Biomedical subjects

M M Baltes

Publications and source records attributed to M M Baltes.

At least 19 recordsLinked to original sources

PubMed2001

Multicenter field trial on possible health effects of toluene. II. Cross-sectional evaluation of acute low-level exposure.

Data on possible acute effects of today's relevant low-level exposure to toluene are contradictory, and information on possible effects of exposure under occupational conditions is largely lacking. In a controlled, multi-center, blinded field trial, effects possibly associated with acute toluene exposure were evaluated in workers of 12 German rotogravure factories. Medical examinations (inquiries on subjective symptoms, and standard tests of psycho-physiological and psycho-motor functions) were performed on almost 1500 volunteers, of whom 1290 were toluene-exposed (1178 men and 112 women), and about 200 participants served as references (157 men and 37 women), but the main aim of the trial was to reveal dose-response relationships. All volunteers were of the morning work-shift (6 h exposure). Both individual ambient air concentrations (time-weighted average) during the work-shift, as well as blood toluene concentrations after the work-shift were measured. Therefore, the medical data could for the first time be correlated with the actual individual body burden (blood toluene level) at the time of testing. In order to largely exclude confounding by chronic toluene exposure, kinetic measurements as well as the psycho-physiological and psycho-motoric tests were performed before and after the work-shift. Except for minor statistical deviations, neither convincing dose-dependent acute effects could be demonstrated with regression analyses in male volunteers at the exposure levels evaluated, nor were significant differences found when applying group statistics (highly toluene-exposed group versus volunteers with negligible exposure). Due to the rather large number of participants, the predictive power of the study is high, especially when compared with previous publications. In two psycho-physiological tests, a few more female volunteers with quite low toluene body burdens (<340 microg/l blood) showed relatively low scores when compared with participants of the reference group. Although evidence for a medical relevance is meager, the small numbers of participants, in both the exposure and the reference groups, hamper a reliable interpretation of the results concerning exposure levels above 85 microg toluene/l blood, and it is difficult to take confounding factors adequately into account. For the end points evaluated and under occupational conditions, neither blood toluene levels of 850 to 1700 microg/l (in the highest exposure group [EXPO-IV] with 56 participants), as measured 1/2 (+/-1/2) h after the work-shift, nor ambient air concentrations (time-weighted average over 6 h) between 50 and 100 ppm (188-375 mg/m(3)) were convincingly associated with alterations in psycho-physiological and psycho-motoric performances or increased the frequency of subjective complaints in male volunteers. For higher dose ranges of toluene exposure (i.e. >1700 microg toluene/l blood [or >100 ppm in ambient air]), our data set is too small for far reaching conclusions. Our data are insufficient for conclusions on a possibly higher susceptibility to toluene of some female workers. Results of kinetic studies and possible effects of long-term exposure are discussed in two accompanying publications (Neubert et al., 2001; Gericke et al., 2001).

Acute Disease↗

PubMed2001

Multicenter field trial on possible health effects of toluene. III. Evaluation of effects after long-term exposure.

