Impact of early parenteral nutrition on muscle and adipose tissue compartments during critical illness.

OBJECTIVE: The goal of enhanced nutrition in critically ill patients is to improve outcome by reducing lean tissue wasting. However, such effect has not been proven. This study aimed to assess the effect of early administration of parenteral nutrition on muscle volume and composition by repeated quantitative CT. DESIGN: A preplanned substudy of a randomized controlled trial (Early Parenteral Nutrition Completing Enteral Nutrition in Adult Critically Ill Patients [EPaNIC]), which compared early initiation of parenteral nutrition when enteral nutrition was insufficient (early parenteral nutrition) with tolerating a pronounced nutritional deficit for 1 week in ICU (late parenteral nutrition). Late parenteral nutrition prevented infections and accelerated recovery. SETTING: University hospital. PATIENTS: Fifteen EPaNIC study neurosurgical patients requiring prescheduled repeated follow-up CT scans and six healthy volunteers matched for age, gender, and body mass index. INTERVENTION: Repeated abdominal and femoral quantitative CT images were obtained in a standardized manner on median ICU day 2 (interquartile range, 2-3) and day 9 (interquartile range, 8-10). Intramuscular, subcutaneous, and visceral fat compartments were delineated manually. Muscle and adipose tissue volume and composition were quantified using standard Hounsfield Unit ranges. MEASUREMENTS AND MAIN RESULTS: Critical illness evoked substantial loss of femoral muscle volume in 1 week's time, irrespective of the nutritional regimen. Early parenteral nutrition reduced the quality of the muscle tissue, as reflected by the attenuation, revealing increased intramuscular water/lipid content. Early parenteral nutrition also increased the volume of adipose tissue islets within the femoral muscle compartment. These changes in skeletal muscle quality correlated with caloric intake. In the abdominal muscle compartments, changes were similar, albeit smaller. Femoral and abdominal subcutaneous adipose tissue compartments were unaffected by disease and nutritional strategy. CONCLUSIONS: Early parenteral nutrition did not prevent the pronounced wasting of skeletal muscle observed over the first week of critical illness. Furthermore, early parenteral nutrition increased the amount of adipose tissue within the muscle compartments.

Prehensile and non-prehensile tails among syngnathid fishes: what's the difference?

All syngnathid fishes are characterized by a tail with a vertebral column that is surrounded by dermal Plates - four per vertebra. Seahorses and pipehorses have prehensile tails, a unique characteristic among teleosts that allows them to grasp and hold onto substrates. Pipefishes, in contrast, possess a more rigid tail. Previous research (Neutens et al., 2014) showed a wide range of variation within the skeletal morphology of different members in the syngnathid family. The goal of this study is to explore whether the diversity in the three-dimensional (3D) shape of different tail types reflects grasping performance, and to what degree grasping tails occupy a different and more constrained diversity. For this, a 3D morphometrical analysis based on surfaces was performed. Four different analyses were performed on the tail skeleton of nine species exhibiting different levels of tail grasping capacities (four pipehorse, three seahorse, one pipefish and one seadragon species) to examine the intra-individual variation across the anteroposterior and dorso-ventral axis. In the two interspecific analyses, all vertebrae and all dermal plates were mutually compared. Overall, intra-individual variation was larger in species with a prehensile tail. The analysis on the vertebrae showed differences in the length and orientation of the hemal spine as well as the inclination angle between the anterior and posterior surface of the vertebral body. This was observed at an intra-individual level across the anteroposterior axis in prehensile species and at an inter-individual level between prehensile and non-prehensile species. Across the anteroposterior axis in prehensile tails, the overall shape of the plates changes from rectangular at the anterior end to square at the posterior end. Across the dorso-ventral axis, the ventral dermal plates carry a significantly longer caudal spine than the dorsal ones in all prehensile-tailed species. It can therefore be concluded that prehensile tails exhibit a larger anteroposterior and dorso-ventral shape variation than non-prehensile ones. However, the hypothesis that there is a more constrained shape variation among prehensile species compared to non-prehensile ones had to be rejected.

Semi-automatic level set segmentation of liver tumors combining a spiral-scanning technique with supervised fuzzy pixel classification.

In this paper, a specific method is presented to facilitate the semi-automatic segmentation of liver tumors and liver metastases in CT images. Accurate and reliable segmentation of tumors is essential for the follow-up of cancer treatment. The core of the algorithm is a level set method. The initialization is generated by a spiral-scanning technique based on dynamic programming. The level set evolves according to a speed image that is the result of a statistical pixel classification algorithm with supervised learning. This method is tested on CT images of the abdomen and compared with manual delineations of liver tumors. The described method outperformed the semi-automatic methods of the other participants of the "3D Liver Tumor Segmentation Challenge 2008". Evaluating the algorithm on the provided test data leads to an average overlap error of 32.6% and an average volume difference of 17.9%. The average, the RMS and the maximum surface distance are 2.0, 2.6 and 10.1 mm, respectively.