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E Mohr

Publications and source records attributed to E Mohr.

At least 55 records · Page 3Linked to original sources
PubMed1997

Clinical global measures of dementia. Position paper from the International Working Group on Harmonization of Dementia Drug Guidelines.

Following is the report of the committee working on clinical global measures for antidementia drug guidelines. The concepts involved in global scales, the distinctions between change and severity scales, advantages and disadvantages of structured interviews, and anchoring of change scores are discussed, and selected existing clinical global scales are described. In addition, the committee assessed the utility of global scales in clinical trials for antidementia drugs. There was a consensus among the members of the working group on the following: (1) Clinical global scales are interview based; in most cases, they include information obtained from caregivers as well as directly from patients, but they can rely on information from the subject only. (2) Clinicians' global ratings are intended to assess clinically meaningful change based on multidimensional clinical assessment and take into account the clinical heterogeneity of dementia by assessing at least cognition, behavior, and functioning. (3) There are two distinct types of clinical global measures: (a) clinicians' interview-based global severity scales, which generally incorporate classification by stage or severity of illness and (b) clinicians' interview-based global change scales, which incorporate global assessment ratings of clinical change. The committee could not reach a consensus on whether global scales should be required in phase II and phase III clinical trials, or whether other specific assessments such as well-designed activities of daily living, cognition, and behavior measures could, when used in appropriate combinations, replace the global as assessments of clinical meaningfulness.

Activities of Daily Living↗
PubMed1996

192 IgG-saporin lesion of basal forebrain cholinergic neurons in neonatal rats.

Seven day old rats received bilateral intraventricular injections (200 ng) of the immunotoxin 192 IgG-saporin. When assayed in adulthood, these rats showed an 84% loss of hippocampal and a 52% loss of cortical choline acetyltransferase (ChAT) activity. ChAT was unaffected in the caudate. Cholinergic neurons immunoreactive (IR) for the low affinity neurotrophin receptor (P75NTR) were severely reduced throughout the basal forebrain nuclei. Cortical and hippocampal norepinephrine were increased and these areas showed ingrowth of ectopic, P75NTR and dopamine beta-hydroxylase IR varicosities. These were probably sympathetic axons. No obvious forebrain dysmorphogenesis was observed and cortical thickness was unaffected. These rats showed no evidence of impaired spatial learning/memory as assessed by the Morris water maze and delayed spatial alternation. However, they were less active on the elevated plus apparatus and spent less time on the open arms, suggestive of increased timidity. 192 IgG-saporin appears to be a powerful tool to selectively lesion basal forebrain cholinergic neurons in the neonatal rat. Surprisingly, the neuromorphological and behavioral sequelae seem minimal. It may be necessary to achieve near-total neonatal destruction of forebrain cholinergic neurons before severe, lasting mnemonic effects are evident.

Acetylcholine↗
PubMed1996

[Quality assurance in hip prosthesis surgery. New type hip prostheses, review of a 3-year material].

This article deals with the short-term results of prosthetic replacement of the hip joint. The investigation was carried out three years after the introduction of a new hip prosthesis - the ITH (" International Total Hip") prosthesis. Our results were analysed retrospectively, the primary goal being quality assessment of the results of our hip surgery. We found that the results of hip prosthetic surgery with the ITH-prosthesis were satisfying, although the frequency of complications was rather high: 185 implantations of the ITH-prosthesis gave 13 cases of deep venous thrombosis; one case of deep infection and subsequent revision surgery; four cases of dislocation of the prosthesis, of which two cases have been subsequently revised; one case of perforation of the femur with later revision; and one case of permanent paralysis of the femoral nerve. The overall rate of revisions was 2.7%. The overall survival of the prosthesis according to Kaplan Meier was 97% after three years.

Adult↗
PubMed1996

A novel approach to the determination and characterization of HIV dementia.

BACKGROUND: Neuropsychological studies of the pattern and extent of cognitive impairment in HIV-infected patients have mostly used deviations from control values and/or cut-off scores as criteria for classification of dementia. There is, however, no agreement as to how to define impairment, and classification is imprecise. METHOD: The current study used a dementia classification matrix, developed with a step-wise linear discriminant analysis of neuropsychological data from patients with primary neurodegenerative dementias, to classify symptomatic HIV patients as demented or non-demented, and further to differentiate cortical and subcortical dementia patterns. Thirty-two male and 2 female patients (mean age 39 +/- 2) with symptomatic HIV disease (mean absolute CD4 count 195 +/- 41) participated in the study. RESULTS: Thirty-five per cent of patients were classified as demented. Of these, 83% showed a subcortical pattern and 17% a cortical profile of deficits. Significant differences between patients classified as subcortically demented and those categorized as normal on neuropsychological measures associated with subcortical integrity further validated the classification. Measures of psychiatric status between subgroups were similar. CONCLUSION: Since certain treatments may delay or reverse cognitive deficits, the use of an objective classification method based on discriminant analysis may help to identify patients who may benefit from therapy.

