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K Andersen

Publications and source records attributed to K Andersen.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Prevalence and incidence of dementia in Denmark. The Odense study].

Prevalence and incidence of dementia were determined for 65-84 year-old persons living in the municipality of Odense and randomly drawn from the Danish Civil Registration System (DCRS). All participants were examined with CAMCOG, the cognitive section of CAMDEX (The Cambridge Examination for Mental Disorders of the Elderly) and the follow-up period was two years. Individualized CAMCOG cut-off scores were determined by multiple linear regression. Possibly demented persons were further examined with the remaining part of CAMDEX and neuropsychological tests. Alzheimer's disease (AD) was diagnosed according to the NINCDS-ADRDA criteria for probable AD, and vascular dementia (VD) and dementias of other types according to the DSM-III-R criteria for dementia. The severity of dementia was determined according to the Clinical Dementia Rating scale. Of the 5,237 persons drawn from the DCRS, 3,346 participated in the prevalence study and 2,452 in the incidence study. The prevalence was 7.1% (66.7% AD, 18.3% VD, and 15.0% dementias of other types). Ninety-six (2.8%) were diagnosed as very mildly demented. The incidence rate was 29.5 new cases per 1,000 person-years and 20.9 for AD. Inclusion of cases with very mild dementia resulted in higher prevalence and incidence rates than generally reported.

Age Distribution↗
PubMed2000

Education and the risk for Alzheimer's disease: sex makes a difference. EURODEM pooled analyses. EURODEM Incidence Research Group.

The hypothesis that a low educational level increases the risk for Alzheimer's disease remains controversial. The authors studied the association of years of schooling with the risk for incident dementia and Alzheimer's disease by using pooled data from four European population-based follow-up studies. Dementia cases were identified in a two-stage procedure that included a detailed diagnostic assessment of screen-positive subjects. Dementia and Alzheimer's disease were diagnosed by using international research criteria. Educational level was categorized by years of schooling as low (< or =7), middle (8-11), or high (> or =12). Relative risks (95% confidence intervals) were estimated by using Poisson regression, adjusting for age, sex, study center, smoking status, and self-reported myocardial infarction and stroke. There were 493 (328) incident cases of dementia (Alzheimer's disease) and 28,061 (27,839) person-years of follow-up. Compared with women with a high level of education, those with low and middle levels of education had 4.3 (95% confidence interval: 1.5, 11.9) and 2.6 (95% confidence interval: 1.0, 7.1) times increased risks, respectively, for Alzheimer's disease. The risk estimates for men were close to 1.0. Finding an association of education with Alzheimer's disease for women only raises the possibility that unmeasured confounding explains the previously reported increased risk for Alzheimer's disease for persons with low levels of education.

Age Distribution↗
PubMed2000

Solid phase synthesis and biological evaluation of enantiomerically pure wasp toxin analogues PhTX-343 and PhTX-12.

PhTX-343 and PhTX-12, analogues of the natural polyamine wasp toxin PhTX-433, were synthesised in 40-60% yields as pure enantiomers using solid phase synthesis techniques. Capillary electrophoresis procedures were developed for chiral separation and determination of enantiomeric purity (ee) of the enantiomers of PhTX-343 and PhTX-12. The methods were optimised with respect to chiral selector, buffer pH, and temperature around the capillary. Thus, rac-PhTX-343 was resolved using a separation buffer containing 30 mM heptakis-(2, 6-di-O-methyl)-beta-cyclodextrin in 50 mM 6-aminocarproic acid (pH 4. 0) at 15 degrees C. rac-PhTX-12 was not resolvable in this system, but could be resolved using a separation buffer containing 10% w/v of dextrin 10, a linear maltodextrin, in 50 mM 6-aminocaproic acid (pH 4.0) at 15 degrees C. Using these methods, the optical purity of the synthetic enantiomers was determined to be ee > 99%. The enantiomers were also characterised by chiroptical methods. The antagonist potency of the enantiomers was tested on nicotinic acetylcholine receptors (human muscle-type nAChR) expressed in TE671 cells, ionotropic glutamate receptors in Xenopus laevis oocytes (expressing recombinant GluR1flop receptors), and locust muscle ionotropic glutamate receptors sensitive to quisqualate (qGluR). The potencies of each pair of enantiomers were similar (eudismic ratio close to 1).

Animals↗
PubMed2000

Cost function estimation: the choice of a model to apply to dementia.

