Brain system segregation and pain catastrophizing in chronic pain progression.

Pain processing involves emotional and cognitive factors that can modify pain perception. Increasing evidence suggests that pain catastrophizing (PC) is implicated, through pain-related self-thoughts, in the maladaptive plastic changes related to the maintenance of chronic pain (CP). Functional magnetic resonance imaging (fMRI) studies have shown an association between CP and two main networks: default mode (DMN) and dorsoattentional (DAN). Brain system segregation degree (SyS), an fMRI framework used to quantify the extent to which functional networks are segregated from each other, is associated with cognitive abilities in both healthy individuals and neurological patients. We hypothesized that individuals suffering from CP would show worst health-related status compared to healthy individuals and that, within CP individuals, longitudinal changes in pain experience (pain intensity and affective interference), could be predicted by SyS and PC subdomains (rumination, magnification, and helplessness). To assess the longitudinal progression of CP, two pain surveys were taken before and after an in-person assessment (physical evaluation and fMRI). We first compared the sociodemographic, health-related, and SyS data in the whole sample (no pain and pain groups). Secondly, we ran linear regression and a moderation model only in the pain group, to see the predictive and moderator values of PC and SyS in pain progression. From our sample of 347 individuals (mean age = 53.84, 55.2% women), 133 responded to having CP, and 214 denied having CP. When comparing groups, results showed significant differences in health-related questionnaires, but no differences in SyS. Within the pain group, helplessness (ß = 0.325; p = 0.003), higher DMN (ß = 0.193; p = 0.037), and lower DAN segregation (ß = 0.215; p = 0.014) were strongly associated with a worsening in pain experience over time. Moreover, helplessness moderated the association between DMN segregation and pain experience progression (p = 0.003). Our findings indicate that the efficient functioning of these networks and catastrophizing could be used as predictors of pain progression, bringing new light to the influence of the interplay between psychological aspects and brain networks. Consequently, approaches focusing on these factors could minimize the impact on daily life activities.

Influence of free fatty acid content and degree of fat saturation in laying hen diets on egg quality, yolk fatty acid profile, and cholesterol content.

The aim of the present study was to evaluate the effect of dietary free fatty acid (FFA) content and the degree of saturation on egg quality, yolk fatty acid (FA) profile, and yolk cholesterol content. For a 15-wk period, a total of 144 laying hens (19-wk-old) were randomly assigned to 8 treatments arranged in a 2 × 4 factorial design, with 2 sources of crude oil (soybean oil and palm oil) and 4 levels of FFA (10, 20, 30, and 45%). The dietary treatments were achieved by progressively substituting the original oils with equivalent amounts of their corresponding acid oils (soybean acid oil and palm fatty acid distillate, respectively). No differences in ADFI or egg mass were found. However, dietary FFA reduced egg production (linear, P < 0.05) and increased the feed conversion ratio (linear, P < 0.05). Higher levels of FFA in soybean diets resulted in higher egg weight with higher albumen and yolk weights (linear, P < 0.01). Palm diets presented higher yolk:albumen ratio than soybean diets (P < 0.001), but the effect of FFA did not follow a linear trend. Hens fed soybean diets laid eggs with higher Haugh units (HU) than palm diets (P < 0.001), although increasing the dietary FFA% reduced the HU values in both (linear, P < 0.001). Palm diets enhanced shell quality with greater resistance to breakage, and higher dry matter and ash content than soybean diets (P < 0.05). No differences in egg chemical composition and yolk cholesterol content were found (P > 0.05). The saturation degree had a significant effect on all the analyzed yolk FA (P < 0.001) except for arachidonic acid (C20:4 n-6), whereas increasing the FFA content did not affect to a great extent. These results show that varying dietary FFA level did not affect egg quality and yolk composition as much as the dietary fat source did, supporting the use of acid oils and fatty acid distillates as fat ingredients for feed.

Effects of free-fatty-acid content and saturation degree of the dietary oil sources on lipid-class content and fatty-acid digestibility along the gastrointestinal tract in broilers from 22 to 37 days of age.

