Schlaf und zirkadiane Rhythmik im Alter

Zusammenfassung: Mit steigendem Alter nimmt die nächtliche Schlafkonsolidierung ab, kurze Nickerchen über den Tag nehmen zu, und die Schlafzeit verschiebt sich in frühere Stunden. Die Schlafregulation hängt von der Interaktion zwischen einem zirkadianen Schrittmacher (biologische Uhr) und dem Schlafhomöostaten (je länger die Wachphase, desto größer der Schlafdruck) ab. Wir konnten an gesunden älteren Personen zeigen, dass sich die Amplitude zirkadianer Rhythmen (z. B. die Melatonin-Sekretion) und die Tiefschlafdauer verringert. Gleichzeitig nimmt die Müdigkeit am Nachmittag zu, wie auch die Tendenz—im Gegensatz zu jüngeren Personen—am frühen Abend einzuschlafen. Da Licht der Hauptzeitgeber ist, um die biologische Uhr zu stabilisieren, brauchen ältere Menschen tagsüber und am Abend genügend Licht und sollten während des Tages keine oder nur kurze Nickerchen machen, um in der Folge den Schlaf in der Nacht zu verbesser

The gastric acid pocket is attenuated in H. pylori infected subjects

Objective Gastric acid secretory capacity in different anatomical regions, including the postprandial acid pocket, was assessed in Helicobacter pylori positive and negative volunteers in a Western population. Design We studied 31 H. pylori positive and 28 H. pylori negative volunteers, matched for age, gender and body mass index. Jumbo biopsies were taken at 11 predetermined locations from the gastro-oesophageal junction and stomach. Combined high-resolution pH metry (12 sensors) and manometry (36 sensors) was performed for 20 min fasted and 90 min postprandially. The squamocolumnar junction was marked with radio-opaque clips and visualised radiologically. Biopsies were scored for inflammation and density of parietal, chief and G cells immunohistochemically. Results Under fasting conditions, the H. pylori positives had less intragastric acidity compared with negatives at all sensors >1.1 cm distal to the peak lower oesophageal sphincter (LES) pressure (p<0.01). Postprandially, intragastric acidity was less in H. pylori positives at sensors 2.2, 3.3 and 4.4 cm distal to the peak LES pressure (p<0.05), but there were no significant differences in more distal sensors. The postprandial acid pocket was thus attenuated in H. pylori positives. The H. pylori positives had a lower density of parietal and chief cells compared with H. pylori negatives in 10 of the 11 gastric locations (p<0.05). 17/31 of the H. pylori positives were CagA-seropositive and showed a more marked reduction in intragastric acidity and increased mucosal inflammation. Conclusions In population volunteers, H. pylori positives have reduced intragastric acidity which most markedly affects the postprandial acid pocket

Schwangerschaftsdepression und deren Behandlung

Zusammenfassung: Etwa 11% aller schwangeren Frauen leiden unter einer behandlungsbedürftigen Depression, welche unbehandelt mit Risiken wie Frühgeburt oder niederem Geburtsgewicht verbunden ist. Da manche Symptome der Depression oft der Schwangerschaft zugeschrieben werden, ist die Diagnose einer Schwangerschaftsdepression nicht immer leicht. Eine weitere Herausforderung ist die Wahl der geeigneten Therapiemaßnahme. Als Behandlungsmöglichkeiten stehen neben Psycho- und Pharmakotherapie auch die Elektrokrampftherapie (EKT) sowie Lichttherapie zur Auswahl. Aktuelle Berichte über Auswirkungen von Antidepressiva auf die Entwicklung des Ungeborenen und postpartale Anpassungsschwierigkeiten führen zu großen Verunsicherungen. Die Entscheidung, welche Therapiemaßnahme ergriffen wird, kann nur mit der werdenden Mutter zusammen getroffen werden; ein sorgfältiges Abwägen der Vor- und Nachteile der Behandlung ist dafür Voraussetzun

Standardized assessment of walking capacity after spinal cord injury: the European network approach

OBJECTIVES: After a spinal cord injury (SCI), walking function is an important outcome measure for rehabilitation and new treatment interventions. The current status of four walking capacity tests that are applied to SCI subjects is presented: the revised walking index for spinal cord injury (WISCI II), the 6 minute walk test (6MinWT), 10 meter walk test (10MWT) and the timed up and go (TUG) test. Then, we investigated which categories of the WISCI II apply to SCI subjects who participated in the European Multicenter Study of Human Spinal Cord Injury (EM-SCI), and the relationship between the 10MWT and the TUG. METHODS: In the EM-SCI, the walking tests were applied 2 weeks and 1, 3, 6 and 12 months after SCI. We identified the WISCI II categories that applied to the EM-SCI subjects at each time point and quantified the relationship between the 10MWT and the TUG using Spearman's correlation coefficients (rho) and linear regression. RESULTS: Five WISCI II categories applied to 71% of the EM-SCI subjects with walking ability, while 11 items applied to 11% of the subjects. The 10MWT correlated excellently with the TUG at each time point (rho>0.80). However, this relationship changed over time. One year after SCI, the time needed to accomplish the TUG was 1.25 times greater than the 10MWT time. DISCUSSION: Some categories of the WISCI II appear to be redundant, while some discriminate to an insufficient degree. In addition, there appear to be ceiling effects, which limit its usefulness. The relationship between the 10MWT and TUG is high, but changes over time. We suggest that, at present, the 10MWT appears to be the best tool to assess walking capacity in SCI subjects. Additional valuable information is provided by assessing the needs for walking aids or personal assistance. To ensure comparability of study results, proposals for standardized instructions are presented

