Overweight and obesity have been suggested as significant factors in irritable bowel syndrome (IBS) development. However, the relationship between overweight/obesity and IBS is unclear. It is known ...that a modified intestinal barrier, especially the permeability of the small intestine (s-IP), can play a significant role in the pathogenesis of both obesity and IBS. Moreover, dietary interventions are essential for treating both pathologies. We evaluated the gastrointestinal (GI) symptoms and the urinary and circulating markers of GI barrier function and integrity, the markers of intestinal dysbiosis and bacterial translocation, in 40 IBS patients with predominant diarrhea (IBS-D) (32 females and 8 males; mean age = 43.5 ± 1.4 years), categorized using their Body Mass Index levels as normal (NW) and overweight (OW). Evaluations were performed before and after 12 weeks of a Low FODMAP Diet (LFD). At the baseline, OW patients showed a significantly higher s-IP than NW. After an LFD, a significant improvement of s-IP in OW patients occurred, along with a significant decrease in markers of epithelial integrity and bacterial translocation. Our findings highlight the close relationship between overweight and the intestinal barrier and support their involvement in IBS-D pathophysiology. Furthermore, the positive role of an LFD in managing overweight IBS-D was highlighted.
Abstract This study aimed at comparing both peripheral and central mechanisms of muscle fatigue between Charcot–Marie–Tooth 1A patients and healthy individuals during a fatiguing voluntary task by ...simultaneous electromyographic and electroencephalographic recordings. Six Charcot–Marie–Tooth 1A patients (3 females, 40 ± 11 years) and 6-matched healthy individuals performed four blocks of sub-maximal isometric knee extensions. At the beginning of the session and after each block, electrically-evoked maximal single-twitch, maximal voluntary contraction and surface-electromyography of the vastus lateralis muscle were measured. The movement-related-cortical potentials were averaged in early (block 1–2) and late (block 3–4) stages of fatigue. The effect of fatigue was demonstrated at peripheral level by the decline of maximal voluntary contraction, maximal twitch and surface electromyography amplitude and at central level by the larger amplitude of movement-related-cortical-potentials during late than early stage of fatiguing sub-maximal contractions. Charcot–Marie–Tooth 1A patients showed lower motor cortex activity during motor planning, with earlier onset and larger prefrontal cortex activity during the late stage of the fatiguing task than healthy controls. These data demonstrate the key role of the prefrontal cortex in the development of fatigue in Charcot–Marie–Tooth 1A patients, which may be activated as a compensatory mechanism for the low motor cortex activation, thus reflecting high awareness of movement complexity.
Previous event‐related potential (ERP) studies mainly from the present research group showed a novel component, that is, the prefrontal negativity (pN), recorded in visual‐motor discriminative tasks ...during the pre‐stimulus phase. This component is concomitant to activity related to motor preparation, that is, the Bereitschaftspotential (BP). The pN component has been reported in experiments based on the visual modality only; for other modalities (acoustic and/or somatosensory) the presence of the pN warrants further investigation. This study represents a first step toward this direction; indeed, we aimed at describing the pN and the BP components in discriminative response tasks (DRTs) for three sensory modalities. In experiment 1 ERPs were recorded in 29 adults in visual and auditory DRT; an additional group of 15 adults participated to a somatosensory DRT (experiment 2). In line with previous results both the pN and the BP were clearly detectable in the visual modality. In the auditory modality the prefrontal pN was not detectable directly; however, the pN could be derived by subtraction of separate EEG traces recorded in a “passive” version of the same auditory task, in which motor responses were not required. In the somatosensory modality both the pN and the BP were detectable, although with lower amplitudes with respect to other two sensory modalities. Overall, regardless of the sensory modality, anticipatory task‐related pN and BP components could be detected (or derived by subtraction) over both the prefrontal and motor cortices. These results support the view that anticipatory processes share common components among sensory modalities.
The novelty of this ERP study is represented by evidence of similar anticipatory brain activities supporting the decision to either act or inhibit in tasks involving target and no‐target stimuli among different sensory modalities. Findings are relevant in light of the interactions between modality‐specific and modality‐independent components of the brain's preparation to optimize upcoming performance and are consistent with Bayesian predictive models of cognition.