The aim of the present study is to assess the effect of the free-fatty-acid (FFA) content and saturation degree of dietary fat (added at 6%) on the fatty-acid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broilers from 22 to 37 d of age. This is essential to determine the potential use of acid oils (refining by-products rich in FFA) in broiler diets as an alternative to crude oils. The study consisted of a 2 × 4 factorial arrangement, which included 2 fat sources (soybean oils - unsaturated, or palm oils - saturated) and 4 levels of FFA (5, 15, 35, and 50%). Samples of digestive content of the gizzard, duodenum, jejunum, ileum and of the excreta were obtained at 37 d of age. Irrespective of the dietary fat source, more than 80% of total FA (TFA) was absorbed in the jejunum. Broilers fed with unsaturated diets had a higher absorption efficiency of FA than did those fed with saturated diets. This conclusion is supported by the lower FFA content and the higher TFA and polyunsaturated FA (PUFA) digestibility coefficients in the ileum (P < 0.001) observed in the former group. The dietary FFA level did not affect the FA absorption process as much as the dietary fat source did. This was supported by the lack of statistical differences among the diets with a similar saturation degree but rather different levels of FFA, for TFA, saturated FA, and PUFA digestibility coefficients both in the jejunum and ileum. However, the interactions reported in the ileum for triacylglycerol and diacylglycerol contents (P < 0.001), as well as for monounsaturated FA digestibility coefficients (P < 0.05) show that the dietary FFA content affects the FA absorption process. The present results show that the inclusion of acid oils in grower-finisher broiler diets with FFA levels up to 35% does not have a negative impact on the FA absorption process.

Effect of fibrous diet and vitamin C inclusion on uniformity, carcass traits, skeletal strength, and behavior of broiler breeder pullets.

This experiment studied the effect of broiler breeder nutritional strategies on uniformity, carcass traits, tibia parameters, and behavior during rearing and prebreeder periods (up to 22 wk of age). One-day-old pullets (n = 384) were randomly assigned to 4 treatments arranged as a 2 × 2 factorial, with 2 fiber levels (control vs. fibrous diet, 15% diluted in AMEn and nutrient content) and 2 vitamin C feed inclusions (0 vs. 200 mg/kg). At 6, 15, and 22 wk, blood sampling was carried out (4 birds/replicate) to determine serum alkaline phosphatase (ALP) levels, and behavior was observed by visual scan sampling. At 22 wk, carcass traits, tibia parameters, and intestinal morphology were assessed (2 birds/replicate), and tail- and wing-feather integrity of all birds were scored. Fibrous diet did not modify BW uniformity, mortality, or tibia growth when compared with control diet. Pullets fed the fibrous diet had lower tibia breaking strength, elastic modulus, and ash content values (P < 0.05). They also had lower ALP serum level at 6 and 22 wk (P < 0.05), their breast muscle was less developed (18.5 vs. 19.8%, P < 0.05), and their abdominal fat deposition was higher (1.14 vs. 0.87%, P < 0.05). At 15 and 22 wk, they performed, on average, 97% less grasping feather pecking and 45% less non-food object pecking behaviors, and their wing-feather score was lower (P < 0.05) at 22 wk. Tail- and wing-feather scores of the control treatments were reduced by vitamin C inclusion (tail: 0.30 vs. 1.15, P < 0.05; wing: 0.98 vs. 1.26, P < 0.05) at 22 wk. In conclusion, fibrous diet improves carcass traits (reduces breast muscle and increases abdominal fat deposition), deteriorates bone mineral deposition and thus skeletal strength, and reduces stereotypic behaviors, improving wing-feather integrity. Vitamin C inclusion improves tail- and wing-feather integrity of lower in feed allowance.

[Transcranial direct current stimulation for the treatment of fibromyalgia: a systematic review]. / Estimulacion transcraneal por corriente directa en la fibromialgia: revision sistematica.