In rotogravure industry, contributing considerably to mass color printing of catalogues and magazines, toluene is still extensively used as paint solvent, and many printers have been exposed to this chemical for several decades. Information on adverse health effects associated with long-term toluene exposure is still controversial. In a multi-center study, adverse health effects possibly associated with long-term toluene exposure were evaluated. In 12 rotogravure factories, 1226 male volunteers were recruited, and sufficient information on exposure and on medical data was compiled for about 1077 of them. Evaluations included: physical examination, standard tests of psycho-physiological and psycho-motoric performances, self-report of subjective symptoms, and data on a variety of laboratory blood tests. The medical data were correlated with the length (months) of toluene exposure, and a rough estimate of the extent of exposure (i.e. highly exposed printers and their helpers versus employees working at locations with low or negligible toluene exposure). A small reference group (n=109) was selected from companies of the paper industry. When linear regression curves were calculated (test results versus duration of exposure), extremely low overall coefficients of determination (r(2) adj.) of a few percent were estimated within the data clouds, with sometimes statistically significant P-values. Closer analyses revealed a strong influence of the confounding factor age, no clustering of abnormal values of highly toluene-exposed volunteers, and the vast majority or all values of the highly and long-term toluene-exposed participants staying within the reference ranges. Thus, no medical relevance of P-values <0.05 could be recognized in this evaluation, and there may have been some border-line deviations or results largely occurring by chance in the large trial. In a small cluster of the many rotogravure printers toluene-exposed for more than 20 years, the highest systolic blood pressure values of the study were found, but many possible confounding factors were not taken into account. Data on acute exposure and possible effects are presented in accompanying papers (Neubert et al., 2001a, Neubert et al., 2001b). Restricting the conclusions to the end points evaluated as well as the apparent limitations of the evaluation, no evidence was found that long-term occupational toluene exposure extending over several decades in the rotogravure industry in the Western part of Germany was convincingly associated with chronic adverse health effects or convincingly altered surrogate markers in still working male volunteers. Several peculiarities and pitfalls arising when interpreting medical data associated with such a type of environmental exposure must be considered. Reversibility of alterations previously induced at higher levels of toluene-exposure, as well as a healthy workers effect, cannot be excluded for some of the medical end points evaluated.

Adult↗

PubMed1999

[Everyday activities in depression and dementia in the elderly. Results of the Berlin study on aging].

We investigated time use of persons assigned to seven groups on the basis of psychiatric diagnoses: (a) no dementia or depression symptoms, (b) individuals with dementia symptoms but no DSM-III-R-diagnosis, (c) individuals with dementia according to DSM-III-R, (d) individuals with depression symptoms but no diagnosis, (e) individuals with depression not further specified (NFS), (f) individuals with depression according to DSM-III-R, and (g) individuals with symptoms of both dementia and depression. In general, time-use parameters were similar across the groups. As expected, however, we found differences in specific dimensions. Demented and depressed individuals differed from others with respect to the duration of passive phases and receptive leisure. Instrumental activities, active leisure, length of the waking day, and time spent alone were indicators with differential validity regarding dementia diagnoses--partly even after controlling for physical morbidity. Moreover, we were able to differentiate between dementia and depression on the basis of instrumental activities after controlling for physical morbidity.

Activities of Daily Living↗

PubMed1999

Time use of old and very old Berliners: productive and consumptive activities as functions of resources.

OBJECTIVES: The aims of this study were to examine time use of elderly women and men and to explain age- and gender-related variance in activity levels in terms of differences in available resources. METHODS: Activities reported in an elderly sample stratified for age and gender (N = 485, Age: 70-103 years) were aggregated into three classes: regenerative, productive, and consumptive activities and regressed on income, presence of a partner in the household, education, walking mobility, and labor force participation. RESULTS: Levels in productive and consumptive activities were decreased in the old-old. Moreover, young-old women spent more time working in the household than any other group. Most of the age- and gender-related variance in activity levels could be explained by differences in available resources. For men, living with a partner was associated with less time spent for productive activities and enhanced leisure time, whereas for women, the reverse was observed. The expected reduction of unpaid work time as a function of income (income effect) was not observed. DISCUSSION: Elderly individuals do contribute to societal production. Allocation of time to productive and consumptive activities is a function of available resources, amounts and effects of which differ for young-old and old-old as well as for women and men.

Activities of Daily Living↗

PubMed1998

[Depression in the very elderly].

In the Berlin Aging Study (BASE) an age and gender stratified sample of 516 persons aged 70 to over 100 was assessed by means of the semi-structured GMS-A interview, the CES-D-self-rating scale and the Hamiltion-Depression-observer-rating scale. Prevalence rates were 4.8% for Major Depression, 9.1% for all DSM III-R specified depressive disorders and 26.9% of subthreshold depression was included. There was no increase in prevalence rates with age but an increase in scores on the self rating CES-D. The prevalence rates for DSM III-R specified depression in females was 10.3% and almost double that of men (5.6%). Depressed persons do not show significant cognitive impairment as measured with the MMSE in comparison to controls. As compared to the total sample higher prevalence rates of overall depression were seen in persons with multimorbidity (36.8%) and lower rates in married persons. 13.2% of the elderly talked about feeling tired with life, 7.9% had thoughts about death and 1.2% reported suicidal ideation, which was closely linked to depressive disorders. In 44% of depressed cases undertreatment was observed. Only 6% got Antidepressants but 40% benzodiazepines.

