The neural foundations of handedness: insights from a rare case of deafferentation.

The role of proprioceptive feedback on motor lateralization remains unclear. We asked whether motor lateralization is dependent on proprioceptive feedback by examining a rare case of proprioceptive deafferentation (GL). Motor lateralization is thought to arise from asymmetries in neural organization, particularly at the cortical level. For example, we have previously provided evidence that the left hemisphere mediates optimal motor control that allows execution of smooth and efficient arm trajectories, while the right hemisphere mediates impedance control that can achieve stable and accurate final arm postures. The role of proprioception in both of these processes has previously been demonstrated empirically, bringing into question whether loss of proprioception will disrupt lateralization of motor performance. In this study, we assessed whether the loss of online sensory information produces deficits in integrating specific control contributions from each hemisphere by using a reaching task to examine upper limb kinematics in GL and five age-matched controls. Behavioral findings revealed differential deficits in the control of the left and right hands in GL and performance deficits in each of GL's hands compared with controls. Computational simulations can explain the behavioral results as a disruption in the integration of postural and trajectory control mechanisms when no somatosensory information is available. This rare case of proprioceptive deafferentation provides insights into developing a more accurate understanding of handedness that emphasizes the role of proprioception in both predictive and feedback control mechanisms.NEW & NOTEWORTHY The role of proprioceptive feedback on the lateralization of motor control mechanisms is unclear. We examined upper limb kinematics in a rare case of peripheral deafferentation to determine the role of sensory information in integrating motor control mechanisms from each hemisphere. Our empirical findings and computational simulations showed that the loss of somatosensory information results in an impaired integration of control mechanisms, thus providing support for a complementary dominance hypothesis of handedness.

Coxa profunda in the diagnosis of pincer-type femoroacetabular impingement and its prevalence in asymptomatic subjects.

In many papers, the diagnosis of pincer-type femoroacetabular impingement (FAI) is attributed to the presence of coxa profunda. However, little is known about the prevalence of coxa profunda in the general population and its clinical relevance. In order to ascertain its prevalence in asymptomatic subjects and whether it is a reliable indicator of pincer-type FAI, we undertook a cross-sectional study between July and December 2013. A total of 226 subjects (452 hips) were initially screened. According to strict inclusion criteria, 129 asymptomatic patients (257 hips) were included in the study. The coxa profunda sign, the crossover sign, the acetabular index (AI) and lateral centre-edge (LCE) angle were measured on the radiographs. The median age of the patients was 36.5 years (28 to 50) and 138 (53.7%) were women. Coxa profunda was present in 199 hips (77.4%). There was a significantly increased prevalence of coxa profunda in women (p < 0.05) and a significant association between coxa profunda and female gender (p < 0.001) (92% vs 60.5%). The crossover sign was seen in 36 hips (14%), an LCE > 40° in 28 hips (10.9%) and an AI < 0º in 79 hips (30.7%). A total of 221 normal hips (79.2%) (normal considering the crossover) had coxa profunda, a total of 229 normal hips (75.5%) (normal considering the LCE) had coxa profunda and a total of 178 normal hips (75.3%) (normal considering AI) had coxa profunda. When the presence of all radiological signs in the same subject was considered, pincer-type FAI was found in only two hips (one subject). We therefore consider that the coxa profunda sign should not be used as a radiological indicator of pincer-type FAI. We consider profunda to be a benign alteration in the morphology of the hip with low prevalence and a lack of association with other radiological markers of FAI. We suggest that the diagnosis of pincer-type FAI should be based on objective measures, in association with clinical findings.

Association between tobacco smoking and prognosis of occupational hand eczema: a prospective cohort study.

