Determinants of bone density in 30- to 65-year-old women: a co-twin study.

Reported effects of body composition and lifestyle on bone mineral density in pre-elderly adult women have been inconsistent. In a co-twin study, we measured bone mineral density, lean and fat mass, and lifestyle factors. Analyzing within pair differences, we found negative associations between bone mineral density and tobacco use (2.3-3.3% per 10 pack-years) and positive associations with sporting activity and lean and fat mass. INTRODUCTION: Reported effects of body composition and lifestyle of bone mineral density in pre-elderly adult women have been inconsistent. METHODS: In a co-twin study of 146 female twin pairs aged 30 to 65 years, DXA was used to measure bone mineral density at the lumbar spine, total hip, and forearm, total body bone mineral content, and lean and fat mass. Height and weight were measured. Menopausal status, dietary calcium intake, physical activity, current tobacco use, and alcohol consumption were determined by questionnaire. Within-pair differences in bone measures were regressed through the origin against within-pair differences in putative determinants. RESULTS: Lean mass and fat mass were associated with greater bone mass at all sites. A discordance of 10 pack-years smoking was related to a 2.3-3.3% (SE, 0.8-1.0) decrease in bone density at all sites except the forearm, with the effects more evident in postmenopausal women. In all women, a 0.8% (SE, 0.3) difference in hip bone mineral density was associated with each hour per week difference in sporting activity, with effects more evident in premenopausal women. Daily dietary calcium intake was related to total body bone mineral content and forearm bone mineral density (1.4 +/- 0.7% increase for every 1000 mg). Lifetime alcohol consumption and walking were not consistently related to bone mass. CONCLUSION: Several lifestyle and dietary factors, in particular tobacco use, were related to bone mineral density. Effect sizes varied by site. Characterization of determinants of bone mineral density in midlife and thereafter may lead to interventions that could minimize postmenopausal bone loss and reduce osteoporotic fracture risk.     

Enhanced adhesion of rat neutrophils to Litomosoides carinii microfilariae in the presence of culture supernatants from mitogen-stimulated lymph node cells.

Microfilariae of the rat filarial parasite Litomosoides carinii are killed by normal rat neutrophils which adhere to them in the presence of antibody and complement. Adherence and killing were increased in the presence of the fluid from 48-hr cultures of Con A- or PHA-stimulated normal rat lymph node cells. Both normal and augmented binding were inhibited by cytochalasin B. The factor(s) responsible for increased binding was non-dialysable, susceptible to heat (56 degrees C, 30 min) and freezing and thawing. Its production was inhibited by cycloheximide. Pretreatment of neutrophils with stimulated culture supernatant for 3 hr, followed by washing, also augmented adherence. Similar pretreatment also enhanced phagocytosis of opsonized sheep erythrocytes and latex particles but did not increase candidacidal activity. These experiments suggest that cell-mediated immune reactions leading to lymphokine production may potentiate anti-filarial antibody-dependent cellular cytotoxicity and general phagocytosis by neutrophils.     

Factor associated with diabetic control and utilization patterns in a low-income, older adult population.

The importance to health educators of identification of factors associated with diabetic control is underscored by the prevalence of the disease and its physical, psychological and economic impacts, all of which appear greatest for the poor. An investigation of social, attitudinal, and physical characteristics of 161 low income, predominantly black and female diabetic clinic patients was conducted. Results indicate that the factors associated with poor control (higher mean fasting blood glucose) include being older, lack of belief in control over health, lack of belief in the efficacy of treatment, a belief that diabetes is less serious than three curable illnesses, reported lack of social support in a crisis with diabetes, reported low satisfaction with the clinic, and finally, higher levels of reported problems with the self-care regimen, particularly diet. Moreover, poor control was also significantly associated with an increase in the number of emergency room visits and clinic visits. Increased clinic visits were also significantly associated with younger age, a higher number of prescribed medications and the requirement for insulin therapy, higher knowledge scores, and two health beliefs, the belief that diabetes is more serious than curable illnesses, and the belief that the treatment is likely to help. More frequent emergency room visits were also associated with being white, a higher number of complications of the disease, and more reported problems with self care. A higher number of days hospitalized was significantly associated with more complications, lower satisfaction with the clinic, and lack of belief in control over health. The results suggest the potential usefulness of a number of activities by health educators to positively influence diabetes control and decrease negative utilization patterns, such as hospitalizations. These include education aimed at refocusing health beliefs to emphasize the individual's control outcomes as well as the efficacy of treatment, and behavioral training to increase practical dietary skills. Finally, altering structural characteristics of clinics to better meet patient needs, such as decreasing waiting times, may encourage patient efforts towards diabetic control.     

A Golgi study of the superficial pyramidal cells in the somatosensory cortex of socially reared old adult rats

Following a series of investigations into the appearance of the basal dendritic skirt of pyramidal cells in the supragranular layers of the occipital cortex of the aged rat, we now extend our findings to the somatosensory cortex of these same animals. Specifically, the total number of dendritic branches increased from 414 to 630 days of age due primarily to an increase in third and sixth order branches. The total number of branchless segments which we have suggested may be a vestige of a portion of the dendritic tree was greater in the 414-day-old group than in the 630-day-old group. The dendritic density was also measured in four specific ranges from the soma (0 to 50 μm, 50 to 100 μm, 100 to 150 μm, 150 to 200 μm). Only the 50 to 100-μm range did not show an increase in density with age. By utilizing an orientation factor in the concentric circle analysis, the increase in dendritic density for the range nearest the soma was found to be only in the upper sector of the dendritic domain. This suggests a shift in the dendritic tree away from the region of primary input in layer IV toward the pial surface. We consider that the increases in dendritic parameters measured are a compensatory-type growth as we earlier suggested in the occipital cortex. The functional meaning of this growth remains undetermined.     

The limbic system in Alzheimer's disease. A neuropathologic investigation.

The morphologic alterations of Alzheimer's disease, presenile and senile dementia, have conventionally been associated with the cerebral cortex; however, it is clear that other areas of the brain, notably the hippocampus and amygdala, are involved as well. These structures, together with others such as the fornix, cingulate gyrus, septal nuclei, and mamillary bodies, constitute the limbic system, which has been recognized as the anatomic substrate of memory, emotion, and learning. Disturbances in these modalities are central to the clinical expression of Alzheimer's disease; therefore, the limbic system was studied in its entirety in 9 patients with Alzheimer's disease and in 3 elderly individuals with Down's syndrome, in whom identical morphologic lesions were present. The findings disclose that the limbic system is regularly involved in Alzheimer's disease, to a severe degree and in a distinctively patterned distribution.