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Biomedical subjects

G E Smith

Publications and source records attributed to G E Smith.

At least 73 records · Page 4Linked to original sources
PubMed1998

REM sleep behavior disorder and degenerative dementia: an association likely reflecting Lewy body disease.

BACKGROUND: REM sleep behavior disorder (RBD) has been reported with various neurodegenerative disorders, most frequently in disorders with Lewy body pathology. RBD often precedes the onset of PD, and a recent prospective study showed that 38% of patients with RBD eventually developed PD. METHODS: We identified 37 patients with degenerative dementia and a history of bursts of vigorous movement of the arms and legs with vocalization during sleep and associated with dream recall. Patients with and without two or more signs of parkinsonism were compared. Clinical, laboratory, and neuropsychometric features were analyzed, and criteria for the clinical diagnosis of dementia with Lewy bodies (DLB) were applied to all patients. RESULTS: Thirty-four of the 37 patients were male with mean age at onset of 61.5 years for RBD and 68.1 years for cognitive decline. RBD commenced before or concurrently with dementia in all patients but two. Parkinsonism (two or more signs) occurred in 54% of the sample (20/37), with a mean age at onset of 69.1 years. Polysomnography (PSG) confirmed RBD in all patients studied. Neuropsychological testing demonstrated impaired perceptual-organizational skills, verbal fluency, and marked constructional dyspraxia in more than one-half the patients. There were no statistically significant differences in the frequency of clinical features or in neuropsychological performance between patients with and without parkinsonism. Thirty-four patients (92%) met criteria for clinically possible or probable DLB. Three patients were autopsied; all had limbic with or without neocortical Lewy bodies. CONCLUSIONS: We report a group of predominantly male patients with a characteristic association of RBD and degenerative dementia. The clinical and neuropsychometric features of the groups of patients with and without parkinsonism are similar. We hypothesize that the underlying pathology in these patients is DLB.

Aged↗
PubMed1998

Rate of medial temporal lobe atrophy in typical aging and Alzheimer's disease.

OBJECTIVES: To determine the annual rates of volumetric change of the hippocampus and temporal horn in cognitively normal elderly control subjects and individually matched patients with AD, and to test the hypothesis that these rates were different. BACKGROUND: Cross-sectional studies consistently reveal cerebral atrophy in elderly nondemented subjects compared with healthy young adults, and greater atrophy in patients with AD relative to elderly control subjects. However, rates of atrophy are estimated most accurately by performing serial measurements in the same individuals. METHODS: MRI-based volumetric measurements of the hippocampi and temporal horns were performed in 24 cognitively normal subjects aged 70 to 89 years who were individually matched with respect to gender and age with 24 patients with AD. Each subject underwent an MRI protocol twice, separated by 12 months or more. RESULTS: The mean annual rate of hippocampal volume loss among control subjects was -1.55+/-1.38% and the temporal horns increased in volume by 6.15+/-7.69% per year. These rates were significantly greater among AD patients: hippocampus, -3.98+/-1.92% per year, p < 0.001; temporal horn, 14.16+/-8.47% per year, p = 0.002. CONCLUSION: A statistically significant yearly decline in hippocampal volume and an increase in temporal horn volume was identified in elderly control subjects who represent typical aging individuals. These rates were approximately 2.5 times greater in patients with AD than in individually age- and gender-matched control subjects.

Aged↗
PubMed1998

Growth of Cowdria ruminantium in tissue culture endothelial cell lines from wild African mammals.

Endothelial cell cultures were established from several wild African mammalian species. Long-term cultures were established from three ruminants, stable antelope (Hippotragus niger), buffalo (Syncerus caffer), and eland (Tragelaphus oryx), and from an omnivore, the bushpig (Potamochoerus porcus). Cowdria ruminanntium was isolated from plasma of clinically affected animals in these four cell lines and in bovine endothelial cells used routinely for C. ruminantium propagation. Nineteen different strains of C. ruminantium from Africa and the Caribbean region were grown and maintained in these cell lines and their growth was comparable with growth in the bovine endothelial cells. The role of sable antelope, eland, and bushpigs in the epidemiology of heartwater is unknown. However, these results extend the number of cell lines that can be used to isolate and grow C. ruminantium.