BACKGROUND: Hand eczema (HE) is a common occupational skin disease. Tobacco smoking is known to be associated with adverse cutaneous effects. However, its influence on the prognosis of occupational HE has not yet been studied. OBJECTIVES: To evaluate relations between smoking status, severity and prognosis of occupational HE in patients taking part in an interdisciplinary tertiary individual prevention programme (TIP). METHODS: In a prospective, multicentre, cohort study 1608 patients with occupational HE taking part in a TIP were recruited and followed up for 3 years. The clinical and self-reported outcome data of smokers and nonsmokers were compared. RESULTS: Nonsmokers and smokers were equally distributed. During the TIP, the average self-reported daily cigarette consumption and the severity of HE decreased significantly (P < 0·01). However, at all time points HE was significantly more severe in smokers than in nonsmokers. This association was not dependent on the self-reported number of cigarettes smoked daily. Smokers had significantly more days of absence from work due to occupational HE than nonsmokers in the year before the TIP (P < 0·01) and in the following year (P = 0·02). After the TIP, smokers reported significantly more often that they had to give up their occupation (P = 0·02) than nonsmokers. CONCLUSIONS: The severity of occupational HE is increased in smokers. Tobacco smoking is associated with a higher number of days of absence from work and with not staying in the workforce owing to occupational HE. Thus, smoking confers a worse prognosis and interferes with the outcome of prevention programmes.

An evaluation of the SPIFE 3000 semi-automated gel electrophoresis system for the identification of hemoglobin variants and comparison of relative electrophoretic mobilities with manual gel electrophoresis methods.

Laboratory identification of hemoglobin (Hb) variants can involve multiple techniques. The use of semi-automated instruments that perform gel electrophoresis and staining, such as the SPIFE 3000 electrophoresis system, can greatly reduce the labor required for these commonly used techniques. We performed a comparison of the method involved in SPIFE 3000 system with those of manual gel electrophoresis. A total of 22 540 samples were analyzed using the SPIFE 3000, and compared with mobilities on cellulose acetate and citrate agar gels using standard manual methods. The results were compared using relative electrophoretic mobilities (REM). Of the 191 Hb variants identified, only 13 had REM that differed from manual electrophoresis when analyzed using the SPIFE 3000 system. One variant (Hb O-Indonesia) showed different mobility on both acid and alkaline gels, two (Hb E, Hb Sunshine Seth) on alkaline gel only, and 10 (Hbs N-Baltimore, N-Seattle, O-Arab, Shelby, Summer Hill, Tak, Hasharon, M-Iwate, Q-Iran, and Setif) on acid gels only. The SPIFE 3000 semi-automated electrophoresis system produces similar results when compared with those of standard manual electrophoresis methods.

[Tick bites and borreliosis in children attending forest kindergarten: a challenge for prevention]. / Zeckenstich- und Borrelioserisiko bei Kindern in Waldkindergärten: eine Herausforderung für die Prävention.

AIM: The aim of this study was to analyse the influence of preventive measures on the risk of being bitten by a tick and of suffering from borreliosis in children attending so-called 'forest kindergartens' (nurseries located in forested areas where children spend all-season full-time outdoors), compared to children attending regular kindergartens. In addition, we aimed to analyse sources of information and the risk of being bitten more than once. METHODS: 53 kindergartens (25 forest kindergartens, 28 regular kindergartens) in the state of Baden-Württemberg, Germany participated in this study and protective parental behaviour was recorded. In a prospective cohort study, the numbers of tick bites and cases of borreliosis were recorded monthly (March to October 2004) using a questionnaire. The influence of preventive measures was estimated using multivariate log-binomial regression. RESULTS: Altogether, 1707 children of 'forest kindergartens' (506 children) and regular kindergartens (1201 children) were included. Parental protective behaviour was significantly better in forest kindergartens compared to regular kindergartens. There were no substantial differences between effect estimates after stratification for parental protective behaviour. For children attending a 'forest kindergarten, the adjusted risk ratio of being tick bitten was 2.6 (3.3-3.0) which was only slightly different from the unadjusted risk, ratio. CONCLUSION: Although protective parental behaviour in 'forest kindergarten' children was significantly better compared to regular kindergarten, children in forest kindergartens are at a considerable risk of tick bites and borreliosis. Implementing effective preventive measures against borreliosis represents a public health challenge.

[Quality of primary medical care after in-patient stroke rehabilitation]. / Versorgungsqualität von Patienten nach Schlaganfallrehabilitation. (Hausärztliche Nordbaden-Schlaganfallnachsorgestudie [HANS]).

