Background and purpose Animal models of skeletal muscle injury should be thoroughly described and should mimic the clinical situation. We established a model of a critical size crush injury of the soleus muscle in rats. The aim was to describe the time course of skeletal muscle regeneration using mechanical, histological, and magnetic resonance (MR) tomographic methods.Methods Left soleus muscles of 36 Sprague-Dawley rats were crushed in situ in a standardized manner. We scanned the lower legs of 6 animals by 7-tesla MR one week, 4 weeks, and 8 weeks after trauma. Regeneration was evaluated at these times by in vivo measurement of muscle contraction forces after fast-twitch and tetanic stimulation (groups 1W, 4W, 8W; 6 per group). Histological and immunohistological analysis was performed and the amount of fibrosis within the injured muscles was determined histomorphologically.Results MR signals of the traumatized soleus muscles showed a clear time course concerning microstructure and T1 and T2 signal intensity. Newly developed neural endplates and myotendinous junctions could be seen in the injured zones of the soleus. Tetanic force increased continuously, starting at 23% (SD 4) of the control side (p < 0.001) 1 week after trauma and recovering to 55% (SD 23) after 8 weeks. Fibrotic tissue occupied 40% (SD 4) of the traumatized muscles after the first week, decreased to approximately 25% after 4 weeks, and remained at this value until 8 weeks.Interpretation At both the functional level and the morphological level, skeletal muscle regeneration follows a distinct time course. Our trauma model allows investigation of muscle regeneration after a standardized injury to muscle fibers.
Objective: To compare different approaches (visual estimation of individual BMI curves with polynomial models) to estimate age at adiposity rebound (AR), as different approaches might lead to different results. AR has been suggested as a critical period between intra-uterine life and early adulthood, and recent data showed that early age at AR is associated with higher body mass later in life. Methods: Longitudinal anthropometric data from the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study were used to obtain individual BMI growth curves. We then compared the visual estimation approach to polynomial models in three different scenarios reflected by different data sets: an idealistic, an realistic, and a realistic scenario with imputed values. Results: In all three scenarios, the visual estimation yielded significantly higher estimates than the polynomial models of 2nd or 3rd order. Cross-tabulations of groups of age at AR (early, medium, and late) showed that truly concordant classification was low, ranging only from 51 to 63%. A closer examination of the data indicated that the differences in estimates were mainly due to differences in the underlying definitions: the polynomial models select the nadir in the growth curve as the age at AR, whereas the visual estimation deviates from this concept in those cases where there is plateau in the growth curve. In the latter instance, the turning point of the growth curve before its increase is selected as the age at rebound. Only when the underlying criteria for the estimation of AR with the visual approach were modified, could concordant results between the two approaches be obtained. Considering the underlying physiological basis, it became clear that approaches which determine AR by simply identifying the nadir in the BMI curve do not reflect AR appropriately. This refers to those cases in which the nadir in the growth curve and the turning point at the onset of the adiposity increase are not identical. Conclusions: Estimating AR with the visual approach appears to best reflect the physiological basis of the AR, and is also preferable, because it resulted in the lowest number of children with missing estimates for age at AR.
Mesenchymal stem cell (MSC) therapy is a promising approach for regaining muscle function after trauma. Prior to clinical application, the ideal time of transplantation has to be determined. We investigated the effects of immediate and delayed transplantation. Sprague-Dawley rats received a crush trauma to the left soleus muscle. Treatment groups were transplanted locally with 2 × 10(6) autologous MSCs, either immediately or 7 days after trauma. Saline was used as sham therapy. Contraction force tests and histological analyses were performed 4 weeks after injury. GFP-labelled MSCs were followed after transplantation. The traumatized soleus muscles of the sham group displayed a reduction of twitch forces to 36 ± 17% and of tetanic forces to 29 ± 11% of the non-injured right control side, respectively. Delayed MSC transplantation resulted in a significant improvement of contraction maxima in both stimulation modes (twitch, p = 0.011; tetany, p = 0.014). Immediate transplantation showed a significant increase in twitch forces to 59 ± 17% (p = 0.043). There was no significant difference in contraction forces between muscles treated by immediate and delayed cell transplantation. We were able to identify MSCs in the interstitium of the injured muscles up to 4 weeks after transplantation. Despite the fundamental differences of the local environment, which MSCs encounter after transplantation, similar results could be obtained with respect to functional muscle regeneration. We believe that transplanted MSCs residing in the interstitial compartment evolve their regenerative capabilities through paracrine pathways. Our data suggest a large time window of the therapeutical measures.
OBJECTIVE:To compare length and stature measurements of young children and to examine the relevance of any difference for comparison with body mass index (BMI) references designed for use from birth to adulthood. SUBJECTS: A total of 426 2-y-old and 525 3-y-old children included in the Dortmund Nutritional and Anthropometrical Longitudinally Designed (DONALD) Study. DATA ANALYSIS: Length and stature were measured to the nearest millimetre using a stadiometre. Agreement between both measurements at age 2 and 3 y, respectively, was determined by mean differences and by comparison with the German BMI reference. RESULTS: The average length of 2-y-old girls and boys was 88.3 (3.1) and 89.9 (3.2) cm, mean differences (stature minus length) were À0.47 (0.65) and À0.45 (0.64) cm. The corresponding BMI values were 16.18 (1.3) and 16.46 (1.2) kg/m 2 , with mean differences of þ 0.17 (0.24) and þ 0.16 (0.23). According to stature, 9.4% of the girls and 10.8% of the boys were overweight (490th percentile), while length classified 7.1 and 9.4% as overweight. Similar mean differences between length and stature were observed at age 3 y: À0.53 (0.62) and À0.47 (0.65) cm in height and þ 0.17 (0.20) and þ 0.14 (0.20) kg/m 2 in the BMI of girls and boys, respectively. According to stature, 7.6 and 7.3% were overweight as opposed to 5.4 and 4.8% using length. The observed differences increased with higher BMI levels. CONCLUSION: Changing measurements from length to stature results in an upward shift of BMI, not reflected in current European BMI references. This small but systematic error may result in misinterpretation of individual BMI levels or trend observations.
At the beginning of the treatment 18% of the inpatients suffered from severe depressive symptoms, and 16.2 % suffered from moderate depressive symptoms. 16.4% of the patients suffered from severe anxiety, and 24.7% suffered from moderate anxiety (HADS). The prevalence rate of the type D pattern was 33.0%. The extent of anxiety and depression was not, as had been anticipated, associated with the severity of the physical symptoms. Although the diabetic foot syndrome improved significantly in most of the patients, the extent of depressive symptoms, anxiety and diabetes-related problems remained almost the same.
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