Africa↗
PubMed1997

Aging, memory, and mild cognitive impairment.

In recent years, patients who are at high risk for developing Alzheimer's disease (AD) have become a focus of study. Several research groups have identified these patients, developed diagnostic criteria, and followed the patients longitudinally. These patients therefore constitute a clinical entity that is suitable for therapeutic interventions. In this article, we report our 5-year experience at the Mayo Clinic in characterizing a group of patients with mild cognitive impairment. These subjects were recruited from community-dwelling individuals who were receiving general medical care in the Department of Internal Medicine. They received the diagnosis of mild cognitive impairment if they met the following criteria: (a) complaint of defective memory, (b) normal activities of daily living, (c) normal general cognitive function, (d) abnormal memory function for age, and (e) absence of dementia. In following more than 75 of these patients, some of whom have been studied for as long as 5 years, it appears that approximately 10% to 15% of the subjects evolve to AD each year. We therefore evaluated the cognitive profiles of these patients at the time of their initial diagnosis in an attempt to predict who would remain stable and who would evolve to AD. Certain features of learning and memory performance indicated patients who were more likely to progress, but the strongest predictor was their apolipoprotein E status. The patients who possessed an epsilon 4 allele were more likely to convert to AD at a more rapid rate then those who were not carriers. Our results and similar data from other study groups indicate that diagnostic criteria can be defined for patients who are likely to convert to AD; the natural history of these patients is becoming apparent, and variables that predict ultimate conversion can be defined. Consequently, patients with mild cognitive impairment constitute an important group for study, particularly form the aspect of therapeutic interventions.

Aged↗
PubMed1997

Free and cued selective reminding test: MOANS norms.

Age-adjusted norms are presented for persons age 56-98 years on the Free and Cued Selective Reminding Test (FCSRT; Buschke, 1984; Grober & Buschke, 1987). These data were obtained via several research projects that are known collectively as Mayo's Older Americans Normative Studies (MOANS). These norms should be useful when the FCSRT is used as a "stand alone" test. They should also promote accuracy in the comparison of any person's FCSRT performance against his or her functioning on any other tests with MOANS norms. The unique features of the FCSRT are discussed. These norms will, hopefully, enhance the utility of the test when it is used in clinical and research investigations of various amnestic disorders.

Aged↗
PubMed1997

Comorbidity of dementia and psychiatric disorders in older persons.

To further investigate the relationship between psychiatric disorders and dementia in elderly patients, the authors drew a population-based, age-stratified random sample from residents of Rochester, Minnesota, age 65 and older. A trained paramedic completed a 90-minute screening interview, including the Symptom Checklist-90, Mini-Mental State Exam, and Auditory-Verbal Learning Test. Persons failing the screens were interviewed by a psychiatrist and a neurologist. DSM-III-R diagnoses were assigned for dementia and other psychiatric disorders. Of 201 participants, 37 were evaluated further by both neurologist and psychiatrist. One received a psychiatric diagnosis alone. Dementia alone was present in four people. Concurrent psychiatric diagnoses and dementia were found in 17 subjects. Much of the psychopathology found in older persons occurs in people with cognitive impairment. Current diagnostic nosology may not be able to capture the interrelatedness of psychiatric syndromes and cognitive impairment in elderly patients.

Aged↗
PubMed1997

Medial temporal atrophy on MRI in normal aging and very mild Alzheimer's disease.