The Bereitschaftspotential (BP) and the P3 are well‐known ERPs usually observed during self‐paced and externally triggered tasks. Recently, the BP was also detected in externally triggered tasks ...before stimulus onset. However, doubts have been raised about the authenticity of the BP in these tasks due to possible overlaps with the previous trial P3 (hereinafter s‐1 P3). Here, we aim to test the authenticity of the BP in externally triggered tasks by comparing ERPs obtained during two visuomotor response tasks with different interstimulus intervals (ISIs) allowing (short‐ISI; 1,000–2,000 ms) or not (long‐ISI; 2,000–4,000 ms) P3‐BP overlaps. In line with previous research, we hypothesize that BP and the s‐1 P3 contribute independently to the scalp‐detected activities during these tasks. ERPs were recorded from 14 healthy participants during the short‐ISI and long‐ISI visuomotor response tasks. Amplitudes and latencies of pre‐ (BP and pN) and poststimulus ERP components (P1, pN1, pP1, N1, pP2, dpP2, N2, P3) were compared between conditions. No effect of ISI was found on the amplitude of any pre‐ and poststimulus components. In contrast, longer ISI is associated with earlier onsets of the BP and pN components. In visuomotor response tasks, the BP is independent from the P3 elicited by the previous trial (s‐1 P3), even using relatively short ISI. Since the different ISIs did not affect the amplitude of the BP and the P3 components, we conclude that also a short ISI can be adopted safely and conveniently to keep a reasonable duration of the overall experiment.
The omissions are infrequent errors consisting in missing responses to the target stimuli. This is the first study aimed at investigating the brain activities associated with omissions in a ...decision-making task. We recorded event-related potentials (ERPs) in 12 subjects which reported a suitable number of omissions in a visual go/no-go task. We investigated both the pre- and post-stimulus brain activities associated with correct and omitted trials. The electrical neuroimaging technique (BESA) was adopted to extract the anterior insula (aIns) activity associated with the prefrontal P2 component (pP2) peaking about 300 ms after the stimulus and reflecting the stimulus–response mapping process. We found that omissions were predicted by a delayed onset (about half a second) of two pre-stimulus components, i.e. the prefrontal negativity (pN) and the Bereitschaftspotential (BP) associated with the top-down control and the motor preparation, respectively. Further, at the post-stimulus stage the omission trials were characterized by the suppression of the pP2 (and the aIns activity as measured by BESA). No differences between omission and correct trials were detected at the level of the P1 and N1 visual components, as well as the P3. These findings would suggest that omissions are attentional lapsebased errors, as indicated by the delayed brain preparation before the stimulus onset. The reduced cortical activity during the preparation phase did not affect the visual processing; in contrast the stimulus categorization process at the level of the anterior insula did not start at all, resulting in the inability to reach a decision.
A sexual dimorphism in liver inflammation and repair was previously demonstrated. Its cellular dissection in the course of acute liver injury (ALI) was explored. BALB/c mice were treated with carbon ...tetrachloride (CCl
) by intraperitoneal injection and killed after 3, 5, and 8 days. Histological and hepatic cell population analyses were performed. The correlation between androgen receptor (AR) expression and liver recruited inflammatory cells was investigated by treatment with the AR antagonist flutamide. Additionally, patients with a diagnosis of drug induced liver injury (DILI) were included in the study, with a particular focus on gender dimorphism in circulating monocytes. A delayed resolution of necrotic damage and a higher expression of proinflammatory cytokines were apparent in male mice along with a slower recruitment of inflammatory monocytes. F4/80
CD11b
macrophages and CD11b
Gr-1
monocytes expressed AR and were recruited later in male compared with female livers after CCl
treatment. Moreover, CD11b
AR
Gr-1
recruitment was negatively modulated by flutamide in males. Analysis of DILI patients showed overall a significant reduction in circulating mature monocytes compared with healthy subjects. More interestingly, male patients had higher numbers of immature monocytes compared with female patients.A stronger cytotoxic tissue response was correlated with an impaired recruitment of CD11b
AR
Gr-1
cells and F4/80
CD11b
macrophages in the early inflammatory phase under AR signaling. During DILI, a dimorphic immune response was apparent, characterized by a massive recruitment of monocytes to the liver both in males and females, but only in males was this recruitment sustained by a turnover of immature monocytes.
Three point mutations (A2143G, A2142G, and A2142C) have been involved in Helicobacter pylori clarithromycin resistance.
To compare the eradication rates among the different point mutations and the ...efficacy of triple therapy and a sequential regimen according to genotypic resistance.
Post hoc subgroup study from a multicenter, randomized trial.
Two hospitals in central and southern Italy between January and December 2001.
156 patients with H. pylori infection.
Real-time polymerase chain reaction for assessing clarithromycin resistance; histology, rapid urease test, and 13C-urea breath test at entry and after 4 to 6 weeks.
7-day triple therapy (20 mg of rabeprazole, 500 mg of clarithromycin, and 1 g of amoxicillin) in 75 patients or a 10-day sequential regimen (20 mg of rabeprazole plus 1 g of amoxicillin for 5 days and 20 mg of rabeprazole, 500 mg of clarithromycin, and 500 mg of tinidazole for the remaining 5 days) in 81 patients. All drugs were given twice daily.