Aged↗

PubMed1998

[Dementias and daily competence: effects beyond ADL and IADL].

Using a time-budget method in a 3 year longitudinal study with a control group design, substantial reductions in the engagement of nonobligatory instrumental, social, and leisure activities could be found in a group of mildly to moderately demented patients. Controlling these changes for differences in baseline parameters, the dementia-specific reduction was about 1 1/2 hours compared to a non-psychiatric control group. These clinically relevant changes in activity levels underscore the importance of these activity domains with regard to the development of diagnostically useful indicators at the early stages of dementia. Time-budget methods seem to be particularly useful to close the diagnostic gap with regard to the assessment of everyday competence indicators especially at early stages of the dementia illness.

Activities of Daily Living↗

PubMed1998

The role of gender in very old age: profiles of functioning and everyday life patterns.

Older men and women have different life contexts as a function of differential longevity and socio-structural opportunities over the life course. The question is whether gender-related differences also occur in psychological and everyday functioning in older adults. Examined were 258 men and 258 women between the ages of 70 and 103 years (M = 85 years), participants in the Berlin Aging Study. Significant gender differences were observed in 13 of 28 aspects of personality, social relationships, everyday activity patterns, and reported well-being. Cluster analysis identified 11 subgroups whose profiles of life conditions and health and psychological functioning could be categorized as more or less desirable (functional). The relative risk of a less desirable profile was 1.6 times higher for women than for men. For older adults, gender as a variable carries differences in physical frailty and life conditions that likely have consequences for psychological functioning.

Activities of Daily Living↗

PubMed1998

Daily life in very old age: everyday activities as expression of successful living.

The goals of this article are (a) to describe the daily life of the very old in terms of frequency, duration, variety, and social and physical contexts of activities, and (b) to examine the effects of background variables (e.g., age, sex, residential and marital status, income, and education) on late life activity engagement. A representative sample of 516 adults aged 70-105 was interviewed about their activities using the Yesterday Interview. In contrast to most research on activity engagement, this measurement approach allows for assessment of both the type and context of activities engaged in during the day preceding the interview. The results indicated high frequencies of obligatory activities but also showed substantial time spent in discretionary activities, with television viewing occupying most of the participants' leisure time. Most activities were done alone and at home. In bivariate and multiple regression analyses, age and residential status had the strongest association with activity frequency, duration, and variety; the oldest-old and those residing in long-term care facilities had lower levels of activity engagement. Results are discussed in terms of their relevance for successful aging.

Activities of Daily Living↗

PubMed1997

Everyday functioning and successful aging: the impact of resources.

The goal of this article is to examine differential aging in everyday functioning between resource-rich and resource-poor older adults. Four groups of older adults were identified on the basis of 2 distinct resource factors: a Sensorimotor-Cognitive factor and a Social-Personality factor. The resource-richest group consisted of those participants who were above the median in both factors; those falling below the median in both factors comprised the resource-poorest group; and 2 additional groups consisted of older adults who were above the median in either 1 of the 2 factors. At the level of mean differences, the 4 groups differed in the length of the waking day, the variability in activities, the frequency of intellectual-cultural and social-relational activities, and resting times. Considering age differences there are more and larger negative age effects in the resource-poorest group than in the resource-richest one. The metamodel of selective optimization with compensation is used to interpret the findings.

Activities of Daily Living↗

PubMed1997

Everyday activity patterns and sensory functioning in old age.