PURPOSE: Since only insufficient information concerning the further development of patients after stroke and rehabilitation is currently available, and since the quality of care provided by family doctors is often classified as insufficient, this quality of care was to be examined on the basis of the rehabilitation results. Of particular interest were the co-operation, the therapeutical quality standards and the risk management, as well as the quality of life and compliance of the patients. METHODS: In 2000, all 223 stroke patients were asked prior to their discharge from three large rehabilitation clinics in North Baden, and subsequently their 210 family doctors, whether they were prepared to participate in this follow-up study. The participating patients were examined at their discharge from the clinic as well as 6 and 18 months later using a standardised documentation package, and quality circles for family doctors were initiated. RESULTS: All patients with atrial fibrillation were treated to prevent thrombosis. Smoking showed a positive trend. Quality of life and knowledge of the sickness trend to increase, depressiveness decreases. 60 % of the contacted family doctors participated in the study, 29 % (33 out of 114 physicians at the end of the study) contributed to improve interdisciplinary co-operation. Although 87 % of the patients said to be well informed, 25 % were dissatisfied with their own compliance. CONCLUSION: The quality of care of stroke patients by family doctors as assessed by indicators for secondary prevention and quality of life is satisfactory under present conditions. Apart from the hypertension control there was no negative trend. However, participation of GPs was insufficient. Co-operative after-care by GP can relatively easily stabilise health conditions following inpatient rehabilitation.

Surveillance scheme for occupational skin disease in the Saarland, FRG. First report from BKH-S.

Occupational skin disease (OSD) is a significant public health concern. To keep OSDs under surveillance, a register of OSDs (BKH-S) was implemented in 1999 in the Saarland, FRG. We conducted a population-based register study to analyse all initial reports of OSDs reported to the BKH-S. 336 cases were prospectively assessed from July 1999 to June 2001. In 78% (n = 263) of the cases an occupational cause for the skin disease was stated, 91% (n = 240) of which fell within 16 occupational groups. This is equivalent to 6.8 cases per 10,000 workers per year within these occupational groups. Notably, young age groups (median age 35 years) were affected with a female predominance. The most frequent final diagnosis was irritant contact dermatitis (75%) followed by allergic contact dermatitis (34%) and atopic dermatitis (19%). The overall prevalence of occupationally relevant delayed-type reactors was 21% and of immediate-type reactors 17%. Work-related delayed-type sensitizations to potassium dichromate (n = 8) and immediate-type sensitizations to natural rubber latex (n = 11) were the most frequently observed. Questionnaire results showed frequent occupational skin contact with wet work (59%), detergents (48%), and disinfectants (38%). The second valid surveillance scheme for OSD in the FRG has been introduced and can be made available for further analysis.

Learning to move amid uncertainty.

We studied how subjects learned to make movements against unpredictable perturbations. Twelve healthy human subjects made goal-directed reaching movements in the horizontal plane while holding the handle of a two-joint robotic manipulator. The robot generated viscous force fields that perturbed the limb perpendicular to the desired direction of movement. The amplitude (but not the direction) of the viscous field varied randomly from trial to trial. Systems identification techniques were employed to characterize how subjects adapted to these random perturbations. Subject performance was quantified primarily using the peak deviation from a straight-line hand path. Subjects adapted their arm movements to the sequence of random force-field amplitudes. This adaptive response compensated for the approximate mean from the random sequence of perturbations and did not depend on the statistical distribution of that sequence. Subjects did not adapt by directly counteracting the mean field strength itself on each trial but rather by using information about perturbations and movement errors from a limited number of previous trials to adjust motor commands on subsequent trials. This strategy permitted subjects to achieve near-optimal performance (defined as minimizing movement errors in a least-squares sense) while maintaining computational efficiency. A simple model using information about movement errors and perturbation amplitudes from a single previous trial predicted subject performance in stochastic environments with a high degree of fidelity and further predicted key performance features observed in nonstochastic environments. This suggests that the neural structures modified during motor adaptation require only short-term memory. Explicit representations regarding movements made more than a few trials in the past are not used in generating optimal motor responses on any given trial.

Impedance control and internal model formation when reaching in a randomly varying dynamical environment.

