The effects of catastrophizing on central motor activity.

BACKGROUND: Pain catastrophizing significantly affects an individual's experience of pain. High pain catastrophizing is associated with increased fear avoidance behaviours, pain intensity and disability. The aim of this investigation was to determine the effect of pain catastrophizing on ongoing brain activity and movement-evoked brain activity during acute orofacial muscle pain. METHODS: Thirty-four healthy, pain-free subjects were recruited. In 17 subjects, the effect of catastrophizing on regional brain activity was determined. In 19 subjects, functional magnetic resonance imaging was used to determine the effects of pain catastrophizing on brain activation patterns during jaw movements in the presence of ongoing pain. RESULTS: We found that in the presence of pain, catastrophizing was significantly correlated with activity in multi-sensory integrative brain regions, including the dorsolateral and medial prefrontal cortices. Importantly, this relationship did not exist when subjects were not experiencing pain. In addition, during repetitive open-close jaw movements in the presence of pain, activity in the primary motor cortex, cerebellar cortex and the trigeminal motor nucleus was positively correlated with pain catastrophizing scores. In contrast, in the dorsolateral prefrontal cortex, as pain catastrophizing scores increased, the magnitude of signal intensity change during jaw movements decreased. Again, no such relationships occurred when the individual was not in pain. CONCLUSIONS: These data show that during pain, catastrophic thinking has a significant impact on activity in motor and sensory integrative regions. Reducing negative coping strategies may be an effective means in reducing fear avoidance behaviours and the intensity of ongoing pain.

Probiotic capsules do not lower plasma lipids in young women and men.

OBJECTIVE: To investigate the effect of probiotic capsules on plasma lipids. DESIGN: A randomized, single-blinded, placebo-controlled, parallel-arm trial. SUBJECTS: Fifty-five normocholesterolemic subjects ages 18-36 (33 premenopausal women and 22 men). INTERVENTION: Each subject consumed either three probiotic capsules each containing a total of 10(9) colony-forming units Lactobacillus acidophilus and Bifidobacterium longum and 10-15 mg fructo-oligosaccharide or three placebo capsules daily for 2 months (men) or two menstrual cycles (women). Plasma lipids were measured before and following the intervention (during the early follicular phase for women). RESULTS: Plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride were not altered by consumption of probiotic or placebo capsules and were not different between treatment groups following the intervention. CONCLUSIONS: These results do not support a beneficial effect of Lactobacillus acidophilus strain DDS-1 and Bifidobacterium longum strain UABL-14 on plasma lipids in normocholesterolemic young women and men. SPONSORSHIP: Supported by the Minnesota Agricultural Experiment Station and UAS Laboratories.

Particle formation by ion nucleation in the upper troposphere and lower stratosphere.

Unexpectedly high concentrations of ultrafine particles were observed over a wide range of latitudes in the upper troposphere and lower stratosphere. Particle number concentrations and size distributions simulated by a numerical model of ion-induced nucleation, constrained by measured thermodynamic data and observed atmospheric key species, were consistent with the observations. These findings indicate that, at typical upper troposphere and lower stratosphere conditions, particles are formed by this nucleation process and grow to measurable sizes with sufficient sun exposure and low preexisting aerosol surface area. Ion-induced nucleation is thus a globally important source of aerosol particles, potentially affecting cloud formation and radiative transfer.

Polar cap mesosphere wind observations: comparisons of simultaneous measurements with a Fabry-Perot interferometer and a field-widened Michelson interferometer.

Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (approximately 86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause.

Repression of the L-asparaginase gene during nodule development in Lupinus angustifolius.

Upon the establishment of an effective nitrogen-fixing symbiosis in amide-transporting plants the enzymatic activity and transcript levels of L-asparaginase are dramatically decreased. This decrease in L-asparaginase activity is essential for the correct functioning of the Rhizobium-legume symbiosis in lupin in which asparagine, synthesized from recently fixed nitrogen, is exported to aerial parts of the plant for use in growth and development. Concomitant with this decrease in L-asparaginase transcript a DNA-binding protein was detected in the nodules. This binding protein was not detectable in ineffective nodules, in nodules treated with nitrate, or in root tips, mature roots, developing flowers or developing seeds. The DNA-binding activity was shown to interact with a 59 bp sequence proximal to the transcription start site. Within this sequence a CTAAAAT direct repeat and a ACTGT/TGTCA incomplete inverted repeat were implicated in the binding of protein to the DNA by DNase I protection experiments. Competitive binding studies with synthesized binding sites were consistent with the CTAAAAT/TGTCA sequence pair proximal to the transcription start site having the highest affinity for the DNA-binding protein. We postulate that this DNA-binding protein is associated with repression of L-asparaginase gene expression in mature lupin root nodules.