Helicobacter pylori infection was eradicated in 11 of 23 patients (48%) with the A2143G mutation and in 14 of 15 patients (93%) with either A2142G or A2142C strains (difference, 45 percentage points 95% CI, 15 to 65 percentage points; P = 0.004). The sequential regimen achieved a higher cure rate than triple therapy in A2143G mutate strains (difference, 49 percentage points CI, 8 to 72 percentage points; P = 0.024).
The post hoc substudy design may require further confirmation. Other limitations are the accessibility to the tool and the cost of investigations (70 euros per patient).
The A2143G mutation seemed to be associated with a very low eradication rate. The sequential regimen achieved a higher cure rate than standard therapy even in patients with these strains.
This review focuses on new and/or less standardized event-related potentials methods, in order to improve their knowledge for future clinical applications. The olfactory event-related potentials ...(OERPs) assess the olfactory functions in time domain, with potential utility in anosmia and degenerative diseases. The transcranial magnetic stimulation-electroencephalography (TMS-EEG) could support the investigation of the intracerebral connections with very high temporal discrimination. Its application in the diagnosis of disorders of consciousness has achieved recent confirmation. Magnetoencephalography (MEG) and event-related fields (ERF) could improve spatial accuracy of scalp signals, with potential large application in pre-surgical study of epileptic patients. Although these techniques have methodological limits, such as high inter- and intraindividual variability and high costs, their diffusion among researchers and clinicians is hopeful, pending their standardization.
Neuroimaging studies have identified so far, several color‐sensitive visual areas in the human brain, and the temporal dynamics of these activities have been separately investigated using the ...visual‐evoked potentials (VEPs). In the present study, we combined electrophysiological and neuroimaging methods to determine a detailed spatiotemporal profile of chromatic VEP and to localize its neural generators. The accuracy of the present co‐registration study was obtained by combining standard fMRI data with retinotopic and motion mapping data at the individual level. We found a sequence of occipito activities more complex than that typically reported for chromatic VEPs, including feed‐forward and reentrant feedback. Results showed that chromatic human perception arises by the combined activity of at the least five parieto‐occipital areas including V1, LOC, V8/VO, and the motion‐sensitive dorsal region MT+. However, the contribution of V1 and V8/VO seems dominant because the re‐entrant activity in these areas was present more than once (twice in V8/VO and thrice in V1). This feedforward and feedback chromatic processing appears delayed compared with the luminance processing. Associating VEPs and neuroimaging measures, we showed for the first time a complex spatiotemporal pattern of activity, confirming that chromatic stimuli produce intricate interactions of many different brain dorsal and ventral areas.
Spatial attention can improve performance in terms of speed and accuracy; this advantage may be mediated by brain processes at both poststimulus (reactive) and prestimulus (proactive) stages. Here, ...we studied how visuospatial attention affects both proactive and reactive brain functions using event‐related potentials (ERPs). At reactive stage, effects of attention on parietal‐occipital components are well documented; little data are available on anterior components. Seventeen participants performed simple and discriminative response tasks, while voluntarily and steadily attending either the left or right visual hemifield throughout one block. Response speed was faster for the attended side. At ERP level, attending to one hemifield did not produce lateralization of proactive components—that is, the BP and the pN. As for poststimulus components, we confirmed the well‐known amplitude effects on the P1, N1, and P3. More interesting are results for the prefrontal components previously neglected in tasks modulating spatial attention. Previous studies suggest that these components reflect perceptual and sensory‐motor awareness (pN1 and pP1 components), and stimulus‐response mapping (pP2 component) associated to anterior insular activity. Spatial attention enhanced the pN1 and the pP1 amplitude but had no effect on the pP2. Overall, results extend knowledge on spatial attention, showing that sustained spatial attention affects the activity of anterior areas, such as the anterior insula, in addition to the known influence on occipital‐parietal areas. Top‐down spatial attention is likely mediated by increased sensory and sensory‐motor awareness for attended events; this effect is evident in reactive, not proactive, brain activity.
Spatial attention can improve performance, and this advantage may be mediated by brain processing at both pre‐ and poststimulus stages. By means of event‐related‐potentials (ERPs) and behavioral measures, here we show that orienting attention toward one side produces faster responses, and this advantage seems to be mainly mediated by processing at poststimulus (reactive) stage. Indeed, sustained spatial attention not only affects the activity on occipital‐parietal areas but also modulates the more anterior areas, such as the anterior insula. Top‐down spatial attention is likely mediated by increased sensory and sensory‐motor awareness for attended events.
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