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Biomedical subjects

L Bäckman

Publications and source records attributed to L Bäckman.

At least 73 records · Page 4Linked to original sources

Semantic mediation of age-related deficits in episodic recognition of common odors.

In the present research, the relationship between various semantic memory functions and episodic odor memory across the adult life span is addressed. In contrast to earlier evidence that odors may be encoded and stored as unique, nonlinguistic whole percepts, the present work suggests that episodic odor information is mediated by factors that can be subsumed under the rubric of semantic memory. Specific olfactory knowledge, such as perceived familiarity and identifiability, is strongly and positively related to episodic odor memory performance. In contrast to research using verbal and visual stimuli, proficiency in complex verbal intellectual abilities, such as vocabulary and fluency, seems to be of minor importance in memory for olfactory information. In agreement with earlier findings, this research indicates that episodic odor memory deteriorates across the adult life span. A similar negative age trend was observed for odor naming. Most importantly, statistical control of odor naming resulted in the elimination of age-related odor memory deficits. These results suggest that age-related failures in accessing specific semantic information of odors determine largely age-related deficits in episodic odor recognition.

Adult↗

Health-related quality of life after liver transplantation.

To gather information regarding how to best assist liver transplant recipients in improving their self-care capacity and well-being, we investigated their total health situation. A retrospective, cross-sectional survey with up to a 10-year follow-up concerning experienced health and quality of life after liver transplantation (LTX) was conducted. The aim of this study was to provide descriptive data on the experienced health and health-related quality of life (HRQOL) after LTX and to evaluate whether the pretransplantation medical conditions affected these parameters. All patients who had undergone LTX, were alive at the time of the study, and had a follow-up of more than 6 months (n = 134) were asked to complete three self-administered questionnaires. The response rate was 95% (n = 120). There was no correlation between pretransplantation Child-Pugh score and HRQOL after LTX. Liver transplant recipients were more limited in their physical health than healthy subjects but were equal in social functioning and mental health. Twenty-six percent suffered from severe bodily pain. A significant difference was reported in all health areas, with the exception of vitality and social functioning, between employed and unemployed transplant recipients. Liver transplant recipients suffered from limited physical functioning many years after transplantation. Their social functioning and mental health were not negatively affected. This study emphasizes that bodily pain and difficulties in performing regular activities because of physical illness are problems frequently experienced by liver transplant recipients.

Adolescent↗

Mild cognitive impairment--an early stage of Alzheimer's disease?

The hypothesis that mild cognitive impairment (MCI) represents an early stage of Alzheimer's disease (AD) was investigated by reviewing recent research from three sources: asymptomatic and symptomatic individuals carrying mutations that cause AD, hospital-samples of non-demented patients with MCI at the initial examination that are followed longitudinally, and community-based incident cases of AD. Studies with asymptomatic mutation carriers of the amyloid precursor protein and presenilin 1 gene have shown a linear and disease-related decline in most cognitive functions that begins approximately 10 years before the expected clinical onset of AD. However, there is considerable overlap between the level of impairment for mutation carriers and non-carriers of the same age during the early preclinical stage of AD. Hospital-based longitudinal studies have shown that non-demented individuals with isolated mild episodic memory impairment may develop clinically diagnosed AD with widespread cognitive deficits in a few years time. Community-based epidemiological studies on the incidence of AD demonstrate that indices of episodic memory, in addition to measures of general cognitive functioning, are useful in predicting early AD. In contrast, subjective memory impairment or age-associated memory impairment are less powerful predictors of future dementia development. In summary, there is converging evidence to demonstrate that preclinical AD is characterized by a common behavioral phenotype, with cognitive decline in several domains, predominantly in episodic memory. The decline appears to start many years before the clinical onset of AD. Moreover, the progression of the impairment appears to be continuous. Finally, this pattern of performance generalizes across etiology of AD (familial or sporadic), clinical onset (early or late), sample composition (hospital or community), and method of assessment.

Aged↗

Bile duct bacterial isolates in primary sclerosing cholangitis: a study of explanted livers.