We investigated the effects of trial-to-trial, random variation in environmental forces on the motor adaptation of human subjects during reaching. Novel sequences of dynamic environments were applied to subjects' hands by a robot. Subjects reached first in a "mean field" having a constant gain relating force and velocity, then in a "noise field," having a gain that varied randomly between reaches according to a normal distribution with a mean identical to that of the mean field. The unpredictable nature of the noise field did not degrade adaptation as quantified by final kinematic error and rate of adaptation. To achieve this performance, the nervous system used a dual strategy. It increased the impedance of the arm as evidenced by a significant reduction in aftereffect size following removal of the noise field. Simultaneously, it formed an internal model of the mean of the random environment, as evidenced by a minimization of trajectory error on trials for which the noise field gain was close to the mean field gain. We conclude that the human motor system is capable of predicting and compensating for the dynamics of an environment that varies substantially and randomly from trial to trial, while simultaneously increasing the arm's impedance to minimize the consequence of errors in the prediction.

Microchip technology in drug delivery.

The realization that the therapeutic efficacy of certain drugs can be affected dramatically by the way in which they are delivered has created immense interest in controlled drug delivery systems. Much previous work in drug delivery focused on achieving sustained drug release rates over time, while a more recent trend is to make devices that allow the release rate to be varied over time. Advances in microfabrication technology have made an entirely new type of drug delivery device possible. Proof-of-principle experiments have shown that silicon microchips have the ability to store and release multiple chemicals on demand. Future integration of active control electronics, such as microprocessors, remote control units, or biosensors, could lead to the development of a 'pharmacy on a chip,' ie 'smart' microchip implants or tablets that release drugs into the body automatically when needed.

Effectiveness of a decentralized, community-related approach to reduce cardiovascular disease risk factor levels in Germany.

AIMS: Conventional community-oriented prevention programmes have been moderately successful in reducing cardiovascular disease risk factor levels in the population. Within the German Cardiovascular Prevention Study, a new decentralized and community-related form of preventive intervention was tested. METHODS AND RESULTS: Interested lay people and general practitioners co-operated in developing activities conducive towards a healthier lifestyle in two towns. Changes in risk factor levels were evaluated by repeated surveys of independent cross-sectional samples in two intervention communities (n=3460, baseline; 2561, final). National survey data (n=4788, baseline; 5311, final) were used to describe secular trends. Six years after the onset of intervention activities the following changes in risk factor prevalence for both sexes combined were observed in the intervention communities (95% CI in brackets): smoking -10.5% (-17.6 to -3.4); hypertension -29.0% (-38.1 to -19. 9); total cholesterol >/=250 mg. dl(-1)-8.1% (-15.4 to -0.9). In contrast to a national increase in the prevalence of obesity, this rate remained stable in the intervention communities. CONCLUSION: Initiating preventive activities developed by community members under the responsibility of local doctors is effective in lowering cardiovascular risk factors at community level. Unlike traditional intervention programmes this new approach does not require external funding and guidance.

Persistence of motor adaptation during constrained, multi-joint, arm movements.

We studied the stability of changes in motor performance associated with adaptation to a novel dynamic environment during goal-directed movements of the dominant arm. Eleven normal, human subjects made targeted reaching movements in the horizontal plane while holding the handle of a two-joint robotic manipulator. This robot was programmed to generate a novel viscous force field that perturbed the limb perpendicular to the desired direction of movement. Following adaptation to this force field, we sought to determine the relative role of kinematic errors and dynamic criteria in promoting recovery from the adapted state. In particular, we compared kinematic and dynamic measures of performance when kinematic errors were allowed to occur after removal of the viscous fields, or prevented by imposing a simulated, mechanical "channel" on movements. Hand forces recorded at the handle revealed that when kinematic errors were prevented from occurring by the application of the channel, recovery from adaptation to the novel field was much slower compared with when kinematic aftereffects were allowed to take place. In particular, when kinematic errors were prevented, subjects persisted in generating large forces that were unnecessary to generate an accurate reach. The magnitude of these forces decreased slowly over time, at a much slower rate than when subjects were allowed to make kinematic errors. This finding provides strong experimental evidence that both kinematic and dynamic criteria influence motor adaptation, and that kinematic-dependent factors play a dominant role in the rapid loss of adaptation after restoring the original dynamics.