In the present study the authors investigated the relationship between visual and auditory acuity and everyday activity functioning. Participants were 516 older adults (70-103 years; equal numbers of men and women) who were members of the age-stratified Berlin Aging Study. Two categories of everyday activity functioning, perceived competence with basic activities of daily living (BaCo; basic competence) and amount of participation in discretionary social and leisure tasks (ExCo; expanded competence), were examined. The results revealed that sensory acuity, particularly vision, was a significant predictor of both BaCo and ExCo (rs ranging from .32 to .47). Indeed, hearing and vision could explain most of the age-related variance in everyday activities. At the same time, in the context of a broader model, evidence for the differential prediction of BaCo and ExCo was found, although there was also evidence for strong general age-related predictive variance that was common to both measures. Discussion focuses on the role of sensory acuity constructs as mediators of age-related variance in psychological and behavioral outcomes and the potential causal implications of this mediation.

Activities of Daily Living↗

PubMed1995

Potential of cognitive plasticity as a diagnostic instrument: a cross-validation and extension.

Examination of the range and limits of cognitive developmental reserve capacity (plasticity) by means of cognitive training has been proffered as a promising diagnostic strategy for the early identification of Alzheimer's disease. Previous findings of differential gains after cognitive training for healthy older persons and older persons at risk for dementia were supported, rendering cognitive plasticity a criterion by which the overlap in performance distributions between healthy older persons and older persons at risk can be reduced. Stepwise hierarchical regression analyses demonstrated that posttraining scores, which represented developmental reserve capacity, explained significantly more variance in mental health status than pretest or baseline performance. Older persons at risk profited significantly less from training in 2 components of fluid intelligence, figural relations, and inductive reasoning. The authors discuss the possibilities of turning this testing-the-limits procedure into an instrument for screening purposes in clinical practice.

Aged↗

PubMed1994

Maintenance and rehabilitation of independence in old age: an intervention program for staff.

Research has attested to the prevalence of a "dependency-support" and "independence-ignore" script characterizing the interactions between staff and elderly residents in long-term care institutions. To examine whether the scripts could be modified, a staff training program (focusing on communication skills, knowledge about aging, and basic behavior principles) was implemented in 3 different institutions. Observational data on staff-resident interactions in the context of self-care were collected pre- and postintervention. Findings revealed significant changes for the experimental group. Specifically, a decrease in dependence-supportive behavior of staff and an increase in their independence-supportive behavior, an increase in independent behavior of residents, and an increase in independence-related interaction patterns were demonstrated.

Adult↗

PubMed1992

The dependency-support script in institutions: generalization to community settings.

This study tested the generalizability of the dependency-support script, a behavioral system describing and explaining dependent behaviors of the institutionalized elderly. A comparative study with 22 community-dwelling elderly was conducted, which identified typical interaction patterns between the elderly and family members or home health nurses. The dominant interaction pattern in the community setting, too, was the dependency-support script. In addition, however, a significant social response to independent self-care behavior was observed, which created a highly ambivalent response contingency. Independent behaviors were followed about twice as often by an incongruent (dependence-supportive) than by a congruent (independence-supportive) response. Expectations of incompetence and of the helping role are offered as explanations.

Activities of Daily Living↗

PubMed1992

Testing for limits of cognitive reserve capacity: a promising strategy for early diagnosis of dementia?

Examination of the range and limits of cognitive reserve capacity (plasticity) by means of cognitive training is proffered as a promising diagnostic strategy for the early (premorbid) identification of dementia, particularly Alzheimer's disease, in nonclinical populations. First data are presented from a sample of elderly independent-living people classified as healthy or at risk (beginning dementia) on the basis of a standardized psychiatric interview. Randomly assigned groups participated in a cognitive training program based on figural relations, a component of fluid intelligence. Stepwise regression analyses demonstrated that only healthy elderly profited from training and that only post-training scores predicted the psychiatric "at risk" diagnosis. The results hold promise for further development of testing-the-limits of individual differences in cognitive reserve capacity to identify premorbid states of dementia in nonclinical samples.

Aged↗

PubMed1990

The daily life of elderly Germans: activity patterns, personal control, and functional health.

