Combining tape stripping and non-invasive reflectance confocal microscopy : an in vivo model to study skin damage.

BACKGROUND: Evaluation of (immuno)histological and cell biological changes in damaged skin requires often an invasive skin biopsy, making in vivo models inappropriate to study skin damage. Reflectance confocal microscopy (RCM) might overcome this limitation. Therefore, we evaluated the use of a tape-stripping model in combination with RCM to provide morphological data on skin damage and recovery. METHODS: In 25 volunteers, a tape-stripping stimulus was applied. The skin was imaged with RCM during 1 week and 3 mm punch biopsies were obtained. RESULTS: Strong correlations between epidermal thickness determined by RCM and conventional histological measurements were found. RCM thickness measurements correlated well with epidermal proliferation. The 10× or 15× repeated tape-stripping resulted in skin damage similar to acute stripping. Mild repeated tape-stripping showed no skin damage. CONCLUSION: Overall, we demonstrated that non-invasive RCM in combination with tape-stripping could be used as model to obtain morphological and cell biological data on skin-material interactions.

Instrumented assessment of the effect of Botulinum Toxin-A in the medial hamstrings in children with cerebral palsy.

This study examined the sensitivity of an instrumented spasticity assessment of the medial hamstrings (MEH) in children with cerebral palsy (CP). Nineteen children received Botulinum Toxin type A (BTX-A) injections in the MEH. Biomechanical (position and torque) and electrophysiological (surface electromyography, EMG) signals were integrated during manually-performed passive stretches of the MEH at low, medium and high velocity. Signals were examined at each velocity and between stretch velocities, and compared pre and post BTX-A (43 ± 16 days). Average change between pre and post BTX-A was interpreted in view of the minimal detectable change (MDC) calculated from previously published reliability results. Improvements greater than the MDC were found for nearly all EMG-parameters and for torque parameters at high velocity and at high versus low velocity (p<0.03), however large inter-subject variability was noted. Moderate correlations were found between the improvement in EMG and in torque (r=0.52, p<0.05). Biomechanical and electrophysiological parameters proved to be adequately sensitive to assess the response to treatment with BTX-A. Furthermore, studying both parameters at different velocities improves our understanding of spasticity and of the physiological effect of selective tone-reduction. This not only provides a clinical validation of the instrumented assessment, but also opens new avenues for further spasticity research.

Three-dimensional head and trunk movement characteristics during gait in children with spastic diplegia.

This study uses a recently developed trunk model to determine which head and trunk kinematic parameters differentiate children with spastic diplegia from typically developing (TD) children while walking. Differences in head and trunk parameters in relation to the severity of the motor involvement (GMFCS levels) were additionally examined. The trunk model consisted of five segments (pelvis, thorax, head, shoulder line, spine). Discrete kinematic parameters (ROM, mean position) and angular waveforms were compared between 20 children with spastic diplegia (age 9.8 years±2.9 years; GMFCS I: n=10, GMFCS II: n=10) and 20 individually age-matched TD children (9.7 years±3 years). A new measure for overall trunk pathology, the trunk profile score (TPS), was proposed and included in the comparative analysis. Compared to TD children, children with GMFCS II showed a significantly higher TPS and increased ROM for pelvis tilt, for thorax and head in nearly all planes, and the angle of kyphosis. In children with GMFCS I, only ROM of thorax lateral bending was significantly increased. Sagittal ROM differentiated best between GMFCS levels, with higher ROM found in children with GMFCS II. Current results provide new insights into head and trunk kinematics during gait in children with spastic diplegia.

Reliability of head and trunk kinematics during gait in children with spastic diplegia.

This study describes the reliability of a clinically oriented model for three-dimensional movement analysis of head and trunk movements in children with spastic diplegia. The model consists of five rigid segments (head, thorax, pelvis, shoulder line, spine) and includes a detailed analysis of spinal segmental movements. Within and between session reliability during gait was tested in 10 children with spastic diplegia (6-14yrs). Reliability of discrete parameters was assessed with the intraclass correlation coefficient (ICC) and similarity of thorax and pelvis waveforms with the coefficient of multiple correlation (CMC). Measurement errors were calculated for all parameters (SEM, σ). Results indicated acceptable within and between session reliability of discrete parameters for thorax, pelvis, shoulder line, angle of kyphosis and the majority of the spinal segmental angles, reflected by low SEMs (<4°) and most ICCs>0.60. Within and between session waveform errors were below 4°. CMCs ranged from poor to very good, with highest values for movements in the frontal and transversal planes. The angle of lordosis showed lower between session reliability for several discrete parameters, although waveform errors were still below 5°. Head parameters showed lower overall reliability. The results of this study support the reliability of the proposed model. Head kinematic parameters should be interpreted with caution, due to difficulties in standardization. Accurate palpation of the spinal markers, especially the lumbar spine, is critical and demands thorough training of the assessor.

A clinical measurement to quantify spasticity in children with cerebral palsy by integration of multidimensional signals.

