Rapid radiosynthesis of [11C] and [14C]azelaic,suberic, and sebacic acids for in vivo mechanistic studies of systemic acquired resistance in plants

A recent report that the aliphatic dicarboxylic acid, azelaic acid (1,9‐nonanedioic acid) but not related acids, suberic acid (1,8‐octanedioic acid) or sebacic (1,10‐decanedioic acid) acid induces systemic acquired resistance to invading pathogens in plants stimulated the development of a rapid method for labeling these dicarboxylic acids with ¹¹C and ¹⁴C for in vivo mechanistic studies in whole plants. ¹¹C‐labeling was performed by reaction of ammonium [¹¹C]cyanide with the corresponding bromonitrile precursor followed by hydrolysis with aqueous sodium hydroxide solution. Total synthesis time was 60 min. Median decay‐corrected radiochemical yield for [¹¹C]azelaic acid was 40% relative to trapped [¹¹C]cyanide, and specific activity was 15 GBq/µmol. Yields for [¹¹C]suberic and sebacic acids were similar. The ¹⁴C‐labeled version of azelaic acid was prepared from potassium [¹⁴C]cyanide in 45% overall radiochemical yield. Radiolabeling procedures were verified using ¹³C‐labeling coupled with ¹³C‐NMR and liquid chromatography–mass spectrometry analysis. The ¹¹C and ¹⁴C‐labeled azelaic acid and related dicarboxylic acids are expected to be of value in understanding the mode‐of‐action, transport, and fate of this putative signaling molecule in plants. Copyright © 2011 John Wiley & Sons, Ltd.     

Poor sleep quality as a risk factor for lapse following a cannabis quit attempt

Treatments for cannabis dependence are associated with high rates of lapse/relapse, underscoring the importance of identifying malleable risk factors that are associated with quit failure. Whereas research has demonstrated that poor sleep quality following cannabis discontinuation is related to subsequent use, there has yet to be an examination of whether poor sleep quality prior to a quit attempt results in a similar pattern of lapse. The present study addressed this gap by examining the role of pre-quit sleep quality on early lapse to cannabis use following a self-guided quit attempt, among 55 cannabis dependent military veterans. Results indicated that participants who experienced poor pre-quit sleep quality had greater risk for lapse within the first 2 days (out of 7) following their quit attempt. Findings are discussed in terms of improving treatments for individuals who report poor sleep quality prior to a cannabis quit attempt.     

MRI assessment of temporomandibular disc position among various mandibular positions: a pilot study

Purpose: The aim of this pilot study was to assess temporomandibular joint disc movement relative to the condyle among centric relation (CR), physiologic rest position (PRP), and maximal intercuspation position (MIP) in healthy patients without signs or symptoms of any temporomandibular disorder. The hypothesis was that as the condyle rotated clockwise or translated anteriorly, the disc would also move in an anterior direction. Material and methods: Magnetic resonance images were obtained on 20 volunteers in CR, physiologic rest, and MIP. Three investigators measured the location of the disc among the different mandibular positions. Results: Disc location differences between CR and PRP exhibited the widest range of measurement. The largest amount of disc protrusion relative to the condyle was found between CR and PRP on the right side. The largest amount of disc retrusion relative to the condyle was found between CR and MIP on the right side. The hypothesis was not supported by the results. Conclusions: According to the results of this pilot study, the direction of movement of the temporomandibular disc does not correlate with the rotational movement of the condyle in hinge positions. Clinical implications: Increased knowledge of temporomandibular disc movement among various mandibular positions in asymptomatic patients may help clinicians recognize deviations in symptomatic patients.