Statistical analysis of cost data is often difficult because of highly skewed data resulting from a few patients who incur high costs relative to the majority of patients. When the objective is to predict the cost for an individual patient, the literature suggests that one should choose a regression model based on the quality of its predictions. In exploring the econometric issues, the objective of this study was to estimate a cost function in order to estimate the annual health care cost of dementia. Using different models, health care costs were regressed on the degree of dementia, sex, age, marital status and presence of any co-morbidity other than dementia. Models with a log-transformed dependent variable, where predicted health care costs were re-transformed to the unlogged original scale by multiplying the exponential of the expected response on the log-scale with the average of the exponentiated residuals, were part of the considered models. The root mean square error (RMSE), the mean absolute error (MAE) and the Theil U-statistic criteria were used to assess which model best predicted the health care cost. Large values on each criterion indicate that the model performs poorly. Based on these criteria, a two-part model was chosen. In this model, the probability of incurring any costs was estimated using a logistic regression, while the level of the costs was estimated in the second part of the model. The choice of model had a substantial impact on the predicted health care costs, e.g. for a mildly demented patient, the estimated annual health care costs varied from DKK 71 273 to DKK 90 940 (US$ 1 = DKK 7) depending on which model was chosen. For the two-part model, the estimated health care costs ranged from DKK 44714, for a very mildly demented patient, to DKK 197 840, for a severely demented patient.

Aged↗
PubMed2000

"Spring rise" of whaleworm (Anisakis simplex; Nematoda, Ascaridoidea) third-stage larvae in some fish species from Norwegian waters.

The seasonal variation in the infection of saithe (Pollachius virens), cod (Gadus morhua), and redfish (Sebastes marinus) from a coastal area of central Norway with Anisakis simplex third-stage larvae (L3) was studied over a period of 1 year. In all three host species there was an increase in the abundance of the parasite in spring, with a peak appearing in March and April. Cod displayed the most distinct seasonal variation, showing a clear abundance peak in April. The abundance peak in April for redfish was not as pronounced. In saithe the abundance over the seasons was less prominent, with a maximum appearing in March and another increase in abundance occurring during July. It is apparent that the causes behind the pattern of infection observed in this study are complex. However, possible explanatory mechanisms are discussed. Arguments are propounded to suggest that the increased supply of parasite eggs from northward-migrating whales in addition to the general spring bloom of plankton constitute the most important factors governing the phenomenon of "spring rise" in A. simplex L3 in the study area.

Animals↗
PubMed2000

Intraaortic balloon pumping for predominantly right ventricular failure after heart transplantation.

BACKGROUND: Right ventricular failure from elevated pulmonary vascular resistance in the recipient is a main cause of early mortality after heart transplantation. When pharmacologic treatment is insufficient, mechanical circulatory assistance has been used to support the failing right ventricle. Considering right and left ventricular interdependence, we investigated whether intraaortic balloon counterpulsation (IABP) might also alleviate predominantly right ventricular dysfunction after heart transplantation. METHODS: Among 278 cardiac recipients, 12 adult patients underwent mechanical circulatory support for cardiac allograft dysfunction. Five patients were treated with percutaneous IABP for early postoperative low cardiac output syndrome characterized by predominantly right ventricular failure. Clinical data and hemodynamic variables were recorded before and during IABP treatment. RESULTS: Cardiac index (CI) and mean arterial pressure (MAP) increased (CI 1.7 +/- 0.1 to 2.5 +/- 0.2, MAP 53 +/- 12 to 71 +/- 7, p < 0.05) within 1 hour after IABP, whereas central venous pressure (CVP) and pulmonary artery wedge pressure (PAWP) decreased (CVP 21.6 +/- 1.7 to 13.8 +/- 3.1, p < .05; PAWP 14.8 +/- 4.9 to 12.4 +/- 3.7, nonsignificant). Within the next 12 hours, CI and mixed venous oxygen saturation increased (p < 0.05) and pulmonary artery pressure decreased (p < 0.05). All 5 patients were weaned successfully and 4 are long-term survivors with adequate cardiac performance at 1 year follow-up. CONCLUSIONS: Intraaortic balloon pumping is a minimally invasive circulatory assist device with proved efficiency in low cardiac output syndromes. This report shows that low output syndrome caused by predominantly right ventricular allograft failure may be an additional indication for IABP.

Adult↗
PubMed2000

CAMCOG as a screening instrument for dementia: the Odense study. Cambridge Cognitive Examination.