INTRODUCTION: Fibromyalgia is a multisymptomatic diffuse chronic musculoskeletal pain syndrome with evidence of central nervous system dysfunction. Accordingly, non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) may be a complementary therapeutic resource to reduce pain perception. AIMS: To review the potential effectiveness of tDCS to reduce pain in fibromyalgia, to identify the most effective neurostimulation parameters and to delimit its safety. PATIENTS AND METHODS: Systematic review of prospective studies reported in PubMed and Cochrane reviews. RESULTS: The anodal tDCS of the left primary motor cortex, at 2mA for 20 minutes with 35 cm2 electrodes on five consecutive days, provides better results in reducing pain (14-59%), and improving sleep quality, with greater accentuation on the fifth day. The clinical improvement persists up to a minimum of 60 days (11-20% reduction of pain). Adverse effects are well tolerated and few. CONCLUSIONS: The experience with tDCS in fibromyalgia is still limited. However, the anodal tDCS in the left primary motor cortex can be recommended with level B (probable therapeutic efficacy) and appears to act through the modification of the sensorial processing of the pain of thalamic inhibitory circuitry.

TITLE: Estimulacion transcraneal por corriente directa en la fibromialgia: revision sistematica.Introduccion. La fibromialgia es un sindrome de dolor cronico difuso musculoesqueletico multisintomatico, con evidencias de una disfuncion del sistema nervioso central. Consecuentemente, tecnicas de estimulacion cerebral no invasiva, como la estimulacion transcraneal con corriente directa (tDCS), pueden ser un recurso terapeutico complementario para reducir la percepcion de dolor. Objetivos. Revisar la potencial efectividad de la tDCS para reducir el dolor en la fibromialgia, identificar los parametros mas efectivos de neuroestimulacion y delimitar su seguridad. Pacientes y metodos. Revision sistematica de estudios prospectivos registrados en PubMed y revisiones Cochrane. Resultados. La tDCS anodica de la corteza motora primaria izquierda, a 2 mA durante 20 minutos con electrodos de 35 cm2 durante cinco dias consecutivos, es la que proporciona mejores resultados en la reduccion del dolor (14-59%) y mejora de la calidad del sueño, con mayor acentuacion en el quinto dia. La mejora clinica persiste hasta un minimo de 60 dias (11-20% de reduccion del dolor). Se tolera bien y tiene escasos efectos adversos. Conclusiones. La experiencia con la tDCS en fibromialgia es todavia limitada. No obstante, la tDCS anodica en la corteza motora primaria izquierda puede recomendarse con un nivel B (probable eficacia terapeutica) y podria actuar mediante la modificacion del procesamiento sensorial del dolor de circuitos inhibitorios talamicos.

Adaptation and validation of the Spanish version of the Spinal Cord Lesion-related Coping Strategies Questionnaire (SCL CSQ-S).

STUDY DESIGN: Cross-sectional validation study. OBJECTIVES: To adapt the Spinal Cord Lesion-related Coping Strategies Questionnaire into the Spanish language (SCL CSQ-S) and to examine the relationship between coping strategies, global quality of life and psychological adaptation. SETTING: Data were collected through individuals with spinal cord injury (SCI) now living in the community who completed their routine follow-up assessment at the Institute Guttmann in Barcelona, Spain. METHODS: Forward and backward translation into Spanish of the English version of the questionnaire. Questionnaires of global Quality of Life, Community Integration, Coping, Depression, Anxiety and Functional Independence were administered to 349 adults with paraplegia and 162 adults with tetraplegia. Statistical analysis included confirmatory factor analysis and regression analysis. RESULTS: The factorial structure of the questionnaire was partly verified. The original correlated, three-factor model sufficiently fit the data obtained in this study: χ(2)(48)=109.46; P<0.001; Comparative Fit Index=0.96; Tucker-Lewis Index=0.96; Root Mean Square Error of Approximation=0.050 (0.038-0.062); Akaike information criterion=13.46. Items were found to be good indicators of their respective latent factors, showing adequate factorial charge ranges (between 0.41 and 0.75). The reliability coefficient (Cronbach's α) for the Acceptance subscale was 0.74, for Social reliance 0.76 and for Fighting spirit 0.69. Coping strategies as measured by SCL-CSQ-S contributed to the prediction of outcomes related to adaptation to disability. CONCLUSION: The results of the study show some evidence for the robustness of the structure of SCL CSQ-S and show that the Spanish version of the questionnaire largely replicate previous results. Coping strategies, especially Acceptance, are related to adaptation to injury.

Psychometric evaluation of the Spanish version of the MPI-SCI.

