Effects of intensity, attention and medication on auditory-evoked potentials in patients with fibromyalgia.

Fibromyalgia (FM) has been associated to an increased processing of somatosensory stimuli, but its generalization to other sensory modalities is under discussion. To clarify this, we studied auditory event-related potentials (AEPs) to stimuli of different intensity in patients with FM and healthy controls (HCs), considering the effects of attention mechanisms and medication. We performed two experiments: In study 1 (n = 50 FM, 60 HCs), the stimuli were presented randomly within the sequence; in study 2 (n = 28 FM, 30 HCs), they were presented in blocks of the same intensity. We analyzed intensity and group effects on N1-P2 amplitude and, only for the FM group, the effect of medication and the correlation between AEPs and clinical variables. Contrary to the expectation, the patients showed a trend of reduced AEPs to the loudest tones (study 1) or no significant differences with the HCs (study 2). Medication with central effects significantly reduced AEPs, while no significant relationships between the N1-P2 amplitude/intensity function and patients' symptoms were observed. The findings do not provide evidence of augmented auditory processing in FM. Nevertheless, given the observed effect of medication, the role of sensory amplification as an underlying pathophysiological mechanism in fibromyalgia cannot be discarded.

Filtering out repetitive auditory stimuli in fibromyalgia: a study of P50 sensory gating.

BACKGROUND: It has been suggested that fibromyalgia (FM) patients show increased sensory processing of nociceptive and non-nociceptive stimuli and also reduced habituation. Although this pattern of increased reactivity has been established for the somatosensory modality, its generalization to other sensory modalities remains controversial. METHODS: Auditory evoked potentials were obtained using a paired-stimuli paradigm from a sample of 52 FM female patients and 55 healthy women matched for age and socio-economic status. Sensory gating of the P50 component, as indicated by P50 suppression rates to the second identical stimuli, was analysed in relation to clinical indices of FM, including algometry of tender points and a number of self-reported questionnaires. RESULTS: Sensory gating mechanisms in FM patients proved to be normal, robust and as efficient as those recorded in control subjects. There was no correlation between P50 suppression rates and indices of clinical or experimental (threshold or tolerance) pain. In addition, P50 sensory gating was not related to the other main symptoms of FM, including fatigue, sleep dysfunction or co-morbid depression, nor to hypersensitivity to noise or headache. CONCLUSIONS: The results indicate that FM patients do not present significant deficits in early sensory gating when processing auditory stimuli, and therefore challenge the 'generalized hypersensitivity' hypothesis of FM.

Convergence between the 1990 and 2010 ACR diagnostic criteria and validation of the Spanish version of the Fibromyalgia Survey Questionnaire (FSQ).

(1) To assess the degree of convergence between the 1990 and 2010 American College of Rheumatology (ACR) diagnostic criteria; (2) To evaluate the validity and reliability of the 2010 ACR criteria; (3) To validate the Spanish version of the Fibromyalgia Survey Questionnaire (FSQ); and (4) To assess the utility of the FSQ to differentiate fibromyalgia (FM) subgroups by disease severity. In the first study, agreement between the 1990 and 2010 ACR criteria for FM diagnosis was analyzed in a sample of 80 FM patients and 59 healthy controls. Algometry (mean threshold and tender points count) and the 2010 ACR indices [Symptom Severity Scale (SSS), Widespread Index (WPI) and Polysymptomatic Distress Scale (PSD)] were correlated with the key symptoms of FM and with indices of disease interference and quality of life. In a second study, we evaluated the validity and internal consistency of the Spanish version of the FSQ, as well as its ability to discriminate between groups of FM patients with low and high symptom severity. There is good agreement between the 1990 and 2010 ACR criteria for FM diagnosis. The 2010 ACR indices (SSS, WPI and PSD) demonstrated very adequate construct validity and appeared to be useful in the assessment of disease severity and global impact of FM. The FSQ had good internal consistency and validity and showed 100 % concordance with 2010 ACR criteria applied by a clinician. In addition, the FSQ proved to be useful in differentiating FM severity subgroups.

Intensity dependence of auditory-evoked cortical potentials in fibromyalgia patients: a test of the generalized hypervigilance hypothesis.

