Estimated prevalence of dementia among elderly black and white community residents

A stratified random sample of 83 black and 81 white community residents aged 65 years and older in a five-county area in the Piedmont region of North Carolina was evaluated for dementia, using the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, and the National Institute of Neurological Disorders and Stroke--Alzheimer's Disease and Related Disorders Association criteria. Of 164 subjects, 26 were found to be demented, resulting in an estimated prevalence rate of dementia in the five-county area of 16% (95% confidence interval, 7.92 to 24.08) for blacks and 3.05% (95% confidence interval, 0 to 6.91) for whites. The estimated prevalence of dementia for white women (2.9%) was similar to that for white men (3.3%), but the rate for black women was distinctly higher than for black men (19.9% and 8.9%, respectively). Blacks were more likely than whites to have a history of stroke, hypertension, and other chronic disorders that might have contributed to the development of dementia. Apart from differences in rates of institutionalization, no other relevant factors were identified that might explain the difference in the prevalence of dementia in these black and white community residents.     

Comparison of two screening tests in Alzheimer's disease. The correlation and reliability of the Mini-Mental State Examination and the modified Blessed test

The Mini-Mental State Examination (MMSE) and the Blessed Orientation-Memory-Concentration test (BOMC), a six-item derivative of the Blessed Information-Memory-Concentration Test, were each administered to 36 patients with a clinical diagnosis of Alzheimer's disease. In 24 patients, both tests were readministered a month later. The correlation between the MMSE and BOMC was -0.83 with a test-retest correlation of 0.89 (MMSE) and 0.77 (BOMC). Factor analysis indicated that the multiple MMSE cognitive components could be explained by two factors, which together accounted for 66% of the variance. These factors are conceptually similar to the components of the BOMC, and so may explain the substantial correlation between the two tests. Since these cognitive status tests seem to be equivalent for Alzheimer patients, the briefer measure (BOMC), which offers additional advantages, may be preferred.     

Complementary use of ultrasound and computed tomography in studies of the pancreas and kidney

113 cases of pancreatic and renal disease studied by both ultrasound and computed tomography (CT) were analyzed retrospectively. CT provided a diagnosis when pancreatic ultrasound was unsuccessful due to overlying bowel gas or obesity and when renal ultrasound was unsuccessful due to obesity, reverberations from ribs, small lesions, or multiple lesions. Conversely, ultrasound provided a diagnosis when CT was unsuccessful due to lack of fat planes or respiratory motion. CT usualy distinguished carcinoma from pancreatitis when ultrasound showed a focal echogenic mass. CT resolved renal cyst from neoplasm when ultrasound showed a mixed echo pattern mass.     

Characterization of nonlymphoid cells derived from rat peripheral lymph

Mesenteric lymphadenectomy in rats is followed by union of peripheral and central lymphatics, allowing the collection of intestine-derived peripheral lymph cells via the thoracic duct for several days. These cells include a proportion of nonlymphoid cells (NLC) that show irregular and heterogeneous surface morphology including long pseudopodia and veils. They stain variably for nonspecific esterase and acid phosphatase and are ATPase-positive. Their nuclei are irregular and some contain cytoplasmic inclusions, some of which show peroxidase activity and/or contain DNA. NLC have a range of densitites generally lower than that of lymphocytes. Freshly collected NLC express the leukocyte-common antigen (defined by monoclonal antibody MRC Ox 1) and Ia antigens (I-A and I-E subregion products defined by monoclonal antibodies) but they show a relative lack of other surface markers normally found on rat B or T lymphocytes (W3/13, W3/25, MRC Ox 12 (sIg), MRC Ox 19) or rat macrophages (FcR, C’R, mannose R, W3/25). In general NLC are only weakly adherent to glass or plastic. Although a subpopulation of NLC appear to have had a phagocytic past, freshly collected NLC fail to phagocytose a variety of test particles in vitro. NLC also appear incapable of pinocytosis in vitro. This heterogeneity may represent distinct subpopulations of NLC or different stages in the development of a single cell lineage. Direct cannulation of mesenteric lacteals shows that the majority of NLC are derived from the small intestine and their precursors appear to be present both in lamina propria and Peyer's patches. Kinetic studies, following irradiation or intravenous tritiated thymidine, show that the majority of NLC turn over rapidly in the intestine with a modal time of 3-5 d. Studies with bone marrow chimeras show that they are derived from a rapidly dividing precursor present in normal bone marrow. NLC occur at very low frequencies in normal thoracic duct lymph at all times following cannulation. The evidence presented suggests that NLC closely resemble mouse lymphoid dendritic cells. This conclusion is supported by evidence already obtained showing that NLC are potent stimulators of the semi-allogeneic rat primary mixed leukocyte reaction. In addition to the ceils resembling dendritic cells rare monocytoid cells are found in thoracic duct lymph of lymphadenectomized specific pathogen-free rats. The proportion of these cells increases greatly when the animals are conventionally housed. It seems probable that the physiological function of NLC is to act as accessory cells in the lymph nodes to which they normally drain. Methods for enriching NLC and thus facilitating analysis of their functions are discussed.     

Predictors of antidepressant use among older adults: have they changed over time?

