Predictive underestimation of difficult direct laryngoscopy in a patient with rheumatoid arthritis-associated immobilized craniocervical junction.

BACKGROUND: The upper cervical spine is a major focus of damage by rheumatoid arthritis (RA). Specific screening for mobility of the upper cervical spine, which is essential for direct laryngoscopy, is lacking. Herein, we present a case of RA with Cormack-Lehane grade IV, which was not predicted by preoperative examination. CASE PRESENTATION: A 66-year-old woman with RA was scheduled for a right total knee arthroplasty and right elbow synovectomy. She had a long history of RA without symptoms related to the cervical spine or spinal cord. Although physical examination suggested moderate risk of difficult intubation with preserved cervical retroflexion, her Cormack-Lehane classification was grade IV under muscle relaxation. Bony integration of the occiput to axis was considered to be the main cause of difficult direct laryngoscopy, and restricted neck rotation was found postoperatively. CONCLUSIONS: RA patients may have limited upper cervical spine motion despite normal cervical retroflexion.

Experiential effects of appetitive and nonappetitive odors on feeding behavior in the blowfly, Phormia regina: a putative role for tyramine in appetite regulation.

In humans, appetite is affected by food experiences and food flavors. In the blowfly Phormia regina, we found that feeding threshold to sugar increased in the presence of the odor of D-limonene and decreased in the presence of the odor of dithiothreitol (DTT). Using these odors as representative nonappetitive and appetitive flavors, we demonstrated the role played by tyramine (TA) in appetite regulation by experiences of food flavors. When fed with sucrose flavored with D-limonene for 5 d after emergence, flies showed subsequent decreased appetite to plain sucrose, whereas when they were fed with sucrose flavored by DTT they showed increased appetite. However, mushroom body (MB)-ablated flies did not show these patterns. This suggests that MB, one of the primary memory centers of the insect brain, is necessary for the flies to apply previous experiences of food flavors to appetitive learning behaviors. In addition, flies' previously acquired decreased or increased appetites showed parallel changes with both octopamine (OA) and tyramine levels in the brain. However, injection experiments with OA, TA, or their agonist and antagonist indicated that TA more directly mediates feeding threshold determination, which was affected by acquired memories of food flavors.