Magnetic resonance imaging (MRI)-based volumetric measurements of medial temporal lobe (MTL) structures can discriminate between normal elderly control subjects and patients with Alzheimer's disease (AD) of moderate to advanced severity. In terms of clinical utility, however, a more important issue concerns the ability of the technique to differentiate between normal elderly control subjects and AD patients with the very mildest form of the disease. We performed MRI-based volumetric measurements of the hippocampus, parahippocampal gyrus, and amygdala in 126 cognitively normal elderly control subjects and 94 patients with probable AD. The diagnosis of AD was made according to NINDS/ADRDA criteria, and disease severity was categorized by Clinical Dementia Rating (CDR) scores. Patients with CDR 0.5 were classified as very mild, CDR 1 as mild, and CDR 2 as moderate disease severity. Volumes of each structure declined with increasing age in control subjects and did so in parallel for men and women. The volume of each measured MTL structure also declined with age in patients with AD. The volume of each MTL structure was significantly smaller in AD patients than control subjects (p < 0.001). Of the several MTL measures, the total hippocampal volumetric measurements were best at discriminating control subjects from AD patients. The mean hippocampal volumes for AD patients relative to control subjects by severity of disease were as follows: very mild AD (CDR 0.5) -1.75 SD below the control mean, mild AD (CDR 1) -1.99 SD, and moderate AD (CDR 2) -2.22 SD. Age- and gender-adjusted, normalized MRI-based hippocampal volumetric measurements provide a sensitive marker of the MTL neuroanatomic degeneration in AD early in the disease process.

Aging↗
PubMed1997

African-American males and prostate cancer: assessing knowledge levels in the community.

Although the available evidence indicates that African-American males are at risk for developing prostate cancer, little is known about the level of awareness among African Americans about prostate cancer or how receptive they are to screening. This study examined the level of knowledge African-American males have about prostate cancer and the factors affecting knowledge levels. Face-to-face interviews were conducted among a sample of African-American males older than 25 years. All respondents were asked if they knew what prostate cancer was (N = 897), and those older than age 40 (N = 556) answered a series of seven questions related to prostate cancer. An index was created that reflected respondents level of knowledge about prostate cancer. Slightly more than 19% of the sample scored relatively high on the index related to prostate cancer knowledge, but 30% answered three or fewer questions correctly. Income, marital status, education, and type of insurance were significantly related to a respondent's level of knowledge. Having a regular physician and discussing prostate screening with a physician were both positively related to a respondent's level of understanding. This study indicates that African-American men do not have adequate knowledge about prostate cancer. Although many African Americans may be getting the prostate cancer message, educational efforts need to be strengthened to reach the less affluent and the less educated. These findings also raise questions about why more African-American men are not being screened and why more primary care physicians are not discussing prostate cancer with their African-American patients.

Adult↗
PubMed1997

Self-esteem and the relation between risk behavior and perceptions of vulnerability to unplanned pregnancy in college women.

This article reports 2 studies testing the hypothesis that individuals with high self-esteem are more likely than those with low self-esteem to interpret information about their personal vulnerability to health risks in a self-serving manner. Study 1 used an experimental paradigm to demonstrate that self-esteem moderates the influence of review of sexual and contraceptive behavior on college women's perceptions of vulnerability to unplanned pregnancy (N = 125). Study 2 used a longitudinal design to demonstrate that self-esteem also moderates the relation between naturally occurring changes in college women's sexual behavior and changes in their risk perception (N = 273). Together, these studies provide evidence that people with high self-esteem use self-serving cognitive strategies to maintain their risk perceptions.

Adaptation, Psychological↗
PubMed1997

Using word recognition tests to estimate premorbid IQ in early dementia: longitudinal data.

This study examined the utility of word recognition scores for estimating actual Verbal IQ scores obtained from 1-5 years earlier. Participants were 271 persons remaining normal and 24 initially normal persons who developed cognitive impairment over longitudinal follow-up. A previously published regression equation based on education and the American modification of the National Adult Reading Test (Nelson, 1982) was used to estimate Mayo Verbal IQ. In spite of correlating well with prior obtained scores (r = .7) the predicted score tended to overestimate the obtained Mayo Verbal IQ. A revised equation was developed in the normal sample, which improved accuracy of prediction. Among the 24 persons who developed cognitive impairment over a 5-year span, the revised predicted scores provided reasonable estimates of initial Mayo Verbal IQ. To aid in clinical interpretation, a table of the normal frequencies of predicted Mayo Verbal IQ minus contemporaneously obtained Mayo Verbal IQ is provided.

Aged↗
PubMed1996

Predictive value of APOE genotyping in incipient Alzheimer's disease.

