205 research outputs found
Can experimentally induced positive affect attenuate generalization of fear of movement-related pain?
Recent experimental data show that associative learning processes are involved not only in the acquisition but also the spreading of pain-related fear. Clinical studies suggest involvement of positive affect in resilience against chronic pain. Surprisingly, the role of positive affect in associative learning in general and in fear generalization in particular has received scant attention. In a voluntary movement paradigm, in which one arm movement (CS+) was followed by a painful stimulus and another was not (CS-), we tested generalization of fear to five novel but related generalization movements (GSs; within-subjects) after either a positive affect induction or a control exercise (Group = between-subjects) in healthy participants (N = 50). The GSs' similarity with the original CS+ movement and CS- movement varied. Fear learning was assessed via verbal ratings. Results indicated that there was an interaction between the increase in positive affect and the linear generalization gradient. Stronger increases in positive affect were associated with steeper generalization curves due to relatively lower pain-US expectancy and less fear to stimuli more similar to the CS-. There was no Group by Stimulus interaction. Results thus suggest that positive affect may enhance safety learning through promoting generalization from known safe movements to novel yet related movements. Improved safety learning may be a central mechanism underlying the association between positive affect and increased resilience against chronic pain. PERSPECTIVE: We investigated to which extent positive affect influences the generalization (i.e., spreading) of pain-related fear to situations similar to the original, pain-eliciting situation. Results suggest that increasing positive affect in the acute pain stage may limit the spreading of pain-related fear, thereby potentially inhibiting transgression to chronic pain conditions
The opportunity to avoid pain may paradoxically increase fear
Fear-avoidance models propose that pain-related fear may spur avoidance behaviour leading to chronic pain disability. Pain-related fear elicits avoidance behaviour, which is typically aimed at reducing fear. We hypothesized that engaging in avoidance may (paradoxically) increase rather than decrease pain-related fear (i.e. bidirectionality hypothesis). In a between-subject design, participants (N=64) were randomly assigned to the avoidance group or the control group. Avoidance group participants were led to believe they could avoid full exposure to a painful heat stimulus by pressing the stop-button, while control group participants believed they were exposed to the full painful heat stimulus at all times. In reality and unknown to the participants, the intensity and duration of the heat stimulus was independent of the avoidance response, and was identical in both groups. During the test, the avoidance response (i.e. pressing the stop-button) was no longer available. As expected, pain-related fear levels were higher after avoiding the painful heat stimulus. Interestingly, in the avoidance group, pain-related fear increased after receiving instructions that avoidance would be possible, even before actually engaging in avoidance behaviour. In the control group, no significant change was observed in pain-related fear throughout the experiment. The eyeblink startle measures did not corroborate this data pattern.PERSPECTIVE: These observations provide partial support for the bidirectionality hypothesis between avoidance behaviour and fear. These findings may have clinical implications and suggest that allowing avoidance behaviours during treatment may thwart fear reduction.</p
The interplay of maternal and offspring obesogenic diets: the impact on offspring metabolism and muscle mitochondria in an outbred mouse model
Consumption of obesogenic (OB) diets increases the prevalence of maternal obesity worldwide, causing major psychological and social burdens in women. Obesity not only impacts the mother’s health and fertility but also elevates the risk of obesity and metabolic disorders in the offspring. Family lifestyle is mostly persistent through generations, possibly contributing to the growing prevalence of obesity. We hypothesized that offspring metabolic health is dependent on both maternal and offspring diet and their interaction. We also hypothesized that the sensitivity of the offspring to the diet may be influenced by the match or mismatch between offspring and maternal diets. To test these hypotheses, outbred Swiss mice were fed a control (C, 10% fat, 7% sugar, and n = 14) or OB diet (60% fat, 20% sugar, and n = 15) for 7 weeks and then mated with the same control males. Mice were maintained on the same corresponding diet during pregnancy and lactation, and the offspring were kept with their mothers until weaning. The study focused only on female offspring, which were equally distributed at weaning and fed C or OB diets for 7 weeks, resulting in four treatment groups: C-born offspring fed C or OB diets (C » C and C » OB) and OB-born offspring fed C or OB diets (OB » C and OB » OB). Adult offspring’s systemic blood profile (lipid and glucose metabolism) and muscle mitochondrial features were assessed. We confirmed that the offspring’s OB diet majorly impacted the offspring’s health by impairing the offspring’s serum glucose and lipid profiles, which are associated with abnormal muscle mitochondrial ultrastructure. Contrarily, maternal OB diet was associated with increased expression of mitochondrial complex markers and mitochondrial morphology in offspring muscle, but no additive effects of (increased sensitivity to) an offspring OB diet were observed in pups born to obese mothers. In contrast, their metabolic profile appeared to be healthier compared to those born to lean mothers and fed an OB diet. These results are in line with the thrifty phenotype hypothesis, suggesting that OB-born offspring are better adapted to an environment with high energy availability later in life. Thus, using a murine outbred model, we could not confirm that maternal obesogenic diets contribute to female familial obesity in the following generations
Measurement of Th-232(n,5n gamma) cross sections from 29 to 42 MeV
The excitation function of the reaction Th-232(n,5n gamma)Th-228 from 29 to 42 MeV has been measured for the first time at the quasi-monoenergetic neutron beam of the UCL cyclotron CYCLONE employing the Li-7(p,n) source reaction. Taking advantage of the good energy resolution of the planar High Purity Germanium (HPGe) detectors, prompt gamma-ray spectroscopy was used to detect the gamma rays resulting from the decay of excited states of nuclei created by the (n,xn) reactions. The neutron beam was characterized by a combination of time of flight measurements carried out using a liquid scintillation detector and a U-238 fission ionization chamber and fluence measurements carried Out using a proton recoil telescope. The preliminary results are compared with calculations performed using the TALYS-0.72 code.International Conference on Nuclear Data for Science and Technology, Proceedings, Apr 22-27, 2007, Nice, Franc
Interstitial cystitis: a rare manifestation of primary Sjögren’s syndrome, successfully treated with low dose cyclosporine
Chronic interstitial cystitis (IC), mostly affecting middle-aged women, is a very rare manifestation of primary Sjögren’s syndrome (pSS). Hereby, we report a 42-year-old woman with pSS, presenting with dysuria, urinary frequency, and suprapubic pain. She was diagnosed to have chronic IC, based upon the cystoscopic biopsy finding of chronic inflammation in the bladder wall. Systemic corticosteroid and azathioprine treatments together with local intravesical therapies were not effective. Therefore, cyclosporine (CSA) therapy was initiated. Initial low dose of CSA (1.5 mg/kg/d) improved the symptoms of the patient, with no requirement for dose increment. After 4 months of therapy, control cystoscopic biopsy showed that bladder inflammation regressed and IC improved. This case suggests that even low doses of CSA may be beneficial for treating chronic IC associated with pSS syndrome
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