BACKGROUND/AIMS: The pathogenesis of the inflammatory lesion in primary sclerosing cholangitis is unknown. The clinical picture is characterized by i.a. episodes of fever, the cause of which also remains speculative. Previous studies of bacterial isolates in the liver or bile ducts in primary sclerosing cholangitis have had the shortcoming of possible contamination associated with the sampling. The aim of this study was to investigate whether bile and bile duct tissue, obtained under sterile conditions in connection with liver transplantation, contain bacteria. METHODS: We studied bile from bile duct walls and bile collected from the explanted livers of 36 patients with primary sclerosing cholangitis and 14 patients with primary biliary cirrhosis. RESULTS: Positive cultures were obtained from 21 of 36 primary sclerosing cholangitis patients, but from none of the primary biliary cirrhosis patients. The number of bacterial strains was inversely related to the time after the last endoscopic retrograde cholangiography. Treatment with antibiotics or intraductal stent, or the occurrence of fever before liver transplantation did not seem to influence the culture results, whereas antibiotic treatment in connection with endoscopic retrograde cholangiography may possibly have reduced the number of isolates in the cultures. Alpha-haemolytic Streptococci were retrieved as late as 4 years after the last endoscopic retrograde cholangiography. Retrospective analysis of liver laboratory tests after endoscopic retrograde cholangiography did not indicate a deleterious effect of the investigation. CONCLUSIONS: The data suggest that antibiotics should be given routinely in connection with endoscopic retrograde cholangiography. They also raise the question of a possible role of alpha-haemolytic Streptococci in the progression of primary sclerosing cholangitis.

Adult↗

Three-year changes in cognitive performance as a function of apolipoprotein E genotype: evidence from very old adults without dementia.

This study examined whether baseline cognitive performance and 3-year longitudinal changes were influenced by apolipoprotein E epsilon 4 (APOE-epsilon 4) allele. Participants consisted of 20 APOE-epsilon 4 (2 epsilon 2/epsilon 4; 17 epsilon 3/epsilon 4; 1 epsilon 4/epsilon 4) and 54 non-epsilon 4 (12 epsilon 2/epsilon 3; 42 epsilon 3/epsilon 3) very old adults without dementia (M = 81.82 +/- 5.06 years) participating in a population-based longitudinal study. Cognitive performance was indexed by the Mini-Mental State Examination and multiple indexes of memory, visuospatial, and verbal performance. The results indicated no significant baseline differences between the 2 APOE groups in any cognitive performance measure. However, analyses revealed that the APOE-epsilon 4 group experienced greater negative change in recognition memory for faces and words. Changes in tasks assessing other abilities did not vary as a function of APOE status. The authors concluded that APOE-epsilon 4 status may not influence cognitive performance in adults without dementia and speculated that when such effects do occur (e.g., decline in recognition memory), these may be related to impending dementia, rather than to the influence of the specific genotype on cognition in normal aging.

Aged↗

Influences of cognitive support on episodic remembering: tracing the process of loss from normal aging to Alzheimer's disease.

Normal older adults, incident Alzheimer's disease (AD) patients, and prevalent AD patients were examined across a 3-year interval in episodic memory tasks that varied in terms of study time, organizability, and retrieval cues. There were marked overall preclinical deficits among the incident AD patients, although these patients were as effective as the normal older adults in utilizing more study time, organizability, and retrieval cues to improve memory at baseline. When these patients were diagnosed with AD at follow-up, they showed negligible gains from increased study time and organizability when memory was assessed with free recall, although they profited from the provision of retrieval cues. This pattern of results was also seen in the prevalent AD patients at both times of measurement. These results indicate that a general impairment of episodic memory may precede reductions in cognitive reserve capacity in the early development of AD.

Aged↗

Influences of thyroid stimulating hormone on cognitive functioning in very old age.

This study investigated the relationship of thyroxine (T4) and thyroid stimulating hormone (TSH) within normal ranges to cognitive performance in very old age. The participants (N = 200) were selected from a population-based study of nondemented persons aged 75 to 96 years (M = 83.9 years). Tasks assessing episodic memory, verbal fluency, visuospatial ability, short-term memory, and perceptual-motor speed were examined. Results indicated that T4 was unrelated to performance. However, TSH was positively related to episodic memory performance, and the effects were independent of the influence of age, level of education, and depressive mood symptoms. There was no reliable effect of TSH on verbal fluency, short-term memory, perceptual-motor speed, or visuospatial functioning. The influence of TSH on episodic memory was interpreted in terms of its potential effects on encoding and consolidation processes.

Affect↗

The link between knowledge and remembering in Alzheimer's disease.

