

Assessment of the older woman.

Our knowledge of the aging woman will continue to grow, and that knowledge will begin with obtaining assessments that are appropriate and complete for this population. It is important to recognize that assessment can lead to improved diagnoses, more appropriate intervention, and improved outcomes, which hopefully will contribute to an improved quality of life for all older women.

Activities of Daily Living↗
PubMed1993

Sexuality and the older woman.

Problems in defining, reporting, and sampling the sexual experience of older women have limited the available information. It should be remembered, however, that an aging population is a sign of societal success, not failure. To date, there has not been a better educated, healthier, wealthier, better-housed, or more self-sufficient generation of older women that at present. Working in the area of sexuality can help improve an important issue in the quality of life for the older woman.

Aging↗
PubMed1992

Sexual function and the older cancer patient.

Cancer and sexual activity are not mutually exclusive or incompatible. Cancer survival is increasing and greater efforts are turning toward enhancement of quality of life. In this regard, sexuality is as important an issue for the older cancer patient as it is for younger patients. It is also clear that there is a pressing need for sexual health information. In one study, 63% of individuals wanted more information on the impact of cancer on sexuality, and 54% wanted to discuss this topic with their physician. Unfortunately, this rarely occurs. A variety of sexual dysfunctions, including loss of libido, impotence, decreased arousability, and orgasmic difficulties, may occur in patients with cancer. This paper explores the effects on sexuality of cancer and normal aging, and reviews some of the therapeutic modalities available to enhance and improve sexual health.

Aging↗
PubMed1991

The effect of recombinant human growth hormone on malnourished older individuals.

Malnutrition in the elderly is often unrecognized and untreated. Reduced secretion of growth hormone (GH) has been suggested as a cause of decreased muscle and bone mass with aging. This pilot study characterized the nutritional response of elderly malnourished subjects to recombinant human GH (rhGH). Subjects were included if they were over 60 years of age, if weight was more than 20% below average body weight (ABW), and if serum albumin concentration was less than 3.8 g/dL. Subjects were divided into two groups: one received 100 micrograms/kg rhGH (Protropin, Genentech) intramuscularly (IM) daily for 21 days; the other received a daily control injection of normal saline (Controls -C) (0.1 mL/kg IM) for the same period of time. During the 3-week period, mid-arm muscle circumference (MAMC) increased an average of 0.6 cm in GH patients but fell in C subjects. There was a non-significant trend to a decreased caloric intake in the control group. Weight increased an average of 4.95 lbs (2.2 kg) in the GH treated group, and decreased an average of 4.9 lbs (2.2 kg) in C subjects (P less than 0.05). Urinary nitrogen retention occurred only in the growth hormone treated subjects (P less than 0.05). Somatomedin C (IGF-1) rose significantly in those treated with GH (P less than 0.05), while there was no change in the control group. There was a significant association between weight change and IGF 1 concentration (r = 0.837, P less than 0.05). Neither clinical edema nor hyperglycemia was noted. These findings suggest that GH may be an effective way of maintaining and enhancing weight in malnourished older individuals.

Aged↗
PubMed1991

Sexuality and impotence in the aging man.

Decreased sexual function commonly occurs with aging but should not be considered a normal event. This article discusses normal physiologic changes and the pathologic events that can lead to erectile difficulties. Proper evaluation can lead to a more appropriate choice of therapeutic agent or device and can benefit the quality of life of the older man and his partner.

Aged↗
PubMed1990

Principles of geriatric care.

The increase in the numbers of elderly in the United States, and their projected continued increase to 21% or more of the population by 2030, has provided impetus for the growth of geriatrics. Recognition of change that is age-related rather than disease-related, and the ways in which the elderly differ from their young counterparts is vital in the care of the elderly. A functional approach and appropriate geriatric assessment have been shown to be beneficial to the individual.

Activities of Daily Living↗