Concurrent treatment of a middle-third clavicle fracture and type IV acromioclavicular dislocation.

Acromioclavicular (AC) dislocation with an associated displaced fracture of the middle third of the clavicle is a rare injury with no established standard treatment. Previous AC fixation techniques described have not included simultaneous internal fixation of the clavicle. We present the case of a 19-year-old man who sustained this combined injury pattern with a type IV AC dislocation. He underwent open reduction and internal fixation of the clavicle fracture with open reduction of the AC joint and coracoclavicular (CC) screw fixation through the plate to stabilize the AC dislocation. The CC screw was removed 3 months after surgery. By 1-year follow-up, the patient had returned to manual labor and normal activities of daily living. In comparison with previously described treatment, his case highlights a unique approach to this rare shoulder entity.

Scaffold-based delivery of autologous mesenchymal stem cells for mandibular distraction osteogenesis: preliminary studies in a porcine model.

PURPOSE: Bone regeneration through distraction osteogenesis (DO) is promising but remarkably slow. To accelerate it, autologous mesenchymal stem cells have been directly injected to the distraction site in a few recent studies. Compared to direct injection, a scaffold-based method can provide earlier cell delivery with potentially better controlled cell distribution and retention. This pilot project investigated a scaffold-based cell-delivery approach in a porcine mandibular DO model. MATERIALS AND METHODS: Eleven adolescent domestic pigs were used for two major sets of studies. The in-vitro set established methodologies to: aspirate bone marrow from the tibia; isolate, characterize and expand bone marrow-derived mesenchymal stem cells (BM-MSCs); enhance BM-MSC osteogenic differentiation using FGF-2; and confirm cell integration with a gelatin-based Gelfoam scaffold. The in-vivo set transplanted autologous stem cells into the mandibular distraction sites using Gelfoam scaffolds; completed a standard DO-course and assessed bone regeneration by macroscopic, radiographic and histological methods. Repeated-measure ANOVAs and t-tests were used for statistical analyses. RESULTS: From aspirated bone marrow, multi-potent, heterogeneous BM-MSCs purified from hematopoietic stem cell contamination were obtained. FGF-2 significantly enhanced pig BM-MSC osteogenic differentiation and proliferation, with 5 ng/ml determined as the optimal dosage. Pig BM-MSCs integrated readily with Gelfoam and maintained viability and proliferative ability. After integration with Gelfoam scaffolds, 2.4-5.8×10(7) autologous BM-MSCs (undifferentiated or differentiated) were transplanted to each experimental DO site. Among 8 evaluable DO sites included in the final analyses, the experimental DO sites demonstrated less interfragmentary mobility, more advanced gap obliteration, higher mineral content and faster mineral apposition than the control sites, and all transplanted scaffolds were completely degraded. CONCLUSION: It is technically feasible and biologically sound to deliver autologous BM-MSCs to the distraction site immediately after osteotomy using a Gelfoam scaffold to enhance mandibular DO.

Motivation from control.

Human motivation is sensitive to value-to the outcomes of actions. People invest mental and physical resources for obtaining desired results or for stopping and reversing undesired ones. Accordingly, people's motivation is sensitive to information about their standing in relation to outcome attainment ('outcome feedback'). In this paper, we argue and present the first evidence for the existence of another motivational sensitivity in humans-a sensitivity to our degree of control on the environment and hence to information about that control ('control feedback'). We show that when actions have even trivial and constant perceptual effects, participants' motivation to perform is enhanced. We then show that increased motivation is not because more information about task performance is available and that motivation is increased only in conditions in which control over the effects can be firmly established by the mind. We speculate on the implications for understanding motivation, and potentially, physical and mental health.

Effect of deep breathing on extracted oxygen and cerebral hemoglobin levels.

This study examines the relationship between oxygen expired and functional near infrared spectroscopy (fNIRS) measured hemoglobin levels in the brain. Analysis of these two signals during normal versus deep breathing provides insight into the dynamics of cerebral physiology. Intersubject variation suggests the existence of two distinct groups with respect to oxygen extraction and hemoglobin levels.