Microchips as Controlled Drug-Delivery Devices.

Controlled-release systems are common in a number of product areas, including foods, cosmetics, pesticides, and paper. Microencapsulated systems, for example, are used for the release of flavors and vitamins in foods, fragrances in perfumes, and inks in carbonless copy paper. Controlled-release systems for drug delivery first appeared in the 1960s and 1970s. In the past three decades, the number and variety of controlled release systems for drug-delivery applications has increased dramatically. Many of these use polymers having particular physical or chemical characteristics such as biodegradability, biocompatibility, or responsiveness to pH or temperature changes. However, recent advances in the field of microfabrication have created the possibility of a new class of controlled-release systems for drug delivery, namely, that of small, programmable devices. Their small size, potential for integration with microelectronics, and ability to store and release chemicals on demand could make controlled-release microchips useful in a number of areas, including medical diagnostics, analytical chemistry, chemical detection, industrial process monitoring and control, combinatorial chemistry, microbiology, and fragrance delivery. More importantly, drug-delivery microchips resulting from this convergence of controlled release and microfabrication technologies may provide new treatment options to clinicians in their fight against disease.

Control strategies for the transition from multijoint to single-joint arm movements studied using a simple mechanical constraint.

Changes were studied in neuromotor control that were evoked by constraining the motion of the elbow joint during planar, supported movements of the dominant arm in eight normal human subjects. Electromyograph (EMG) recordings from shoulder and arm muscles were used to determine whether the normal multijoint muscle activity patterns associated with reaching to a visual target were modified when the movement was reduced to a single-joint task, by pinning the elbow to a particular location in the planar work space. Three blocks of 150 movements each were used in the experiments. Subjects were presented with the unconstrained task in the first and third blocks with an intervening block of constrained trials. Kinematic, dynamic, and EMG measures of performance were compared across blocks. The imposition of the pin constraint caused predictable changes in kinematic performance, in that near-linear motions of the hand became curved. This was followed by changes in limb dynamic performance at the elbow. However, changes in EMG activity at the shoulder lagged the kinematic changes substantially (by about 15 trials). The gradual character of the changes in EMG timing does not support a primary role for segmental reflex action in mediating the transition between multijoint and single-joint control strategies. Furthermore, the scope and magnitude of these changes argues against the notion that human motor performance is driven by the optimization of muscle- or joint-related criteria alone. The findings are best described as reflecting the actions of a feedforward adaptive controller that has properties that are modified progressively according to the environmental state.

[The problem of evidence-based guidelines using the example of the treatment of obesity]. / Zur Problematik Evidenz-basierter Leitlinien am Beispiel der Adipositas-Behandlung.

Despite many therapeutic strategies used by experts and general practitioners, the obesity problem has still increased in the developed countries. Therefore it is necessary to provide evidence-based references for good clinical practice. The guideline presented in Cologne in 1997 was published in an improved form in 1998. However, the consequences and circumstances do not only promise benefit but lead to new questions: Where are the indications for implementation and the participation of the main users, the general practitioners? Why should the procedures of tests and consensus not used additionally? The co-morbidity, biography, genetics, and the number of relapses of patients are probably not emphasized enough, the use of drugs could be considered more carefully. Although the reviewed guideline is important, there is a lack in providing the information and in advice for procedures of co-operation in primary health care. The great therapeutic problem and understanding for the daily practice has not been estimated enough.

Place therapies for older adults: conceptual and interventive approaches.

The study of place transitions-moves between places as well as changes occurring in environments of elders who age in place-is a relatively new, diverse research area of high relevance for adult developmentalists and gerontologists. This article explores the usefulness of a tractable model of environmental stress and proposes three potential "place therapies" that may minimize the negative impacts of place transitions upon older adults. Specifically, a transactional model of environmental stress linked to behavior setting theory is proposed for understanding both positive and negative outcomes associated with different kinds of place transitions. Three distinct "place therapies" are considered as interventions that may hold promise for preventing, ameliorating, and enriching the diverse impacts of place transitions on older adults and their environmental milieu.