OBJECTIVE: The Cambridge Cognitive Examination (CAMCOG) score is correlated with age and sociodemographic variables. The aim of the study was to determine an individualized CAMCOG cut-off score for dementia, taking such correlates into account. METHOD: From the general population 150 people aged 65-84 years were examined with CAMDEX which includes CAMCOG, and a neuropsychological test battery. Data from 130 non-demented people were entered in setwise multiple regression analyses to identify variables predicting the CAMCOG score. RESULTS: The variables age, social class, matrimonial status, general knowledge and intellectual level explained 66% of the variance of the CAMCOG scores. A cut-off defined as a difference between actual and predicted CAMCOG score < or = -4.41 resulted in a sensitivity of 88.2% and a specificity of 89.2% for very mild to moderate dementia. CONCLUSION: It is possible to determine an individualized CAMCOG cut-off score for dementia in its early stages.

Age Factors↗
PubMed2000

Prevalence of dementia and major subtypes in Europe: A collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group.

The last comparison of prevalence figures of dementia across European studies was 10 years ago. Using studies conducted in the 1990s, the authors compare the age- and sex-specific prevalence of dementia, AD, and vascular dementia (VaD) across European population-based studies of persons 65 years and older. Data from these studies were also pooled to obtain stable estimates of age- and sex-specific prevalence. A total of 2346 cases of mild to severe dementia were identified in 11 cohorts. Age-standardized prevalence was 6.4% for dementia (all causes), 4.4% for AD, and 1.6% for VaD. The prevalence of dementia increased continuously with age and was 0.8% in the group age 65 to 69 years and 28.5% at age 90 years and older. The corresponding figures for AD (53.7% of cases) were 0.6% and 22.2%, and for VaD (15.8% of cases), 0.3% and 5.2%. Variation of AD prevalence across studies was greatest for men. In the VaD subtype, a large variation across studies was observed, as well as a difference in prevalence between men and women that was age dependent. Dementia is more prevalent in women, and AD is the main contributor to the steep increase of prevalence with age.

Age Factors↗
PubMed2000

Incidence of dementia and major subtypes in Europe: A collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group.

The authors examined the association of incident dementia and subtypes with age, sex, and geographic area in Europe. Incidence data from eight population-based studies carried out in seven European countries were compared and pooled. The pooled data included 835 mild to severe dementia cases and 42,996 person-years of follow-up. In all studies a higher proportion of cases were diagnosed with AD (60 to 70% of all demented cases) than vascular dementia (VaD). The incidence of dementia and AD continued to increase with age up to age 85 years, after which rates increased in women but not men. There was a large variation in VaD incidence across studies. In the pooled analysis, the incidence rates increased with age without any substantial difference between men and women. Surprisingly, higher incidence rates of dementia and AD were found in the very old in northwest countries than in southern countries. This study confirms that AD is the most frequent dementing disorder in all ages, and that there is a higher incidence of dementia, specifically AD, in women than men among the very old. Finally, there may be regional differences in dementia incidence.

Age Factors↗
PubMed2000

Prognosis with dementia in Europe: A collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group.

The effect of dementia on time to death and institutionalization in elderly populations is of importance to resource planning, as well as to patients and their carers. The authors report a collaborative reanalysis of nine population-based studies conducted in Europe to compare dementia cases and noncases in risk of and time to death and to institutionalization. Prevalent and incident cases were more likely than noncases to reside in an institution at baseline and were more likely to enter institutional care. Prevalent cases also had over twice the risk of death compared to noncases and survival for men with dementia was consistently lower than that for women with dementia of the same age group.

Age Factors↗
PubMed1999

Analogues of neuroactive polyamine wasp toxins that lack inner basic sites exhibit enhanced antagonism toward a muscle-type mammalian nicotinic acetylcholine receptor.

Philanthotoxin-433 (PhTX-433), a natural polyamine wasp toxin, is a noncompetitive antagonist of certain ionotropic receptors. Six analogues of PhTX-343 (a synthetic analogue of the natural product), in which the secondary amino groups are systematically replaced by oxygen or methylene groups, have been synthesized by coupling of N-(1-oxobutyl)tyrosine with 1,12-dodecanediamine, 4,9-dioxa-1, 12-dodecanediamine, or appropriately protected di- and triamines, the latter being obtained by multistep syntheses. The resulting PhTX-343 analogues were purified and characterized, and their protolytic properties (stepwise macroscopic pK(a) values) were determined by (13)C NMR titrations. All analogues are fully protonated at physiological pH. The effects of these compounds on acetylcholine-induced currents in TE671 cells clamped at various holding potentials were determined. All of the analogues noncompetitively antagonized the nicotinic acetylcholine receptor (nAChR) in a concentration-, time-, and voltage-dependent manner. The amplitudes of acetylcholine-induced currents were compared at their peaks and at the end of a 1 s application in the presence or absence of the analogues. Most of the analogues were equipotent with or more potent than PhTX-343. The dideaza analogue PhTX-12 [IC(50) of 0.3 microM (final current value)] was the most potent, representing the highest potency improvement (about 50-fold) yet achieved by modification of the parent compound (PhTX-343). Thus, the presence of multiple positive charges in the PhTX-343 molecule is not necessary for antagonism of nAChR. In contrast, the compounds were much less potent than PhTX-343 at locust muscle ionotropic glutamate receptors sensitive to quisqualate (qGluR). The results demonstrate that the selectivity for different types of ionotropic receptors can be achieved by manipulating the polyamine moiety of PhTX-343.