AIDS Dementia Complex↗
PubMed1996

Utility of clinical trial batteries in the measurement of Alzheimer's and Huntington's dementia.

Tests used as outcome measures in clinical trials of antidementia agents are not typically employed as part of diagnostic evaluations, and little information exists as to the sensitivity of these tests in terms of either differentiating demented patients from normal individuals or in distinguishing dementias of various types and etiologies. Sensitivity to mild dementia and sensitivity to impairment of various neuropsychological domains are, however, prerequisites for valid use of an instrument as an outcome measure in this context. The present study was undertaken to directly compare six different tests (three traditional psychometric tests and three clinical trial batteries) in terms of their sensitivity to detect and distinguish between mild dementia in patients with either Alzheimer's disease (n = 15) or Huntington's disease (n = 15), when compared to normal controls (n = 15). Tests included the Mattis Dementia Rating Scale, the Mini-Mental State Examination, the Wechsler Memory Scale-Revised, the Alzheimer's Disease Assessment Scale-Cognitive Subscale, the Computerized Drug Research (CDR) Cognitive Assessment System, and the Repeatable Battery for the Assessment of Dementia (RBAD). All of the tests were roughly equivalent in terms of their ability to discriminate normal subjects from mildly demented patients. Only the CDR and RBAD, however, were able to reliably discriminate between the two patient groups. The results are discussed in terms of the applicability of these tests as outcome measures for clinical trials in dementing disorders.

Adult↗
PubMed1996

Attentional deficits in Alzheimer's, Parkinson's, and Huntington's diseases.

INTRODUCTION: Attentional deficits have been shown in Alzheimer's disease but it is unknown whether this reflects disease specific impairment or is present in other neurodegenerative disorders. MATERIALS & METHODS: We administered a verbal dichotic listening task (free recall and selective allocation to the left or right ear) to 17 patients with Alzheimer's disease, 19 patients with Huntington's disease, 10 patients with idiopathic Parkinson's disease with clinical evidence of dementia (DemPD), 22 non-demented patients with Parkinson's disease (PD), and 22 healthy controls. Patients with dementia were matched for dementia severity and performance in the 3 recall conditions was used as a measure of attentional capacity. RESULTS: Patients with dementia (Alzheimer and Huntington patients, DemPD) were less accurate than those without dementia (PD and normal subjects). Demented subjects performed at comparable levels regardless of specific diagnosis; likewise those without dementia also achieved similar levels. All groups had a right ear preference under the free recall condition. Alzheimer and Huntington patients showed consistent right ear preference under all recall conditions, while PD patients, like controls, could selectively allocate attention to the left under left ear recall, regardless of the presence of dementia. CONCLUSION: The findings suggest a double dissociation. Non-selective attentional processing is affected by dementia presence versus absence but not by specific disease, while selective attentional processing shows disease specific impairments, regardless of the presence of dementia.

Aged↗
PubMed1996

[Changes of serum enzymes, lactate and hemoglobin concentrations in the blood of young trotting horses due to training exertion].

Until the age of about 2 years, trotters normally grow up on pasture without any kind of training. In the stud farm Lindenhof (Templin, Germany), however, these first 2 years are used for a special fitness training for the young animals: 2-3 times a week, a group of the yearlings is forced to run a distance of about 1700 m on a track at an average speed of up to 10 m/s. Until now, little was known about changes of blood parameters which may occur during such special exercise. This study therefore investigated the activity of selected serum enzymes (aspartate-amino-transferase (AST), alanine-amino-transferase (ALT), gamma-glutamyl-transferase (gamma-GT), lactic dehydrogenase (LDH), alkaline phosphatase (AP), creatine kinase (CK)) and the variations of hematocrit, hemoglobin, lactate, protein, and urea concentration before and after exercise. Except for activity of AP and CK and concentration of urea, all parameters showed a distinct increase after exercise. In particular, the rise in lactic-acid concentration with values up to 23.08 mmol/l was remarkable, however, none of the parameters reached a pathological level. It is therefore concluded that exercise for young trotters over a medium distance-even at high speed-does not cause any injury of myocardium, skeletal muscles or liver cells.

Animals↗
PubMed1995

Effect of hypoosmolality on the abundance, poly(A) tail length and axonal targeting of arginine vasopressin and oxytocin mRNAs in rat hypothalamic magnocellular neurons.

Arginine vasopressin (AVP) and oxytocin (OT) mRNAs are targeted to the axonal compartment of rat hypothalamic magnocellular neurons. Salt-loading results in a considerable rise in hypothalamic and axonal AVP mRNA but only a moderate increase for axonal OT mRNA. Here we report that hypoosmolality gives rise to a rapid decrease of axonal AVP encoding transcripts to undetectable levels after 2 weeks. The levels of OT mRNA in the axonal compartment did not change significantly. In the hypothalamus the mRNA for AVP also decreased. The size of the poly(A) tract of AVP encoding transcripts appeared to be strictly correlated with plasma osmolality. In contrast, the amount and size of OT encoding mRNAs were only moderately or not influenced by hypoosmolar stimuli.