[Risk factors for recurrence in bipolar manic-depressive patients]. / Einflüsse auf die Rückfälligkeit bipolar Manisch-Depressiver.

A prospective multidimensional study with 71 remitted bipolar outpatients (37 bipolars without, 34 with psychotic symptoms during acute mania) was made to assess relevant influential factors on relapse and readmission to hospital: characteristic data of previous course, psycho(patho)logical state and personality after remission, personality disorders, and ways of coping. In the course of the 5 years after the first examination, 48% of the patients were readmitted, 60% of them because of a (schizo)manic state. The study confirms the prognostic relevance of past course, e.g. number of previous episodes and mania-quotient. A further risk-factor are residual psychopathological alterations which persist after remission ("negative symptoms" of strictly bipolars, increased vulnerability for dynamic derailment for the bipolars with psychotic symptoms). Patients with "syntonic" personality in the free interval suffered less relapses. The relevance of other personality traits differed in the diagnostic subgroups of nonpsychotic and psychotic bipolars. Active coping was positively correlated with staying healthy, but the correlations were weak.

Four years of practice-based and exercise-supported behavioural medicine in one community of the German CINDI area. Countrywide Integrated Non-Communicable Diseases Intervention.

The main goal of the preventive intervention study in one community of the German CINDI (Countrywide Integrated Non-Communicable Diseases Intervention programme of the WHO) area was to improve cardiovascular health by reducing the risk factors smoking, hypertension, obesity, hypercholesterolaemia, and by changing sedentary lifestyle. The intervention was performed by using the special "Three-Level-Strategy", which is characterised by activities of primary care physicians in the usual consulting hour (1st level), with patient groups in their practices (2nd level), and at community level (3rd level) where a special work group and a co-ordinating general practice are co-operating. To evaluate the occurrence of the risk factors in practice and the local population, four cross-sectional random samples (N(total) = 4881) were carried out in seven practices from 1992 to 1995. On the community level, 23 special exercise-based health groups (N(total) = 600) were established and were investigated by means of a questionnaire, related to behaviour and health beliefs. A "Local Health Information System" facilitated the evaluation, the management of the data, and the organisation of the health programme. The results of the practice samples showed a significant reduction of smoking (-17.8%) and hypertension (-31.5%) (p < 0.01). The exercise-based groups were combined with nutritional counselling or relaxation and were accepted very well by the participants (83.8%). The participants considerably improved their health behaviour: 82% discussed health in their family, 37.3% stated an increase of healthy nutrition, 52% of relaxation; 86.2% intended to regularly increase physical activity in leisure time and 82 % could not imagine regular health training without exercise meetings. We conclude that the practice-based "Three-Level-Strategy" provides a strong support for successful long-term prevention of cardiovascular risk, particularly, when exercise-based health training sessions are performed in order to change sedentary lifestyle. When organised on community level, they might have a positive impact on the health behaviour of the whole community. Physical activity can be used as a "prodrug" for health promotion in a holistic way.

[What can family physicians contribute to health promotion in schools?]. / Welchen Beitrag können niedergelassene Arzte zur Gesundheitsförderung an Schulen leisten?

Although several German schools have developed and tested concepts of a goal-directed health education, a stable and continuous implementation is missing. In this field free-practising physicians can support public health efforts. In the area Bruchsal/Ostringen it is demonstrated, that especially those primary care physicians, who work according to the "Three-Level-Concept of Free-Practising Physicians", can successfully use their geographical and social proximity to schools in their neighbourhood for a log-lasting implementation of recurring health-related activities. Within ten years 1389 students in schools, further ca. 500 outside schools, were directly included in interactive learning in the framework of preventive measures, e.g. during school health days. 10 physicians (4 of them continuously) cooperated in these activities, which had been planned in close collaboration with teachers and parents, considering the different age groups. From the very beginning--although sometimes limited in scale--each activity was evaluated. Pupils in the age group 10-12 years generally showed the highest interest in health-related diet, 17-26% were physically more active. Promising are the results with respect to smoking: one fifth of the smoking students intended to quit as a consequence of the health activities in their schools.