The hormone corticotropin (ACTH) is employed as therapy for diverse neurological disorders, but the mechanisms for its efficacy remain unknown. ACTH promotes the release of adrenal steroids (glucocorticoids), and most ACTH effects on the central nervous system (CNS) have been attributed to activation of glucocorticoid receptors. However, in several human disorders, ACTH has therapeutic actions that differ qualitatively or quantitatively from those of steroids. This study tested the hypothesis that ACTH directly influences limbic neurons via the recently characterized melanocortin receptors and focused on the effects of ACTH on the expression of corticotropin-releasing hormone (CRH), a neuropeptide involved in neuroimmune functions and in certain developmental seizures. The results demonstrated that ACTH potently reduced CRH expression in amygdala neurons. This down-regulation was not abolished by experimental elimination of steroids or by blocking their receptors and was reproduced by a centrally administered ACTH fragment that does not promote steroid release. Importantly, selective blocking of melanocortin receptors prevented ACTH-induced down-regulation of CRH expression. Taken together, these data indicate that ACTH activates central melanocortin receptors to modulate CRH gene expression in amygdala, supporting the notion that direct, steroid-independent actions of ACTH may account for some of its established clinical effects on the CNS.
Context:Primary patellar dislocation continues to be a common problem facing clinicians today. These injuries are associated with significant morbidity and a substantial recurrence rate. Myriad operative and nonoperative options have been described to treat these injuries, although the evidence-based literature is sparse.Evidence Acquisition:PubMed was searched from 1970-2010 to identify publications on patellar dislocations, including clinical presentation, natural history, radiographic workup, and treatment.Results:The initial workup of a patella dislocation includes a history, physical examination, and radiographs. If there is evidence of a displaced osteochondral fragment or hemarthrosis, then magnetic resonance imaging should be obtained. The treatment of first-time patella dislocators has been controversial, and no study has demonstrated a clear benefit to early operative intervention.Conclusion:First-time patellar dislocations should be treated conservatively unless there is evidence of a displaced osteochondral fragment.
The realistic expectation for short-term postoperative survival in the elderly patient with a cervical spine injury is 87.8%. With a complete neurologic injury, 80.0% short-term survival was observed. Incomplete neurologic injury yielded 83.3% short-term survival. Close to 100.0% survival can be expected with no neurologic injury.
The present paper deals with the effect of surface heat and mass transfer on magnetohydrodynamic flow of Powell-Eyring fluid over a vertical stretching sheet. The effects of thermophoresis, Joule heating and chemical reaction are also considered. The governing non-linear partial differential equations of the model are transformed into coupled non-linear ordinary differential equations using a similarity transformation and solved numerically by Runge-Kutta method and analytically by homotopy analysis method (HAM). The convergence is carefully checked by plotting h-curves. For different dimensionless parameters, numerical and analytical calculations are carried out and an investigation of the obtained results shows that the flow field is influenced considerably by the buoyancy ratio and thermal radiation, chemical reaction and magnetic field parameters. A totally analytical and consistently applicable solution is derived which agrees with numerical results.
The new knee-support apparatus allows accurate recording of quadriceps twitches. The ease of use in ventilated patients and excellent inter- and intraoperator agreement suggest that this technique is suitable for cross-sectional and longitudinal studies in critically ill patients. Muscle Nerve 57: 784-791, 2018.
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