STUDY DESIGN: Postal surveys. OBJECTIVES: To confirm the factor structure of the Spanish version of the MPI-SCI (MPI-SCI-S, Multidimensional Pain Inventory in the SCI population) and to test its internal consistency and construct validity in a Spanish population. SETTING: Guttmann Institute, Barcelona, Spain. METHODS: The MPI-SCI-S along with Spanish measures of pain intensity (Numerical Rating Scale), pain interference (Brief Pain Inventory), functional independence (Functional Independence Measure), depression (Beck Depression Inventory), locus of control (Multidimensional health Locus of Control), support (Functional Social Support Questionnaire (Duke-UNC)), psychological well-being (Psychological Global Well-Being Index) and demographic/injury characteristics were assessed in persons with spinal cord injury (SCI) and chronic pain (n=126). RESULTS: Confirmatory factor analysis suggested an adequate factor structure for the MPI-SCI-S. The internal consistency of the MPI-SCI-S subscales ranged from acceptable (r=0.66, Life Control) to excellent (r=0.94, Life Interference). All MPI-SCI-S subscales showed adequate construct validity, with the exception of the Negative and Solicitous Responses subscales. CONCLUSIONS: The Spanish version of the MPI-SCI is adequate for evaluating chronic pain impact following SCI in a Spanish-speaking population. Future studies should include additional measures of pain-related support in the Spanish-speaking SCI population.

Efficacy of low-dose tylvalosin for the control of clostridiosis in broilers and its effect on productive parameters.

The study was carried out under field conditions in a commercial farm, and 1,440 as-hatched Ross-308 broilers were included. Broilers were randomly distributed into 24 experimental 4-m(2) pens (60 broilers/pen). Pens were randomized to the 3 treatment groups: a) tylvalosin 10 mg/kg of live BW during 2 d, b) positive control (tylosin during 2 d), and c) negative control (no treatment). The drugs were provided in the water supply. Mortality, individual BW, and feed intake were assessed. Clostridium presence was assessed in fecal and cecal samples, coccidian oocyst counts were assessed in fecal samples, and bacterial diversity was assessed in ileal content. Live BW at 42 d old was significantly better in the tylvalosin group than in tylosin and no-treatment groups, with tylvalosin-treated broilers reaching 80 to 100 g higher final live weight. Average daily gain results mirrored BW findings. The improvement of feed conversion rate with tylvalosin amounted to 0.13 and to 0.10 versus tylosin and no-treatment, respectively, with mortality being similar in all groups. Significantly reduced sulfite-reducing Clostridium and Clostridium perfringens counts in tylvalosin and tylosin groups versus the no-treatment group were observed in cecum content samples. In conclusion, according to the present study results, tylvalosin, at doses substantially lower than registered for poultry in Europe, has proven effective in controlling the colonization of the cecum by Clostridium ssp. in broilers, improving some productive performances.

Referred sensations and neuropathic pain following spinal cord injury.

It has been proposed that painful and non-painful referred sensations (RSs) are associated with reorganization of sensory pathways in patients with complete spinal cord injury (SCI). In order to investigate the referred sensation (RS) phenomenon and its correlation with neuropathic pain (NP) 48 patients with complete SCI, 24 with chronic NP and 24 without pain or paraesthesias were studied using clinical examination and neurophysiological tests. Patients reporting RSs were re-examined at 2 and 10weeks after the first examination. We defined the presence of RS as sensations perceived below the injury level in response to touch and pinprick stimuli in various body points above the injury level. The examination was carried out by one researcher applying the stimuli to the patient under two visual conditions (open and closed eyes), and then asking the patient to make tactile self-stimulation. Seven patients with SCI and NP (29%) reported RS below the injury level. RS were well located and consistently evoked at repeated examinations. Touch and pinprick stimulation elicited similar RS that were non-painful in six patients and painful in one. Visual feedback did not change RS perception and characteristics. None of the patients in the SCI group without NP presented RS. In conclusion, our results indicate that RS is relatively frequent in patients with complete SCI and NP. The common occurrence of RS in patients with NP and the location of the sensations in the same area as NP suggest that pain and RS share common pathophysiological mechanisms.