Animals↗
PubMed1999

Gender differences in the incidence of AD and vascular dementia: The EURODEM Studies. EURODEM Incidence Research Group.

OBJECTIVE: To study the difference in risk for dementing diseases between men and women. BACKGROUND: Previous studies suggest women have a higher risk for dementia than men. However, these studies include small sample sizes, particularly in the older age groups, when the incidence of dementia is highest. METHODS: Pooled analysis of four population-based prospective cohort studies was performed. The sample included persons 65 years and older, 528 incident cases of dementia, and 28,768 person-years of follow-up. Incident cases were identified in a two-stage procedure in which the total cohort was screened for cognitive impairment, and screen positives underwent detailed diagnostic assessment. Dementia and main subtypes of AD and vascular dementia were diagnosed according to internationally accepted guidelines. Sex- and age-specific incidence rates, and relative and cumulative risks for total dementia, AD, and vascular dementia were calculated using log linear analysis and Poisson regression. RESULTS: There were significant gender differences in the incidence of AD after age 85 years. At 90 years of age, the rate was 81.7 (95% CI, 63.8 to 104.7) in women and 24.0 (95% CI, 10.3 to 55.6) in men. There were no gender differences in rates or risk for vascular dementia. The cumulative risk for 65-year-old women to develop AD at the age of 95 years was 0.22 compared with 0.09 for men. The cumulative risk for developing vascular dementia at the age of 95 years was similar for men and women (0.04). CONCLUSION: Compared with men, women have an increased risk for AD. There are no gender differences in risk for vascular dementia.

Aged↗
PubMed1999

The crystal structure of rubisco from Alcaligenes eutrophus reveals a novel central eight-stranded beta-barrel formed by beta-strands from four subunits.

Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) is involved in photosynthesis where it catalyzes the initial step in the fixation of carbon dioxide. The enzyme also catalyzes a competing oxygenation reaction leading to loss of fixed carbon dioxide, thus reducing the net efficiency of photosynthesis significantly. Rubisco has therefore been studied extensively, and a challenging goal is the engineering of a more photosynthetically efficient enzyme. Hexadecameric rubiscos fall in two distinct groups, "green-like" and "red-like". The ability to discriminate between CO2 and O2 as substrates varies significantly, and some algae have red-like rubisco with even higher specificity for CO2 than the plant enzyme. The structure of unactivated rubisco from Alcaligenes eutrophus has been determined to 2.7 A resolution by molecular replacement and refined to R and Rfree values of 26.6 and 32.2 %, respectively. The overall fold of the protein is very similar to the rubisco structures solved previously for green-like hexadecameric enzymes, except for the extended C-terminal domains of the small subunits which together form an eight-stranded beta-barrel which sits as a plug in the entrance to the central solvent channel in the molecule. The present structure is the first which has been solved for a red-like rubisco and is likely to represent a fold which is common for this group. The small subunits in general are believed to have a stabilizing effect, and the new quaternary structure in the oligomer of the present structure is likely to contribute even more to this stabilization of the assembled rubisco protein.

Alcaligenes↗
PubMed1999

Relative contributions of a single-admission 12-lead electrocardiogram and early 24-hour continuous electrocardiographic monitoring for early risk stratification in patients with unstable coronary artery disease.