The Mayo Alzheimer's Disease Center/Alzheimer's Disease Patient Registry is a prospective, longitudinal project of aging and dementia in a community setting. Over 400 pairs of individuals have been studied through this project, and extensive data on clinical, radiological, neuropathological, and biological variables have been gathered. Previous case-control studies on this group of subjects have documented the role of the apolipoprotein E (APOE) epsilon 4 as a risk factor for dementia. Subsequent analyses between APOE and the age of the patients with dementia have shown that most of the epsilon 4 effect is manifest in subjects under 75 years of age. We have also used this patient resource to study a group of individuals who are at risk for dementia by virtue of having a significant memory impairment. We have designated these patients as having a mild cognitive impairment because they have abnormal memory function but do not reach criteria for dementia. Over the course of several years of follow-up, these subjects evolve to dementia at a rate of approximately 15% per year. The presence of an APOE epsilon 4 carrier status is the best predictor of subsequent development of dementia in these individuals. These studies indicate that APOE is an important risk factor for AD, and in patients with a mild cognitive impairment, APOE may be useful in predicting who is likely to progress to dementia.

Aged↗
PubMed1996

Patterns, trends, and toxicological significance of chlorinated hydrocarbon and mercury contaminants in bald eagle eggs from the Pacific coast of Canada, 1990-1994.

Bald eagle (Haliaeetus leucocephalus) eggs were collected during incubation, 1990-1992, from 16 nests near three bleached-kraft pulp mills, from six nests in the Fraser River estuary and from seven nests at a reference site on the Pacific coast of Canada. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were present in all eggs in a qualitatively similar pattern among sites. Mean concentrations of 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) were significantly higher in eggs collected from near three kraft pulp mill sites in the Strait of Georgia (44, 45, 84 ng/kg) than from the reference area in Johnstone Strait (15 ng/kg). There were few differences among sites in mean organochlorine pesticide levels, indicating the diffuse distribution of those chemicals and the domination of atmospheric inputs. Mean concentrations of total polychlorinated biphenyls (PCBs) were highest in eggs from the Strait of Georgia (4.86 mg/kg) and the PCB congener pattern was significantly different between that area and both the lower Fraser valley and Johnstone Strait. Mean mercury concentrations, which were mainly methyl-mercury, were significantly higher in eggs collected from the lower Fraser Valley (0.258 mg/kg) and Johnstone Strait (0.294 mg/kg) compared to the Strait of Georgia (0.188 mg/kg). Individual and regional variation in concentrations of organochlorine pesticides, PCBs and mercury in eagle eggs were thought to be influenced mainly by dietary differences. Toxicologically, in 1990, mean TCDD-toxic equivalents (TEQs) in bald eagle eggs were about two-fold greater than a lowest-observed-effect level, suggested elsewhere for this species, of 210 ng/kg TEQs. In the Strait of Georgia, PCCDs and PCDFs made a greater contribution to TEQs than non-ortho and mono-ortho PCBs, whereas the reverse was true for eggs outside the strait. Mean eggshell thickness was less than the pre-1947 value at all sites, although there was no significant relationship between eggshell thickness and DDE concentrations. Levels of other organochlorine pesticides and mercury were below those considered to be toxic.

Analysis of Variance↗
PubMed1996

Cause of death in Alzheimer's disease.

Cause of death among 917 of the 959 subjects in a population-based incidence cohort with Alzheimer's disease (AD) during the years 1960 to 1984 was compared to that of an age- and gender-matched control group (n = 703). In general, a summary of the diagnostic codes entered anywhere on a death certificate suggests that control subjects had more cardiovascular disease and neoplasms than did patients, while patients more often had a diagnostic code of bronchitis/pneumonia (P < 0.01). By logistic regression, this difference remained statistically significant after adjusting for age and gender.

Alzheimer Disease↗
PubMed1996

Subjective memory complaints, psychological distress, and longitudinal change in objective memory performance.