[Characteristics of chronic neuropathic pain and their relationship with psychological well-being in spinal cord injury patients]. / Características del dolor neuropático crónico y su relación con el bienestar psicológico en pacientes con lesión medular.

AIMS: To determine the prevalence of neuropathic pain (NP) in a sample of patients with spinal cord injury (SCI), to examine the relation between clinical, demographic and psychological characteristics with the prevalence of NP after SCI and the different types of NP, and to study predictive factors. PATIENTS AND METHODS: Transversal observational study of 260 patients who attended their annual revision. Main outcome measures included presence/absence of NP, psychological well-being index, detailed pain history and 0-10 numerical rating scale of average pain intensity. RESULTS: 93 patients (36%) with SCI had NP. Of the patients with NP, 35% showed pain at level, while 65% showed NP below the level of injury. The only variable with a predictive value on the prevalence of NP was older age at the time of SCI. Statistically significant differences were observed between the prevalence of NP and the perception of psychological well-being; patients with NP were the ones with more psychological distress. As for the different types of NP, the variables with predictive value on the classification of NP were early onset of pain at level, and incompleteness of the lesion in the below level NP. CONCLUSION: The results of this study show that NP appears frequently after SCI being more prevalent in patients who suffered the injury at more advanced ages. NP has a negative impact on the perception of psychological well-being.

Características del dolor neuropático crónico y su relación con el bienestar psicológico en pacientes con lesión medular / Characteristics of chronic neuropathic pain and their relationship with psychological well-being in spinal cord injury patients

Objetivos. Determinar la prevalencia del dolor neuropático (DN) en una muestra de pacientes con lesión medular (LM), examinar la relación entre las características clínicas, demográficas y psicológicas con la prevalencia del DN después de una LM y a su vez con los diferentes tipos de DN, y estudiar el valor predictivo de los factores más significativos. Pacientes y métodos. Estudio transversal observacional de un total de 260 pacientes que acudieron a una revisión anual. Las principales medidas de resultados incluyeron presencia/ausencia de DN, índice de bienestar psicológico, historia detallada del dolor y escala de puntuación numérica de 0-10 para la media de intensidad del dolor. Resultados. 93 pacientes (36%) con LM tenían DN. De los pacientes que presentaron DN, un 35% mostró dolor a nivel de la lesión, mientras que un 65% presentó DN por debajo. La única variable con capacidad predictiva sobre la prevalencia del DN fue la edad en el momento de la LM. Se observaron diferencias estadísticamente significativas entre la prevalencia del DN y la percepción de bienestar psicológico; el grupo de pacientes con DN fue el que tuvo proporcionalmente un malestar psicológico mayor. En cuanto a los diferentes tipos de DN, las variables con capacidad predictiva sobre la clasificación del DN eran el inicio temprano del dolor en el DN a nivel y el hecho de que la lesión sea incompleta en el DN por debajo. Conclusión. El DN aparece con frecuencia después de la LM y se da de forma más común en aquellos pacientes que han sufrido la lesión a edades más avanzadas. El DN tiene un impacto negativo en la percepción de bienestar psicológico

Aims. To determine the prevalence of neuropathic pain (NP) in a sample of patients with spinal cord injury (SCI), to examine the relation between clinical, demographic and psychological characteristics with the prevalence of NP after SCI and the different types of NP, and to study predictive factors. Patients and methods. Transversal observational study of 260 patients who attended their annual revision. Main outcome measures included presence/absence of NP, psychological wellbeing index, detailed pain history and 0-10 numerical rating scale of average pain intensity. Results. 93 patients (36%) with SCI had NP. Of the patients with NP, 35% showed pain at level, while 65% showed NP below the level of injury. The only variable with a predictive value on the prevalence of NP was older age at the time of SCI. Statistically significant differences were observed between the prevalence of NP and the perception of psychological well-being; patients with NP were the ones with more psychological distress. As for the different types of NP, the variables with predictive value on the classification of NP were early onset of pain at level, and incompleteness of the lesion in the below level NP. Conclusion. The results of this study show that NP appears frequently after SCI being more prevalent in patients who suffered the injury at more advanced ages. NP has a negative impact on the perception of psychological well-being