Neuropeptide Y Attenuates Stress‐Induced Bone Loss Through Suppression of Noradrenaline Circuits

Chronic stress and depression have adverse consequences on many organ systems, including the skeleton, but the mechanisms underlying stress‐induced bone loss remain unclear. Here we demonstrate that neuropeptide Y (NPY), centrally and peripherally, plays a critical role in protecting against stress‐induced bone loss. Mice lacking the anxiolytic factor NPY exhibit more anxious behavior and elevated corticosterone levels. Additionally, following a 6‐week restraint, or cold‐stress protocol, Npy‐null mice exhibit three‐fold greater bone loss compared to wild‐type mice, owing to suppression of osteoblast activity. This stress‐protective NPY pathway acts specifically through Y2 receptors. Centrally, Y2 receptors suppress corticotropin‐releasing factor expression and inhibit activation of noradrenergic neurons in the paraventricular nucleus. In the periphery, they act to control noradrenaline release from sympathetic neurons. Specific deletion of arcuate Y2 receptors recapitulates the Npy‐null stress response, coincident with elevated serum noradrenaline. Importantly, specific reintroduction of NPY solely in noradrenergic neurons of otherwise Npy‐null mice blocks the increase in circulating noradrenaline and the stress‐induced bone loss. Thus, NPY protects against excessive stress‐induced bone loss, through Y2 receptor‐mediated modulation of central and peripheral noradrenergic neurons. © 2014 American Society for Bone and Mineral Research.     

Placebo effect in burning mouth syndrome: a systematic review

Placebo controls play a critical role in the evaluation of any pharmacotherapy. This review surveys the placebo arm in 12 randomized controlled trials (RCTs) investigating burning mouth syndrome (BMS) and documents a positive placebo response in 6 of them. On average, treatment with placebos produced a response that was 72% as large as the response to active drugs. The lack of homogeneity in the use of placebos adds to the difficulty in comparing results and aggregating data. Future RCTs investigating BMS would benefit from larger sample sizes, adequate follow‐up periods, and use of a standard placebo.     

艾滋病合并隐球菌脑膜炎18例临床分析

目的　提高对艾滋病 (AIDS)合并隐球菌脑膜炎的认识。方法　对赤道几内亚巴塔地区医院 18例AIDS合并隐球菌脑膜炎患者进行临床综合分析。结果　 18例AIDS合并隐球菌脑膜炎患者的临床主要表现为 :发热、剧烈头痛、极度乏力、肢体痛、脑膜刺激征及消瘦与脱水等。脑脊液 (CSF)培养均为新型隐球菌生长 ;涂片及隐球菌多糖荚膜抗原 (ELISA法 )检测的阳性率分别为 77 8% (14/ 18) ,94 4% (17/ 18)。结论　隐球菌脑膜炎为AIDS常见机会性感染及主要致死病因之一。     

Thermal sensory and pain thresholds in the tongue and chin change with age,but are not altered in burning mouth syndrome

Background: Burning mouth syndrome (BMS) is a chronic orofacial pain syndrome that occurs in middle‐aged and postmenopausal women and poses a therapeutic challenge to dermatologists and dentists. It has been suggested previously that BMS is a small‐fiber neuropathy. Aims: This study was designed to examine thermal sensory and pain thresholds in the oral mucosa and chin, both innervated by the trigeminal nerve, in patients with BMS, as well as in healthy controls. In addition, the study proposed to examine whether there are any differences in oral thermal and pain sensations between the advanced age group, where BMS is prevalent and a younger group. Results: Thermal and pain thresholds of BMS patients did not differ significantly from those of healthy subjects. An increased threshold to thermal warmth and a decreased threshold for cold sensation for the tongue and chin were noted in the group over 50 years in comparison with younger subjects, indicating a decreased sensitivity to thermal stimuli. The group over 50 years of age displayed an increased sensitivity to cold pain and a decreased sensitivity to hot pain in the tongue (compared with the chin). Conclusion: BMS patients do not demonstrate alterations in thermal and pain detection, thus failing to support a true small nerve neuropathy in this condition.