Citations

This study investigated the psychometric properties of the Mattis Dementia Rating Scale (DRS), including its internal consistency, sensitivity to age and education effects, pattern of change scores, convergent validity and predictive utility. Age and education effects and stability were assessed in a sample of 280 cognitively normal persons over age 55. All other features were assessed in a sample of 274 persons with cognitive impairment, including 221 newly diagnosed dementia patients and 53 patients with mild cognitive impairment. Both samples were drawn from the Mayo Clinic Alzheimer's Disease Patient Registry. Within the normal sample, Pearson correlation coefficients for DRS Total score with age, education and intelligence were all significant, p < .0001; MAYO Full Scale IQ (FSIQ) shared approximately 20% variance with DRS Total score. Internal consistency was greater than .7 for Construction, Conceptualization, Memory, and Total score, greater than .65 for Attention and less than .5 for Initiation and Perseveration. DRS subscales cores for Memory, Attention, and Conceptualization were significantly correlated with appropriate indices from the WAIS-R or Wechsler Memory Scale-Revised, as assessed in the Mayo Older Americans Normative Studies, providing convergent validity for these DRS scales. Importantly, proportional hazards modeling revealed initial DRS Total score to be a significant predictor of longitudinal institutionalization and mortality outcomes.

Alzheimer disease and type 2 diabetes are characterized by increased prevalence with aging, a genetic predisposition, and comparable pathological features in the islet and brain (amyloid derived from amyloid β protein in the brain in Alzheimer disease and islet amyloid derived from islet amyloid polypeptide in the pancreas in type 2 diabetes). Evidence is growing to link precursors of amyloid deposition in the brain and pancreas with the pathogenesis of Alzheimer disease and type 2 diabetes, respectively. Given these similarities, we questioned whether there may be a common underlying mechanism predisposing to islet and cerebral amyloid. To address this, we first examined the prevalence of type 2 diabetes in a community-based controlled study, the Mayo Clinic Alzheimer Disease Patient Registry (ADPR), which follows patients with Alzheimer disease versus control subjects without Alzheimer disease. In addition to this clinical study, we performed a pathological study of autopsy cases from this same community to determine whether there is an increased prevalence of islet amyloid in patients with Alzheimer disease and increased prevalence of cerebral amyloid in patients with type 2 diabetes. Patients who were enrolled in the ADPR (Alzheimer disease n = 100, non-Alzheimer disease control subjects n = 138) were classified according to fasting glucose concentration (FPG) as nondiabetic (FPG &lt;110 mg/dl), impaired fasting glucose (IFG, FPG 110–125 mg/dl), and type 2 diabetes (FPG &gt;126 mg/dl). The mean slope of FPG over 10 years in each case was also compared between Alzheimer disease and non-Alzheimer disease control subjects. Pancreas and brain were examined from autopsy specimens obtained from 105 humans (first, 28 cases of Alzheimer disease disease vs. 21 non-Alzheimer disease control subjects and, second, 35 subjects with type 2 diabetes vs. 21 non-type 2 diabetes control subjects) for the presence of islet and brain amyloid. Both type 2 diabetes (35% vs. 18%; P &lt; 0.05) and IFG (46% vs. 24%; P &lt; 0.01) were more prevalent in Alzheimer disease versus non-Alzheimer disease control subjects, so 81% of cases of Alzheimer disease had either type 2 diabetes or IFG. The slope of increase of FPG with age over 10 years was also greater in Alzheimer disease than non-Alzheimer disease control subjects (P &lt; 0.01). Islet amyloid was more frequent (P &lt; 0.05) and extensive (P &lt; 0.05) in patients with Alzheimer disease than in non-Alzheimer disease control subjects. However, diffuse and neuritic plaques were not more common in type 2 diabetes than in control subjects. In cases of type 2 diabetes when they were present, the duration of type 2 diabetes correlated with the density of diffuse (P &lt; 0.001) and neuritic plaques (P &lt; 0.01). In this community cohort from southeast Minnesota, type 2 diabetes and IFG are more common in patients with Alzheimer disease than in control subjects, as is the pathological hallmark of type 2 diabetes, islet amyloid. However, there was no increase in brain plaque formation in cases of type 2 diabetes, although when it was present, it correlated in extent with duration of diabetes. These data support the hypothesis that patients with Alzheimer disease are more vulnerable to type 2 diabetes and the possibility of linkage between the processes responsible for loss of brain cells and β-cells in these diseases.

We present an efficient feature selection algorithm for computer aided detection (CAD) computed tomographic (CT) colonography. The algorithm (1) determines an appropriate piecewise linear network (PLN) model by cross validation, (2) applies the orthonormal least square (OLS) procedure to the PLN model utilizing a Modified Schmidt procedure, and (3) uses a floating search algorithm to select features that minimize the output variance. The undesirable "nesting effect" is prevented by the floating search approach, and the piecewise linear OLS procedure makes this algorithm very computationally efficient because the Modified Schmidt procedure only requires one data pass during the whole searching process. The selected features are compared to those obtained by other methods, through cross validation with support vector machines (SVMs).

We have investigated the significance of the method of treatment on the oncological and functional outcomes and on the complications in 184 patients with soft-tissue sarcomas of the adductor compartment managed at three international centres. The overall survival at five years was 65% and was related to the grade at diagnosis and the size of the tumour. There was no difference in overall survival between the three centres. There was, however, a significant difference in local control with a rate of 28% in Centre 1 compared with 10% in Centre 2 and 5% in Centre 3. The overall mean functional score using the Toronto Extremity Salvage Score in 70 patients was 77% but was significantly worse in patients with wound complications or high-grade tumours. The scores were not affected by the timing of radiotherapy or the use of muscle flaps. This large series of soft-tissue sarcomas of the adductor compartment has shown that factors influencing survival do not vary across the international boundaries studied, but that methods of treatment affect complications, local recurrence and function.