Physiological responses to low-force work and psychosocial stress in women with chronic trapezius myalgia

<p>Abstract</p> <p>Background</p> <p>Repetitive and stressful work tasks have been linked to the development of pain in the trapezius muscle, although the underlying mechanisms still remain unclear. In earlier studies, it has been hypothesized that chronic muscle pain conditions are associated with imbalance in the autonomic nervous system, predominantly expressed as an increased sympathetic activity. This study investigates whether women with chronic trapezius myalgia show higher muscle activity and increased sympathetic tone at baseline and during repetitive low-force work and psychosocial stress, compared with pain-free controls.</p> <p>Methods</p> <p>Eighteen women with chronic trapezius myalgia (MYA) and 30 healthy female controls (CON) were studied during baseline rest, 100 min of repetitive low-force work, 20 min of psychosocial stress (Trier Social Stress Test, TSST), and 80 min recovery. The subjects rated their pain intensity, stress and energy level every 20 min throughout the experiment. Muscle activity was measured by surface electromyography in the trapezius muscle (EMGtrap) and deltoid muscle (EMGdelt). Autonomic reactivity was measured through heart rate (HR), skin conductance (SCL), blood pressure (MAP) and respiration rate (Resp).</p> <p>Results</p> <p>At baseline, EMGtrap, stress ratings, and HR were higher in MYA than in CON. Energy ratings, EMGdelt, SCL, MAP and Resp were, however, similar in the two groups. Significant main group effects were found for pain intensity, stress ratings and EMGtrap. Deltoid muscle activity and autonomic responses were almost identical in MYA and CON during work, stress and recovery. In MYA only, pain intensity and stress ratings increased towards the end of the repetitive work.</p> <p>Conclusion</p> <p>We found increased muscle activity during uninstructed rest in the painful muscle of a group of women with trapezius myalgia. The present study could not confirm the hypothesis that chronic trapezius myalgia is associated with increased sympathetic activity. The suggestion of autonomic imbalance in patients with chronic local or regional musculoskeletal pain needs to be further investigated.</p

The thermal and magnetic properties of the Fe89.8Ni1.5Si5.2B3C0.5 and Fe81B13Si14C2 amorphous alloys

This paper investigates the thermal and magnetic properties of two iron based amorphous alloys with different Fe-content: Fe89.8Ni1.5Si5.2B3C0.5 and Fe81B13Si14C2. The XRD results show that the thermal induced structural changes occur in the temperature range of 3000C - 8500C for the Fe89.8Ni1.5Si5.2B3C0.5 amorphous alloy. The appearance of the first crystallization peaks on DSC thermograms of Fe81B13Si4C2, amorphous alloy is perceived already at 4500C. The initial magnetization curves of the as-cast sample of the Fe89.8Ni1.5Si5.2B3C0.5 amorphous alloy, obtained at the frequencies of 50 Hz, 400 Hz and 1000 Hz show the excellent match. The maximum relative magnetic permeability for Fe89.8Ni1.5Si5.2B3C0.5 alloy sample is achieved at magnetic field strength of about 20 A/m for all frequencies, whereas the values of about 7000 were obtained at the frequencies of 50 Hz and 400 Hz. The influence of frequency on total power losses, for both alloys exhibits the increase of core losses with frequency increase. The amorphous alloy Fe89.8Ni1.5Si5.2B3C0.5 toroidal core exhibits about 3 time higher total power losses. [Projekat Ministarstva nauke Republike Srbije, br. 172057

Risk Factors for Anaplastic Thyroid Cancer

Background. Anaplastic thyroid cancer (ATC) is a form of thyroid cancer with very poor prognosis, but is fortunately quite rare. Its aetiology is unknown and not well researched. Aim. The aim of this study was to identify potential risk factors for ATC. Material and Method. Case-control study of 126 ATC patients (77 females and 49 males) and 252 controls individually matched by gender, age, and place of abode. In statistical analysis we used a Cox regression model. Results. Univariate logistic regression showed that the risk factors for ATC are low education level, type B blood group, goitre, other nonthyroid malignancies, diabetes, late menarche, and an early first pregnancy. Multivariate logistic regression analysis showed that independent risk factors for ATC are low education level (OR = 1.42, 95% CI = 1.09-1.86), type B blood group (OR = 2.41, 95% CI = 1.03-5.66), and goitre (OR = 25-33, 95% CI = 5.66-126.65). Conclusion. Independent risk factors for ATC are: low education level, type B blood group, and goitre

Is mitochondrial DNA divergence of near easter crested newts, Triturus karelinii group, reflected by differentiation of skull shape

The Eurasian Triturus karelinii group of crested newts comprises three distinct, geographically coherent mitochondrial DNA lineages, designated as the eastern, central and western lineage. These three lineages are genetically as diverged as other, morphologically well-differentiated crested newt species. However, on the ground of restricted morphological studies the three lineages have been considered morphologically uniform. We analyze skull shape in the T. karelinii group using geometric morphometric techniques and interpret the results in a phylogenetic context. We found a high divergence between populations and variable patterns of sexual dimorphism within mitochondrial DNA lineages, significant divergence in skull shape including significant divergence in allometry of the ventral skull side in females, and lack of concordance between the pattern of morphological and genetic variation within lineages and between lineages. The observed pattern indicates that ecologically mediated divergences could play an important role in the evolution of skull shape. Reconstruction of the evolutionary trajectory of the T. karelinii group indicates that the eastern lineage largely retains the ancestral skull shape and that the central and western lineages possess a derived skull shape. Skull shape does not clearly support the presence of three discrete geographical groups as suggested by the mitochondrial DNA data, but the amount of shape changes between T. karelinii lineages is similar to that between T. karelinii lineages and the outgroup species, T. macedonicus