Current research on the influence of cognitive support (e.g., activation of task-relevant prior knowledge, item organizability, retrieval cues) on episodic remembering in normal aging and Alzheimer's disease (AD) is reviewed. Examining the effects of cognitive support on memory may shed light on the relationship between knowledge and remembering, and also provides relevant information pertaining to the development of cognitive intervention procedures. A series of studies from our own and other laboratories reveal a number of interesting empirical regularities. First, AD results in problems in utilizing cognitive support for improving memory. Conceivably, this reduction in cognitive reserve capacity is due to both the overall severity of the episodic memory impairment in AD, as well as to dementia-related deficits in the semantic network that guides encoding and retrieval of information. Nevertheless, AD patients are able to utilize cognitive support in episodic memory tasks, although they typically need more support than their healthy aged counterparts to show memory facilitation. Specifically, it is critical to provide support at both encoding and retrieval in order to demonstrate performance gains in AD. Moreover, successful utilization of retrieval support in this disease is most likely to occur when the encoding requirements force the individual to engage in elaborative cognitive activity (e.g., generation of task-relevant knowledge, categorical organization). Finally, a reduction in cognitive reserve capacity occurs later in the pathogenesis of AD than a generalized episodic memory impairment. This observation reflects the insidious nature of AD, and suggests that the transition from normal aging to AD may be continuous rather than discrete.

Aged↗

Executive deficits in major depression.

Clinically depressed patients and control subjects were examined by means of different tests to assess executive functions (the Wisconsin Card Sorting Test, the Stroop Color Word Test and a test of verbal fluency). The results indicate that the depressed patients were generally slower than the controls, as reflected by longer retrieval times for both words and colours. Furthermore, the depressed patients showed impairment with regard to altering behaviour appropriately in response to feedback. However, there were no depression-related increases in perseverative responses, and the ability to inhibit irrelevant information was unaffected by depression. No relationship was found between specific depressive symptoms or the severity of depression and cognitive performance. The overall pattern of results suggests that depression may affect various executive functions in a differentiated manner.

Analysis of Variance↗

Preclinical symptoms of major depression in very old age: a prospective longitudinal study.

OBJECTIVE: The authors' goal was to examine whether individuals diagnosed as having major depression experienced greater levels of depressive symptoms and cognitive dysfunction up to 3 years before the clinical diagnosis was rendered. METHOD: The study included 185 subjects 75 years old or older who participated in a population-based longitudinal survey in Stockholm. Ten of the subjects were diagnosed as depressed up to 3 years after initial screening, and these individuals were compared with the 175 subjects who were not depressed at 3-year follow-up. Depression was diagnosed according to DSM-III-R and DSM-IV criteria. Psychiatric signs and symptoms were assessed by physicians using a structured interview. Cognitive functioning was assessed with the Mini-Mental State. RESULTS: At the initial screening, the patients later diagnosed as depressed had a greater number of depressive symptoms, such as dysphoria and appetite disturbance, and their symptoms were also more severe than those of the nondepressed subjects. Moreover, the depressed subjects suffered from a more severe lack of interest and psychomotor disturbance and had lower Mini-Mental State scores. CONCLUSIONS: There are preclinical markers for individuals who will become depressed after a 3-year interval. Major depression may have a more chronic nature in very old age, in contrast to the relatively short clinical onset of depression seen in younger adults. The authors conclude that standard diagnostic instruments such as DSM-IV may have to take this lengthy course of impairment into consideration when dealing with very old adults.

Adult↗

Reactions to predictive testing in Huntington disease: case reports of coping with a new genetic status.

A predictive testing program for Huntington disease has been available in Stockholm, Sweden since October 1990. Psychosocial assessments were performed throughout the testing program to evaluate the impact of the risk situation itself and the effect of predictive testing, and to identify those individuals who were most vulnerable to severe stress and anxiety reactions. All subjects underwent neurological, neuropsychological, and psychiatric examinations. Individuals undergoing predictive testing were assessed twice by a genetic counsellor before receiving their results, and at 10 days (gene carriers only) and then 2, 6, 12, and 24 months after receiving the results. The process of coping with the test results and the psychological adjustment to knowledge about new genetic status have been shown to vary considerably. In this report, we describe the results obtained from two gene carriers and two noncarriers. The four persons chosen represent different ways of coping with the outcome of the test and of integrating knowledge about their genetic status into everyday life. These cases illustrate common themes and recurrent problems often surfacing during the counselling and testing process. The longitudinal evaluations provide information about the impact, adaptation, and long-term effects of living with a new genetic status.

Adaptation, Psychological↗

Detection of mild dementia in community surveys. Is it possible to increase the accuracy of our diagnostic instruments?