Most clinical tools for measuring spasticity, such as the Modified Ashworth Scale (MAS) and the Modified Tardieu Scale (MTS), are not sufficiently accurate or reliable. This study investigated the clinimetric properties of an instrumented spasticity assessment. Twenty-eight children with spastic cerebral palsy (CP) and 10 typically developing (TD) children were included. Six of the children with CP were retested to evaluate reliability. To quantify spasticity in the gastrocnemius (GAS) and medial hamstrings (MEH), three synchronized signals were collected and integrated: surface electromyography (sEMG); joint-angle characteristics; and torque. Muscles were manually stretched at low velocity (LV) and high velocity (HV). Spasticity parameters were extracted from the change in sEMG and in torque between LV and HV. Reliability was determined with intraclass-correlation coefficients and the standard error of measurement; validity by assessing group differences and correlating spasticity parameters with the MAS and MTS. Reliability was moderately high for both muscles. Spasticity parameters in both muscles were higher in children with CP than in TD children, showed moderate correlation with the MAS for both muscles and good correlation to the MTS for the MEH. Spasticity assessment based on multidimensional signals therefore provides reliable and clinically relevant measures of spasticity. Moreover, the moderate correlations of the MAS and MTS with the objective parameters further stress the added value of the instrumented measurements to detect and investigate spasticity, especially for the GAS.

A systematic review of arm activity measures for children with hemiplegic cerebral palsy.

OBJECTIVE: To identify psychometrically sound and clinically feasible assessments of arm activities in children with hemiplegic cerebral palsy for implementation in research and clinical practice. DATA SOURCES: PubMed, CINAHL, Cochrane Library, Web of Science and reference lists of relevant articles were searched. REVIEW METHODS: A systematic search was performed based on the following inclusion criteria: (1) evaluative tools at the activity level according to the International Classification of Functioning, Disability and Health; (2) previously used in studies including children with hemiplegic cerebral palsy aged 2-18 years; (3) at least one aspect of reliability and validity in children with cerebral palsy should be established. Descriptive information, psychometric properties and clinical utility were reviewed. RESULTS: Eighteen assessments were identified of which 11 met the inclusion criteria: eight functional tests and three questionnaires. Five functional tests were condition-specific, three were generic. All functional tests measure different aspects of activity, including unimanual capacity and performance during bimanual tasks. The questionnaires obtain information about the child's abilities at home or school. The reliability and validity have been established, though further use in clinical trials is necessary to determine the responsiveness. CONCLUSIONS: To obtain a complete view of what the child can do and what the child actually does, we advise a capacity-based test (Melbourne Assessment of Unilateral Upper Limb Function), a performance-based test (Assisting Hand Assessment) and a questionnaire (Abilhand-Kids). This will allow outcome differentiation and treatment guidance for the arm in children with cerebral palsy.

Upper limb motor and sensory impairments in children with hemiplegic cerebral palsy. Can they be measured reliably?

PURPOSE: To establish interrater and test-retest reliability of a clinical assessment of motor and sensory upper limb impairments in children with hemiplegic cerebral palsy aged 5-15 years. METHOD: The assessments included passive range of motion (PROM), Modified Ashworth Scale (MAS), manual muscle testing (MMT), grip strength, the House thumb and Zancolli classification and sensory function. Interrater reliability was investigated in 30 children, test-retest reliability in 23 children. RESULTS: For PROM, interrater reliability varied from moderate to moderately high (correlation coefficients 0.48-0.73) and test-retest reliability was very high (>0.81). For the MAS and MMT, total score and subscores for shoulder, elbow, and wrist showed a moderately high to very high interrater reliability (0.60-0.91) and coefficients of >0.78 for test-retest reliability. The reliability for the individual muscles varied from moderate to high. The Jamar dynamometer was found to be highly reliable. The House thumb classification showed a substantial reliability and the Zancolli classification an almost perfect reliability. All sensory modalities had a good agreement. CONCLUSIONS: For all motor and sensory assessments, interrater and test-retest reliability was moderate to very high. Test-retest reliability was clearly higher than interrater reliability. To improve interrater reliability, it was recommended to strictly standardize the test procedure, refine the scoring criteria and provide intensive rater trainings.

Multitude and temporal variability of ecological niches as indicated by the diversity of cultivated bacterioplankton.

The diversity of cultured planktonic bacteria was analyzed. Bacterial strains were isolated from a eutrophic lake (Zwischenahner Meer, Niedersachsen, Germany) at three different sampling dates (October 1997, April and May 1998). Phylogenetic diversity was assessed by polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and sequencing of 16S rRNA gene fragments. Enterobacterial repetitive intergenic consensus (ERIC)-PCR revealed a high genomic diversity within the strain collections, which exceeded the diversity of the 16S rRNA gene sequences considerably. The composition of each of the three strain collections was unique since strains isolated at different dates always exhibited different ERIC-PCR fingerprints. Growth tests with 59 different carbon substrates demonstrated that even strains with identical ERIC-PCR fingerprints, isolated on one sampling date, differed in their physiology. The culturable fraction investigated in the present study constituted a relatively small fraction (

Separation of bacterial cells by isoelectric focusing, a new method for analysis of complex microbial communities.

A simple isoelectric focusing (IEF) method for whole bacterial cells was developed. In a pH gradient of 2 to 10 and an electric field of 11.5 V cm-1, mixtures of cells from the three different bacterial strains Chlorobium limicola 6230, Pseudomonas stutzeri DSM 50227, and Micrococcus luteus DSM 20030 could be separated. A density gradient of Ficoll prevented convective currents in the system. The method was tested with a concentrated mixture of bacteria from a shallow eutrophic lake and yielded up to 10 different bands. Species composition in each IEF band was analyzed by PCR plus denaturing gradient gel electrophoresis (DGGE). Each IEF band exhibited a different species composition. After the separation of cells by IEF three times more 16S ribosomal DNA signals could be detected by DGGE than in the unfractionated natural bacterial community. It is concluded that the resolution of these molecular biological methods is significantly enhanced if cells are first separated by IEF. At the same time, the IEF fractions are enriched for certain species, which can be used in subsequent cultivation experiments.