Animals↗
PubMed1995

Differential subcellular mRNA targeting: deletion of a single nucleotide prevents the transport to axons but not to dendrites of rat hypothalamic magnocellular neurons.

It has previously been shown that mRNA encoding the arginine vasopressin (AVP) precursor is targeted to axons of rat magnocellular neurons of the hypothalamo-neurohypophyseal tract. In the homozygous Brattle-boro rat, which has a G nucleotide deletion in the coding region of the AVP gene, no such targeting is observed although the gene is transcribed. RNase protection and heteroduplex analyses demonstrate that, in heterozygous animals, which express both alleles of the AVP gene, the wild-type but not the mutant transcript is subject to axonal compartmentation. In contrast, wild-type and mutant AVP mRNAs are present in dendrites. These data suggest the existence of different mechanisms for mRNA targeting to the two subcellular compartments. Axonal mRNA localization appears to take place after protein synthesis; the mutant transcript is not available for axonal targeting because it lacks a stop codon preventing its release from ribosomes. Dendritic compartmentation, on the other hand, is likely to precede translation and, thus, would be unable to discriminate between the two mRNAs.

Animals↗
PubMed1995

The functional neuroanatomy of Tourette's syndrome: an FDG-PET Study. II: Relationships between regional cerebral metabolism and associated behavioral and cognitive features of the illness.

We analyzed F-18 fluoro-deoxyglucose PET scans carried out in 18 drug-free patients with Tourette's syndrome (TS) in order to evaluate relationships between cerebral metabolism and complex cognitive and behavioural features commonly associated with this disorder. These features (obsessions and compulsions, impulsivity, coprolalia, self-injurious behavior, echophenomena, depression, and measures of attentional and visuospatial dysfunction) were associated with significant increases in metabolic activity in the orbitofrontal cortices. Similar increases, although less robust, were observed in the putamen and, in the case of attentional and visuospatial measures, in the inferior portions of the insula. On the other hand, behavioral and cognitive features were not associated with metabolic rates in other subcortical (midbrain, ventral striatum), paralimbic (parahippocampal gyrus), or sensorimotor regions (supplementary motor area, lateral premotor or Rolandic cortices), in which metabolism had, in some cases more robustly, distinguished these TS patients from controls (Braun et al., 1993). These results suggest that a subset of regions in which metabolic activity appears to be associated with the diagnosis of TS per se, may be explicitly associated with the emergence of complex behavioral and cognitive features of the illness. This is most conspicuous in the orbitofrontal cortices, and it is consistent with the observation that these features resemble the elements of a behavioral syndrome typically seen in patients with lesions of the orbitofrontal cortex.

Adult↗
PubMed1995

Canadian guidelines for the development of antidementia therapies: a conceptual summary.

The magnitude of the problems faced by Canadian society as a result of an aging population has been identified. Perhaps the most important concern related to this greying of Canada is the increasing incidence of dementia and Alzheimer's disease. Therapeutic options for these disorders have been limited to date. Advances in biotechnology and molecular biology will offer novel approaches to treatment. These and the expansion of more traditional therapeutic avenues require guidelines with the aim of optimizing their development.

Aged↗
PubMed1995

Cognitive and quantified electroencephalographic correlates of cycloserine treatment in Alzheimer's disease.

Cycloserine acts as a potent and selective modulator of the N-methyl-D- aspartate (NMDA) receptor-associated glycine recognition site, which may be a possible mechanism for this compound's positive effects on memory formation and retrieval processes in animals. Studies in normal human volunteers have shown that cycloserine can have significant positive effects on cognitive processing in the elderly and can ameliorate memory deficits induced by subcutaneously administered scopolamine. Based on this profile, a double-blind, placebo controlled, parallel group (three drug dosages) study was conducted as part of a larger study to assess the efficacy and safety, as well as the cognitive and central nervous system (CNS) impact, of 6 months of cycloserine treatment in patients (N = 40) with probable dementia of the Alzheimer type (DAT). The Cognitive Drug Research Computerize Assessment System (CDR System) served as the primary outcome measure of efficacy. CNS activity was assessed using quantified electroencephalography (QEEG). Safety measures included adverse effects documentation and analysis of blood chemistry/hematology. Cycloserine proved to be a safe agent in this population at the doses given but failed to show any statistically significant effects in the areas of cognition and global clinical ratings and did not indicate significant CNS activity on QEEG. These findings suggest that cycloserine has no measurable therapeutic effect on Alzheimer's disease at the doses given.

Aged↗