Difficulty of elderly SCI subjects to translate motor recovery -"body function"- into activity of daily living

The objective of this retrospective analysis was to determine whether outcome of body functions and activities as well as length of stay of inpatient rehabilitation is related to age in patients with traumatic spinal cord injury (SCI). Data were collected from a European network of 17 SCI rehabilitation centers (EM-SCI) and 237 traumatic SCI subjects were included. Assessments were performed at one, six and twelve months after SCI. The measures analyzed were: motor score according to the American Spinal Injury Association, Spinal Cord Independence Measure (SCIM), gait speed and length of stay. Correlation analysis was applied to quantify the association between age and change in the outcome measures. A positive relationship was found between age and neurological recovery in both the first and second 6 month- period of assessment. A negative relationship was found between age and change in SCIM in the second six month period after SCI. A negative relationship between age and gait speed was observed in the first half year. Length of stay was not associated with age. It is concluded that age is an important determining factor for functional outcome after SCI and that elderly patients have difficulties in translating an improvement in neurological outcome into functional changes. Therefore, rehabilitation approaches should focus on functional training in elderly subjects

A comparison of healthy human and swine articular cartilage dynamic indentation mechanics

Articular cartilage is a multicomponent, poroviscoelastic tissue with nonlinear mechanical properties vital to its function. A consequent goal of repair or replacement of injured cartilage is to achieve mechanical properties in the repair tissue similar to healthy native cartilage. Since fresh healthy human articular cartilage (HC) is not readily available, we tested whether swine cartilage (SC) could serve as a suitable substitute for mechanical comparisons. To a first approximation, cartilage tissue and surgical substitutes can be evaluated mechanically as viscoelastic materials. Stiffness measurements (dynamic modulus, loss angle) are vital to function and are also a non-destructive means of evaluation. Since viscoelastic material stiffness is strongly strain rate dependent, stiffness was tested under different loading conditions related to function. Stiffness of healthy HC and SC specimens was determined and compared using two non-destructive, mm-scale indentation test modes: fast impact and slow sinusoidal deformation. Deformation resistance (dynamic modulus) and energy handling (loss angle) were determined. For equivalent anatomic locations, there was no difference in dynamic modulus. However, the HC loss angle was ~35% lower in fast impact and ~12% higher in slow sinusoidal mode. Differences seem attributable to age (young SC, older HC) but also to species anatomy and biology. Test mode-related differences in human-swine loss angle support use of multiple function-related test modes. Keeping loss angle differences in mind, swine specimens could serve as a standard of comparison for mechanical evaluation of e.g. engineered cartilage or synthetic repair material

Double-network acrylamide hydrogel compositions adapted to achieve cartilage-like dynamic stiffness

Since articular cartilage has a limited potential for spontaneous healing, various techniques are employed to repair cartilage lesions. Acrylate-based double-network (DN) hydrogels containing ~90% water have shown promising properties as repair materials for skeletal system soft tissues. Although their mechanical properties approach those of native cartilage, the critical factor—stiffness—of DN-gels does not equal the stiffness of articular cartilage. This study investigated whether revised PAMPS/PAAm compositions with lower water content result in stiffness parameters closer to cartilage. DN-gels containing 61, 86 and 90% water were evaluated using two non-destructive, mm-scale indentation test modes: fast-impact (FI) and slow-sinusoidal (SS) deformation. Deformation resistance (dynamic modulus) and energy handling (loss angle) were determined. The dynamic modulus increased with decreasing water content in both testing modes. In the 61% water DN-gel, the modulus resembled that of cartilage (FI-mode: DN-gel = 12, cartilage = 17; SS-mode: DN-gel = 4, cartilage = 1.7MPa). Loss angle increased with decreasing water content in fast-impact, but not in slow-sinusoidal deformation. However, loss angle was still much lower than cartilage (FI: DN-gel = 5, cartilage = 11; SS: DN-gel = 10, cartilage = 32°), indicating somewhat less ability to dissipate energy. Overall, results show that it is possible to adapt DN-gel composition to produce dynamic stiffness properties close to normal articular cartilag