UNLABELLED: On the basis of recent evidence concerning the amplification of incoming stimulation in fibromyalgia (FM) patients, it has been proposed that a generalized hypervigilance of painful and nonpainful sensations may be at the root of this disorder. So far, research into this issue has been inconclusive, possibly owing to the lack of agreement as to the operational definition of "generalized hypervigilance" and to the lack of robust objective measures characterizing the sensory style of FM patients. In this study, we recorded auditory-evoked potentials (AEPs) elicited by tones of increasing intensity (60, 70, 80, 90, and 105 dB) in 27 female FM patients and 25 healthy controls. Fibromyalgia patients presented shorter N1 and P2 latencies and a stronger intensity dependence of their AEPs. Both results suggest that FM patients may be hypervigilant to sensory stimuli, especially when very loud tones are used. The most noteworthy difference between patients and control subjects is at the highest stimulus intensity, for which far more patients maintained increased N1-P2 amplitudes in relation to the 90-dB tones. The larger AEP amplitudes to the 105-dB tones suggest that defects in an inhibitory system protecting against overstimulation may be a crucial factor in the pathophysiology of FM. Because a stronger loudness dependence of AEPs has been related to weak serotonergic transmission, it is hypothesized that for many FM patients deficient inhibition of the response to noxious and intense auditory stimuli may be due to a serotonergic deficit. PERSPECTIVE: The study of auditory-evoked potentials in response to tones of increasing intensity in FM patients may help to clarify the pathophysiology of this disorder, especially regarding the role of inhibition deficits involving serotonergic dysfunction, and may be a useful tool to guide the pharmacologic treatment of FM patients.

Body dissatisfaction and its interrelations with other risk factors for bulimia nervosa in 12 countries.

BACKGROUND: It is widely accepted that risk factors for bulimia nervosa, mainly body dissatisfaction, are dependent on cultural factors. However, to date few studies have compared data from different cultures with an appropriate methodology. Therefore we aimed to gather reliable information on body dissatisfaction and other risk factors for bulimia from different nations and to reveal their functional interrelations. METHODS: A series of 10 silhouettes, designed to be as far as possible free from cultural and other detailed aspects, was shown to 1,751 medical and nursing students in 12 nations. A functional model was applied to each sample and tested by structural equation methodology. RESULTS: The most extreme body dissatisfaction was found in northern Mediterranean countries, followed by northern European countries. Countries currently undergoing a process of westernization show an intermediate amount of body dissatisfaction, and non-western countries demonstrate rather low values. Body dissatisfaction is the most important influence on dieting behaviour in most countries. CONCLUSIONS: Despite ongoing adoption of western values worldwide, we observe remarkable differences in body dissatisfaction between different cultures. That body dissatisfaction seems disturbingly partly detached from the actual BMI, i.e. possible overweight, as well as from feelings of low self-esteem in some western countries, raises new questions about the possible origin of the pressure to be thin.

Teoría tridimensional de la personalidad: aplicación a los trastornos por abuso de sustancias / Tridimensional theory of personality: applications to substance abuse disorders

Introducción: Hemos valorado el peso que las dimensiones de Cloninger desempeñan en el desorden de abuso de sustancias, y analizado la hipotética independencia de estas dimensiones entre sí y si mantienen alguna correlación con variables demográficas. Metodología: 20 abstinentes a las drogas y 20 controles, todos varones, completaron el Cuestionario Tridimensional de Personalidad. Resultados: Todos los valores de la escala de Buscador de Novedad (BN) fueron superiores en el grupo abstinente. Las diferencias más notables fueron las correspondientes a las subescalas 'excitable' y 'extravagante'; también obtuvimos una significativa, aunque menor diferencia en la subescala 'desordenado'. En la escala 'Evitación de Daño' (ED) sólo 'fatigabilidad' fue significativamente superior en el grupo abstinente. Con respecto a la 'Dependencia de Recompensa' (DR), el valor de la subescala 'persistencia' fue sin embargo sustancialmente menor en los sujetos abstinentes. El análisis de correlación demostró que las tres dimensiones eran mutuamente independientes en los controles. Sin embargo, en el grupo abstinente BN correlacionó positivamente con ED y negativamente con 'persistencia'. No se encontró ninguna correlación entre las dimensiones y las variables demográficas en ambos grupos. Conclusiones: Un elevado comportamiento buscador de sensaciones y una baja persistencia parecía ser la característica principal de nuestros sujetos abstinentes. Ambos parámetros explicarían en parte su elevada tendencia a buscar sustancias y posiblemente la alta tasa de recaídas encontrada en poblaciones similares. Finalmente, indicar que la hipótesis de Cloninger acerca de la mutua independencia de las dimensiones se cumplía sólo en el grupo control (AU)

Increased acidophilia of eosinophil granules after EDTA treatment.