Aging processes are often described as an interacting system of personal and environmental conditions. It is surprising, therefore, to find an almost complete lack of reliable data describing the everyday lives of the elderly in terms of external components such as type of activities, locations, and companionship. The present study is an attempt to remedy this lack of information and thereby provide a basis for a better understanding of aging processes. Forty-nine mobile and independently living elderly people (mean age = 72.7) recorded their daily activities over a period of 6 months. During a randomly selected week per month they kept a prestructured diary about what activities they engaged in, where, when, and with whom. In addition, functional health and personal control beliefs were assessed. The diaries were coded along 37 activity categories (inter-rater reliability estimated via Cohen's Kappa: M = .93), 5 categories for location and 6 categories for companionship. The major findings can be summarized as follows: The typical activity profile is characterized, in terms of highest frequency, by obligatory activities. In terms of time, however, they make up but little more than half of the day, predominantly the mornings. Afternoons and evenings, were mostly spent with leisure activities. The paths of daily lives of the elderly were marked by two geographic domains. The first and foremost is the home, followed by public places. With regard to the relationship between activities and personal control, we find a close relationship particularly when functional health is low.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

PubMed1987

Further observational data on the behavioral and social world of institutions for the aged.

This study is an extension of previous observational work on the social ecology of dependence and independence in the institutionalized elderly. Observations of everyday, naturally occurring interactions between elderly residents of two different long-term institutions and their social partners were extended such that, aside from the identification of type of behavior, the dyadic form and continuity of each behavior was specified. The following were among the major results: (a) Previously found interaction patterns between elderly residents and their social partners, replicated in both a nursing home and a home for the chronically ill, supported the notion of discrepant social ecologies for dependent versus independent behaviors of residents: (b) specification of each behavioral act as to its dyadic form underscored the fact that the interactions were controlled largely by social partners and not by the elderly residents; (c) coding continuity or discontinuity of behavior suggested that independent behaviors were maintained by chaining; and (d) elderly residents in the home for the chronically ill evinced, as expected, more dependence-related behaviors.

Activities of Daily Living↗

PubMed1983

On the social ecology of dependence and independence in elderly nursing home residents: a replication and extension.

A sample of 40 elderly residents was observed for 14 days on each of three consecutive occasions separated by 3 months. The observations focused on interactions involving the elderly resident and social partners. The results indicated a high level of stability across occasions in resident behaviors. The interactional and behavioral profiles observed were similar across length of institutionalization, sex, and health status of residents for the institutional context studied. Examination of interactional patterns for the different resident behaviors, however, revealed quite discrepant social contingencies. Following dependent self-care behaviors of residents, interactional responses by social partners represented a continuous supportive behavior contingency; following independent self-care behaviors, no social contingencies were observed. Similarly, obstructively engaged and nonengaged resident behaviors were not followed by any social contingencies; following constructively engaged behaviors of residents, an intermittent supportive contingency by social partners was found. The results are discussed in relation to learned helplessness and control.

Aged↗

PubMed1980

Etiology of dependence in older nursing home residents during morning care: the role of staff behavior.

Previous findings indicate that elderly nursing home residents' dependent and independent behavior are modifiable and thus partly a function of reinforcing environmental events. The present study was an attempt to explicate such functional relationships in terms of naturally occurring resident--staff interactions. An observational-operant design was implemented with a sample of 17 staff members and 36 elderly nursing home residents. Sequential observations of resident--staff interactions were recorded daily during morning care over a 23-day period. Frequency analysis of each behavior recorded revealed that of the 1,428 observed behaviors in the presence of staff, resident behaviors constituted 563 and staff behavior 865 of the total. Residents performed independent behaviors most frequently, whereas dependence-supportive behavior was the most frequent staff behavior. As to resident--staff interactions, sequential analyses showed that independent behavior by the elderly was followed more often by dependence-supportive than by independence-supportive behavior by the staff. Staff dependence-supportive behavior was the most frequent consequence for dependent behavior by the elderly. The sequential data, with regard to resident--staff interactions in morning-care situations, allow the inference that independent behavior in self-maintenance care is not maintained by staff behavior but perhaps by intrinsic reinforcers or reinforcing agents other than staff, whereas dependent behavior is directly maintained by staff reinforcement.

Activities of Daily Living↗