OBJECTIVE: Antidepressant use increased substantially among older adults with the introduction of the new-generation medications such as the selective serotonin reuptake inhibitors. The authors analyzed data from two follow-up intervals-1986-1987 to 1989-1990 (interval 1) and 1992-1993 to 1996-1997 (interval 2)-from a community-based cohort of 4,162 older adults to determine predictors of future antidepressant use. METHOD: Information on antidepressant use, demographic and health characteristics, and categories of depressive symptoms-positive affect, negative affect, somatic complaints, and interpersonal problems-were obtained. Logistic regression was used to control simultaneously for multiple variables predicting antidepressant use during the two intervals. Repeated-measures logistic regression (with generalized estimating equations) was employed to model the probability of antidepressant use, with adjustment for the effect of time. RESULTS: Prior antidepressant use and white race were strong predictors of future use during both intervals. Negative affect was the only additional significant predictor of use during interval 1. In contrast, low positive affect scores, cognitive impairment, and poorer health were additional significant predictors during interval 2. In a repeated-measures model, race, prior antidepressant use, poor health, low positive affect scores, and somatic complaints varied as predictors over time. Negative affect and cognitive impairment were consistent predictors over time. CONCLUSIONS: The predictors of antidepressant use by older adults changed over time, with health-related measures of quality of life, such as positive affect, health status, and somatic complaints, becoming more prominent as predictors of use.     

Modeling association in longitudinal binary outcomes: a brief review

In order to better understand aging, longitudinal studies are run in which participants are evaluated repeatedly and selected end-points (e.g., score on a cognitive screen, falls, occurrence/reoccurrence of a condition) are examined. The objective of the present paper is primarily to describe the methods available that take into account correlation between binary outcomes, and in particular to model the association of binary outcomes after controlling for covariates by using an implementation of generalized estimating equations (GEE) called 'alternating logistic regression' (ALR). In GEE, association within longitudinal outcomes is accounted for but not estimated. Alternating logistic regression, however, basically enables simultaneous estimation of pair-wise odds ratios of outcomes within a cluster, while accounting for the dependence of the outcome on covariates. A sub-sample (n=2458) from a community-based sample of Duke Established Populations for Epidemiologic Studies of the Elderly is used. In the example used here, logistic regression using GEE and ALR is used to model binary outcomes at three time points (baseline, three and six years later) and to control for covariates in a representative community-based sample 65 years of age and older (n=2458). The outcomes indicate any problem versus no problem on a five-item activities of daily living (ADL) scale in a community sample. The ALR model, however, provides insight into decline in ADL from baseline to each of the time-points whereas GEE does not. In both controlled and uncontrolled analyses, decline in ADL over three and six-year intervals (baseline to three years later, baseline to six years and three years post-baseline to six years post-baseline) is significant.     

A cytokine switch induced by human seminal plasma: an immune modulation with implications for sexually transmitted disease

The immunosuppressive activity of human seminal plasma may be one factor in the aetiology of sexually transmitted disease and could be particularly important for the spread of human immunodeficiency virus (HIV). The advent of virus that can preferentially infect Langerhans cells of the genital mucosa underscores the relevance of seminal plasma effects. Virally infected cells are eradicated by the killing activity of T cells and natural killer (NK) cells and this cytotoxicity is stimulated by IL-12 (previously known as natural killer cell stimulatory factor) and partly inhibited by IL-10 (previously known as cytokine synthesis inhibitory factor). We have examined the effects of human seminal plasma on the production of these key cytokines. Cytokine production was measured in rapidly diluted, fresh, lipopolysaccharide (LPS)-stimulated, whole blood since this provided leukocytes with minimal exposure to prostaglandin. Prostaglandin concentrations and cytokine release were measured by ELISA. Addition of human seminal plasma diluted up to 100,000 times (0.001%) to blood cell cultures led to a marked increase in the IL-10/IL-12 ratio (P <0.02). A dose- dependent increase in the ratio was observed in five separate experiments, from a control value of 1 (no seminal plasma) to a mean value of 80 (1% seminal plasma). This cytokine switch was also seen when seminal plasma was substituted by pure prostaglandin E (PGE) and 19-OH PGE (the main prostaglandin constituent of human seminal plasma). Lipid-extracted seminal plasma was considerably less active at high dilutions than whole seminal plasma at the same dilution. However, its activity could be restored by the addition of synthetic PGE and 19- hydroxy PGE. A stimulation of IL-10 and a decrease in IL-12 in host- defence cells of the lower female reproductive tract will seriously affect the ability of cytotoxic T cells and NK cells to recognise and destroy virally infected cells. In addition, the stimulation of IL-10 will inhibit the release of the anti-HIV activity from CD8+ve cells. The cytokine switch reported here, activated by semen deposition, would exercise a key inhibitory control over vital immune defences in the lower genital tract, with ablation of cell-mediated responses and immunosurveillance.      

Use and cost of outpatient visits of AD patients: CERAD XXII.

OBJECTIVE: To determine the probability, frequency, and cost of outpatient visits of patients with AD in the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) as a function of stage of dementia and institutional status. METHODS: Clinical information on 388 patients with AD enrolled in CERAD who had no serious comorbidities at baseline and for whom the stage of disease and institutional status were known, were linked to Health Care Financing Administration Physician/Supplier and Outpatient Standard Analytic (institutional outpatient) files for 1991 through 1995. None was registered in a health maintenance organization. Repeated measures regression models were used to examine the relationship of stage of disease to probability, frequency, and cost of outpatient visits for institutionalized and noninstitutionalized patients, with demographic characteristics and calendar time controlled. RESULTS: The annual proportion of patients with AD and a Medicare-reimbursed outpatient visit ranged from 81% to 95% and was not related to stage of dementia or institutional status. Among those with at least one outpatient visit, however, those living at home had fewer visits than did those in institutions, but their number of visits increased as dementia worsened. Those in institutions had a larger number of outpatient visits, but these did not vary significantly by stage of dementia. Neither location of residence nor stage affected the cost of outpatient visits. CONCLUSION: Among those with an outpatient visit, the frequency of visits and their relationship to stage of disease depends on institutional status.