Patients with unstable coronary syndromes are a heterogeneous group with varying degrees of ischemia and prognosis. The present study compares the prognostic value of a standard electrocardiogram (ECG) obtained at admission to the hospital with the information from 24-hour continuous electrocardiographic monitoring obtained immediately after admission. The admission ECGs and 24 hours of vectorcardiographic (VCG) monitoring from 308 patients admitted with unstable coronary artery disease were analyzed centrally regarding standard electrocardiographic ST-T changes, ST-vector magnitude (ST-VM), and ST change vector magnitude episodes. End points were death, acute myocardial infarction, and refractory angina pectoris within a 30-day follow-up period. ST-VM episodes (> or = 50 microV for > or = 1 minute) during VCG monitoring was the only independent predictor of death or acute myocardial infarction by multivariate analysis. ST-VM episodes during vectorcardiography was associated with a relative risk of 12.7 for having a cardiac event, hypertension was associated with a relative risk of 1.7, and ST depression on the admission ECG was associated with a relative risk of 5.7. Patients with ST depression at admission had an event rate (death or acute myocardial infarction) of 17% at 30-day follow-up. Patients without ST depression could further be risk stratified by 24 hours of VCG monitoring into a subgroup with ST-VM episodes at similar (8%) risk and a subgroup without ST-VM episodes at low (1%) risk (p = 0.00005). Continuous VCG monitoring provides important information for evaluating patients with unstable coronary artery disease. It is recommended that patients not initially estimated at high risk based on the admission ECG are referred for 24 hours of VCG monitoring for further risk stratification.

Aged↗
PubMed1999

Purification, crystallization and preliminary X-ray studies of two isoforms of Rubisco from Alcaligenes eutrophus.

Two different isoforms of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from Alcaligenes eutrophus have been purified and crystallized. Both isoforms crystallize in space group P43212. Crystals of isoform I (unit-cell dimensions a = 112.0 and c = 402.7 A) diffract to 2.7 A, whereas isoform II (unit-cell dimensions a = 111.8 and c = 400.0 A) presently diffract to 3.2 A, using synchrotron radiation in both cases.

Alcaligenes↗
PubMed1999

Rates and risk factors for dementia and Alzheimer's disease: results from EURODEM pooled analyses. EURODEM Incidence Research Group and Work Groups. European Studies of Dementia.

OBJECTIVE: To investigate the risk of AD associated with a family history of dementia, female gender, low levels of education, smoking, and head trauma. BACKGROUND: These putative factors have been identified in cross-sectional studies. However, those studies are prone to bias due to systematic differences between patients and control subjects regarding survival and how risk factors are recalled. METHODS: The authors performed a pooled analysis of four European population-based prospective studies of individuals 65 years and older, with 528 incident dementia patients and 28,768 person-years of follow-up. Patients were detected by screening the total cohort with brief cognitive tests, followed by a diagnostic assessment of those who failed the screening tests. Dementia was diagnosed with the Diagnostic and Statistical Manual of Mental Disorders, 3rd ed. (revised), and AD was diagnosed according to National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria. Incident rates and relative risk (95% CI) express the association of a risk factor for dementia. RESULTS: Incident rates for dementia and AD were similar across studies. The incidence of AD increased with age. At 90 years of age and older the incidence was 63.5 (95% CI, 49.7 to 81.0) per 1,000 person-years. Female gender, current smoking (more strongly in men), and low levels of education (more strongly in women) increased the risk of AD significantly. A history of head trauma with unconsciousness and family history of dementia did not increase risk significantly. CONCLUSION: Contrary to previous reports, head trauma was not a risk factor for AD, and smoking did not protect against AD. The association of family history with the risk of AD is weaker than previously estimated on the basis of cross-sectional studies. Female gender may modify the risk of AD, whether it be via biological or behavioral factors.

Age Distribution↗
PubMed1999

Incidence of very mild to severe dementia and Alzheimer's disease in Denmark: the Odense Study.

OBJECTIVE: Calculation of incidence of dementia and AD, including cases in the earliest phases of the diseases. BACKGROUND: Establishment of incidence estimates is important for the future planning of the health care system, and incidence studies can offer insights into risk factors. METHODS: A total of 5,237 persons age 65 to 84 years were randomly drawn among people living in the municipality of Odense, Denmark. Of this sample 3,086 persons were eligible for the incidence study. All participants were examined with CAMCOG, the cognitive section of The Cambridge Examination for Mental Disorders of the Elderly (CAMDEX), and the follow-up period was 2 years. Using multiple linear regression, the CAMCOG cutoff score was individualized to detect even minor cognitive decline with optimal precision. Possibly demented persons were further examined with the remaining part of the CAMDEX and neuropsychological tests. AD was diagnosed according to National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probable AD, and vascular dementia and dementia of other types were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) criteria for dementia. Finally, the severity of dementia was determined according to the Clinical Dementia Rating scale. RESULTS: The incidence rate for very mild to severe dementia was 29.5 per 1,000 person-years and 20.9 for AD, and the rates were similar for men and women. CONCLUSION: Application of an individualized cutoff for the screening instrument resulted in detection of a substantial number of cases with very mild dementia, which subsequently resulted in higher incidence rates than those reported in most other studies.

Age Distribution↗