OBJECTIVE: To investigate the accuracy of cognitive tests and clinical dementia diagnosis in distinguishing between mildly demented and nondemented subjects. DESIGN: Three-year longitudinal follow-up of a community-based cohort sample. Using the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised as criterion variable, subjects were classified as demented and nondemented based on the results of cognitive test performance at time 1. These subjects were then examined prospectively for development of dementia at time 2. PARTICIPANTS: The sample consisted of 63 mildly demented (Mini-Mental State Examination score > 18 < 24) and 398 nondemented subjects at time 1. At follow-up, due to death and refusal of participation, the sample consisted of 108 demented and 217 nondemented subjects. RESULTS: The group of subjects who were considered to be demented according to the results of the cognitive tests and nondemented by the clinical diagnosis at time 1 had a higher incidence of dementia at time 2 than did the subjects who were considered to be nondemented according to both cognitive tests and clinical diagnosis. Among the incident dementia cases, subjects considered to be demented according to the cognitive tests but nondemented by the clinical diagnosis performed at a lower level on most cognitive tests were older, had less education, and consisted of more women than did the group of subjects who were considered to be demented by the clinical diagnosis and nondemented by the cognitive tests at time 1. CONCLUSIONS: A combination of cognitive tests, especially tasks assessing episodic memory, can detect many subjects in a preclinical state of dementia who could be missed in the clinical diagnostic procedure due to subjects' relatively high age, low education, and female sex. However, cognitive tests also may miss a sizable proportion of prevalent dementia cases due to possible insensitivity to the same demographic variables. These findings indicate the need of integration between clinical and cognitive data to increase the accuracy in detecting dementia in an early phase.

Aged↗

Longitudinal and psychometric profiles of two cognitive status tests in very old adults.

Forty-four nondemented adults, over the age of 75 years, were tested at six-month intervals spanning two years. Study goals were to examine the validity of the Mini-Mental State Examination (MMSE) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R), to assess the long-term reliability of these instruments, and to examine the longitudinal profile of this sample. Results showed that the MMSE was moderately correlated with the WAIS-R. The MMSE had low internal consistency, although the total score behaved reliably across the five occasions. The WAIS-R scales showed a high degree of internal consistency and test-retest reliability. WAIS-R performance remained stable across occasions; however, decline was evident in the MMSE subtests of Attention and Language.

Aged↗

Encoding-retrieval interactions in mild Alzheimer's disease: the role of access to categorical information.

Normal old adults and patients in an early phase of Alzheimer's disease (AD) were presented with photographs of common objects under two different encoding conditions: naming and naming along with category decisions. Memory was assessed with free recall, category cued recall, and recognition. For both groups, recognition was superior to cued recall which was higher than that for free recall. Most importantly, cue utilization in AD was optimized in the naming + category decision condition, although the normal old showed equivalent gains from cues following both encoding conditions. These results suggest that AD patients require more cognitive support at encoding than normal old adults to make effective use of retrieval cues. Dementia-related deficits in processing categorical information spontaneously may underlie the observed group differences in patterns of performance.

Adult↗

Rescue therapy with tacrolimus (FK 506) in renal transplant recipients--a Scandinavian multicenter analysis.

All renal allograft recipients (n = 32) in Sweden and Norway who were converted from cyclosporin (CyA)-based immunosuppression to FK 506 (tacrolimus) between October 1992 and June 1995 were analyzed retrospectively. The reasons for conversion were acute refractory rejection (n = 21), chronic rejection (n = 4), and suspected CyA toxicity (n = 6); one patient was converted for psychological reasons. The mean time from transplantation to conversion was 29 (range 1-243) weeks and there was a mean follow-up of 46 (2-143) weeks. Overall graft survival was 59%, with graft survival 52% in patients converted because of acute rejection, 50% in patients converted because of chronic rejection, and 83% in patients converted because of CyA toxicity. There was no significant correlation between preconversion serum creatinine and outcome. Seventy-two percent of the patients had significant side effects during FK 506 treatment, the most frequent ones being neurological and gastrointestinal symptoms. These improved after dose reduction. Two patients became overimmunosuppressed and developed lymphoma. One patient died of the primary kidney disease, hemolytic uraemic syndrome. We conclude that FK 506 therapy is able to salvage kidneys with acute refractory rejection and that it is an alternative in patients with CyA toxicity. However, the risk of overimmunosuppression must be considered.

Administration, Oral↗