Impaired contractile function of the supraspinatus in the acute period following a rotator cuff tear

Background: Rotator cuff (RTC) tears are a common clinical problem resulting in adverse changes to the muscle, but there is limited information comparing histopathology to contractile function. This study assessed supraspinatus force and susceptibility to injury in the rat model of RTC tear, and compared these functional changes to histopathology of the muscle. Methods: Unilateral RTC tears were induced in male rats via tenotomy of the supraspinatus and infraspinatus. Maximal tetanic force and susceptibility to injury of the supraspinatus muscle were measured in vivo at day 2 and day 15 after tenotomy. Supraspinatus muscles were weighed and harvested for histologic analysis of the neuromuscular junction (NMJ), intramuscular lipid, and collagen. Results: Tenotomy resulted in eventual atrophy and weakness. Despite no loss in muscle mass at day 2 there was a 30% reduction in contractile force, and a decrease in NMJ continuity and size. Reduced force persisted at day 15, a time point when muscle atrophy was evident but NMJ morphology was restored. At day 15, torn muscles had decreased collagen-packing density and were also more susceptible to contraction-induced injury. Conclusion: Muscle size and histopathology are not direct indicators of overall RTC contractile health. Changes in NMJ morphology and collagen organization were associated with changes in contractile function and thus may play a role in response to injury. Although our findings are limited to the acute phase after a RTC tear, the most salient finding is that RTC tenotomy results in increased susceptibility to injury of the supraspinatus

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Prevalence and factors associated with stunting and thinness among adolescent students in Northern Ethiopia: a comparison to World Health Organization standards

BACKGROUND Adolescence is last chance for curbing the consequences of malnutrition and breaking the intergenerational cycle of malnutrition and poor health. This study aimed to assess the prevalence and the factors associated with stunting and thinness among in-school adolescents in northern Ethiopia using the 2006 World Health Organization (WHO) standards. METHODS In-school adolescents (n  = 348, 10–19 years old) were randomly selected to participate in this cross-sectional study. Anthropometric measurements were carried out to determine the proportion of adolescents who were stunted (height-for-age < −2 Standard Deviation (SD)) and thin (body-mass-index-for-age < −2 SD). T-test was employed to evaluate mean weight and height differences between groups. Pearson chi-square, chi-square trend and Fisher’s exact tests were used to explore the crude association of categorical outcome variables and associated factors. Crude and adjusted associations between the outcome variables (stunting and thinness) and independent variables (socio-demographic, eating behavior and sanitation) were also determined using logistic regression. Stata version 11.1 was used to analyze the data. RESULTS The height of the adolescents was 147.6 ± 11.2 cm (mean ± SD) and weight was37.2 ± 9.5 kg. The mean Z-scores of height-for-age and body-mass-index (BMI)-for-age of adolescents were −1.49 and −1.29, respectively. The prevalence of stunting and thinness among adolescents was 28.5 % (boys = 37.7 %; girls = 21.2 %; P = 0.001) and 26.1 % (boys = 32.4; girls = 21.6 %; p  = 0.017), respectively. Adolescents in 13–15 year old age group (Adjusted Odds ratio (AOR) = 2.23; 95 % CI: 1.22, 4.08), boys (AOR = 2.53; 95 % CI: 1.52, 4.21) and rural residents (AOR = 2.15; 95 % CI: 1.20, 3.86) had significantly higher odds of being stunted compared to their counterparts. Furthermore, boys had higher (AOR = 1.97; 95 % CI: 1.19, 3.25) odds of being thin compared to girls. Compared to those 10 to 12 years of age, adolescents in 16 to 19 years of age were 53 % (AOR = 0.47; 95 % CI: 0.23, 0.95) less likely to be thin. CONCLUSIONS Undernutrition is widely prevalent among adolescents in northern Ethiopia. Sex, age and area of residence significantly associated with adolescent undernutrition. The study underlines the need for nutrition interventions targeting rural and boy adolescents.Yohannes Adama Melaku, Gordon Alexander Zello, Tiffany K. Gill, Robert J. Adams and Zumin Sh

Immunohistochemical evaluation of Tenascin distribution in different stages of pulp development in mice

History and Objectives: Morphogenesis is achieved by the effect of different tissue factors including mesenchymal-epithelial interaction, but its chemical basis is unknown. One of the most appropriate models is the mammalian tooth, especially its pulp. The phenomena migration, proliferation and differentiation within dental pulp are affected by the components of extracellular fluid. In this respect, tenascin is one of these components that is involved in the initial stages of development and differentiation of some fetal tissues including teeth and is important in the pathogenesis of tumors. Materials and Methods: The present study was conducted on 40 ball-c mice. Different development stages of dental pulp were evaluated within the days 12-19, using immunohistochemical methods and monoclonal antibody against tenascin. Results: The finding showed that at the bud stage, tenascin is found in the ectomesenchymal tissue and basement membrane of enamel organ in a high quantity and there is reduction in its level in cap stage. With developmental progression, the tenascin level increases significantly in early bell stage for pulp and in late bell stage in cortex. Conclusion: Tenascin can play an important role in morphogenesis during development of pulp. In this respect, epithelial-mesenchymal interaction is very important. Therefore, it is recommended to conduct more studies to determine the role of tenascin in the differentiation oddentoblasts following injury