The acidophilic reaction of eosinophil leucocyte granules from human, pig and horse blood smears was investigated by using May-Grünwald-Giemsa staining after previous treatment with EDTA and sodium citrate solutions. The same peak at 530 nm, but absorption values considerably higher than those of controls, were found in eosinophil granules after application of chelating agents, indicating that removal of metal cations could unmask basic groups in these structures.

Oxidized p-phenylenediamine: observations on the staining reaction in epoxy embedded tissues.

p-Phenylenediamine (PPD) is easily oxidized to brown compounds which stain acidic substrates. On account of the spontaneous oxidation process, the colour of PPD increases and becomes ochre-brown in a few days, showing an absorption peak at lambda = 510 nm with shoulder at about 440 to 460 nm. Studies on the application of oxidized PPD as a stain for semi-thin sections revealed that some tissue components could be clearly visualized. After glutaraldehyde fixation, semi-thin and thin sections of animal tissues were treated with 0.5% aqueous PPD solutions which were aged for variable times at room temperature. Microvilli, goblet cell mucin, mast cell granules, cartilage matrix, collagen, elastin, keratohyalin granules, acrosomes, cytoplasmic granules of Drosophila hydei salivary glands and chromatin showed positive staining reactions after treatment of semi-thin sections with oxidized PPD (7-10 days aged) for 20-30 minutes. Microspectrophotometric studies revealed an absorption peak at lambda = 520-530 nm and a shoulder at lambda = 440-460 nm in goblet cell mucin stained by oxidized PPD. In the presence of anionic macromolecules, the main peak of oxidized PPD solutions showed a strong hyperchromism. Thin sections stained by oxidized PPD did not appear contrasted, but the treatment with 0.125% gold chloride (AuCl3) induced massive gold deposits in structures stained by oxidized PPD. Hyperchromic shifts were also produced in oxidized PPD solutions after the addition of small amounts of AuCl3. This procedure can be used as a simple and rapid staining method for epoxy sections, giving selective contrast for some tissue components.

Alterations in the cytochemical activity of several phosphatases in hepatocytes from rats exposed prenatally to ethanol.

The activities of acid phosphatase, alkaline phosphatase, glucose-6-phosphatase, uridine diphosphatase, inosine diphosphatase, thiamine pyrophosphatase and 5'-nucleotidase have been investigated cytochemically in hepatocytes of the offspring of alcohol-fed rats, using cerium ions as a capturing agent and qualitative and quantitative electron microscopy. All these enzyme activities were decreased in the experimental animals compared with controls not exposed to ethanol. The pattern of deposition of the product of glucose-6-phosphatase activity in the cisternae of the endoplasmic reticulum was also different in the two groups. The phosphatases analyzed are functional markers of different cell components, and the results suggest that prenatal exposure of rats to ethanol causes functional alterations in the endoplasmic reticulum, Golgi apparatus, lysosomes and plasma membrane of hepatocytes.

Qualitative and quantitative ultrastructural alterations in hepatocytes of rats prenatally exposed to ethanol with special reference to mitochondria, golgi apparatus and peroxisomes.

To assess the effect of ethanol on the liver of the offspring of alcohol-fed rats, the hepatocytes of newborn rats whose mothers were fed: a) a liquid diet containing alcohol, b) the same diet isocalorically balanced, or c) a chow diet, were analyzed using both quantitative and qualitative electron microscopy as well as cytophotometric and biochemical methods. Hepatocytes of chow-fed and pair-fed controls showed differences in the amounts of glycogen and lipids as well as in several stereologically measured variables including mitochondria, Golgi apparatus and smooth endoplasmic reticulum. These differences are probably due to the composition of the diet. Rats prenatally exposed to alcohol showed increases in the hepatocyte and mitochondria volumes and in the number of peroxisomes. Moreover, the Golgi apparatus of these cells appeared disorganized and composed exclusively of small size vesicles, suggesting an impairment of their function.