Between 1992 and 1993, the Memory Function Questionnaire General Frequency of Forgetting Scale (MFQ-GEN), the Symptom Checklist-90-Revised General Severity Index (GSI), and Mayo Cognitive Factor Scales Learning and Retention (MCFS-LRN and MCFS-RET) current and change scores were obtained for 294 of 397 (74%) participants, ages 55-97 years, originally assessed in a 1988-1990 normative study. In multiple regression modeling, the GSI and MCFS-LRN current score contributed 20% and 3%, respectively, to MFQ-GEN variance. Thus, emotional status was a better predictor of subjective memory ratings than either absolute objective memory performance or objective longitudinal memory change. Persons who developed cognitive impairment over the longitudinal interval reported greater memory problems, but memory complaints had little sensitivity in identifying these persons. In an approximate census sample of these older people, minor memory problems were reported to be frequent but not serious.

Aged↗
PubMed1996

Neutralization of bovine concanavalin-A T cell supernatant-mediated anti-Cowdria ruminantium activity with antibodies specific to interferon gamma but not to tumor necrosis factor.

In an earlier study we demonstrated that Concanavalin-A stimulated bovine T cell supernatants inhibited the growth of Cowdria ruminantium in bovine endothelial cells in vitro. An investigation was conducted to identify the cytokines which were responsible for this growth inhibition. Addition of antiserum against bovine interferon gamma (IFN gamma) reproducibly neutralized the inhibitory effect of the T cell supernatants, whereas addition of antisera against bovine tumor necrosis factor alpha (TNF alpha) had no effect. The inhibitory effect of IFN gamma on C. ruminantium growth was not mediated by the production of nitric oxide as there was no detectable difference in nitric oxide levels in cultures that were supplemented with T cell supernatants compared with those that were not. The IFN gamma mediated anti-C. ruminantium effect highlights the importance of cell mediated immune responses in control of these infections and in particular incriminates the protective role of T cells, or cells that secrete IFN gamma.

Animals↗
PubMed1996

Evaluation of a recombinant hemagglutinin expressed in insect cells as an influenza vaccine in young and elderly adults.

Healthy subjects <45 years old (young adults) or >65 (elderly adults) were randomized in double-blind fashion to receive intramuscularly subvirion trivalent influenza vaccine, placebo, or 15, 45, or 135 microgram of the hemagglutinin (HA) of the influenza A/Beijing/32/92 (H3N2) virus expressed in insect cells by a recombinant baculovirus (rHA0). All vaccines were well tolerated. Both young and elderly adults manifested serum hemagglutination-inhibition, virus neutralizing, and HA-specific IgG ELISA antibody responses to rHA0 vaccine. In young adults given 135 microgram of rHA0, the vaccine was significantly more immunogenic than subvirion influenza vaccine. Elderly adults also had increased antibody responses to 135 microgram of rHA0 compared with subvirion vaccine, but the difference was not statistically significant. These results demonstrate that high-dose rHA0 vaccines are well tolerated and effectively induce both functional and binding serum HA-specific antibody in young and elderly adults.

Adolescent↗
PubMed1996

Recombinant baculovirus influenza A hemagglutinin vaccines are well tolerated and immunogenic in healthy adults.

In a prospective double-blind trial, the reactogenicity and immunogenicity of recombinant baculovirus influenza A vaccines containing purified full-length hemagglutinin (HA) were compared with standard trivalent inactivated vaccine (TIV). The recombinant baculovirus influenza A vaccines (rHA0) were monovalent (containing 45 micrograms of A/Beijing/92[H3] and 15, 45, and 135 micrograms of A/Texas/91[H1]) and bivalent (containing 45 micrograms of both A/Beijing/92 and A/Texas/91). The bivalent rHA0 vaccine produced fewer local side effects than the TIV (50% vs. 88%, P = .003). The hemagglutinin inhibition (HAI) responses (defined as a > or = 4 increase in HAI) to A/Beijing rHA0 in the monovalent A/Beijing/92, the bivalent vaccine, and the TIV were 68%, 76%, and 46%, respectively (P = .086). Increasing doses of A/Texas rHA0 (15 micrograms [60%], 45 micrograms [69%], and 135 micrograms [76%]) and bivalent HA (76%) gave better immunologic responses to H1 than did TIV (31%; P = .003).

Adolescent↗